Cataract after laser iridotomy

Ophthalmology Volume 113, Number 7, July 2006 situ keratomileusis to correct refractive errors after penetrating keratoplasty. J Refract Surg 2003;19:301– 8. 4. Nagy ZZ. Laser in situ keratomileusis combined with topography-supported customized ablation after repeated penetrating keratoplasty. J Cataract Refract Surg 2003;29:792– 4. 5. Spadea L, Bianco G, Balestrazzi E. Topographically guided excimer laser photorefractive keratectomy to treat superficial corneal opacities. Ophthalmology 2004;111:458 – 62.

Cataract after Laser Iridotomy Dear Editor: We read with great interest Lim et al’s article on cataract progression after laser peripheral iridotomy (LPI).1 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.2 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.1,3 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. MICHAEL TSATSOS, MD TOM EKE, MD, FRCOPHTH Norwich, United Kingdom References 1. Lim L, Hussain R, Gazzard G, et al. Cataract progression after prophylactic laser peripheral iridotomy. Potential implications for the prevention of glaucoma blindness. Ophthalmology 2005;112:1355–9.

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2. Jacobi PC, Dietlein TS, Luke C, et al. Primary phacoemulsification and intraocular lens implantation for acute angleclosure glaucoma. Ophthalmology 2002;109:1597– 603. 3. Hsiao CH, Hsu CT, Shen SC, Chen HS. Mid-term follow up of Nd:YAG laser iridotomy in Asian eyes. Ophthalmic Surg Lasers Imaging 2003;34:291– 8.

Author reply Dear Editor: We 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. We were surprised to learn that eyes with better acuities and clear lenses also were offered primary phacoemulsification for the management of occludable angles. Apart from eliminating pupil block, a potential benefit of lens removal is widening of the angle, which may prevent future intraocular pressure (IOP) rises and the development of chronic glaucoma. However, these potential benefits must be weighed against the loss of accommodation after lens extraction and the risks of surgery such as endophthalmitis, suprachoroidal hemorrhage, and retinal detachment. As these eyes have occludable angles only with normal IOPs and optic discs, primary phacoemulsification for clear lenses may not be justifiable in all cases. GUS GAZZARD, MD, FRCOPHTH LAURENCE S. LIM, MBBS RAHAT HUSAIN, MRCOPHTH STEVE K. L. SEAH, FRCS(ED), FRCOPHTH TIN AUNG, PHD, FRCS(ED) Singapore

Orbital Ischemia Dear Editor: In their recent article, Leibovitch et al1 reported an ischemic orbital compartment syndrome after lumbar spine surgery with secondary visual loss, proptosis, and ophthalmoplegia. A similar case was described from the University of Iowa2 of a 45-year-old male who suffered a cervical fracture and underwent facedown spinal surgery at an outside institution. Upon awakening from surgery, he had no light perception vision in the right eye, complete right-sided ptosis and ophthalmoplegia, and a combined central retinal artery and central retinal vein occlusion. An emergent lateral canthotomy was performed but did not improve the vision, and the patient eventually developed a total retinal detachment. I think that it is important to recognize, as noted by Leibovitch et al, that the orbital compartment syndrome presentation differs from that of visual loss due to perioperative ischemic optic neuropathy due to spinal surgery. A recent practice