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CONGENITAL
GLAUCOMA
By Shubham Vasudeva
CONGENITAL GLAUCOMAS
They are a group of diverse disorders in which abnormal high intraocular pressure results due to developmental abnormalities of the angle of anterior chamber obstructing the drainage of aqueous humour.
CLASSIFICATION
1. Primary congenital glaucoma(without asso. anomalies)
> True congenital glaucoma (IUL- birth)
> Infantile congenital glaucoma (up to 3 yrs)
> Juvenile glaucoma (>3yrs)
2. Developmental glaucoma(with asso. anomalies)
> Glaucoma asso. with iridocorneal dysgenesis
> Glaucoma asso. aniridia
> Glaucoma asso. with ectopia lentis syndromes
> Glaucoma asso. with phakomatosis
> Miscellaneous conditions
Pathogenesis
Primary congenital glaucoma is due to failure or abnormal development of the trabecular meshwork
Maldevelopment of trabeculum including the iridotrabecular junction (trabeculodysgenesis) is responsible for impaired aqueous outflow resulting in raised IOP.
Trabeculodysgenesis is characterized by absence of the angle recess with iris having a flat or concave direct insertion into the surface.
The iris may not completely separate from the cornea that the angle remains closed by persistent embryonic tissue.
Pathogenesis of Glaucomatous Ocular Damage
Main Theories are:
1 Mechanical changes due to the rise of IOP
2 Vascular perfusion of the optic nerve head
3 Defective autoregulation
Above is shown a typical nerve appearance with damage from glaucoma. Note that the center of the nerve has an excavated or "scooped out" appearance.
CUPPING OF OPTIC DISC IN GLAUCOMA
CLINICAL FEATURES
1. Photophobia, blepharospasm, lacrimation & eye rubbing are often occur together.
These are thought to be caused by irritation of corneal nerves, which occurs as a result of the elevated IOP.
Photophobia is usually the initial sign, but is not enough by itself to arouse suspicion in most cases.
2. Corneal signs : Corneal signs include its oedema, enlargement and Descemet’s breaks.
Corneal oedema – It is frequently the first sign which arouses suspicion
Corneal enlargement- It occurs along with enlargement of globe-buphthalmos especially when the onset is before the age of 3yrs
.
Haab’s straie (Tears and break in Descement’s membrane)-
These occur because Descement’s membrane is less elastic than the corneal stroma. Tears are usually peripheral and concentric with the limbus.
3. Sclera becomes thin and appears blue due to underlying uveal tissue.
4. Anterior Chamber becomes deep.
5. Iris may show iridodonesis and atrophic patches in late stage
6. Lens becomes flat due to stretching of zonules and may even
subluxate. 7. Optic disc may show variable cupping and atrophy especially after third
year.
8. IOP is raised which is neither marked nor acute
9. Axial myopia may occur because of increase in axial length which may give rise to anisometropic ambylopia.
MANAGEMENT OF CONGENITAL GLAUCOMA
CLINICAL FEATURES
Symptoms
- Epiphora
- Photophobia
- Blepharospasm
Examination
- Reduced visual acuity
- Buphthalmos
- Corneal diameter > 12 mm
- Corneal edema
- Haab’s striae
- Elevated IOP
- Optic atrophy
The same infant as the previous photo. Although the red reflex from the flash can be partially seen, a whitish haze covers the entire corneal surface.
This infant presented with hazy bilateral corneal opacities on the initial newborn exam. The diagnosis of was relatively easy as there was a strong family history of congenital glaucoma.
Examination under General Anaesthesia
IOP
normal is 10-15 mm Hg under anaesthesia -
anaesthetics and preoperative dehydration lowers IOP.
Vernier callipers are used to measure the corneal diameter in infants.
Gonioscopy
anterior chamber deep with normal iris structure
angle open with concave or flat insertion of iris root with abnormal tissue
giving shagreen, glistening appearance
may also have absent angle recess, peripheral iris hypoplasia, tenting of
peripheral iris pigment epithelium, thickened uveal trabecular meshwork.
Stretch marks in the cornea (Haab’s striae) from the high
intraocular pressure in a patient with congenital glaucoma (need
cropping and arrows).
