Role of optic zone diameter in scleral lens fitting in traumatic aniridia with scarred cornea – A case report

Scleral lenses (SLs) are large-diameter rigid gas-permeable lenses that vault over the entire cornea and rest on the bulbar conjunctiva overlying the sclera and maintain a fluid reservoir, which along with the rigidity of the lens masks irregular astigmatism and reduces the aberrations. A 20-year-old male had decreased vision, photophobia, and double vision due to an open globe injury with a shuttle bat 1 year back, followed by which he underwent corneal tear repair and multiple retinal surgeries. He was advised for penetrating keratoplasty elsewhere and came for a second opinion. Based on a diagnostic fitting approach, an 18.5 mm diameter SL was applied on the right eye, with which vision improved from 6/60, N36@ 10 cm to 6/7.5 and reduced the higher-order aberrations but a slightly higher vault was observed. Therefore, a 16.5 mm diameter SL was applied but with this lens, vision decreased to 6/12 with effort, and in both lenses, the patient reported binocular diplopia. Therefore, a combination of management, larger optic zone SLs, and a Fresnel prism was prescribed, which improved the patient’s vision, and reduced diplopia. The purpose of the case report is to emphasize the role of optic zone diameter in SL fitting, particularly in cases of traumatic scarred cornea with eccentric pupils and the importance of co-management.