Phacoviscocanalostomy versus cataract surgery only in patients with coexisting normal-tension glaucoma: midterm outcomes

PURPOSE: To compare the midterm efficacy and safety of phacoviscocanalostomy (viscocanalostomy, phacoemulsification, and intraocular lens IOL] implantation) and cataract surgery (phacoemulsification and IOL implantation) in patients with normal-tension glaucoma (NTG) and cataract. SETTING: Sensho-kai Eye Institute, Kyoto, Japan. METHODS: Thirty-one eyes had phacoviscocanalostomy, and 35 eyes had uncomplicated cataract surgery only. The intraocular pressure (IOP), postoperative antiglaucoma medications, and visual outcomes were compared between groups. RESULTS: The mean follow-up was 34.9 months+/-19.8 (SD) (range 7 to 78 months). At 36 months, the mean preoperative IOP and postoperative IOP were 17.2+/-1.5 mm Hg and 14.1+/-1.6 mm Hg, respectively, in the phacoviscocanalostomy group and 16.7+/-1.4 mm Hg and 15.6+/-3.4 mm Hg, respectively, in the cataract surgery only group. The differences between groups were significant at all time points (P<.05). The success probabilities of the phacoviscocanalostomy group achieving 20% and 30% IOP reductions with (or without) medications were 78.5% (67.4%) and 35.5% (37.4%) at 24 months and 58.0% (44.2%) and 28.0% (26.6%) at 48 months, which were significantly better than the probabilities in the cataract surgery only group, which were 16.0% (9.5%) and 5.7% (2.9%) at 24 months (P<.001 for each comparison, Kaplan-Meier life-table analysis with log-rank test). Based on the modified Aulhorn-Greve classification, the visual acuity and visual fields did not deteriorate in the phacoviscocanalostomy group; the visual fields deteriorated in 6 eyes in the cataract surgery only group during the follow-up (P=.024). CONCLUSION: Phacoviscocanalostomy lowered IOP and maintained postoperative visual outcomes; it was safe and effective in elderly patients with coexisting NTG and cataract.