Retinal detachment 2016

RETINAL DETACHMENTSB , PR , PPV

Indoredrishti.wordpress.com

DR DINESH MITTAL DR SONALEE MITTAL

DRISHTI EYE HOSP VIJAYNAGAR INDORE

RETINAL DETACHMENT SURGERY FLOWCHART

RETINAL DETACHMENT

• retinal detachment is used to describe a separation of the neurosensory retina from retinal pigment epithelium (RPE).• A retinal detachment re-establishes the potential space that exists between the original layers of the embryonic optic cup.

TYPES OF RETINAL DETACHMENT RD• Three categories of RD are rhegmatogenous, exudative, and tractional.• Rhegmatogenous RD are sometimes referred to as primary detachments, while both exudative and tractional detachments are called secondary or nonrhegmatogenous detachments .

RHEGMATOGENOUS RD•Rhegmatogenous detachments are the most common form of retinal detachment. They are caused by a break in the retina through which fluid passes from vitreous cavity into subretinal space.• The responsible break(s) can be identified preoperatively in more than 90%of cases, but occasionally presence of a minute, unseen break must be assumed.

EXUDATIVE RD•Exudative detachments, also called serous detachments, are due to an associated problem that produces subretinal fluid without a retinal break. This underlying problem usually involves the choroid as a tumor or an inflammatory disorder.

TRACTIONAL RD

•Tractional detachments occur when pathologic vitreoretinal adhesions or membranes mechanically pull the retina away from the pigment epithelium without a retinal break. The most common causes include PDR , ROP , proliferative sickle retinopathy, and penetrating trauma. •Retinal breaks may subsequently develop, resulting in a combined tractional and rhegmatogenous detachment.

MECHANISM OF RHEGMATOGENOUS RETINAL DETACHMENT

• requirements for a rhegmatogenous RD include a retinal break and low-viscosity vitreous passing through break into the subretinal space. The usual sequence causing retinal detachment is vitreous liquefaction followed by a PVD that causes traction at site of significant vitreoretinal adhesion with a subsequent retinal tear. Fluids from vitreous cavity then pass through tear into subretinal space .

Characteristics Rhegmatogenous RD• (1) the existence of liquefied vitreous gel • (2) tractional forces that can precipitate a retinal break • (3) the presence of a retinal break that will allow the passage of liquefied vitreous into the subretinal space . •All three factors need to be present to cause a rhegmatogenous retinal detachment.

RHEGMATOGENOUS RD

LIQUEFIED VITREOUS , TRACTION AND TEAR REQD FOR RD

•For example, if a tear or hole is present in the absence of tractional forces and liquid vitreous, it is unlikely that retina will detach. Examination of postmortem eyes indicates that approximately 5 to 10% of eyes have full-thickness retinal defects without any apparent detachment. Subclinical retinal detachments are defined as having less than 1 to 2 disc diameters of subretinal fluid and usually do not progress.

TYPES OF BREAKS

•Retinal breaks may be subdivided into tears, holes, and dialyses . Tears are produced by traction on the retina, whereas holes are due to a gradual thinning of the retina . Tears usually occur suddenly, with the retina frequently appearing completely normal before the acute event. Atrophic holes appear to develop slowly, whereas traumatic dialyses probably occur acutely.

TYPES OF BREAKS

•Most breaks causing retinal detachment are associated with vitreoretinal traction in the vicinity of the break(s). Dialyses usually feature traction on the retina immediately posterior to the break, and if traction is confined to the retina anterior to the dialysis, a giant tear is more likely to evolve.

Horseshoe tear with flap adherent to posterior cortical vitreous

Horseshoe tears HST• Also referred to as flap or U-shaped tears, HST occur in

most cases at the irregular posterior margin of the vitreous base during posterior vitreous detachment.• The flap thus remains adherent to the posterior vitreous

surface following the creation of a tear . Preexisting vitreoretinal adhesion and traction applied to this point via the vitreous are required for creation for HST. Because of the associated vitreous traction, flap tears frequently lead to detachment. Horseshoe tears are most common in middle age and appear most often near the equator of the eye

Operculated tear with free operculum adherent to detached cortical vitreous

Inferior retinal dialysis

Giant retinal tear

Retinal Break Location vs. Age

Distribution of Retinal Breaks

Lattice degeneration associated with multiple round atrophic holes

PROLIFERATIVE VITREORETINOPATHY

•The most ominous and clinically significant finding in retinal detachment is presence of proliferative vitreoretinopathy (PVR), the process that is responsible for the vast majority of surgical failures of retinal reattachment surgery. The consequence of cell migration and elaboration of collagen is the formation of membranes involving the inner and outer surfaces of the retina, as well as the vitreous.

PVR• In time, and under the influence of mediators of inflammation, the membranes contract, distorting the retina into folds . Localized contracture in the periphery is referred to as a star fold , and a similar process in the posterior pole is referred to as a macular pucker .

•RD is usually associated with decreased IOP secondary to increased resorption of fluid from subretinal space. Uveitis may also decrease production of aqueous humor to the point of hypotony and eventual phthisis.•Rubeosis iridis may also develop in long-standing detachment, resulting in NVG . When a long-standing detachment is repaired, glaucoma may replace relative hypotony due to damage to trabecular meshwork.

PREOPERATIVE EVALUATION ANDDIAGNOSTIC APPROACH

• The diagnosis of rhegmatogenous RD is suggested by symptoms of floaters, photopsia, peripheral vision loss, and decreased vision. In patients with clear media, the diagnosis is confirmed by I / O with scleral depression. Slit-lamp biomicroscopy with a three-mirror contact lens may also be helpful in identification of retinal pathology. The location and type of retinal breaks, as well as the size and duration of retinal detachment, are factors that help determine the timing and type of SB procedure performed.

PREOPERATIVE ASSESSMENT• Having taken a careful history (and noted relevant systemic

health problems and past ophthalmic history), anterior and posterior segments of the eye are carefully examined using slit lamp biomicroscopy and I / O• A particular note is made of the following:• Macular involvement• The presence of vitreous detachment• Significant ocular co-pathology, which may affect management

( glaucomatous optic neuropathy, aphakia with vitreous in anterior chamber, a history of strabismus surgery)• The number and position of the retinal breaks.

PREOPERATIVE EVALUATION ANDDIAGNOSTIC APPROACH

• In patients with opaque media, the retinal status may not be visualized. Diagnostic USG is critical in establishing RD . •Optical coherence tomography (OCT) is useful in documenting subretinal fluid, especially in the macula, and the extent of any accompanying intraretinal edema or epiretinal proliferation .

