Screening of donated whole globes for photorefractive keratectomy

To introduce a screening method for diagnosis of photorefractive keratectomy (PRK) in donated whole globes.

Donated whole globes with either no or an unknown history of refractive surgery on family interview were evaluated in the Central Eye Bank of Iran. After disinfection of globes by immersion in 3% povidone iodine for 3 minutes, followed by irrigation with 0.9% normal saline, gross inspection and slit-lamp biomicroscopic examination of the corneas were performed. Corneas with a disciform, round-shaped hazy area within the central 8 mm of the cornea, suggestive of previous PRK (case), and corneas without this criterion (control) were excised and sent for histopathology. Then, sensitivity and specificity of the screening method were calculated by analyzing the histopathology results of case and control corneas.

Twelve thousand five hundred fifty-four donated whole globes from 6832 donors were examined. Twenty case corneas from 10 donors and 54 controls from 27 donors were evaluated by histopathology. Age and sex of the donor population in both case and control groups were comparable with the entire donor population. PRK was confirmed by histopathology in all 20 case corneas but not in any of the control corneas. Both the sensitivity and specificity of this screening method were 100%.

Gross inspection of donated whole globes after exposure to povidone iodine followed by slit-lamp biomicroscopic examination, with particular attention to finding a midperipheral-to-midperipheral disciform hazy area within the central 8 mm of cornea, is a safe, simple, and inexpensive screening method, with high sensitivity and specificity for diagnosing PRK.