Catract in the adult eye Done by :Bena bint yusuf Al-sayed Under the supervision of DR: Khalid al...

Catract in the adult eyeCatract in the adult eye

Done by :Bena bint yusuf Al-Done by :Bena bint yusuf Al-ssayedayed

Under the supervision ofUnder the supervision of

DR: Khalid al ArfajDR: Khalid al Arfaj

Objectives:

1) Infection control.

2) Surgical technique.

3) Intraocular lenses.

4) Optical refraction consideration.

5) Outcomes.

6) Complications.

7) Intraocular co morbidity .

Infection prophylaxis :

Of great importance potentially sever consequence of endophthalmitis

two emerging concerns :1- increased resistance of (STAPH.A) to broad spectrum of

antibiotics including ( last generation fluoroquinolones )

2- increased occurrence of acute endophthalmitis more than a week after surgery ..

Cont ..Infection prophylaxis :

Historically : the expected incidence of sporadic endophthalmitis = (0.5-1 case per thousands of routine cataract procedures )

Since 1994 :

incidence after cataract sx increased

incidence after other AS procedures has been on the decline

Cont ..Infection prophylaxis :Y!???

increased use of clear corneal incisions (post op instability ,leakage, potential influx of microbs ) than sclerocorneal incisions .

4 large cases found no greater likehood of infection with corneal versus other types of incision

Cont ..Infection prophylaxis :

Other factors associated with increased rate of endophthalmitis :

1) rupture of the posterior capsule .

2) Vitreous loss.

3) Prolonged surgery .

4) Immunodeficiency.

5) Active blephritis .

6) Lacrimal duct obstruction.

7) Inferior incision location .

8) Male gender , older age .

Cont ..Infection prophylaxis :3 Retrospective studies suggest greater

endophthalmitis incidence with planned ECCE when compared by phaco ..

Type of IOL optic material polypropylene loop support ( higher rate of infection ) ..

Greater risk of IOL related contamination of the of the AS when the IOL comes in contact with ocular surface prior to implantation ..

No evidence

Cont ..Infection prophylaxis :

Contaminated surgical product ..

Contaminated operating room environment ..

Patient periocular flora source of microbes responsible for most cases of sporadic post op infection..

Cont ..Infection prophylaxis :Prophylactic strategies :

1. applying topical antibiotic eyedrops before surgery .

1. Applying 5% povidine iodine to the conjuctival cul de sac .

2. Preparing the periocular skin with 10% povidine iodine .

Cont ..Infection prophylaxis :

4. Sterile draping of the eyelid margines .

5. Adding antibiotic to the irrigating solution .

6. Instilling intracameral antibiotic at the close of surgery .

7. Applying topical antibiotics eyedrops after surgery .

8. Systemic antibiotics are rarely used.

8. systemic antibiotics rarely used.

Cont ..Infection prophylaxis :

Antisepsis of the periocular surface, typically with povidone iodine, is achieved.

All incisions are closed in a watertight fashion .

Antibiotic use on the day of surgery is important rather than waiting until the next day.

Any additional prophylactic antibiotic strategy in the perioperative period is up to the ophthalmologist to determine.

:Toxic anterior segment syndrome

Sterile ..post op..inflammatory reaction ..(12-48hrs) following surgery and can mimic infectious endophthalmitis ..

Signs : (limbus to limbus ) corneal edema. Sever AC cells and flare ,fibrin, and hypopyon .

Atonic pupil, secondary glucoma, corneal decompensation

Toxic anterior segment syndrome

Treatment:

Respond to anti –inflammatory medication but permanent intraocular damage can occur .

Cultures from the AC and the vitreous should be taken to role out infection and treatment by antibiotic should be initiated.

Toxic anterior segment syndromeEtiology: Heat stable gram negative endotoxin from municipal

water supplies . Use of chemical detergent and enzymes for cleaning the

instrument . Ointment seepage through clear corneal incisions. Denatured (OVD) residual . Solutions of nonphysiologic PH and osmolartity . IOL polishing compounds dilution error result in very high dose intracameral AB.

Toxic anterior segment syndrome

2 studies :

a) Published (questionnaire)(54 centers) most common factors were related to :

1. Inadequate cleaning + sterilization of ophthalmic solution .

2. Inadequate flushing of phacoemulsification and irrigation and aspiration of the handpieces .

3. Inappropriate use of enzymatic cleanser detergents, ultrasound bathes for cleaning and steralization of the instrument .

