S. K. Gibran, FRCS, MMS

Glaucoma shunt valves are frequently chosen for the treatment of refractory glaucoma that has been unresponsive to medical and surgical filtration measures. The shunt valves mainly fall into two categories, restrictive and nonrestrictive. The Ahmed glaucoma valve, introduced in 1993, is a restrictive valve. Its structural specifications allow a simple operative procedure, self-regulation and prevention of postoperative complications.

Ectopia lentis is a therapeutic challenge for ophthalmologists. It may occur as an isolated condition following ocular trauma or in association with other ocular and systemic disorders. Minimal subluxation of the lens may be asymptomatic, but in more severe cases serious visual disturbances may arise. This is most important in children, when amblyopia (often bilateral) may be disastrous.