Abstract
Purpose: :
To evaluate the efficacy of Laser Iridotomy (LI) performed on patients with anatomically narrow angles, with appositional closure on dark room gonioscopy (DRG), by second year ophthalmology residents under the supervision of attending physicians at a teaching institution.
Methods: :
A retrospective chart analysis of LI’s performed by different second year residents between 2007 and 2009. Demographical data, refractive error, pre- and post-procedure intraocular pressure (IOP), laser settings with duration, best corrected visual acuity (BCVA), Shaffer angle grading on DRG of all 4 quadrants, complications, and time of follow-up were collected and evaluated.
Results: :
We enrolled fifty-five eyes (31 patients), average age 64+/-8.9yrs, majority were Hispanic, 81% were females, and 85% of eyes were hyperopic (average refractive error +1.37 +/-1 diopter). The follow up period ranged from 1 week to 25 months with an average of 10.27+/-7.8 months. Both Argon and Yag lasers were used. Laser settings were on average 661mw (range: 300 to 1350mw), with spot size of 50um and duration of 0.02 seconds. The mean number of burns was 66.5+/- 65. The average duration of procedure was 8+/-4 minutes with a range of 3-26 minutes. Upon comparison of the number of open angle quadrants using the Shaffer angle grading, there was an increase in the number of open angle quadrants from 0.17 (pre-procedure) to 2.81 (one week post-procedure) (p < 0.001). There was no significant difference between the mean IOP pre and immediate post procedure, from 15.4mmHg to 14.8mmHg (p>0.2). BCVA on average improved by 0.6 Snellen line. There was a 31% failure rate defined as persistent closed angles (Shaffer grade 0 or 1). Of these failures, non patent opening requiring touch up LI occurred in 5 eyes (29%), plateau iris syndrome requiring PICP occurred in 5 eyes (29%), phacomorphic narrow angle requiring cataract extraction occurred in 4 eyes (23.5%), and one eye developed PAS needing surgical intervention with glaucoma drainage implant in addition to IOP lowering medications.
Conclusions: :
Results of this study suggest that although residents have no prior experience in performing laser iridotomy, they are successful in opening a closed angle in majority of patients with relative pupillary block without any complications.
Keywords: laser • iris • outflow: trabecular meshwork