Toxic anterior segment syndrome

b)Retrospective study 60 cases of TASS , incidence of 0.22%

1. 2 identifiable clusters .

2. more than half sporadic and un explained

Visual outcome were excellent based on 6month follow up reported on 40% of the cases .

Surgical Techniques  

The preferred method to remove a cataract:

extracapsular extraction, most commonly by phacoemulsification..

In a randomized trial of ECCE and small-incision phacoemulsification there were :

fewer surgical complications. visual acuity was significantly better. lower incidence of posterior capsular opacification (PCO)

in the phacoemulsification group during the 1-year follow-up period.

Cont ..Surgical Techniques The ideal technical elements of a successful cataract procedure

currently include the following:

1) A secure, watertight incision that minimizes surgically induced astigmatism or reduces pre-existing corneal astigmatism

2) Thorough removal of all lens material.

3) Minimal or no trauma to the corneal endothelium, iris, and other ocular tissues.

4) Capsular bag fixation of an appropriate posterior chamber IOL

Cont ..Surgical Techniques incision :

small-incision :preferred for a number of reasons:

1.Amenable to self-sealing wound construction .2.Fewer or no sutures are needed for secure closure. 3.Safer in the event of sudden patient movement or a suprachoroidal hemorrhage during surgery4.Fewer physical restrictions postoperatively. 5. Less initial postoperative inflammation 6.Less unwanted astigmatic change 7.Earlier and greater long-term stability of the refraction

Large-incision

1.mature nuclei.2.weak zonules.3.higher risk of corneal decompensation

Intraocular lens ..a)Rigid polymethyl methacrylate (PMMA) .

b)Foldable IOLs:

1. most common choice following phacoemulsificationimplanted through smaller incisions.

2. classified according to their optic material: (silicone hydrophilic acrylic, hydrophobic acrylic, and collagen/hydroxy ethyl methacrylate [HEMA]-copolymer based.)

3. All foldable IOL materials are associated with minimal giant-cell foreign-body reaction

Each IOL is associated with unique positive and negative attributes with regard to material, design, and insertion system.

Cont..Intraocular lens ..

When combined with a sharp posterior optic-edge and an overlapping capsulorrhexis Silicone and hydrophobic acrylic foldable IOLs are associated with a low incidence of PCO..  

Cont..Intraocular lens ..

Noncapsular-bag IOL fixation ( anterior chamber IOL or a posterior chamber IOL positioned in the ciliary sulcus.)

Zonular abnormalities Anterior or posterior capsular tears.

Suturing of posterior chamber IOL haptics to the iris or sclera may be necessary in the absence of sufficient residual capsular support

Accommodating or plate haptic IOLs, require capsular-bag fixation.

Cont..Intraocular lens ..

single-piece acrylic IOLs should not be implanted in the ciliary sulcus because of associated risks such as:

1.IOL decentration .

2.Posterior iris chafing that cause transillumination defects.

3.Pigment dispersion.

4.elevated IOP.

5.recurrent hyphema, and inflammation.

Cont..Intraocular lens ..

Multiple studies support the efficacy of all three methods of IOL fixation

Anterior chamber and iris

Scleral sutured posterior chamber-in the absence of adequate capsular support.

Optical and Refractive Considerations

A)Spherical IOLs:

positive spherical aberration.  

B)Aspheric IOLs: reduce or eliminate the spherical aberration of the eye. The potential advantages and disadvantages can be affected

by

( pupil size, IOL tilt and decentration, and whether the spherical aberration of the IOL and the patient's cornea were custom matched).  

Cont..Optical and Refractive ConsiderationsC)Toric IOLs : Reduce eyeglass dependence after cataract surgery due to corneal

astigmatism. Better predictability and stability of correction. Do not correct irregular astigmatism, they should not be used in patients

who will require a rigid contact lens.  

Effective: Axis and magnitude of keratometric astigmatism must be accurately

measured. Accurately and permanently aligned..

misalignment may reduce the desired refractive effect or may even worsen the overall astigmatism

Cont..Optical & Refractive Considerations:

Monovision :

one eye is corrected for distance vision and the fellow eye is corrected for intermediate or near vision.

success of monovision :

depends on interocular blur suppression .

the overall monovision acceptance rate following cataract and IOL surgery was 90% in a cataract population that desired independence of correction with eyeglasses.

Cont..Optical & Refractive Considerations:

Monovision :

In a small, nonrandomized study comparing patients who had bilateral multifocal IOLs versus bilateral monofocal IOLs implanted to achieve monovision, there was no statistical difference in bilateral uncorrected distance and near vision, or in the satisfaction scores.

