0520 Associations Between CBC Derived Blood Indices and Macular Thickness in Patients with Obstructive Sleep Apnea

Abstract Introduction Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia and sleep fragmentation, driving a chronic inflammatory state reflected in elevated cytokines and altered hematologic indices. Optical coherence tomography (OCT) enables quantitative assessment of retinal structure, and prior studies suggest that OSA is associated with retinal changes. Although neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), and platelet-to-lymphocyte (PLR) ratios have been evaluated as inflammatory markers in OSA, findings remain inconsistent and relationships between these indices and OCT parameters have yet to be explored. Additional ratios including hemoglobin-to-platelet (HPR), lymphocyte-to-red blood cell (LRR), platelet-to-monocyte (PMR), hemoglobin-to-lymphocyte (HLR), and monocyte-to-red blood cell (MRR) remain to be examined. Defining these associations may improve OSA risk stratification and clarify retinal involvement. Methods CBC values from 66 OSA patients were reviewed, and macular OCT scans were available for 19 after excluding those with macular pathology. OCT parameters included central, inner, and outer macular thickness across four quadrants. A control cohort of 55 patients had CBC values available and 7 of the 55 had OCT scans. Inflammatory indices were calculated for all OSA. Primary analyses assessed associations between inflammatory indices and macular thickness using Spearman correlation. Secondary analyses compared macular thickness and inflammatory indices between OSA patients and controls using independent-samples t tests, Mann–Whitney U tests, or MANOVA. Significance was set at p < 0.05. Results No inflammatory indices demonstrated statistically significant correlations with central or ring-based macular thickness in the OSA group (all p > 0.05). Central macular thickness did not differ between OSA patients and controls. Inner ring thickness was significantly reduced in OSA (286.0 ± 20.7 μm vs 334.1 ± 7.7 μm, p = 0.00017), while outer ring thickness was greater (335.2 ± 27.9 μm vs 294.2 ± 8.4 μm, p = 0.0016). Compared with controls, OSA patients had higher NLR, PLR, and MRR and lower WNR, HPR, and PMR (all p < 0.01). Conclusion In this cohort, CBC-derived inflammatory indices were not associated with macular thickness measurements in OSA patients. Although macular thickness differences were observed between OSA and control subjects, small sample sizes limit definitive interpretation. Larger studies with paired CBC–OCT datasets are needed. Support (if any)