Congenital glaucoma

Buphthalmos
Congenital Glaucoma

1. Not associated with other major ocular abnormalities. Associated with other major ocular abnormalities e.g. Aniridia, Iridocorneal dysgenesis (Axenfeld Rieger, Peter) IOP is elevated during intra-uterine life manifest prior to age of 3 years IOP rises between the age of 3 - 16 years

2. Impaired aqueous outflow due to maldevelopment of the anterior chamber angle (trabeculo-dysgenesis) Abnormal mesodermal membrane occluding the AC angle Absent or non canalised canal of Schlemm Anterior insertion of iris root

3. A large eye as a result of stretching due to elevated IOP prior to the age of 3 years. The thinned sclera often appears blue due to increased visualization of the underlying uvea. Complications include myopia and lens subluxation.

4. Lacrimation, photophobia & blepharospasm Large eye Cloudy cornea

5. Cornea >12 mm prior to the age of one year or >13 mm at any age is highly suspicious. Measured by a caliber Due to diffuse stromal oedema 2ry to high IOP

6. Cornea H orizontal Curvilinear breaks In Descemet membrane

7. IOP IOP is elevated, but less than expected due to enlarged elastic globe, thinned cornea

8. Optic disc Asymmetry or a cup/disc ratio of >0.3 is suspicious. In contrast to the adult eye, the scleral canal enlarges as a part of generalised enlargement of the globe. Cup size may therefore be increased from neuronal loss ( irreversible ), enlargement of scleral canal ( reversible ) or both.

9. Gonioscopy May be normal or reveal trabeculodysgenesis, vaguely characterized by an anteriorly located iris insertion and a hypo plastic appearing peripheral iris An older concept of a discrete (Barkan) membrane has not been definitively confirmed.

10. Refraction Using retinoscopy Usually revealed myopia (Axial) but less than expected, because of; flattened cornea flat (stretched) lens

11. Inborn error of metabolism Birth trauma Keratitis Congenital NLD obstruction Corneal erosion Keratitis Megalocornea (normal IOP, clear cornea, no AC angle anomalies)

12. Ab interno TM incision

13. Ab externo TM incision using a trabeculotome Used when corneal opacity prevents adequate angle visualisation