Ophthalmoscopy

Features of Direct vs. Binocular Indirect Ophthalmoscopy

Optical principles of direct method of ophthalmoscopy

Optics INDIRECT OPHTHALMOSCOPY

INDIRECT OPHTHALMOSCOPE•Due to high illumination, binocular viewing, and high-quality optics, a good indirect ophthalmoscope and aspheric lens provide good resolution in spite of low magnification. Substantial advantages gained include a very wide field of view, stereoscopy, large depth of focus, and dynamic examination capability.

INDIRECT OPHTHALMOSCOPE•During the early stages of learning indirect ophthalmoscopy, it is essential to accept that one has to work with a smaller image size; after a time, one ceases to be troubled by it. After enough experience with indirect ophthalmoscopy, one is rarely aided in an evaluation of detail by increased magnification

INDIRECT OPHTHALMOSCOPE•Magnification is increased by moving the examiner’s head closer to the patient’s eye (rather than examining at nearly arm’s length as is usual). •Using a lower power condensing lens, such as a 14 diopter lens, also provides more magnification .

Comparison of INDIRECT Lenses

•When examining for RD , perhaps even more important than the field of view is the viewable field. Direct ophthalmoscopy permits the study of 60% to 70% of the total fundus area in a well-dilated, emmetropic eye . Thus, peripheral examination is very difficult, and as explained above, even when the periphery can be seen with the direct ophthalmoscope, the image is very blurry.

•so practically , direct ophthalmoscope is rarely used to examine beyond the posterior pole. Since 30% of the retina lies anterior to the equator, failure to study this region will result in overlooking serious pathology in many, if not most cases. •Diseases such as senile retinoschisis, peripheral uveitis, and most retinal tears and detachments defy evaluation by any other technique.

Illumination• Image brightness of a DIRECT is low due to limited power output. DIRECT ophthalmoscope operated by batteries provide about one-half watt of illumination.• Instruments operated through transformers deliver several times this amount, but never more than several watts.• I / O can deliver up to 18 watts of output. Better illumination results in improved resolution and improved performance in presence of media opacities

ROLE OF DIRECT OPHTHALMOSCOPY•Most retina surgeons dilate pupil and examine posterior pole of retina with slit lamp biomicroscopy using a 78 or 90 diopter lens or a contact lens, and they use I / O to examine the periphery. If this equipment and the expertise to use it are available, direct ophthalmoscope offers no added benefit for the dilated patient. In the undilated eye, the direct ophthalmoscope can be useful in providing a limited view of the posterior pole

INDIRECT OPHTHALMOSCOPE

Choice of condensing lenses•The most commonly used condensing lens is a 50-mm +20 diopter lens. The higher the power of the condensing lens, the less magnified the image will be and the wider the field of view. Lower-power lenses have to be held farther from patient’s eye. A 20D lens gives a good compromise between field size and magnification, and permits a convenient working distance from the patient’s eye.

Choice of condensing lenses•Lenses of 28-D or 30D power provide a substantial advantage when examining patients with poorly dilating pupils or patients with extremely complicated retinal topography . lowest power that is practical to use in binocular indirect ophthalmoscopy is about 14D. These lenses offer the advantage of higher magnification, but 78 or 90 diopter lenses are usually used with a slit lamp when higher magnification is desired

Indirect lenses: 78, 28, and 20 diopters

Correct position of head for beginning examination of fundus

Position is unsatisfactory forgeneral examination of fundus

Use of patient’s own hand as target has several advantages

Lens is grasped between ball of thumb and tip of index finger. Wrist extended, & third finger extended as pivot

Manner in which lens is moved closer to or away from eye is shown

Alignment of eyepiece, condensing lens, pupil, and scleral depression on visual axis

technique of holding lens is shown

Two techniques for manipulating thimble scleral depressor

Normal fundus with principal structures labeled

Fundus photograph of subtle demarcation line

DETECTION OF RETINAL BREAKS•The entire retina should be carefully examined for retinal breaks by binocular indirect ophthalmoscopy, supplemented by scleral indentation for periphery . While breaks may be found in any area, the distribution of the subretinal fluid is a clue to the most likely location of a primary retinal break

Finding the retinal break•Missed retinal breaks are an important cause of surgical failure so the preoperative examination should be very thorough.• Even when a break has been found, it is essential to complete examination of the retina, as most retinal detachments have more than one break.• Their location is carefully documented on a chart that can be referred to subsequently during surgery .

•These drawings should show the location of retinal breaks in relation to easily visible retinal landmarks such as small hemorrhages, vascular bifurcations, and areas of pigmentation.•This carefully documented preoperative assessment has many advantages. If in doubt, an area of retina can be re-examined alternately with I/O and slit lamp to establish whether a break is truly present. • Drawings made can be referred to if retinal view becomes obscured during surgery.

Color Code for Retinal Drawings

LINCOFF’S RULES

•Lincoff has shown how the location of retinal breaks determines the distribution of subretinal fluid .• Review of the retinal drawings will therefore determine whether break location is consistent with the subretinal fluid distribution.• When the distribution of fluid does not seem to obey Lincoff’s rules reexamine the retina to ensure that no breaks have been missed

An inferior detachment slightly higher on the temporal side pointing to a break on that side

A subtotal retinal detachment – the break is usually close to the upper border of the fluid on the side it is highest.

Fluid crosses midline superiorly implying a superior break near 12 o’clock . fluid has tracked down further nasal implying the break is slightly to the nasal side

The presence of bullae implies a superior break. A shallow sinus of fluid leads to a small superonasal break

LOCATION OF BREAK• If one superior quadrant is detached, the break is apt to be near the upper edge of detachment. When the superior half of the retina is detached, break is most likely near the 12-o’clock meridian.• An inferior quadrantic detachment usually has break near the upper edge of the detachment or in the meridian bisecting the area of detachment.

• If the inferior half is symmetrically detached, the break could be anywhere with in the detachment, but when the fluid is higher on one side of an inferior detachment than break is usually on the higher side.• In a total retinal detachment, break is often between 10- and 2-o’clock meridians. If there are inferior bullae, examiner should assume that a retinal break is above horizontal meridian. In the presence of a demarcation line, the break is often found in the meridian that bisects the demarcated area.

• When the detachment has progressed rapidly, the break is usually superior, fairly large, and probably located nearer the equator than the ora. If the history suggests slow progression of the detachment, a small, inferior, or extremely peripheral break should be sought.•The quadrant of first detectable field loss is a valuable indication of location of break . Special attention should be paid to all areas of abnormality : lattice degeneration, meridional folds, pigmentation, opercula, and hemorrhage .

Proliferative vitreoretinopathy (PVR) grade A, pigment clumps.

Mild fixed fold.

Star fold.

Rolled posterior edge of retinal break

Severe PVR

Severe PVR D-3

Subretinal fibrosis. (A) Diffuse sheet with strands. (B) Multiple strands

RD SURGERY Practice•RD is an uncommon disease, affecting approximately 1 in 10,000 people in general population per year. incidence of retinal breaks is 5% to 7% of the population.•Obviously, many retinal breaks have minimal risk for possible development of a RD . This includes asymptomatic, small, round atrophic holes near the ora serrata.•However, equatorial HST with relevant symptoms progress to RD in most cases.

TREAT OR WAIT•Probably all surgeons would agree that a large HST near the equator in the superior temporal quadrant, with new-onset symptoms of flashes and floaters and associated vitreous hemorrhage, should be treated prophylactically to avoid RD .• In contrast, most would not advise treatment of a small, round atrophic hole near the inferior ora serrata in an asymptomatic patient with no history of prior detachment.

Risk Factors for Rhegmatogenous RD

Subclinical RD

Prophylactic treatment

Laser burns surrounding a retinal tear and focal retinal detachment

Summary of Treatment of Retinal Breaks

SURGICAL ANATOMY•The thickness of the sclera varies. It is thickest around the optic nerve (1.2 mm) and thinnest under the recti behind their insertions so attempts to pass scleral sutures under the muscles are particularly hazardous. Where scleral mattress sutures are more typically passed, at the equator, it is approximately 1 mm thick. • Passage of sutures is facilitated by the lamellar arrangement of collagen fibers, which allows spatulated (or “side cutting”) needles to follow a plane between lamellae.

Retinopexy•The indent from the explant closes retinal breaks but retinopexy is required to produce an enduring bond between the retina & retinal pigment epithelium that will persist even if the indent disappears.•Retinopexy was initially achieved using diathermy in association with lamellar scleral dissection and scleral implants.• Cryotherapy has supplanted diathermy because it can be performed without scleral dissection .• Intraoperative cryopexy remains a quick and simple technique.

Scleral Buckling Surgery•Though primary VIT has become increasingly utilized, an essential surgical procedure for the repair of rhegmatogenous RD is SB . The goal of SB is to close retinal breaks by indenting eye wall, preventing the passage of liquefied vitreous into the subretinal space. This flexible approach incorporates the benefits and advantages of different techniques and materials, maximizing the rate of anatomical and visual success while minimizing potential complications .

HISTORICAL REVIEW•Recognition of vitreoretinal traction and retinal breaks in the pathogenesis of retinal detachment by Gonin in 1919 ushered in the era of repair, in which drainage of subretinal fluid and treatment of retinal breaks were employed. Custodis, thirty years later, introduced the concept of scleral buckling.

Father of RD surgery

HISTORICAL REVIEW•The introduction of binocular I / O and scleral depression by Schepens in 1951 revolutionized the localization of peripheral retinal pathology. Advancements were made when Schepens combined scleral dissection, diathermy, and intrascleral implantation of silicone buckles for scleral buckling. •Lincoff refined Custodis’ procedure by using silicone sponge explants and cryotherapy.

Scleral Buckling three basic steps in closing retinal breaks & reattaching the retina• 1 Conducting thorough preoperative and intraoperative examinations with the goal of locating all retinal breaks and assessing any vitreous traction on the retina. 2. Creating a controlled injury to the retinal pigment epithelium and retina to produce a chorioretinal adhesion surrounding all retinal breaks so that intravitreal fluid can no longer reach the subretinal space. 3. Employing an appropriate technique, such as scleral buckling and/or intravitreal gas, to approximate the retinal breaks to underlying treated retinal pigment epithelium.

Scleral Buckling SB•The fundamental goal of scleral buckling is the functional closure of all retinal breaks, so that normal physiological forces can maintain a permanent state of attachment. Drainage of subretinal fluid and scleral buckling will usually close the responsible break(s) immediately

several beneficial effects of SB• 1 reduction of vitreoretinal traction by displacing the eye wall and retina centrally•2. displacement of subretinal Fluid away from the location of the retinal break and scleral buckle•3. postoperative increase in the height of the scleral buckle•4. approximation of retinal break and adjacent vitreous gel .

several beneficial effects of SB•5. increase in resistance to fluid flow through the retinal break, with consequent increase in the relative reattachment forces;•6. alteration in the concave shape of the eyeball, resulting in a change in the effect of intraocular currents that encourage liquid vitreous to enter the subretinal space.

PRINCIPLES OF SB•The most important skill required in surgery for RD is the ability to detect all retinal breaks and additional areas of vitreoretinal pathology. SB is performed to produce functional closure of retinal breaks . Various kinds and shapes of silicone are used, including segments of silicone sponge as well as solid silicone shaped into bands for encircling the eye and into additional forms to augment the width and height of the buckle in selected areas .

PRINCIPLES OF SB•Following localization and treatment of retinal breaks and areas of vitreoretinal degeneration, the silicone buckling element is sutured to the scleral surface. Drainage of subretinal fluid is performed in majority of cases. Intravitreal gas injection is sometimes employed in conjunction with scleral buckling. Problems encountered at any point of the procedure may require modifications in technique.

Cryotherapy• Cryotherapy (cryopexy) produces an effective pigment epithelial–retinal adhesion without scleral complications that characterize diathermy. This provides cryotherapy with significant advantages: • (1) retinal pathologic conditions can be treated without the need for scleral dissection; and • (2) retinal breaks can be treated regardless of their location in relation to vortex veins or long posterior ciliary vessels or nerves.

Cryotherapy•The histologic response after cryo depends on whether the RPE alone or RPE and the overlying detached retina together are frozen.The ability to treat detached retina is another significant advantage over both diathermy and photocoagulation. If only the RPE is frozen without freezing overlying retina, the RPE –retinal adhesion that forms once the retina is reattached shows pigment epithelial hyperplasia and loss of retinal outer segments .

Cryotherapy•Therefore the normal microvillous interdigitations seen between retina and RPE are missing. If both the RPE and overlying retina are frozen, the adhesion that results after reattachment demonstrates cellular connections between the retina and RPE consisting of desmosome formation between retinal glia and RPE or direct contact between retinal glia and Bruch’s membrane.

