Development of a prediction rule to estimate the probability of acceptable intraocular pressure reduction after selective laser trabeculoplasty in open-angle glaucoma and ocular hypertension.
OBJECTIVE
To develop and validate a prediction rule to estimate the probability of acceptable intraocular pressure (IOP) reduction after selective laser trabeculoplasty (SLT) in ocular hypertension and open-angle glaucoma.


METHODS
The study population was derived from a cohort of 220 patients with ocular hypertension, open-angle glaucoma, or normal tension glaucoma. A > or =20% reduction in IOP (mm Hg) from the baseline IOP at 6 months after SLT was considered treatment success. Logistic multivariate regression modeling was performed to develop a prediction rule.


RESULTS
In multivariate logistic regression analyses, pre-SLT IOP and maximum IOP were identified as independent predictors for > or =20% IOP reduction at 6 months with adjusted odds ratios of 1.3 and 0.9, respectively, controlling for sex, diagnosis, pigment of anterior chamber, and washout of eye drops. The area under receiver operator characteristic curve was 0.716. Calibration of this prediction rule showed good agreement between predicted and observed probabilities of acceptable IOP reduction. If a probability of acceptable IOP reduction of 50% or greater is used as the minimal clinical threshold for treatment, the prediction rule had a sensitivity and specificity of 91.3% and 30.4%, respectively.


CONCLUSIONS
SLT efficacy is positively associated with IOP elevation before SLT treatment and adversely associated with the maximum IOP ever recorded in history. Pigmentation of the anterior chamber angle, diagnosis, washout of eye drops, and sex are not associated with SLT treatment efficacy. This prediction rule should be further validated with a comparable prospective clinical study cohort.
Mao
Alexander J
AJ
Department of Ophthalmology, Ivey Eye Institute, St Joseph's Hospital, Lawson Health Research Institute, University of Western Ontario. alex.mao@lhsc.on.ca
Pan
Xiao-Jing
XJ
McIlraith
Ian
I
Strasfeld
Maurice
M
Colev
George
G
Hutnik
Cindy
C
D019540:Area Under Curve; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009798:Ocular Hypertension / Q000503:physiopathology / Q000601:surgery; D011237:Predictive Value of Tests; D011336:Probability; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014130:Trabeculectomy / Q000379:methods*