Compare changes in retinal nerve fiber layer (RNFL) thickness between eyes assigned to intravitreous ranibizumab or panretinal photocoagulation and assess correlations between changes in RNFL and visual field sensitivity and central subfield thickness.
Eyes with proliferative diabetic retinopathy were randomly assigned to ranibizumab or panretinal photocoagulation. Baseline and annual follow-up spectral domain optical coherence tomography RNFL imaging, optical coherence tomography macular imaging, and automated static perimetry (Humphrey visual field 60–4 algorithm) were performed.
One hundred forty-six eyes from 120 participants were analyzed. At 2 years, for the ranibizumab (N = 74) and panretinal photocoagulation (N = 66) groups, respectively, mean change in average RNFL thickness was −10.9 ± 11.7 μm and −4.3 ± 11.6 μm (difference, −4.9 μm; 95% confidence interval [−7.2 μm to −2.6 μm]; P < 0.001); the correlation between change in RNFL thickness and 60-4 Humphrey visual field mean deviation was −0.27 (P = 0.07) and +0.33 (P = 0.035); the correlation between change in RNFL thickness and central subfield thickness was +0.63 (P < 0.001) and +0.34 (P = 0.005), respectively.
At 2 years, eyes treated with ranibizumab had greater RNFL thinning than eyes treated with panretinal photocoagulation. Correlations between changes in RNFL thickness, visual field, and central subfield thickness suggest that the decrease in RNFL thickness with ranibizumab is likely due to decreased edema rather than loss of axons.
When eyes with proliferative diabetic retinopathy were treated with ranibizumab, retinal nerve fiber layer thinning was greater than it was in eyes treated with panretinal photocoagulation; correlations between changes in retinal nerve fiber layer thickness, visual field, and central subfield thickness suggest that this is likely due to decreased edema.
*Feinberg School of Medicine, Northwestern University, Chicago, Illinois;
†Jaeb Center for Health Research, Tampa, Florida;
‡Paducah Retinal Center, Paducah, Kentucky;
§Washington University School of Medicine, St. Louis, Missouri;
¶Medical College of Wisconsin, Milwaukee, Wisconsin;
**Department of Ophthalmology, Duke University, Durham, North Carolina; and
††Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Reprint requests: Isoken Odia, OD, Jaeb Center for Health Research, 1530 Amberly Drive, Suite 350, Tampa, FL 33647; e-mail: firstname.lastname@example.org
Supported through a cooperative agreement from the National Eye Institute and the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, U.S. Department of Health and Human Services EY14231, EY23207, and EY18817. Genentech provided ranibizumab for the study and funds to DRCR.net to defray the study's clinical site costs.
A complete list of all DRCR.net investigator financial disclosures can be found at www.drcr.net.
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The National Institutes of Health participated in oversight of the conduct of the study and review of the manuscript but not directly in the design or conduct of the study or in the collection, management, analysis, or interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication. Per the DRCR.net Industry Collaboration Guidelines (available at http://www.drcr.net), the DRCR.net had complete control over the design of the protocol, ownership of the data, and all editorial content of presentations and publications related to the protocol.