Predictors of visual field progression in acute and primary angle-closure disease: role of posture-related IOP changes and anterior segment structure.

PURPOSE: To demonstrate longitudinal structural and functional changes and predictors in patients with acute primary angle-closure (APAC) attack compared to non-acute primary angle-closure glaucoma (PACG) treated with laser peripheral iridotomy (LPI). METHODS: Intraocular pressure (IOP) was assessed quarterly in this retrospective and longitudinal study, with IOP fluctuation calculated. Retinal nerve fiber layer (RNFL) thickness, mean deviation (MD), and visual field index (VFI) were assessed biannually using optical coherence tomography (OCT) and VF testing. IOP in supine and lateral decubitus positions (LDP) were measured using rebound tonometry (Icare Pro). Anterior segment structures were assessed using anterior segment OCT. Linear mixed models analyzed MD and VFI changes and their predictors. RESULTS: APAC (40 eyes) exhibited long-term RNFL thinning and VF deterioration comparable to non-acute PACG (40 eyes). APAC had greater IOP elevation at LDP (5.2 vs. 2.4 mmHg, P < 0.001) and long-term IOP fluctuation (8.6 vs. 7.1 mmHg, P = 0.048). Multivariable analysis revealed that greater LDP IOP elevation (β=-0.06, P = 0.001) and peripheral anterior synechiae (PAS) (β=-0.37, P = 0.007) were predictive of MD decline in APAC. Female (β=-0.30, P = 0.023), higher LV (β=-1.17, P = 0.002), greater IOP fluctuation (β=-6.40, P < 0.001), and worse baseline VFI (β=-0.01, P < 0.001) predicted VFI deterioration in PACG. Greater LV (β = 0.09, P = 0.006), smaller angle opening distance (β=-0.27, P = 0.002), trabecular iris space area (β=-0.60, P = 0.003), and scleral spur angle (β=-0.002, P = 0.007) were associated with greater IOP fluctuation in PACG. CONCLUSION: In APAC, greater LDP IOP elevation and PAS may be early indicators for progression, while baseline greater LV and long-term IOP fluctuation predicted visual deterioration in non-acute PACG.