Comparison of the old and new W.H.O. leprosy disability grading scheme for ocular disabilities.

We compared the old (1970) and new (1988) World Health Organization schemes for classifying the ocular disabilities in leprosy patients. 509 leprosy patients from eight resettlement villages in central South Korea were examined and graded by eye according to both of the schemes. A more liberal definition of severely disabled in 1988 resulted in a 119% increase in eyes graded as severely disabled in this population. 59 eyes were graded as severely disabled by the old scheme and 129 eyes were so graded according to the new scheme. Keratitis, one of three measures of moderate disability in the old scheme, was replaced by corneal anaesthesia in the new scheme, but this change did not make a substantial difference in the number of patients in the moderately impaired category. In the absence of longitudinal studies documenting the significance of keratitis, it is unclear whether the change in an improvement. The new disability scheme improved upon the old by removing the criteria for mild impairment.