Otago glaucoma surgery outcome study: long-term results of trabeculectomy--1976 to 1995.
OBJECTIVE
To provide data on the long-term results of trabeculectomy performed in the province of Otago, New Zealand.


METHODS
Retrospective noncomparative case series.


METHODS
A total of 289 eyes of 193 patients (excluding 4 eyes lost to follow-up soon after operation); all trabeculectomies performed for the first time on cases of primary glaucoma from 1976 through 1995.


METHODS
Standard Cairns trabeculectomy.


METHODS
Intraocular pressure, visual acuity, visual field damage.


RESULTS
Trabeculectomy was effective in controlling intraocular pressure at a level of 21 mmHg or less, with probabilities of 0.93 (95% confidence interval [CI], 0.90-0.97), 0.87 (95% CI, 0.82-0.93), and 0.85 (95% CI, 0.77-0.92) at 5, 10, and 15 years, respectively, after surgery. The mean visual acuity improved from 20/60 to 20/40 immediately after trabeculectomy but then declined steadily over the postoperative years. The decline in visual acuity led to blindness in 47 eyes. The Kaplan-Meier estimated probability of retaining useful vision (visual acuity > 20/400 and visual field > 5 degrees radius) in the overall group was 0.87 (95% CI, 0.79-0.91), 0.72 (95% CI, 0.60-0.79), and 0.6 (95% CI, 0.43-0.69) at 5, 10, and 15 years, respectively, after surgery. Those eyes that had good preoperative visual acuity (visual acuity > or = 20/30) had a significantly better chance of retaining useful vision (P = 0.02).


CONCLUSIONS
The intraocular pressure was well controlled by trabeculectomy, but a steady long-term decline in visual acuity and visual field occurred, decreasing the probability of an eye retaining useful vision up to the time of death to approximately 0.6.
Molteno
A C
AC
Department of Ophthalmology, University of Otago Medical School, Dunedin, New Zealand.
Bosma
N J
NJ
Kittelson
J M
JM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D015812:Glaucoma, Angle-Closure / Q000503:physiopathology / Q000601:surgery*; D005902:Glaucoma, Open-Angle / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D011183:Postoperative Complications; D011336:Probability; D012189:Retrospective Studies; D014130:Trabeculectomy; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology