Abstract
Purpose: :
To describe the relationship between single digit intraocular pressure (IOP) after glaucoma filtering surgery and visual field progression.
Methods: :
A retrospective chart review of 40 patients from a private practice with diagnosis of advanced glaucoma (open angle, angle closure) on full tolerated medical therapy who underwent trabeculectomy or phacoemulsification with trabeculectomy in one or two eyes. Inclusion criteria was specific for eyes with single digit IOP (<10 mmhg) post surgery, at least 3 years follow-up, and no IOP lowering agents post surgery. Data collected for each patient included; average (last 3 visits) of pre-op and post-op IOP, pre-op and post-op vision, type of surgery, years of surgery, visual field description (3 years post op; stable, mild progression, definite progression) by glaucoma specialist, and surgery complications if any. After all data was gathered, T-student test was used for statistical analysis of results.
Results: :
From the 40 patients included in the study 16 had trabeculectomy and 24 had phacoemulsification with trabeculectomy. The average pre-op IOP was 20mmhg. Post op mean IOP was 6 mmhg. There was a mean of 70% IOP reduction in all operated eyes (p<0.0001). In 87.5% of patients the visual field remained stable over 3 years follow-up post surgery. Only 5 operated eyes experienced a mild to definite progression in the visual field with 10 and 2.5% respectively. 70% of patients did not experienced any surgery complications, but among the 30% who did the most common complications post surgery were corneal edema, and macular hypotony.
Conclusions: :
Single digit IOP after glaucoma filtering surgery appears to be effective in maintaining stable visual fields over 3 years.
Keywords: intraocular pressure • visual fields • low vision