Posterior segment visualization problems with multifocal intraocular lenses

ACTAOPHTHALMOLOGICA SCANDINAVICA 1996 -

Letters to the Editor Posterior segment visualization problems with multifocal intraocular lenses Sir,

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ultifocal intraocular lenses are being used with increasing frequency - some of the newest technology involves diffractive intraocular lenses. These lenses can provide definite optical advantagesto the patient in terms of improve uncorrected near vision and a functional uncorrected distance vision. However, we highlight here a particular problem encountered by us with such an implant. A 50-year-old male patient presented to the retina serviceof our hospital with a complaint of loss of vision in the right eye for the last 2 months. He had undergone extracapsular cataract extraction with intraocular lens implantation in this eye 18 months before with satisfactory visual recovery.There was no complaint in the left eye. On examination, the best-corrected visual acuity was perception of light with accurate projection in the right eye. The anterior segment in the right eye was unremarkable except for the presence of a diffractive multifocal in-

traocular lens in the posterior chamber. The posterior capsule was intact and transparent. Indirect ophthalmoscopy revealed a total retinal detachment with advanced proliferative vitreo-retinopathy (grade C 3). A retinal break was localized in the inferonasal quadrant. Examination of the left eye was essentially within normal limits. Vitreo-retinal surgery was performed for the detachment in the right eye; however, distinct visualization of the posterior segment with the operating microsocpe (Zeiss OPMI - CS) was found to be impossible and various exacting steps of the surgery, including internal drainage of the sub-retinal fluid etc., were performed with the aid of the indirect ophthalmoscope. Visualization with the latter was found to be adequate, due probably to the strong illumination provided by the same. Fluid-gas exchange was performed and retina was settled; silicon oil was injected for internal tamponade.

Postoperatively, the retinal status has been stable and 3 months after the vitreo-retinal surgery, the patient has a best-corrected visual acuity of 6/36. In conclusion, we recommend that diffractive multifocal intraocular lenses, such as they are currently designed, be used judiciously, especially for patients at a high risk of developing retinal detachment, since these lenses render visualization of the posterior segment with the operating microscope less than optimal. Further, newer designs of these intraocular lenses should aim at overcoming this limitation.

Kupin et al. (1995), using adjunctive mitomycin C in primary trabeculectomy showed that severe myopia predisposes to a post-operative hypotonous maculopathy, which may be irreversible (Jampl et al. 1992).It is clear that under such conditions (severe myopia) a simultaneous bilateral trabeculectomy should not be performed.

Jampl HD, Pasquale LA & Dibernado C (1992): Hypotony Maculopathy following trabeculectomy with mitomycin C. Arch Ophthalmol 110: 1049-1050. Kupin TH, Juzych MS, Shin SH, Khatana AK & Olivier MMG (1995): Adjunctive mitomycin C in primary trabeculectomy in phakic eyes. Am J Ophthalmolll9: 3039. Thompson SM & Rokerya S (1995): Bilateral simultaneous trabeculectomy. Acta Ophthalmol Scand 73: 543-546.

Key words: multifocal IOL - visualization problems.

Atul Kumar, MD; Mallika Goyal, MD and Hem Kumar Tewari, MD Dr Rajendra Prasad Centre for Ophthalmic Sciences All India Institutes of Medical Sciences New Delhi 110029, India.

Bilateral simultaneous surgery Dear Sir,

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would like to comply with the request of the Chief Editor (Ehlers 1995) and give my opinion concerning simultaneous bilateral trabeculetomy (Thompson & Rokerya (1995): Acta Ophthalmol Scand 73: 543-546). Although these authors reported that operating simultaneously on both eyes offered some advantages, they also mention in their paper that: ‘Ophthalmic surgeons are traditionally reluctant to operate both eyes at once’, and: ‘The most common reason for this, is the fear of serious complications affecting both eyes’. I think that a caveat is warranted in certain specific cases.

Key words: bilateral surgery - simultaneous bilateral trabeculectomy.

References Ehlers N (1995): Bilateral surgery. Acta Ophthalmol Scand 73: 542.

Sincerely, D. 0.E. Gebhardt, Ph.D Anna van Burenlaan 1 2341 VE Oegstgeest The Netherlands.

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