A. Del Monte

Retinitis Pigmentosa: A Symposium on Terminology and Methods of Examination

This report represents a summary of opinions expressed at a meeting of specialists interested in retinitis pigmentosa (RP) and allied diseases, at which an attempt was made to define some minimum guidelines for ocular evaluation of these disorders. The term RP would be reserved for a group of hereditary disorders that diffusely involve photoreceptor and pigment epithelial function, and should not be used when a secondary cause is suspected. RP may be classified by genetic type (single cases without known affected relatives should be termed isolated or simplex), by the topography of retinal involvement, and by the severity of disease (to identify subtypes with mild or localized disease). Patients should have at least one comprehensive examination that conforms to basic standards, preferable early in the course of the disease. The visual field examination should use both a small and a large test light. Electroretinographic testing should (1) use a full-field stimulus, and (2) routinely document three independent responses (cone, rod, and mixed cone-rod). Patients should be identifiable for future study or therapeutic trials. They should be counseled about the disease and followed regularly. No specific therapy exists at present for most of these diseases, but optical and night vision aids are available. Sunglasses for outdoor use are recommended until more is known about whether long-term exposure to bright sunlight alters the course of these diseases.

In vitro culture of human retinal pigment epithelium for biochemical and metabolic study

The proper functioning of the many types of ocular epithelium, most notably the retinal pigment epithelium (RPE), is critical to the sensory functions of the human eye. We have developed new techniques for the in vitro culture of human RPE using collagen coated tissue culture dishes and Epithelial Growth Factor. These techniques increased culture success using pairs of donor eyes from 25% to 87%. Human RPE has been cultured for up to 4 months while retaining marked pigmentation and epithelioid characteristics. Use of pure cultures of human RPE will allow biochemical study of this important tissue.