Long-Term Intraocular Pressure Control After Nd-YAG Laser Iridotomy in Chronic Angle-Closure Glaucoma.

To evaluate the long-term results of Nd-YAG laser iridotomy, a retrospective study was undertaken of 52 consecutive patients (78 eyes) who had chronic angle-closure glaucoma and who had undergone Nd-YAG laser iridotomy. After a mean follow-up of 22 months, the intraocular pressure was <22 mm Hg without additional treatment in 7 eyes (9%) and with glaucoma medication in 40 eyes (51.3%). At the last follow-up visit, the intraocular pressure was between 22 and 24 mm Hg with an average of two medications in eight eyes (10.2%). Trabeculectomy was required in 23 eyes (29.5%). Those eyes with an intraocular pressure on presentation of >35 mm Hg, or with three or more quadrants of angle closure or with a cup:disc ratio of >0.6, were more likely to undergo trabeculectomy. However, linear discriminant analysis of the ocular findings on presentation revealed that those eyes that underwent trabeculectomy could only have been predicted in 78% and that 36% of eyes identified as being at risk that were subsequently controlled with or without glaucoma medication would have undergone unnecessary trabeculectomy (prediction accuracy: 57%). This study confirms that the current practice of Nd-YAG laser iridotomy, followed if necessary by medical therapy and trabeculectomy, is effective in the management of chronic angle-closure glaucoma. However, careful follow-up of intraocular pressure control and visual field performance is required in patients with advanced disease.