Cataract after Laser Iridotomy

Abstract

We read with great interest Lim et al’s article on cataract progression after laser peripheral iridotomy (LPI).1Lim L. Hussain R. Gazzard G. et al.Cataract progression after prophylactic laser peripheral iridotomy. Potential implications for the prevention of glaucoma blindness.Ophthalmology. 2005; 112: 1355-1359Abstract Full Text Full Text PDF PubMed Scopus (59) Google Scholar They looked at fellow eyes in South Asian patients after acute primary angle closure (APAC) in the other eye. There was a significant rate of cataract progression, with 5 of 65 patients (7.7%) requiring cataract extraction within 1 year of LPI. The authors speculated that this could be related to the iridotomy itself or the amount of laser power required or due to the natural age-related changes in the lens. They also questioned whether their findings would apply to other racial groups or to patients who had not had an APAC episode. To address some of these questions we reviewed our own experience. For patients with occludable angles, we offer a choice of treatment. Patients can choose to have either LPI (normally done on the same day) or phacoemulsification with an intraocular lens implant, normally done within 2 months.2Jacobi P.C. Dietlein T.S. Luke C. et al.Primary phacoemulsification and intraocular lens implantation for acute angle-closure glaucoma.Ophthalmology. 2002; 109: 1597-1603Abstract Full Text Full Text PDF PubMed Scopus (156) Google Scholar Phacoemulsification is offered regardless of the visual acuity or degree of lens opacity. Approximately one third of such patients choose primary phacoemulsification. Therefore, those who choose LPI would more likely have either clear lenses or only relatively asymptomatic lens opacities at the time of LPI. We reviewed our records for all such patients who had LPI for occludable angles. We looked at Caucasian patients who had not had any episodes of APAC, with at least 1 year’s follow-up. All patients had LPI done by the same clinician (TE). Mean laser power was 108.7 millijoules (standard deviation: 91.80, range: 11–400) per eye. Fifty-three patients (100 eyes) were reviewed. At 1 year after LPI, phacoemulsification had been performed or scheduled in 6 of 53 patients (11% of patients, 7% of eyes). By 2 years, a total of 11 patients (21% of patients, 13% of eyes) had been scheduled for phacoemulsification. Our findings are in broad agreement with studies of LPI in Asian eyes.1Lim L. Hussain R. Gazzard G. et al.Cataract progression after prophylactic laser peripheral iridotomy. Potential implications for the prevention of glaucoma blindness.Ophthalmology. 2005; 112: 1355-1359Abstract Full Text Full Text PDF PubMed Scopus (59) Google Scholar, 3Hsiao C.H. Hsu C.T. Shen S.C. Chen H.S. Mid-term follow up of Nd:YAG laser iridotomy in Asian eyes.Ophthalmic Surg Lasers Imaging. 2003; 34: 291-298PubMed Google Scholar In our Caucasian population with LPI for occludable angles and no previous episode of APAC, 11% requested cataract surgery within 1 year. Whether the development of cataract after LPI is due to the laser or the iridotomy or is simply part of the natural history of this condition remains uncertain. Cataract after Laser Iridotomy: Author ReplyOphthalmologyVol. 113Issue 7PreviewWe were most interested to read Tsatsos and Eke’s findings of an 11% cataract extraction rate at 1 year after neodymium:yttrium–aluminum–garnet prophylactic laser peripheral iridotomy (LPI) in Caucasians. This evidence for a significant incidence of post-LPI cataract is of note, particularly when one considers that visually significant cataracts most likely were excluded in the third who elected to undergo phacoemulsification rather than LPI. Naturally, the limitations of a retrospective study without a control group are present, and these only serve further to highlight the need for a carefully conducted prospective randomized controlled trial in the relevant target populations before widespread prophylaxis can be recommended at a population-based level. Full-Text PDF