Relationship Between Posterior Vitreous Detachment and Macular Dimensions in Myopic Eyes

Janarthanam Jothi Balaji,1 Rajiv Raman,2 Vasudevan Lakshminarayanan3 1Department of Optometry, Medical Research Foundation, Chennai, Tamil Nadu, 600006, India; 2Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Chennai, Tamil Nadu, 600006, India; 3Theoretical and Experimental Epistemology Lab, School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, CanadaCorrespondence: Janarthanam Jothi Balaji, Department of Optometry, Medical Research Foundation, 18, College Road, Nungambakkam, Chennai, Tamil Nadu, 600006, India, Tel +91 44-42271500, Email jothibalaji@gmail.comBackground: Posterior vitreous detachment (PVD) can result in serious pathologic events at the vitreoretinal interface. This study aims to assess the relationship between PVD, macular thickness (MT), and the foveal avascular zone (FAZ) in myopic eyes.Methods: This retrospective study evaluated 63 myopic subjects’ data who were examined between January 1 and June 30, 2019. The myopes were grouped on a severity scale, namely mild, moderate, high, and very high using their spherical equivalent (SE). The PVD classification was based on OCT images. The status of the PVD and MT were evaluated with the Macular Cube 200× 200 images, the FAZ with an OCTA Angioplex, and the dimensions were calculated using a customized algorithm.Results: The study population (114 eyes) had a median (range) age was 26.00 (22.00– 28.00) years and the females constituted 62.3% of the dataset. In this population, 10 eyes had no PVD in any quadrant, and 73 eyes had incomplete PVD in all four quadrants. The inferior quadrant had the maximum rate of PVD occurrences and the nasal quadrant had the least number of occurrences. High myopic eyes exhibited significantly increased low foveal volume (p = < 0.01). The inferior part of the para- and perimacular area showed a significant thinning in very high myopic eyes (p = < 0.050). The very high myopic eyes showed a significant alteration of FAZ’s circularity index (p = 0.002).Conclusion: In high and very high myopic eyes, an increasing trend of partial PVD is seen, most commonly in the inferior quadrant. A significant alteration in foveal volume and circularity index of the FAZ is seen in high and very high myopic eyes.Keywords: posterior vitreous detachment, foveal avascular zone, OCT, macular thickness, myopia