•Current cryotherapy instrumentation employs expansion of high-pressure nitrous oxide at the tip of a probe generating temperatures as low as −89°C. Temperature effect is confined to the tip of the probe by an insulating sleeve. A probe 2.0 to 2.5 mm in diameter usually is used for retinal work. Treatment of retinal breaks & pathologic conditions requires accurate placement of the cryoprobe tip. The surgeon must be certain that the indentation visualized with the I / O is the tip of the probe and not the shaft .

• The goal is to surround all retinal breaks with 1 to 2 mm of contiguous treatment. Treatment should include freezing of overlying retina, because this results in a stronger adhesion than does treatment of RPE alone. To avoid damage of refreezing, treatment should not significantly overlap. The treatment end point is retinal whitening without ice crystal formation. Slight whitening of retina because of retinal edema is noted several minutes after freezing, which helps to assess adequacy of treatment. If retinal treatment is impossible because of bullous retinal elevation, treatment of RPE alone may be performed, or treatment can be deferred until after drainage of SRF .

•For flap retinal tears, treatment is performed contiguously around the tear and then extended anteriorly to the ora serrata. Care is taken not to freeze bare RPE in the bed of the retinal break where there is no overlying retinal tissue. Small retinal breaks and atrophic retinal holes can be treated with single freezes centered on the retinal break

•Cryopexy remains the choice of most retinal surgeons for the intraoperative treatment of retinal breaks during scleral buckling

Cryotherapy is applied by the surgeon under direct visualization with I / O .

Encircling silicone bands are traditionally Fixed with a single mattress suture

•Example 1: A detachment with a single elevated equatorial tractional tear . This may be closed successfully using a single radial sponge without drainage of subretinal fluid. If a silicone tire is used in the same situation the indent may not be high enough to close retinal breaks without subretinal fluid drainage and/or gas injection.

•Example 2: A detachment due to a series of round retinal holes . The holes are anterior to equator at various distances from the ora. They may be treated with a circumferential explant. A very high indent is not required because there is no traction on the breaks and the fluid is very shallow. As the distance from the ora varies the broader indentation from a tire can close all the breaks.

•Example 3: A pseudophakic eye with a total RD . Good visualization of the peripheral retina is impeded by peripheral capsule opacification and limited pupil dilatation . No tears are seen. An internal approach using PPV has many advantages here. If this is not possible, an encircling tire may be used. The buckle may be secured just behind rectus muscle insertions to support the anterior retina where breaks are likely to be located. The tire supports whole area of subretinal fluid . The placement of an encircling silicone band in the groove of the tire maintains the height of the indent so that undetected retinal breaks remain closed.

Example 4: Three tractional tears are present . can be treated with separate radial sponges or with a single buckle.

•Example 5: Three tractional tears are again present but they are too close together to be easily closed with individual radial sponges . A circumferential buckle is an easier option. A high circumferential sponge may be used but it can be difficult to close all breaks because of variable distances from limbus. high circumferential sponges are likely to result in fishmouthing .• circumferential tire combined with subretinal fluid drainage and/or gas injection may be used.

Retinal dialysis. Provided indent is high enough (a 3-mm circumferential sponge usually works well), and subretinal fluid drainage is usually unnecessary

FISHMOUTHING

Fishmouth Retinal Tears•There are three basic techniques in the management of fishmouth retinal tears. The easiest is to decrease the height of the circumferential buckle. This usually is effective only if buckle height is excessive. Placement of a radial element beneath the circumferential element effectively closes most fishmouth tears .

Fishmouth Retinal Tears• The radial element increases surface area of pigment

epithelium and choroid beneath break, thereby decreasing disparity between retinal surface area & surface area of bed of buckle. Injection of an intravitreal gas bubble, combined with positioning, also effectively closes fishmouth tears. The gas is injected through pars plana under direct visualization with the I/O . During the injection, care must be taken to avoid formation of multiple small bubbles, which may then pass through the tear into the subretinal space. This can be prevented by injecting into most superior aspect of vitreous cavity. With accurate positioning, a bubble of 0.3 ml is adequate to close retinal breaks of up to one clock hour.

• Isolation of the four rectus muscles usually allows adequate access to all areas of the sclera necessary to perform scleral buckling. •The suture is passed through the sclera at one half to three fourths depth over a distance of 3 to 5 mm, usually in a horizontal mattress fashion. A combination of adequate depth and length is necessary for maximum suture strength. Once the proper scleral depth has been obtained, the suture should be passed at that level .

• . Uneven passage of the needle induces buckling of the sclera, which may lead to perforation. After the needle has been passed through the sclera and the tip brought out, the needle is released from the needle holder and the tip is grasped. It is important to complete passage of the needle along the arc of the needle, avoiding posterior pressure or dragging on the hub of the needle, which may perforate through the remaining underlying sclera .

WIDTH OF SUTURES•Usually sutures are placed a minimum of 2 mm farther apart than width of scleral contact for a given element ( 9 mm apart for a 7 mm element). To ensure that the most posterior edge of the retinal break is supported, the surgeon places posterior suture a minimum of 2 to 3 mm posterior to scleral localization mark.

MANAGEMENT OF SUBRETINAL FLUID • rationale for drainage of SRF is twofold: to diminish intraocular volume so as to allow elevation of buckle without difficulties with elevated IOP and to allow the retina to settle on the elevated buckle by removing fluid from the subretinal space. drainage of SRF places the retinal breaks in juxtaposition to the buckle, thereby facilitating closure of the breaks. Although many retinal detachments can be effectively managed without drainage as described later, we prefer to drain retinal detachments with one or more of the following characteristics:

MANAGEMENT OF SRF •1. Bullous detachments. Drainage is usually necessary in these cases so that retinal break can be placed in juxtaposition to buckle. This is particularly valid if confluent retinopexy around tear cannot be obtained

because of the bullous elevation.•2. Inferior breaks. Inferior breaks tend to settle less readily on the buckle than do superior breaks, perhaps because of gravity. Also, inferior breaks are less effectively managed postoperatively with air injections.

MANAGEMENT OF SRF •3. Proliferative vitreoretinopathy. PVR may prevent the retina from settling, resulting in open retinal breaks. We drain all cases of grade B or greater that undergo scleral buckling.•4. Highly myopic detachments and aphakic or pseudo-phakic detachments. The syneresis of the vitreous that occurs in myopia or following lens extraction may be a factor in the failure of these retinas to settle on the buckle without drainage.