The left eye of this congenital glaucoma patient is noticeably larger than the right eye. The patient has buphthalmos of the left eye
Examination under General Anaesthesia
Optic nerve
- normally pink with small cup
- preferential neural loss of superior and inferior
poles
- cupping may be reversible if IOP lowered initially
Axial length
- enlarged but may reverse with reduced IOP
DIFFERENTIAL DIAGNOSIS
Nasolacrimal duct Obstruction
X-linked congenital megalocornea without
glaucoma
Birth trauma
Keratits or uveitis
Retinoblastoma
DIFFERENTIAL DIAGNOSIS
Corneal dystrophies and dysgenesis
Inborn errors of metabolism
Intrauterine inflammations (congenital syphilis
and rubella)
Optic nerve pit, coloboma, or physiologic cupping
TREATMENT
Surgical
mainstay treatment
goniotomy for clear corneas
trabeculotomy for hazy corneas ,success rates
similar
trabeculectomy and shunt procedures only when
goniotomy or trabeculotomy fails
GONIOTOMY
Involves making a horizontal incision at the
midpoint of the superficial layers of the trabecular
meshwork
May need to be repeated
Eventual success rate is about 85%
Results are poor if the corneal diameter is 14mm
or more because Schlemm’s canal obliterated.
The goniotomy surgery involves entering
the anterior chamber with a sharp
goniotomy knife and making an opening
incision through the abnormally
developed trabecular meshwork to allow
greater outflow of the aqueous fluid and
thereby, lower the IOP .
Often 120 degrees (out of 360 degrees
total) of the trabecular meshwork can be
treated with goniotomy in a single setting.
Goniotomy. A fine surgical knife is used to open the drainage angle (trabecular meshwork) in order to lower the intraocular pressure.
TRABECULOTOMY
If corneal clouding prevents visualization of
the angle or when repeated goniotomy has failed
Partial thickness scleral flap is fashioned
Schlemm canal is found and a trabeculotome is inserted into
Schlemm canal and then rotated into the anterior chamber
Technically highly demanding, requires previous experience, and
good anatomical landmarks to achieve predictable results
Schlemm canal may be difficult to canalize because of hypoplasia or
angle anomaly
Trabeculotomy surgery involves making an external incision and
identifying the Schlemm’s canal from the outside, inserting a fine
instrument into the Schlemm’s canal, and breaking through the
trabecular meshwork to increase the aqueous outflow .
Typically, 120-140 degrees of trabecular meshwork can be treated
by trabeculotomy in a single surgery.
If one surgical technique is unsuccessful in decreasing the IOP, the
other technique can be utilized in a fresh area of the trabecular
meshwork (the area not previously operated upon) to increase
the success of the surgery.
Even after initial control of the intraocular pressure is established
with surgery, a periodic monitoring is necessary to ensure the IOP
doesn’t increase again and the glaucoma go out of control.
Trabeculotomy. A trabeculotome instrument is used to open the drainage angle (trabecular meshwork) in
order to lower the intraocular pressure.
TREATMENT
Medical
Temporary measures to control IOP and to clear cloudy
cornea prior to surgery
Administer beta-adrenergic antagonists, CAI’s(carbonic
anhydrase inhibitors).
avoid alpha2-adrenergic agonists under 3 years
occlude nasolacrimal drainage system for 2 minutes
after administration.
•Medications can be used as an adjunct therapy either before or after
the surgical treatment.
• Medications may be utilized temporarily after the diagnosis until
surgery can be performed. If the initial surgery fails to completely
control the IOP, topical medications can be used to bring the glaucoma
under control.
• The systemic side effects of topical medications are greater in infants
than in adults because of the smaller body mass.
•Because of potential systemic side effects, the first line of
medications that are commonly employed is the topical carbonic
anhydrase inhibitors.
• After the CAI, the next choices are topical prostaglandin
analogs or beta-blockers .
•The prostaglandin analogs (e g.latanoprast) appear to be safe
in children; however, there are no long-term data on the safety
of these medications in children. Topical beta-
blockers(eg .timolol , carvedilol) should be used with caution
in children because of the well-known systemic side effects.
•Finally, topical alpha-2 agonist (brimonidine) should be
AVOIDED in infants because it’s been associated with severe
respiratory depression (breathing difficulty).
PROGNOSIS
Good in asymptomatic patients
diagnosed before 24 months.
Guarded in symptomatic patients diagnosed after
24 months even if IOP controlled after surgery.
Developmental Glaucoma Associated With Ocular Or Systemic Abnormalities
Microphthalmos
Corneal anomalies (microcornea, megalocornea, cornea
plana, sclerocornea, corneal staphyloma)
Anterior segment dysgenesis (Axenfield-Rieger syndrome, Peters anomaly, iridoschisis)
Aniridia
Lens anomalies (congenital cataracts, lens dislocation, microspherophakia)
Persistent hyperplastic primary vitreous Congenital ectropion-uvea syndrome ectropion
THANK
YOU