Phototherapeutic Keratectomy Using High Ablation Depth For Management Of Advanced Case Of Reis-Bucklers' Corneal Dystrophy

Phototherapeutic keratectomy (PTK) plays an important role in the management of Reis-Bucklers’ corneal dystrophy. It plays a major role in visual rehabilitation of patients. The usage of PTK for the treatment of advanced presentation of anterior corneal dystrophies is difficult due to the limitation of depth of ablation. This case highlights the use of high ablation depth PTK as one of the management strategies to visually rehabilitate a patient of advanced Reis-Bucklers’ corneal dystrophy.

Cornea and Refractive Surgery Services, LV Prasad Eye Institute, Hyderabad, India

A 32-year-old lady presented with Reis-Bucklers’ corneal dystrophy in both eyes. The patient had history of progressive diminution of vision since the age of 6 years and attacks of recurrent corneal erosions. The uncorrected visual acuity (UCVA) was 20/800 in both eyes. Slit lamp examination of both eyes showed dense diffuse greyish deep epithelial opacities involving the visual axis in a fishnet pattern. Anterior segment optical coherence tomography (AS-OCT) imaging of both eyes cornea showed a thick band of hyperreflective material in the epithelial and subepithelial area which was 158 microns thick in right eye and 144 microns thick in left eye including the epithelium, bowman’s membrane, and anterior stroma.
PTK was planned for the visual rehabilitation and symptomatic comfort of the patient, right eye followed by left eye 2 weeks later. The overall depth of the central corneal opacity due to Reis-Bucklers’ dystrophy in our case was about 150 microns in both eyes. The patient had not sought any surgical intervention for her eye condition since childhood. As a result of this, the corneal subepithelial deposits had become quite thick over a period. The residual clear stroma beneath the opacity was measured to be around 480 microns on AS-OCT. Hence, we decided to plan PTK for this patient, even though it involved high ablation depth. 

In advanced cases of Reis-Bucklers’ corneal dystrophy, the deposits replacing the basal epithelial cells and the Bowman’s membrane are accumulated over time. This provides additional thickness to the anterior cornea with relatively uninvolved mid to deep stroma. Hence in these cases, PTK with higher ablation depth can be planned safely as it will ablate the added deposits and not deep into the stroma.