MANAGEMENT OF SRF•5. Chronic detachments. SRF in chronic RD becomes viscous . High osmolarity of fluid may slow resorption by pigment epithelium.•6. Poor RPE function. Detachments in patients with ARMD and high myopia are characterized by prolonged resorption of SRF , because of decreased ability of the RPE to remove fluid from the subretinal space.•7. Eyes intolerant of sustained IOP rises, such as those with known glaucoma.

selection of external drainage site Obviously the location of SRF is a primary concern. We prefer to select our drainage site after placement of scleral sutures and loose placement of the buckle. This ensures that the location or amount of the SRF has not changed during the placement of sutures. It is not necessary to drain where the fluid is greatest but where there is adequate fluid to safely enter the subretinal space. When possible drain just above or below the horizontal meridian, either temporally or nasally . This location avoids the major choroidal vessels and vortex veins. vortex veins can be identified and thereby avoided.

DRAINAGE SITE LOCATION

SRF DRAINAGE•The horizontal meridian allows easy access to sclera, although in patients with large noses or tight orbits the nasal approach sometimes can be difficult. If SRF in the horizontal meridian is inadequate, drainage must be performed elsewhere. Usually either side of vertical rectus muscles avoids major choroidal vessels. We try to avoid drainage through areas that have received cryotherapy because of the choroidal hyperemia and congestion that cryotherapy induces.

SRF DRAINAGE•Drainage can be performed via either a radial sclerotomy or external needle drainage . External needle drainage is technically more challenging. It is performed either with the scleral buckle left loose as originally described by Charles or with it tightened to an appropriate height and the sutures permanently tied.

Encirclement•Segmental buckles provide local support which often fades. This may lead to reopening of breaks if insufficient retinopexy has been applied.

• Encirclement produces permanent support of the vitreous base retina.

Encirclement•Encirclement has a role in certain situations:• Early PVR• detachment in which breaks are difficult to detect eg aphakic and pseudophakic RD .• Multiple breaks in three or more quadrants.•Encirclement is produced with a combination of a local silicone tire (confined to the areas of visible breaks) with a 2-mm band, which lies in the gutter of the tire and encircles the globe before being attached to itself.

Encirclement•The 2-mm band is often too narrow to support breaks and its primary purpose is to maintain the height of the indent from the tire.

The steps are:•1. A 360° peritomy with slinging of all four rectus muscles.•2. Break localization, retinopexy and pre-placement of the mattress sutures of the tire. •Generally two sutures are required per quadrant.

The steps are:•3. Threading the tire and band together under the recti and mattress sutures. Ensure that both limbs of all the mattress sutures are above the buckle as it is not uncommon to leave one under the encirclement by mistake. Some thought needs to be given to where the ends of the band will be secured at this stage. It is also important to ensure that the band does not become twisted.

The steps are:

•4. Subretinal fluid drainage is required in the majority of cases. The exact stage at which it is performed is variable but it may be done now to create space for the indent.

•5. Tighten the mattress sutures over the tire to create a local indent.

•6. Place a small holding stitch over the band in each quadrant where there is no tire to stop it bow stringing forward when tightened. These are placed at the equator (approximately 12 mm behind the limbus).•7. Fasten the ends of the band to each other. A Watzke sleeve is a small silastic tube designed to secure the ends and allow adjustment of the tension in the band. The steps for engaging the ends of the band in the sleeve with a specially designed cross acting (“Watzke”) forceps are illustrated .

•8. The ends of the band are pulled to create the encircling indent. A 6-mm shortening will produce approximately a 1-mm indent, irrespective of the size of the globe. The end point of this tightening is best judged ophthalmoscopically; a shallow indent should be just visible. •9. The optic nerve perfusion should be checked and, if necessary steps taken to normalize it such as paracentesis, SRF drainage , or adjusting the buckle.

Pneumatic Retinopexy

PNEUMATIC RETINOPEXY•Sulfur hexafluoride (SF6) and perfluoropropane (C3F8) are the gases most frequently used with PR. Success also has been reported with sterile room air.

PNEUMATIC RETINOPEXY• The value of the intraocular bubble is based on three

features: buoyancy, surface tension, and isolation of retinal tears from intraocular currents.

• Buoyancy applies upward pressure on the detached retina. The surface tension of the bubble closes the retinal break and prevents the bubble from passing into the subretinal space. With the break closed, the retinal pigment epithelial pump removes the subretinal fluid.

PNEUMATIC RETINOPEXY• Because of their low solubility in water, SF6 and C3F8 tend to diffuse from the eye very slowly. However, the nitrogen and oxygen that are in solution in surrounding tissues of the eye are much more soluble and pass relatively quickly into the gas bubble, following the law of partial pressures. The net result is the initial expansion of a bubble of pure SF6 or C3F8 within the vitreous, followed by gradual resorption.

CASE SELECTION AVOIDED IN•1. Breaks larger than 1 clock-hour or multiple breaks extending over more than 1 clock-hour of the retina.•2. Breaks in the inferior 4 clock-hours retina.•3. Presence of PVR grade C or D .•4. disability precluding maintenance of the required positioning.•5. Severe or uncontrolled glaucoma.•6. Cloudy media precluding full assessment of the retina.

PR presents a advantage IN • 1. Macular breaks and other posterior retinal breaks.

Posterior retinal breaks are difficult to treat with SB, so PR is the procedure of choice in many of these cases, especially in phakic eyes. It also has been reported as an effective option in the treatment of optic pits with macular detachment.• 2. Redetachment or persistent detachment after SB . When

SRF accumulates or persists because of a superior break after SB, PR may be much easier to perform than buckle revision. This is especially effective if the break is located on or anterior to the buckle.

PR presents a advantage IN•3. Isolated tears under the superior rectus. Placing a segmental buckle under a vertically acting muscle runs the risk of iatrogenic diplopia; this is eliminated with PR.•4. Filtering blebs. If a functioning filtering bleb is present, or if a filtering procedure may be necessary in future, PR should be considered.

PR presents a advantage IN•5. Impending macular detachment. Because PR can be performed promptly in the office without delays required to prepare a patient for the operating room, & because the gas bubble can be used proactively to move the fluid away from the macula .•6. Bullous detachment. When RD is highly bullous, retinal tears can be difficult to localize and treat with SB, a problem which is avoided by two-session PR.

