Outcomes of viscocanalostomy and phaco-viscocanalostomy in patients with advanced glaucoma

Purpose: To determine the medium-term outcomes for patients with advanced glaucoma undergoing viscocanalostomy. Methods: All patients with advanced glaucoma (Mean Deviation -12.00 dB or above) and patients with poor visual acuity secondary to advanced glaucoma which precluded formal visual-field assessment undergoing viscocanalostomy (VC) and phaco-viscocanalostomy between 2010 and 2014 under the care of a single surgical team were included. Intraocular pressure (IOP), visual acuity and visual field outcomes were assessed from data prospectively collected into a surgical outcome database. Success was defined at two IOP cut-off points: IOP ≤ 21mmHg and ≤ 16 mmHg with (qualified) or without (complete) medications. Results: 135 patients were included. Mean IOP changed from 23.6 ± 6.4 mmHg pre-operatively to 15.3, 15.8 and 14.8 mmHg between 1 and 3 years, a change of 35%, 33.5% and 39% respectively. Qualified success for an IOP ≤ 21mmHg was achieved in 95.66% at year 1, 90.6% at year 2 and 80% at year 3. Qualified success for an IOP ≤ 16 mmHg was achieved in 66.6% at year 1, 66.05% at year 2 and 60% at year 3. The cumulative probability for achieving an IOP ≤ 21mmHg with or without drops was 86.1, 81.4 and 81.4% at 12, 24 and 36 months. During the follow up period 11 patients (8%) failed to achieve adequate IOP control and needed further surgical intervention. Eleven (8.1%) patients needed an intervention (Yag goniopuncture) following viscocanalostomy. Four patients (2.9%) had some post-operative complication, which resolved within two weeks following surgery. Nine patients (6.7%) lost more than 2 Snellen lines. There was no significant change in the MD across time points. Conclusion: Viscocanalostomy is a safe and effective method of controlling IOP in the medium-term in patients with advanced glaucoma.