To evaluate the effects of trans-scleral diode laser cyclophotocoagulation (TSDLC) on best corrected visual acuity (BCVA) in patients with refractory glaucoma.

The medical records of 148 eyes of 148 patients with refractory glaucoma who were followed-up for over 6 months after TSDLC were analyzed retrospectively. Among them, 49 eyes of 49 subjects who had BCVA greater than no light perception (NLP) before TSDLC were classified as Group 1 and the other 99 eyes of 99 patients who had NLP vision were classified as Group 2. The outcomes of TSDLC including change in BCVA following surgery were analyzed for all patients and 49 subjects.

The mean follow-up period in Group 1 was 19.1 ± 13.5 months and 16.7 ± 12.7 months in Group 2. The intraocular pressure (IOP) and the number of IOP lowering medications decreased in both groups (both p < 0.001). In all subjects, there was no significant difference between BCVA before surgery and at the last follow-up (2.4 ± 0.9 log MAR and 2.5 ± 0.8 log MAR, respectively, p = 0.612). However, in Group 1, BCVA was decreased from 1.4 ± 1.0 to 1.9 ± 1.1 log MAR after the TSDLC ( p < 0.001). In those patients, visual loss ≥ 0.2 log MAR was found in 31 eyes (63.3%) and light perception was lost in 15 eyes (30.6%). After treatment, corneal edema developed in 5 eyes (3.4%), phthisis bulbi and chronic hypotony occurred in 3 eyes each (2%) and iridocydlitis occurred in 2 eyes (1.4%).

TSDLC in patients with refractory glaucoma showed an efficient reduction in IOP and the number of IOP-lowering medications. However, there was a significant loss in BCVA in many patients and therefore, careful monitoring regarding potential visual loss is necessary when considering TSDLC in glaucoma patients with useful vision.