One-session / two-session procedure•PR can be done in one session, with cryopexy applied to the retinal breaks just before gas injection, or as a two-session procedure, with initial gas injection followed by laser 1 or 2 days later, when the retina is reattached. One-session procedures always involve cryopexy, since laser cannot be applied to detached retina. Two-session procedures are usually, but not always, done with the laser.

Injection of gas•With the ocular surface still sterile and the patient supine, the head and the eye are turned a total of approximately 45° to one side to place the pars plana injection site uppermost. The gas usually is injected temporally unless pars plana epithelium is detached or large retinal breaks are present in that area, in which case another site is selected. The injection is made 3–4 mm posterior to the limbus with a 12 mm , 30-gauge needle.

Injection of gas•The needle is directed toward center of vitreous & inserted to a depth of 7 or 8 mm to ensure penetration of pars plana epithelium and anterior hyaloid face. It is then partially withdrawn so that approximately 9 mm of needle shaft is seen outside eye, leaving only 3 mm of the needle tip inside globe. With injection site uppermost & needle vertical, the gas is injected moderately briskly. This technique creates one single bubble at the needle tip rather than multiple small bubbles, often referred to as “fisheggs” .

Multiple small intravitreal gas bubbles (“Fish eggs”) with subretinal gas

SUMMARY OF PROCEDURE•The following constitutes sequence of PR :•1. Anesthetic: topical/subconj or retrobulbar•2. Cryopexy: if one-session procedure, in lieu of laser•3. Sterilization of ocular surface: povidone–iodine solution•4. Paracentesis: limbal, or via pars plana if capsule is open•5. Intravitreal gas injection: 0.4–0.6 mL of SF6

SUMMARY OF PROCEDURE•6. Second paracentesis and/or ocular compression: as needed to open artery•7. Special procedures: e.g., steamroller if needed (cryopexy should not be performed before steamroller)•8. Antibiotic and patch: draw arrow•9. Laser: next day or when retina is reattached (in lieu of cryopexy as two-session procedure) with 360° laser if desired.

OURS MODIFICATION•Most frequently, WE do a one-session procedure using cryopexy instead of laser. our procedure differs from the technique used by majority of retina surgeons in following three ways:•1. We perform paracentesis prior to, rather than following, gas injection.•2. We usually inject SF6 instead of C3F8.•3. We inject a larger gas bubble, 0.5–0.6 mL in most cases.

Primary Vitrectomy in Rhegmatogenous RD

PPV•Compared to SB, PPV offers several advantages. The view of the retinal periphery is enhanced, identification of retinal breaks is rendered easier, achievement of complete intraoperative retinal attachment is possible, the risks of hemorrhage or retinal incarceration inherent to external drainage procedure applied during SB is eliminated, and the technique is less likely to cause a refractive change.

PPV• In addition, recent introduction of small-gauge vitrectomy has shifted paradigm of standard vitreous surgery to microincision vitrectomy surgery that is less invasive, affords fast recovery, & is sutureless ( MIVS). As a result of these advances, VR surgeons now have more procedural choices when treating RRD patients. Further, recently trained VR surgeons may be more familiar with application of PPV (compared to SB) .

PATIENT SELECTION FOR PPV •SB and/or PR serve as the first treatment option(s) in patients with localized detachment in one quadrant together with single neighboring breaks. Young age and anteriorly located small holes in phakic patients encourage the use of SB. The success rates of final reattachment are 90–95%.

PATIENT SELECTION FOR PPV •PPV is indicated for PTs with wide and bullous RD, older patients with a liquefied vitreous. Presence of RD with marked traction with different anterior posterior depth of breaks, presence of breaks in multiple quadrants, or the absence of an apparent retinal break in a pseudophakic patient, are all good candidates for the use of PPV. RD of preoperative PVR grade C, GRT , and macular hole RD, are all commonly treated using PPV.

Developments In Vitrectomy•Recent developments in PPV including small-gauge systems, wide-angle viewing systems, and endoilluminators, as well as adjuvants, including triamcinolone acetonide suspension, PFCL , and SF6,C3F8 led the choice of surgical technique for the treatment of RRD with medium-complexity shift more and more towards PPV.• During the last 5 years, several surgeons have reported that primary vitrectomy is method of choice in 40–80% of RRD PTs .

PRINCIPLES OF VITRECTOMY•The principles of vitrectomy to treat RRD are release of tractional forces that precipitated the retinal break, and the closure and reattachment of breaks to the underlying RPE . The surgical procedure requires: (1) removal of the vitreous gel and preretinal tractional membrane; (2) intraoperative flattening of the detached retina; (3) application of retinopexy; and (4) placement of a tamponade in vitreous cavity.

PRINCIPLES OF VITRECTOMY•Abnormal vitreoretinal traction (either perpendicular or tangential) increases vitreous mobility caused by PVD, and atypical posterior extension of the anterior vitreous base predisposes to formation of retinal tears. Therefore, removal of the vitreous gel and any abnormal preretinal structure releases the tractional force causing retinal breaks and detachment.

PRINCIPLES OF VITRECTOMY•After release of abnormal VR traction, the detached retina must be reattached. To stabilize and flatten detached retina, a heavy liquid is initially applied; this is subsequently replaced by sterile air. If the retina is mobile and becomes flattened in air, a nonexpansive gas–air mixture is used to achieve a postop gas tamponade. Although silicone oil is not routinely used in instances of uncomplicated RRD, use of silicone oil should be considered if eyes have multiple inferior breaks .

•Retinopexy has been used to create retinal–RPE adherence. Both forms of retinopexy (cryopexy, and laser ) cause tissue destruction and cellular proliferation and should be used as little as possible. Continuous laser retinopexy is preferable to cryopexy . However, if peripheral breaks in phakic eyes are to be treated, cryopexy is preferred, because endolaser probe can

touch crystalline lens. The risk of postop PVR may be minimized if retinal pigment epithelial cells dispersed after cryopexy are thoroughly aspirated via a heavy liquid–air exchange.

