Effect of axial length reduction after trabeculectomy on the development of hypotony maculopathy

To measure changes in axial length before and after trabeculectomy with noncontact, partial coherence laser interferometry and identify patient factors that lead to the development of hypotony maculopathy and axial length shortening in 25 eyes with intraocular pressure (IOP) ≤ 6 mmHg at 4 weeks after mitomycin C-augmented trabeculectomy.

A retrospective comparative case series. Hypotony maculopathy was identified with both ophthalmoscopy and spectral-domain optical coherence tomography. Axial length and IOP were serially measured pre- and postoperatively. Logistic regression analysis was performed to identify factors associated with the presence of hypotony maculopathy at 4 weeks after trabeculectomy and multiple regression analysis to identify factors associated with axial length changes.

Ten eyes exhibited hypotony maculopathy, whereas the remaining 15 did not. Patients with hypotony maculopathy were significantly younger (47.7 ± 6.2 years) compared with those without it (63.3 ± 9.6 years, P = 0.0002, unpaired t test). The percent reduction of axial length after trabeculectomy was significantly larger in the former group (5.91 ± 2.76 %) compared with the latter group (1.51 ± 0.91 %) (P = 0.0001, Mann-Whitney U test). Multivariate analyses showed that only age was associated with the presence of hypotony maculopathy, with an odds ratio of 0.82 (P = 0.0075), when age, sex, type of glaucoma, lens status, percent changes in axial length and IOP before and after trabeculectomy, and central corneal thickness were included as independent variables (R (2) = 0.543, P = 0.003).

Age-dependent axial length reduction is a risk factor for the development of hypotony maculopathy after trabeculectomy.