Retina Society 2017 (Day 4): Diabetic Retinopathy

Esther Lee Kim, MD
Vitreoretinal Surgery Fellow
Massachusetts Eye and Ear, Harvard Medical School

The final day of the 50th anniversary Retina Society meeting began with a comprehensive discussion of Diabetic Retinopathy led by Glenn Jaffe and Shlomit Schaal. This robust session involved 21 talks that spanned clinical trials, genetic analyses, and imaging studies.

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Here, we share some of the highlights:

Ala Moshiri discussed his mouse gene knockout project, where his team knocked out a single gene one at a time in a mouse model. After each mutation iteration, the mouse underwent a complete fundus exam by an experienced ophthalmologist to look for ocular abnormalities. Through this method, they found 236 genes that affected the eye. 51 were previously published in the literature, but 181 were novel genes required for normal eye function and morphology. Specifically, 92 genes were found to affect the retina. Of these, 18 were previously published, but 74 novel genes were identified. Researchers will now cross-reference these 74 potential new retinal genes with whole genome sequencing from patients with a presumed hereditary retinal degeneration. We look forward to these results!

Christopher Riemann sought to identify the real-world functionality of Iluvien as part of the USER Study Group. We know that Iluvien shows near zero order kinetics for up to 3 years. The FAME trial demonstrated its efficacy in DME. The authors here found stable or improved anatomical and functional outcomes with a significantly reduced treatment burden. Mean time to cataract surgery was 249 days.

Interjecting this session was an excellent ocular melanoma talk by J. William Harbour. Based on 163 primary uveal melanomas, he created a bioinformatics genomics database at Bascom Palmer. He reiterated the three key prognostic mutations: BAP1 (class 2), SF3B1 (class 1B), and EIF1AX (class 1A). He questioned the assumption that all uveal melanomas tumors will progress to high-risk tumors if left untreated. He made the point that tumor size and the propensity to metastasize have more to do with the genetics of the tumor rather than simply the duration of the tumor. Best would be to identify these high-risk profile tumors early to prevent future metastasis. The subsequent discussion pointed out that the holy grail would be to have non-invasive genetic biomarkers, as the only way to assess a tumor’s risk profile currently is with an invasive biopsy.

Anthony Obeid presented an interesting talk on patient non-compliance in diabetic retinopathy. In a large retrospective study, he found an overall non-compliance rate of 25%. Non-compliance was defined as a 12-month period of no follow-up. Authors also found greater non-compliance in younger patients and in those with a lower adjusted gross income. African-Americans and “unreported” races had significantly higher non-compliance rates than that of Caucasians and Asians. No significant difference in non-compliance existed based on visual acuity. Interestingly, history of receiving the annual influenza vaccine was a good predictor of compliance. This supports the old adage that the past predicts the future!

SriniVas Sadda sought to answer, “Are all areas of retinal non-perfusion the same in diabetic retinopathy?” He sub-classified areas of non-perfusion as posterior (involving the posterior pole), mid-peripheral (up to the equator), and far peripheral (beyond to the ora serrata). Generally, non-perfusion was most common and severe in the mid-periphery, and this area may be the most relevant to the severity of DME. This raises the question as to whether this specific area should be targeted in the future with targeted retinal photocoagulation (TRP).

Sadda

Amani Fawzi beautifully highlighted OCTA findings in diabetic retinopathy. First, she was able to consistently identify a third capillary plexus (intermediate capillary plexus) along the inner plexiform layer which demonstrated the smallest FAZ area among the three capillary plexuses. In addition, she found increased superficial capillary flow as well as non-perfusion in patients with diabetes but no diabetic retinopathy, perhaps serving as an early marker for diabetic retinopathy in the future.

Kudos to all those who faithfully attended the last day of the meeting and gleaned several fascinating pearls from today’s talks!