Pars Plana Vitrectomy Step by Step• Instruments• 1. 3-port trocar• 2. 120D or 90D magnifying glass• 3. Light pipe• 4. Vitreous cutter• 5. Scleral depressor• 6. Fluid needle

Individual steps• 1. Insertion of trocar cannulas• 2. Phacoemulsification• 3. Focussing• 4. Core vitrectomy• 5. Induction of posterior vitreous detachment• 6. Trimming of vitreous base• 7. Anterior vitrectomy

Individual steps• 8. Internal search for retinal breaks• 9. Laser photocoagulation of peripheral breaks• 10. Cryotherapy of peripheral breaks• 11. Intraoperative tamponade• 12. Postoperative tamponade• 13. Removal of trocar cannulas• 14. Sclerotomy sutures

Core vitrectomy

SB / PR / PPV• Complicated detachments are usually managed with PPV ,

whereas localized, relatively simple cases are usually managed with a “walling-off” (demarcating) procedure employing laser or cryotherapy, with PR, or with a small and localized scleral buckling procedure. Between these two extremes lies a large percentage of cases, probably 50% or more, in which any of the three major options might be considered; combinations of the three are also employed by many surgeons in selected situations. Regardless of technique, if all retinal breaks are surgically closed, and PVR or other more unusual complications do not develop, the procedure will be anatomically successful .

Advantages of SB • As the standard of care for decades, SB success and

complication rates are relatively well understood. SB is usually an extraocular procedure (except for the frequently optional steps of draining SRF and/or injecting gas), and the risk of endophthalmitis is low, even when drainage is performed. The cost of equipment and accessory materials is considerably less than for PPV , although much more than for PR. Progressive cataract formation following surgery is much less likely than with PPV . Unlike PR and PPV in general, no special postop positioning is usually required with SB , which may be an important consideration in individuals with arthritis or back trouble.

Disadvantages of SB • Placement of an encircling buckle frequently induces myopia.

Postop muscle imbalance and altered refractive errors are important complications that are more commonly seen following SB than after PR or PPV . Compared to PR, important disadvantages of scleral buckling include the necessity of performing the procedure in an operating room, with the attendant costs, delays, and additional equipment. More patient morbidity occurs following SB than after PR. Compared to PPV , disadvantages include increased difficulty in the management of very large and/or posterior retinal breaks, and increased patient morbidity following repairs of relatively difficult cases. Whereas experience with the procedure was extensive in the past, a growing number of VR training programs appear to be providing less extensive experience with this procedure.

OPTIMAL METHODS FOR TREATMENT

SB VS PR VS PPV

ROUND HOLE RD• In eyes with round hole RD , causative breaks are small round holes, often associated with lattice degeneration. •Patients affected are typically young, low myopes, presenting with blurring of vision and a visual field defect. Some patients are asymptomatic and picked up on routine examination .

ROUND HOLE RETINAL DETACHMENT•A common misconception is that a pigment line, or “tide mark” or “demarcation line” posterior to the area of detachment will prevent progression. This is not the case, though such a line does imply stability of the extent of the detachment for at least some months.

Conservative management•Patients with peripheral, or asymptomatic RD not threatening the macula, can be considered for conservative management. When adopting a conservative approach to these cases, it is important to consider other factors in addition to the characteristics of the detachment, including the powers of observation of the patient and their ability to attend urgently if they experience symptoms of progression. Many surgeons recommend routine examination at regular intervals, for example every 6 months or annually.

Conservative management• However, progression is more likely to occur between follow-up

examinations, and if the patient is unable to detect a change, then there is a risk of the macula detaching before treatment can be applied. Thus, even if subsequent treatment is anatomically successful, the patient may be left with worse vision than if they had received surgical treatment at presentation. This risk has to be balanced against risks of complications of surgery, particularly in this form of detachment, where as we have seen, the risk of progression is small. A patient who develops chronic discomfort, diplopia, or visual loss following surgery for an asymptomatic problem is not surprisingly dissatisfied.

Treatment Laser demarcation•The extent of RD can be limited by creating a surrounding adhesion between the retina and RPE . This is the principle of retinopexy, & is widely used to treat retinal tears. Principle can also be applied to wider areas of RD with a view to limiting progression.• Such treatment of course does nothing to resolve an existing detachment, so this choice “writes off” the detached area of retina. This is appropriate in patients with asymptomatic RD , or those with very minimal symptoms.

Treatment Laser demarcation• The aim of demarcation treatment is to create a band of effective chorioretinal adhesion, which completely surrounds area of detachment. This generally means applying treatment from ora to ora, just posterior to the fluid . Although cryo could be used, laser is preferred as it causes less tissue damage, and less inflammatation to the external eye. There is evidence that adhesion stronger than normal appears within 24 hours of application of treatment, but maximum strength is achieved between 3 and 14 days later. Therefore, laser demarcation is not suitable for rapidly progressive detachments.

Scleral buckling•The primary success rate of SB in round hole RD is very high, but there is a risk of ocular morbidity.

DETACHMENT DUE TO RETINAL DIALYSIS•There is often a long interval between the creation of the dialysis,& development of a symptomatic RD . In the series of traumatic RD , the time from trauma to RD was up to 40 years, though in 80% of cases, was less than 2 years. The progression of the detachment can be slow, and this may be related to lack of vitreous detachment. If the detachment is not detected until the macula becomes involved, then the final visual acuity can be compromised.

DETACHMENT DUE TO RETINAL DIALYSIS•Conservative management :• The considerations and options for management of pts with limited detachment secondary to dialysis are identical to those for pts with round hole detachments. Cases with signs of chronicity, such as tidemarks and retinal cysts, have probably been stable for some time & with a relatively low risk of progression.

Treatment Laser demarcation•Limited detachments secondary to dialysis respond well to laser demarcation. This is particularly true for the majority of detachments from dialysis which are in the inferotemporal quadrant. Walling off of the affected area here results in a permanent field defect superonasally, which is likely to be less important to the patient, than inferotemporal field loss.

Scleral buckling•Dialysis respond well to segmental SB procedures . the primary success rate varies from 96% to 100 % .

RETINAL DETACHMENT SECONDARY TO “U” (“HORSESHOE”) TEARS HST

•Conservative management of limited RD is adopted less commonly than in RRD due to round holes or dialyses. This is because patients usually present with symptoms associated with PVD, & there are rarely signs of fluid being longstanding. There is therefore much less confidence that fluid will remain stationary or progress slowly. Furthermore, continuing vitreous traction is an additional factor leading to faster progression.

HST RD Laser demarcation

•Although laser creates an instant adhesion, this is not of full strength for up to 14 days. Rapidly progressing fluid may extend through area of demarcation before a strong enough adhesion develops. •This form of treatment should therefore be used with caution in patients with RRD secondary to “U” tears.

