Authors: Yelin Yang, Sohel Somani

Author Disclosure Block: Y. Yang: None. S. Somani: None.

Abstract Body:

Purpose: Obstructive sleep apnea (OSA) is characterized by intermittent nocturnal hypoxemia, which may lead to increased inflammatory markers. Many of the same inflammatory mediators have also been found to be elevated in patients with diabetic macular edema (DME). However, the relationship between OSA and DME is not well defined. The objective of this study is to determine differences in inflammatory markers expressed in DME patients in the presence or absence of OSA.
Study Design: Prospective, cross sectional study
Methods: Patients with optical coherence tomography (OCT) proven, treatment naive DME were enrolled in the study. All patients were stratified into 2 groups based on the result of their overnight polysomnography testing: OSA positive (OSA+) was defined as having an apnea-hypopnea index (AHI) of greater than 15, and OSA negative (OSA-) was defined as having an AHI <15. Aqueous humor and serum samples were collected prior to their first anti-VEGF injection. Multiplex immunoassay was performed for cytokines including VEGF, placental growth factor (PGF), intercellular adhesion molecule (ICAM-1), IL2, IL3, IL6, IL 8, IL10, IL17, vascular cell adhesion molecule (VCM1), monocyte chemoattractant protein (MCP1), epidermal growth factor (EGF), Angiotensin 2, TGFB, pigment epithelial derived factor (PEDF) and pigment epithelial derived factor (PEDF). Bonferroni correction was used to adjust for multiple comparisons, with statistical significance defined as p < 0.003.
Results: DME positive patients were enrolled in the study. Mean age was 62 years, and 19 patients (76%) were male. At baseline, the median BCVA in the study eye was 20/50, and the mean central retinal thickness on OCT was 416m. 20 patients were OSA+. The mean and minimum O2 saturation in the OSA+ group was 93.0% and 79.9% respectively, while in the OSA- group it was 95.1% and 87.6 %, respectively. Adjusting for multiple comparisons, there were no significant differences between OSA- and OSA+ group for both aqueous and serum cytokines. OSA + group had higher levels of serum PGF, ICAM, IL8, IL17, VCAM1, MCP1, angiotensin, PDGF, TGFB as well as aqueous VEGF but this was not statistically significant. IL2, IL3, IL10, and EGF levels were unmeasurable in both serum and aqueous samples.
Conclusions: OSA + group had higher serum inflammatory markers and aqueous VEGF level but this did not reach significance. Further research is needed to characterize the biochemical relationship between OSA and DME.