Abstract
Purpose:
Myopia is associated with various ocular complications, including glaucoma, and the risk of glaucoma has been reported to increase as degree of myopia become higher. On the other hand, it has not been fully elucidated yet whether high myopia is associated with outcomes of glaucoma surgery. The purpose of this study was to investigate influences of high myopia (defined as axial length >26.0 mm in this study) on surgical outcomes after trabeculectomy with mitomycin C for Japanese patients.
Methods:
This was a retrospective, hospital-based, case-control study. Eighty-three eyes with primary open angle glaucoma or exforiation glaucoma were included. All of the 83 eyes were underwent fornix-based trabeculectomy with or without cataract surgery by a same operator (MH) between January 2005 and December 2011. The rates of postoperative complications (such as shallow anterior chamber, choroidal detachment, or hypotonic maculopathy) and additional glaucoma surgery (including scleral flap suture, bleb revision, and trabeculectomy) were compared between the highly myopic group (HM group, 30 eyes) and the non-highly myopic group (NHM group, 53 eyes) by Fisher’s exact test. Postoperative intraocular pressure (IOP) >21 mmHg, <5 mmHg, <20% reduction, or additional glaucoma surgery were defined as failure, and success rates were compared between the two groups by log-rank analysis.
Results:
The HM group was significantly younger than the NHM group (61.1 ± 12.7 and 68.9 ± 11.1 years, respectively; P <0.005). The HM group also had worse preoperative best corrected visual acuity (BCVA) than NHM group (0.44 ± 0.60 and 0.13 ± 0.31 in logMAR unit, respectively; P <0.05). Preoperative IOP (21.6 ± 5.4 mmHg in the HM group and 23.1 ± 7.3 mmHg in the NHM group, P = 0.35) as well as post 2-years IOP (11.2 ± 3.2 and 11.6 ± 4.2, P = 0.69) were not significantly different between the two groups. The 2-year success rates with or without glaucoma medication was 59.5 % in the HM group and 65.4 % in the NHM group (P = 0.59). There was no statistically significant difference between the two groups in the incidence rate of each postoperative complication or additional glaucoma surgery.
Conclusions:
The highly myopic patients were younger and had worse preoperative BCVA in this study. High myopia had no statistically significant influence on surgical outcomes of trabeculectomy with mitomycin C.