Cont..Optical & Refractive Considerations:

Presbyopia-correcting IOLs:

1) multifocal .

2)accommodative. (the lens changes position or shape within the eye).  

.  Presbyopia-correcting IOLs:

Multifocal IOLs:

dividing incoming light into two or more focal points .

Classified :

Refractive or diffractive.

Multifocal IOLs:

Optical effects:

Improving near vision when compared with monofocal IOLs and that unaided distance visual acuity was similar in the two groups.

Reduced contrast sensitivity, halos around point sources of light. There may be a symptomatic reduction in the quality of distance

vision, particularly if other ocular pathology is present. The candidacy of patients with amblyopia or abnormalities of the

cornea, optic disc, and macula for a multifocal IOL must be carefully considered.

.  Presbyopia-correcting IOLs:

Accommodative presbyopia-correcting IOLs:

Change position or shape in the eye with accommodative effort.

Without the loss of contrast sensitivity inherent with multifocal IOLs

Outcomes:

1)The ASCRS National Cataract Database .

2)The American Academy of Ophthalmology National Eyecare Outcomes Network (NEON)

3) Phacoemulsification cataract surgery performed by ophthalmology residents.

4)The Cataract Patient Outcomes Research Team (PORT) study :

patients younger than 65 showed greater improvement than those over 65. patients with more severe symptoms and more severe dysfunction showed greater improvement than those with less severe symptoms or dysfunction

Outcomes:

5)Another study used a validated visual function questionnaire and a variety of psychophysical methods to assess visual improvement in patients with symptomatic cataracts but preoperative Snellen acuitybetter than or equal to 20/50:

patients with symptomatic nonadvanced cataract, Snellen acuity in isolation will not accurately predict who will benefit from surgery.  

Complications of Cataract Surgery :The most common ocular complications :

posterior capsular tear, anterior vitrectomy, or

both during surgery (3.5%).

PCO after surgery (4.2%).

1)Incision Complications :

 Not watertight including postoperative wound leak

Hypotony.

Endophthalmitis.

Too smallincrease the risk of wound burn (ultrasound stromal thermal damage) occurs at 60º C or higher.

Too large leakage of fluid from the wound and destabilize the anterior chamber.

2)Iris Complications: 

A-Iris prolapse can result from:

intraoperative floppy iris syndrome (IFIS) poorly constructed incision.

B-causes of surgical iris trauma :

iris aspiration or agitation with the phacoemulsification tip. sphincterotomies, and excessive stretching or manipulation with

expansion devices and instruments.

3)Corneal Complications:Corneal Descements membrane :

Improper instrument entry into the anterior chamber can lead to Descemet's membrane tears or detachment.

Corneal endothelium : Any mechanical injury Prolonged ultrasonic power during nuclear removal. Intraocular solutions with a nonphysiologic osmolarity or pH. Chemical insult from toxic contaminants or improperly

formulated intraocular solutions and medications. Prolonged elevated IOP can lead to further endothelial

decompensation and corneal edema.

4)Prolonged Inflammation

  Etiology: Persistent iritis retained lens fragments.

History of uveitis.

Subacute infection with Propionibacterium acnes.

Insufficient administration of postoperative anti-inflammatory medication.

5)Posterior Capsular Tear or Zonular: :RATE :They range from 1.6% up to 9% in high-risk patients with previous pars plana vitrectomy.

Risk factors older age, male gender, glaucoma. diabetic retinopathy, brunescent or white cataract. inability to visualize the posterior segment preoperatively. pseudoexfoliation (exfoliation syndrome). small pupils, axial length greater than 26 mm. use of systemic sympathetic alpha-1a antagonist medication, previous trauma, inability of the patient to lie flat,. resident-performed cataract surgery.

Intraoperative risk factors: loose zonules, need for capsular stain, and miosis.

6)Retained Lens Fragments   Incidence :

is 0.18% to 0.28%.

What to do ?

1-Anterior vitrectomy, with stable placement of an appropriately sized and designed IOL, if available.  

2- increased risk of inflammation and elevated IOP, strong consideration should be given to referring patients who have retained lens fragments to a retina surgeon during the early postoperative period.

Then?!!

 The most appropriate timing of the secondary pars plana vitrectomy is unclear

the eye should be carefully monitored for complications, such as elevated IOP and inflammation, as long as retained nuclear fragments are present

7)Retinal Detachment 

Rate:

range from 0.26% to 4.0%.