PNEUMATIC RETINOPEXY PR•Given that PR is a relatively quick and simple procedure, with less morbidity than SB , it is worth considering as an initial procedure. This is particularly the case for patients who have “classic” indications, as the success rate appears higher in this group. In a subgroup of patients with phakic eyes, single breaks, and fluid confined to one superior quadrant, the primary success rate was 97%. There is evidence that PR is less effective in aphakic & pseudophakic eyes.

PR AS ADJUNCT TO SB•Most surgeons who use pneumatic retinopexy, apply it as a primary procedure, and then employ scleral buckling if it fails.

SCLERAL BUCKLING• It is important to understand that SB achieves only closure, and not sealing of the retinal break, the latter being the role of retinopexy. The implication of this is that SB alone has same initial success rate whether retinopexy is applied or not, but if indentation fades, or the SB is removed, the RD will recur.

VITRECTOMY•As surgeons became comfortable using vitrectomy techniques to manage cases of vitreous pathology and complex RD , it became clear that the advantages of an internal approach could also be useful for simpler cases. Kloti was the first to report using vitrectomy for superior bullous detachments. A subsequent series reported on vitrectomy and fluid–gas exchange in 29 cases of RRD, in which scleral buckling would have been the usual approach.

VITRECTOMY•The reattachment rate following one operation was 79%, increasing to 93% after two operations. These results compared favorably with rates for conventional surgery. Vitrectomy offers a more successful approach for simple detachments with significant vitreous opacity, or for those with posterior breaks which would otherwise require a large SB . Other agreed indications include eyes with thin sclera which would make SB difficult or dangerous.

CONCLUSION• The treatment of RRD has advanced since Gonin. Both primary and final success rates are now high, and it is only a small minority of cases whose retinas remain detached after one or more operations. There is broad agreement about best method for some categories of RD , but for majority of cases, there is both lack of agreement, and lack of an evidence base to make rational choices of technique. The goal of treatment should be to choose a method for any particular case that has the best chance of anatomical success, but with the lowest risk of introducing further ocular morbidity.

TWELVE REPRESENTATIVE CASES

Quadrantic detachment with one break.

HST WITH RD• excellent candidate for PR, in the absence of

contraindications not related to the eye. PR avoids placement of a SB under a vertically acting muscle. It also affords the opportunity to promptly protect the macula from impending detachment, and the “steamroller” technique should be used in this case. If the tear causing a quadrantic detachment is present elsewhere in the upper eight clock-hours of the periphery, PR is still an excellent choice, although positioning for tears in the oblique and lateral meridia will be more difficult than for a 12-o’clock tear. If the tear is in the inferior four clock-hours, PR is usually contraindicated.

HST WITH RD• if the break remains widely open after buckling, the surgeon may release the Fluid by untying the sutures to restore normal IOP and then draining the Fluid. If significant fish mouthing occurs, a gas injection may be employed with the SB if the break is located in superior two thirds of the fundus.

Total detachment with one break.• If a single tear is found and there are no other suspicious areas, and if the fundus can be thoroughly examined, PR is still an excellent choice if the tear is in the upper eight clock-hours . SB technique differs from case number 1 in that most surgeons prefer to drain SRF , although many cases have been managed satisfactorily without drainage.

Total detachment with one break.•An encircling (instead of segmental or PR ) should be considered if any of following conditions is present •1 The break is not in the expected position.•2. There is question of integrity of peripheral retina.•3. There is evidence of PVR .•4. The peripheral retina cannot be examined in all areas.

Detachment with multiple breaks at same distance from ora

•PR is an option only if all open breaks are within a several clock-hour arc in the upper eight clock-hours of the eye. •Vitrectomy is a reasonable choice in a pseudophakic eye.• If SB is chosen, an encircling buckle is recommended

Detachment with multiple breaks at different distances from ora

• Vitrectomy is a good choice in this instance, especially in a pseudophakic eye and when distances from the ora differ widely. • PR is only occasionally useful, when limited breaks are appropriately positioned .• SB for this case involves a broad, grooved silicone implant employed to place all the breaks on a broad buckle. Each break is marked to ensure they all are adequately supported. The implant is usually used in association with an encircling band.

Detachment with multiple breaks at different distances from ora

•The implant is used in association with an encircling band. It is sutured to the surface of the globe, with at least one (and often with two) broad mattress sutures per quadrant over its extent, and the band is routinely anchored to the sclera in the remaining quadrant(s). SRF Drainage is drained.

“Aphakic detachment” with multiple small ora breaks

• In an aphakic/pseudophakic detachment, retinal breaks are tiny and visualization may be patchy, so some of the breaks may not be found. An encircling buckle with or without vitrectomy is frequently employed. It should be placed immediately posterior to the ora breaks. Drainage of SRF is usually required .PPV without scleral buckling is also a common choice. A 360-degree peripheral laser photocoagulation is often applied.

“Aphakic detachment” with multiple small ora breaks

• If the view is excellent and breaks are appropriately limited, PR is an option, but it carries a lower single operation success rate than buckling and/or vitrectomy .

Detachment with peripheral break and macular hole

•Macular holes in this instance are usually secondary cystic changes and not causally related to the RRD. These cases are generally managed with no treatment to the apparent macular hole. If, however, fluid reaccumulates around the posterior hole in the early postoperative course, a second procedure—usually PR—is required to close the hole .

Detachment due to macular break•Detachments caused by macular breaks are generally seen in association with high myopia .•PPV WITH internal tamponade is the procedure of choice .

Detachment with retinal dialysis• A detachment with a retinal dialysis is seen most often in the inferotemporal periphery in juveniles or young adults. Patients are typically phakic, and SB is the procedure of choice. The posterior margin of dialysis should be treated with contiguous cryotherapy and by securing a segmental buckle to the surface of the globe with several mattress sutures. The buckle should be placed just behind the posterior edge of the break. Drainage of SRF is optional .

Detachment with giant break.• A GRT is generally defined as a break spanning 90 degrees or

more. Especially where a rolled-over flap exceeding 180 degrees is present, vitrectomy with or without a low, encircling SB is the procedure of choice . The use of PFCL liquid greatly facilitates this procedure. After removal of all adherent vitreous and peeling of all membranes, the infolded retina is flattened against the wall of the eye with PFCL

Detachment with giant break• Photocoagulation is applied entirely surrounding break. Then a gas–fluid exchange is performed on top of PFCL , taking care to remove all water at the edge of the break. PFCL is carefully replaced with air while continuing to desiccate the edge of break and preventing it from slipping posteriorly. Critical postoperative positioning is required is required for 5–10 days .

THANK YOU

DR DINESHDR SONALEE