The Alaska Blind Child Discovery project: rationale, methods and results of 4000 screenings.

BACKGROUND: Photoscreening allows lay persons to adapt the Enhanced Brückner Test to preschoolers in an attempt to identify refractive amblyopia. The Alaska Blind Child Discovery (ABCD) project is charitably funded and administered. METHODS: MTI photoscreening was offered to children in rural and urban communities in southern Alaska from 1996 through June 1999. Parents answered questions concerning the child's health, family ocular history and whether the child had any eye "Warning Signs." The MTI images were interpreted by two eye doctors using a modification in MTI published guidelines. RESULTS: Out of 4000 screenings performed on 3930 children, there was an overall "not normal" interpretation of 9% and an inconclusive rate of 1%. The mean S.D. age was 3.9 2 years. Only 6% had had a prior eye exam. The average number of Polaroid pictures per screening was 1.16. Follow-up data on "not normal" results was obtained on just over 50%. The positive predictive value during the first two years was 77% but improved to 92% from 1998-1999. Affirmative answers to the questions concerning previous eye exam, child's health, siblings eye health and positive "Warning Signs" were significantly associated with "not normal" interpretations but affirmative answers about eye health of mother, father and relatives were not. Community penetrance of photoscreening to the target age-group ranged from only 5% for Anchorage to almost 100% for the Bristol Bay public health nurses. Five percent of parents of "positive" results surveyed would not have recommended screening for their friends. Equipment functioned dependably even in remote Alaska. CONCLUSION: Charitable volunteer Polaroid photoscreening detected amblyopia and significant pediatric eye disease in over 300 children during the first 3.5 years of ABCD.

Orthokeratology. Part II: Evaluating the Tabb method.

This summary of the experimental design and methodology of a study evaluating ocular response to orthokeratology presents a method of orthokeratology that involves modifying the optic zone diameter, intermediate, and peripheral curve zones of a PMMA contact lens. An evaluation of the Tabb method of orthokeratology to determine the ocular tissue changes most responsible for observed refractive and acuity changes found that noncorneal parameters measured did not change, whereas two corneal parameters measured did change as orthokeratology occurred. The corneal parameters that appeared most involved in refractive and acuity changes were corneal thickness and shape factor. The Tabb method of orthokeratology did not cause an increase in corneal with-the-rule astigmatism.

Orthokeratology: part I historical perspective.

This history of orthokeratology includes contributions made by Jessen, Ziff, Nolan, Paige, Gates, May, Grant, Fontana, Tabb, Freeman, Shed, Kerns, and Binder to the use of contact lenses for myopia reduction. It reviews the early use of extremely flat lenses to flatten corneas and the more recent use of lenses fit with apical clearance to reduce myopia. The controlled studies of Kerns and Binder are described and the need for further research is indicated.

Extended wear of Hydrocurve II55 soft contact lenses.

Nine myopic subjects (eighteen eyes) were fit with Hydrocurve II55 soft lenses and completed an average of seven months of extended wear with comfort and no significant side effects. Significant changes included horizontal meridian subjective refraction (myopia increased 0.26 D), PEK horizontal central power (0.23 D steepening), and PEK horizontal shape factor (increased .10). Papillary hypertrophy increased in 14 of 18 eyes but no subject had a giant papillary response. Conjunctival sample showed an increase in cellular infiltrates. Corneal aesthesiometry showed a significant increase in sensitivity. A safe, effective regimen for extended wear with normal myopic eyes was developed. Fitting and follow-up recommendations were made.

Overview of extended wear contact lenses.

Extended wear of contact lenses is an attractive alternative to daily wear regimens. Immediate application has been for therapeutic purposes. Recently, cosmetic investigations have occurred, primarily outside of the United States. Regardless of the application, extended wear requires careful patient selection, fitting and post-fitting care to insure that ocular integrity has not been disturbed.