Risk factors: Axial length more than 23 mm. Posterior capsular tear, younger age, male gender Lattice degeneration, zonular dehiscence Retinal detachment in the fellow eye.

7)Retinal Detachment..cont In one study:

Mean interval between cataract surgery and retinal detachment was 39 months.

but the increased risk of retinal detachment in pseudophakic eyes may continue for as long as 20 years.

In a single-surgeon prospective case series of 22 years duration the risk of retinal detachment after phacoemulsification for female patients with axial length less than 24 mm and age 60 or younger was zero

NO statistically significant difference in the probability of retinal detachment after ECCE compared with phacoemulsification

8)Suprachoroidal Hemorrhage..cont   Incidence :

0.15% to 0.19% .

Associated with:

myopia, glaucoma, diabetes, atherosclerotic vascular diseases, and hypertension.

Anticoagulation with warfarin does not significantly increase the risk of choroidal hemorrhage.

8)Suprachoroidal Hemorrhage..cont  

Signs and symptoms : Pain Dark shadowing and loss of red reflex Elevated IOP Shallowing of the anterior chamber Iris prolapse.

9) Cystoid Macular Edema  Clinically significant CME occurs infrequently after routine

uncomplicated small-incision cataract surgery (1.2% to 3.3%)

Often responds well to medical therapy.

Permanent impairment of central visual acuity.

Risk factors : Previous uveitis. Posterior capsule rupture with vitreous loss. Retained lens material, diabetic retinopathy Epiretinal membrane, prior vitreoretinal surgery, Nanophthalmos, retinitis pigmentosa, a History of pseudophakic CME in the fellow eye

9) Cystoid Macular Edema  Anatomic diagnosis: OCT, which is less invasive than fluorescein angiography.

Snellen visual acuity may underestimate the impact of CME on visual

function.

Treatment: Topical anti-inflammatory medications are used to prevent and to treat

established CME. (NSAIDs) alone or in combination with corticosteroids are more effective

than topical corticosteroids alone in preventing and treating acute and chronic

Intravitreal antiangiogenesis agents for treatment of CME there is insufficient evidence to support their use at this time.

9) Cystoid Macular Edema   Although perioperative prophylactic use of NSAIDs for

prevention of CME has been advocated for high-risk eyes based on a number of studies, there is no published evidence that the final visual outcome is improved with routine use of prophylactic NSAID

10)Intraocular Pressure  

Acute postoperative IOP elevation pain.

optic nerve damage

vascular occlusion.

Causes :

excess amounts of the OVD remain in the eye.

Prevention:

Topical aqueous suppressants and intracameral carbachol are most beneficial.

11) Endophthalmitis ..

Complications of Intraocular Lenses  The most common reasons for explantation of foldable IOLs : Dislocation or decentration. Glare or optical aberrations,. Incorrect power. Opacification.

The incidence of multifocal IOL explants secondary to glare/optical aberrations is increasing

Although uncommon, explantation of multifocal IOLs may become necessary if optical side effects are intolerable.

Intraocular lenses may also be damaged during implantation, and it may be necessary for the surgeon to consider intraoperative lens implant exchange.  

Cont.. Complications of Intraocular Lenses

Dislocation/decentration has been reported with virtually all IOL materials and models, including both one- and three-piece

The major predisposing factors found for IOL subluxation in one study were secondary implantation, posterior capsular rupture, and mature cataracts.

The complication of interpseudophakic opacification can occur when lens epithelial cells migrate in between the optics of two piggybacked IOLs (especially two hydrophobic acrylic IOLs) that have both been implanted within the capsular bag. This dense fibrocellular material is difficult to remove and may require explantation of both IOLs.  

Ocular Comorbidities

Preoperative ocular comorbidities may have a significant effect on the outcome of cataract surgery:

AMD Diabetic retinopathy (e.g. from moderate

nonproliferative to severe nonproliferative diabetic retinopathy).

cataract surgery does not appear to increase the risk of progression of adequately treated proliferative diabetic retinopathy or macular edema.

Cont ..Ocular Comorbidities

Pseudoexfoliation (exfoliation syndrome) capsular rupture and retained nuclear fragments

Cont..Ocular Comorbidities

Higher risk for intraoperative and postoperative complications :

Previous eye surgery. very large and very small eyes, deeply set eyes,. Small pupils or posterior synechiae, scarred or cloudy corneas,

weak or absent zonules. Prior ocular trauma. Use of alpha-1a antagonists.

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