SEVERE CORNEOSCLERAL INFECTION - A COMPLICATION OF BETA-IRRADIATION SCLERAL NECROSIS FOLLOWING PTERYGIUM EXCISION

Objectives: To assess the precipitating factors, clinical course, and treatment of 11 cases of severe intraocular infections of radionecrosi s after pterygium excision in an attempt to minimize the devastating o cular sequelae. Design and Setting: From the database of cases of radi onecrosis at Royal Perth (Australia) Hospital and Lions Eye Institute, Perth, we identified 11 cases of severe intraocular infection complic ating radionecrosis. We reviewed the case notes and the available radi otherapy records (n=8). Patients: Eleven patients admitted during an 8 -year period. Results: Mean (+/-SD) dose of radiotherapy was 22.7 +/- 1.0 Gy and mean latency period, 14.45 +/- 2.5 years. Among the six pro ven bacterial cases, Pseudomonas was identified in four, Staphylococcu s aureus in one, and Streptococcus pneumoniae was involved in one bila teral case. Among the four fungal cases, Petriellidium boydii was indi cated in two, and Fusarium and Scedosporium inflatum in one each. The condition may remain undiagnosed for some time and mimic a posterior s cleritis, serous retinal detachment, or pseudotumor. Interventions: Ea rly debridement and culture, close microbiological assistance; and sys temic antimicrobials for a prolonged period. Perforation or incipient perforation necessitated penetrating keratoplasties in seven patients and repeated keratoplasties in three. Main Outcome Measures: The use o f radiotherapy following pterygium excision should be limited and only low doses used. Ulcer beds and calcific plaques at sites of radionecr osis should not be directly covered without first performing adequate sterilization. Removal of plaques may precipitate sepsis; ulcer beds a nd plaques harbor infective agents. Conclusion: Severe radionecrosis m ay expose a patient to a lifelong risk of intraocular sepsis and profo und visual morbidity. Conjunctival autografting is a safer method to r educe recurrence rate after pterygium excision.