Ultrasound-Based Assessment of Posterior Vitreous Detachment in Healthy Eyes: Clinical and Biometric Factors...

Background/Objectives: Posterior vitreous detachment (PVD) is an age-related physiological process, yet the clinical and biometric factors influencing its progression remain incompletely characterized in adults undergoing routine ophthalmic evaluation at a tertiary center. Characterizing expected vitreous patterns is essential for interpreting vitreoretinal interface changes in disease. This study aimed to identify independent clinical and biometric factors associated with more advanced PVD stages in adults without macular pathology. Methods: In this cross-sectional observational study, 340 eyes from 198 consecutive adults undergoing routine ophthalmological evaluation at a tertiary hospital (March 2022-April 2023) were analyzed. Eyes with current or past macular disease were excluded. Demographic variables, systemic comorbidities and ocular history were recorded. Axial length was measured using optical biometry IOLMaster 700 (Carl Zeiss Meditec, Jena, Germany). Vitreous status was assessed with 10-MHz B-scan ultrasonography and classified as no PVD, partial PVD or complete PVD. Analyses were performed at the eye level. Given its cross-sectional design, this study evaluates associations and cannot establish causal relationships. Bivariate comparisons examined associations between clinical variables and PVD grade. Multivariable modeling was conducted using a clustered generalized estimating equations (GEE) ordinal logit model as the primary analysis, and a secondary independent-eye ordinal logistic regression model was used to evaluate the proportional-odds assumption and model robustness. Results: Mean age was 55.6 ± 18.3 years, and 68.5% of eyes were from female participants. No PVD, partial PVD and complete PVD were present in 30.9%, 43.5% and 25.6% of eyes, respectively. In the primary GEE model, axial length (OR 1.35; p < 0.001), systemic hypertension (OR 7.13; p < 0.001), and prior cataract surgery (OR 2.13; p = 0.020) were independently associated with more advanced PVD stages. Age showed a modest but significant association with increasing PVD severity (OR 1.03; p = 0.012). Sex and diabetes mellitus were not associated with PVD grade. The independent-eye ordinal model yielded consistent effect directions. Conclusions: In adults without macular disease, more advanced PVD stages are independently associated with axial elongation, systemic hypertension, and previous cataract surgery, while age shows a mild but significant association. These findings provide clinically useful contextual reference information for interpreting vitreoretinal interface changes in health and disease. These associations should not be interpreted as causal due to the cross-sectional nature of the study.