I am happy to respond to Dr Rao regarding our publication. We defined the surgical failure as an intraocular pressure (IOP) of 21 mm Hg or more (criterion A) and an IOP of 18 mm Hg or more (criterion B) with or without medications, which means qualified successes. Because the level at which postoperative IOP medication should be started depends largely on the surgeon, we did not evaluate the complete successes in this study. Although we do not have enough data about the comparison of the complete successes between trabeculotomy versus trabeculectomy, we had collected data regarding the numbers of postoperative medications at 1, 2, 3, 4, and 5 years after the surgery. The mean ± standard deviation numbers of postoperative medications in eyes with steroid-induced glaucoma that underwent trabeculotomy were 0.9 ± 1.1 at 1 year (n = 101), 1.0 ± 1.1 at 2 years (n = 76), 1.1 ± 1.2 at 3 years (n = 44), 1.3 ± 1.2 at 4 years (n = 28), and 1.1 ± 1.1 at 5 years (n = 21). In eyes with steroid-induced glaucoma that underwent trabeculectomy with mitomycin C, these numbers were 0.4 ± 0.9 at 1 year (n = 29), 0.6 ± 1.1 at 2 years (n = 23), 0.7 ± 1.2 at 3 years (n = 15), 0.8 ± 1.2 at 4 years (n = 13), and 0.3 ± 0.5 at 5 years (n = 7). The number at 1 year was significantly less ( P = .02) in eyes with steroid-induced glaucoma that underwent trabeculectomy with mitomycin C than eyes that underwent trabeculotomy, whereas there were no significant differences between the 2 groups at 2 years ( P = .18), 3 years ( P = .30), 4 years ( P = .22), or 5 years ( P = .07) after surgery. We cannot exclude the possibility that postoperative medications might have improved the success rate in steroid-induced glaucoma patients with trabeculotomy. Our results indicate that there is no significant difference for qualified success for criterion A between trabeculotomy and trabeculectomy with mitomycin C for steroid-induced glaucoma patients. For criterion A, 5 eyes (11.9%) were defined as failures within 5 years after trabeculectomy with mitomycin C, whereas 22 eyes (18.2%) were defined as failures within 5 years after trabeculotomy. However, Kaplan-Meier survival curve analysis, which adjusted the timing of failure and follow-up duration, could not detect the significant difference between the 2 groups.
IOPs in patients with open-angle glaucoma should be reduced as low as possible to prevent progression of visual filed defect. Despite abnormally high IOP, many patients with steroid-induced glaucoma are diagnosed before manifestation of glaucoma optic neuropathy. Strict IOP management is unnecessary for these steroid-induced glaucoma patients, unlike for primary open-angle glaucoma patients. Therefore, trabeculotomy is considered as an option for the surgical management of steroid-induced glaucoma patients. Moreover, trabeculectomy with mitomycin C adds the risk of bleb infection for patients who have been being treated with corticosteroids. Actually, among Japanese surgeons, trabeculotomy is performed more widely, rather than trabeculectomy with mitomycin C, in the surgical treatment of steroid-induced glaucoma.
Five (4.1%) of 121 eyes with steroid-induced glaucoma that underwent trabeculotomy were defined as surgical failures because of an additional surgery, whereas 3 (2.8%) of 108 eyes with primary open-angle glaucoma that underwent trabeculotomy were defined as surgical failures because of an additional surgery. It is unlikely that an additional surgery after trabeculotomy would have reduced the success rate for primary open-angle glaucoma eyes.