Choroidal Measurements in Decision Making for Retinopathy of Prematurity: A Decision Tree Analysis

Abstract

Objective: To compare the choroidal thickness and vascular profile of premature infants with ROP (retinopathy of prematurity) using a handheld SD-OCT device. Design: A prospective cross-sectional case-control study Subject: All ROP patients examined under sedation or general anesthesia in Farabi Eye Hospital or Mahdie Hospital from 2020 to 2022. Methods: We performed horizontal SD-OCT scans through the fovea in 164 eyes of 82 premature infants. Premature infants included 2 groups (infants with ROP requiring treatment [as treatment group] vs. infant without ROP or with ROP not- requiring treatment [as no-treatment group]) Choroidal thicknesses (CT) were measured at 5 points, including the fovea, 250 µm, and 500µm mm nasal and temporal to the fovea. The choroidal vascularity index (CVI) and choroidal stromal index (CSI) were also calculated. The classification and regression tree (CRT) algorithm was used to predict the need for treatment based on all OCT characteristics. Main outcome: Treatment-require ROP patients. Results: Mean CT was higher in 500 micrometers nasal to the fovea compared to temporal CT (275.8 ± 64.8 and 257.1 ± 57.07, P value<0.03). No statistically significant difference was found regarding CVI, corrected CVI, and temporal and nasal CT in the treatment group versus the no-treatment group. The foveal CT was significantly lower in ROP patients with the plus disease compared to not-plus ROP (P value=0.03. ANOVA, Bonferroni posthoc test). CT was not significantly different between plus and pre-plus patients (P-value=0.9, ANOVA, Bonferroni posthoc test). No significant relationship was found between the stage of ROP and choroidal thickness (P value>0.05, GEE). The decision tree analysis showed that in infants with ROP, the most important predictor for the need for treatment is CVI. Conclusion: This study delineated the possible effectiveness of choroidal measurements as an additive to decision-making for ROP. We also demonstrated that choroidal involution is associated with the presence of pre-plus/plus, not with the stage of ROP. We demonstrated that choroidal measurements are very sensitive but not specific tools for assessing the need for treatment in ROP patients.