Severe visual loss and recovery post trabeculectomy- A case report

Glaucoma is a progressive optic neuropathy and a leading cause of blindness. Neural losses from glaucoma are irreversible, and so the aim of glaucoma treatment is to slow progression and minimize the risk of further damage. Visual loss post filtration surgery in patients with advanced glaucomatous optic nerve damage is a rare but dreaded complication. Functional improvement is not expected. We report the case of a patient who experienced a significant loss of vision following glaucoma surgery that was followed by late visual recovery. We will also review the literature regarding this phenomenon.

A 60-year old male presented with a history of right pseudoexfoliative glaucoma and uncontrolled intraocular pressure(IOP) on medical and laser treatment. He underwent a successful right Mitomycin C augmented trabeculectomy combined with phacoemulsification. Unexpectedly, he experienced a marked decrease in vision from 0.3 to hand motion with no identifiable explanation. The loss of vision continued for almost 4 months before a significant improvement in vision occurred and his visual acuity came up to 0.6. Although the mechanism of loss or improved vision cannot be proven, it is likely that post operative IOP spikes which were repeatedly above 30 mmHg in the first week, resulted in ganglion cell dysfunction rather than apoptosis which can explain the improvement in vision in the later months when pressure was maintained at target.

and Importance: Although rare, Wipe out phenomenon is possible in the setting of advanced glaucomatous optic neuropathy. However, functional improvements may occur following IOP control. Glaucoma surgery should be offered early to those with advanced disease.