An anterior segment optical coherence tomography study of the anterior chamber angle after implantable collamer lens-V4c implantation in Asian Indian Eyes

PURPOSE: To quantitatively assess anterior chamber and angle parameters by anterior segment optical coherence tomography (AS-OCT) in myopic eyes undergoing Implantable Collamer Lens (ICL V4c) implantation. METHODS: Prospective noncomparative observational case series. Pre and postoperative (1(st) and 3(rd) month) AS-OCT angle parameters (anterior chamber depth [ACD], anterior chamber angle [ACA], Angle opening distance [AOD], trabecular iris space area [TISA], scleral spur angle [SSA]) were evaluated in 32 eyes (16 patients). SPSS version 20 with paired t-test for intragroup and Mann-Whitney U value test for intergroup comparisons. RESULTS: It included 6 (37.5%) males and 10 (62.5%) females. Preoperative ACA of 34.6 ± 2.3° reduced to 32.2 ± 2.4°, 31.9 ± 2.5° at 1 and 3 months postoperatively (P = 0.001). Preoperative mean AOD500, AOD750, TISA500, TISA750, SSA of 0.34 ± 0.06 mm, 0.52 ± 0.15 mm, 0.09 ± 0.02 mm(2), 0.20 ± 0.04 mm(2), 34.27 ± 4.6° decreased to 0.32 ± 0.06 mm, 0.48 ± 0.15 mm, 0.08 ± 0.02 mm(2), 0.17 ± 0.05 mm(2), 32.5 ± 4.3° at 1-month (P = 0.001); 0.32 ± 0.06 mm, 0.47 ± 0.13 mm, 0.08 ± 0.02 mm(2), 0.17 ± 0.05 mm(2) and 32.4 ± 4.6° (P = 0.001) at 3-months, respectively. Correlation analysis between preoperative ACD/intraocular pressure (IOP) was − 0.62 (P = 0.0002) [1(st) month], −0.40 (0.024) [third month]; between IOP/postoperative ACA, AOD500, AOD750, TISA500, TISA750, SSA was − 0.04 (0.81), −0.03 (0.85), −0.08 (0.64), −0.12 (0.48), −0.10 (0.57), −0.06 (0.73) at 1 month; −0.09 (0.58), 0.04 (0.78), 0.12 (0.48), −0.02 (0.9), −0.04 (0.79), 0.02 (0.88) at 3 months; between ICL vault/ACA, AOD500, AOD750, TISA500, TISA750, SSA was 0.38 (0.02), 0.24 (0.17), 0.21 (0.25), 0.05 (0.75), 0.15 (0.41), 0.27 (0.13) at 1(st) month; 0.19 (0.28), 0.06 (0.71), −0.03 (0.85), 0.005 (0.97), 0.05 (0.78), 0.07 (0.68) at 3(rd) month. CONCLUSION: Postoperatively significant angle narrowing was noted. There was a negative correlation between IOP and preoperative ACD. There was no significant correlation between IOP and ICL vault with postoperative AS-OCT angle parameters.