Purpose
To report the 5-year incidence of visual impairment after mitomycin C-augmented trabeculectomy and the risk factors of visual impairment among primary open angle glaucoma (POAG) patients, as determined from the Collaborative Bleb-Related Infection Incidence and Treatment Study (CBIITS).
Methods
Among POAG patients registered to the CBIITS, patients with eyes meeting the following qualifications were excluded from the study: those having an onset and/or deterioration of any diseases that resulted in visual impairment with no relation to trabeculectomy during the follow-up period; eyes with < 20/60 at the entry. The definitions of visual impairment were <3/60 as legal blindness, ≥ 3/60 and < 20/60 as low vision, and ≥0.2 log MAR deterioration during the period as visual acuity loss.
Results
A total of 407 eyes of 407 POAG patients including 237 males and 170 females were analyzed. The demographics of enrolled patients were mean age of 63.3±11.6 years, mean refractive error of -2.85±3.57D, and mean Humphrey Field Analyzer mean deviation (HFA-MD) of -17.9±7.4 dB. During the study period, visual acuity significantly deteriorated from 0.0457±0.153 to 0.187±0.421 (P<0.0001). The incidence of blindness, low vision, and visual acuity loss were 3.2%, 10.8%, and 25.6%, respectively. Multivariate logistic regression analysis revealed that pre-operative visual acuity, HFA-MD, and intraoperative complication are the risk factors for visual impairment.
Conclusions
The incidence of visual impairment and its risk factors after mitomycin C-augmented trabeculectomy among POAG patients are revealed. Ophthalmologists should recognize these results before using mitomycin C-augmented trabeculectomy.