Long-Term Changes in Lamina Cribrosa Curvature Index After Trabeculectomy in Glaucomatous Eyes

This study aimed to evaluate both short-term and long-term changes in the lamina cribrosa curvature index (LCCI) following trabeculectomy and investigate the factors influencing these changes.

In this retrospective, observational study, 40 eyes of 40 patients with glaucoma who underwent trabeculectomy and had a follow-up of at least 2 years were included. Optic nerve head area was scanned by using spectral-domain optical coherence tomography before surgery (Pre_OP), within 6 months postoperatively (Post_OP1), and at the last visit (Post_OP2). LCCI values calculated from B-scan images at six different planes (0°, 30°, 60°, 90°, 120°, and 150°) and their mean values were compared. Univariate and multivariate linear regression analyses were used to identify the clinical factors associated with the amount of LCCI changes.

The mean follow-up time was 38.3 ± 16.8 months. At Post_OP1, the mean LCCI decreased from 9.28 ± 2.58 to 7.91 ± 2.57 (P < 0.001), and the mean intraocular pressure decreased from 22.0 ± 7.6 mm Hg to 12.2 ± 3.8 mm Hg (P = 0.001). At Post_OP2, the mean LCCI was maintained at 7.74 ± 2.49 (P = 0.56 when compared to Post_OP1 and P < 0.001 when compared to Pre_OP). The mean intraocular pressure was 12.6 ± 5.4 mm Hg (P = 0.67 when compared to Post_OP1 and P < 0.001 when compared to Pre_OP). Long-term LCCI changes were associated with baseline age (P = 0.04), spherical equivalent (P = 0.02), mean IOP during follow-ups (P = 0.02), and preoperative LCCI (P = 0.04).

Glaucomatous eyes undergoing trabeculectomy demonstrated reductions in the LCCI after a mean follow-up of over 3 years. Greater long-term LCCI reduction was associated with younger age, lower mean IOP during follow-up period, greater spherical equivalent refractive error, and preoperative LCCI.