Purpose: To investigate the efficacy of mydriases as a test for
determining the need for iridotomy in narrow angles.
Method: A retrospective study of 80 eyes diagnosed , on routine exam, as
having narrow angles was undertaken to determine the efficacy of mydriasis and
clinical evaluation alone as a test for determining the need for iridotomy. All patients, referred from a general
ophthalmologist, underwent evaluation of discs, IOP and angles prior to and
following mydriasis with neosenephrine 1.5% and mydriacil 1%. Angles were graded according to Shaffer
classification.
Results: Of 80 eyes, iridotomy was recommended in 32. Average pre-dilated IOP of eyes
undergoing iridotomy was 22, 19 in non-iridotomy eyes. In all, 32 eyes underwent iridotmy, all
had pre-dilated angles graded I or less.
All had some appositional closure post-dilation. 48 eyes had pre-dilated angles graded I
to III. No appositional closure
occurred in any of these eyes post-dilation. Therefore, no iridotomy was
recommended. No acute attacks or
increase in IOP has occurred in any of these eyes followed for an average of 4
years. All of these eyes were
followed by having pressure measurements twice a year with gonioscopy yearly.
Conclusions: Dilation and clinical evaluation appears to be adequate for
determining the need for P.I. in symptom free patients with narrow angles. Initial IOPs may be signficant. Patients with narrow angles not having
iridotomies showed no untoward effects over a 4 year period, suggesting narrow angles per se are not an
indication for P.I.