OBJECTIVE
To evaluate the ability of a retina specialist’s grading of 30° color stereoscopic fundus photographs to identify areas of significant retinal thickening as assessed by the Retinal Thickness Analyzer (RTA) and to determine whether this ability was affected by the presence of retinal pathology.
MATERIALS AND METHODS
Thirty-two eyes in 29 patients clinically diagnosed as having diabetic macular edema underwent RTA scanning and nonsimultaneous 30° color stereoscopic fundus photography. Retinal thickness maps of the macular area were generated, and regions with significant retinal thickening (>2 SD above normal values) were identified. A retina specialist reader, masked to the RTA measurements, identified areas with macular edema on the stereoscopic fundus photographs, which subsequently were overlaid on the retinal thickness maps. The sensitivity (percent of significant retinal thickening areas identified by the retina specialist grading the stereoscopic fundus photographs) was calculated separately for areas with and without retinal pathology. Specificity of the stereoscopic fundus photograph grading was assessed similarly.
RESULTS
The retina specialist’s stereoscopic fundus photography grading identified 78.8% of areas with significant retinal thickening (range over eyes: 20.4%-100%) and was slightly more likely to identify significant retinal thickening when pathology was present (89.6%) than when pathology was not present (78.4%; pooled risk ratio, 1.14 [95% CI=0.54, 2.42]). Specificity of stereoscopic fundus photography grading was 58%, ie, 42% of areas without significant retinal thickening were (incorrectly) identified as edematous by the stereoscopic fundus photograph grading. This misidentification was more likely if pathology was present (76.9%) than if pathology was not present (41.1%; pooled risk ratio, 1.87 [95% CI=1.28, 2.73]).
CONCLUSION
This study shows the determination of macular edema by a retina specialist reading color stereoscopic fundus photographs is sensitive but not specific with reference to edema identified by the RTA. Furthermore, the presence of retinopathy tends to cause false-positive readings with reference to edema identified by the RTA. These findings indicate the need to use objective, quantitative methods in clinical studies to detect and monitor macular edema. [Ophthalmic Surg Lasers Imaging 2003;34:7-16]
AUTHORS
From the Department of Ophthalmology, Wonkwang Medical Science Center, Wonkwang University School of Medicine (YK), Korea; Wilmer Eye Institute, Johns Hopkins School of Medicine (SV, YD, SROC, NMB, APS, RZ), Baltimore, Maryland; and Scheie Eye Institute, University of Pennsylvania Health Systems (JA), Philadelphia, Pennsylvania.
Accepted for publication August 7, 2002.
Preliminary results of this study were presented at the Association for Research in Vision and Ophthalmology, May 11-16, 1997, Fort Lauderdale, Florida. Supported by CURIMS (Chonam University Research Institute of Medical Sciences) Grant E96-1, Wonkwang University (YY) and by NEI grants EY06976 (RZ), EY01765 (Wilmer Institute), and EY12693 (SV).
Dr. Zeimer holds a patent on the Retinal Thickness Analyzer and is a consultant for Talia Technologies Ltd, Neve Ilan, Israel. The details of this arrangement are monitored in accordance with the policies of the Johns Hopkins School of Medicine Committee on Conflict of Interest. None of the other authors have any financial interest in the Retinal Thickness Analyzer.
Address reprint requests to Ran Zeimer, 355 Wilmer/Woods, Johns Hopkins Hospital, 600 N Wolfe St, Baltimore, MD 21287-9131.
