Classification of hypotony maculopathy based on optical coherence tomography findings and risk factors for visual outcomes

Purpose To classify hypotony maculopathy (HM) using optical coherence tomography (OCT) findings and to investigate the associations among morphological types, clinical factors, and visual outcomes.
Methods We retrospectively reviewed 60 eyes that developed HM after trabeculectomy. HM was classified according to the distribution and configuration of chorioretinal undulations on OCT B-scans. Between-group comparisons were performed, and factors associated with the morphological classification and logMAR best-corrected visual acuity (BCVA) at 3 months after HM onset (3-month BCVA) were determined.
Results HM was classified into three OCT-based types by categorizing chorioretinal undulations as folds (U-shaped troughs) or spikes (V-shaped troughs): Type 1, folds only on vertical scans; Type 2, folds on both vertical and horizontal scans; Type 3, folds on both scans, with spikes. Axial length in Type 3 was significantly longer than that in Type 2 (P = 0.034). Subfoveal choroidal thickness was significantly thinner in Type 3 than in Types 1 and 2 (both P < 0.001). Minimum intraocular pressure (IOP) was significantly higher in Type 1 than in Types 2 and 3 (P < 0.001 and P = 0.003, respectively), with no difference between Types 2 and 3. In multivariable analysis using Type 1 as the reference group, minimum IOP was significantly associated with Type 2 (P = 0.001). For Type 3, both minimum IOP (P = 0.03) and subfoveal choroidal thickness (P = 0.02) showed significant associations. The 3-month BCVA was significantly worse in Type 3 than in Types 1 and 2 (P < 0.001 and P = 0.007, respectively). Chorioretinal spikes and preoperative BCVA were significantly associated with 3-month BCVA (both P < 0.001). Exploratory receiver operating characteristic analysis assessed the discriminative ability of subfoveal choroidal thickness for the presence of chorioretinal spikes (AUC = 0.876). A thickness of 195.0 μm was identified as a candidate cutoff value (sensitivity 92.3% and specificity 72.3%).
Conclusions In HM following TLE, chorioretinal spikes and preoperative BCVA are significantly associated with the 3-month BCVA. In HM, a thin subfoveal choroid (< 195.0 μm), may be associated with chorioretinal spikes, suggesting the need for careful postoperative IOP and OCT monitoring.