Congenital Retinal Dystrophy and Corneal Opacity in Trisomy 8 Mosaicism Donald U. Stone, MD, and R. Michael Siatkowski, MD Trisomy 8 mosaicism can present with a wide variety of systemic and ophthalmologic manifestations. We report a patient with an extinguished electroretino- gram and diffuse retinal pigment epithelial abnormal- ities suggestive of a rod-cone dystrophy, which has not been previously reported in association with trisomy 8. A finding that has been described in several patients with trisomy 8 is a central corneal opacity, but there are no data regarding the natural history of this find- ing; the corneal opacity in our patient spontaneously improved. This case expands the clinical spectrum of this rare entity. Trisomy 8 mosaicism has been associated with multiple ophthalmologic findings. 1,2 The most common is strabis- mus, found in more than 50% of patients; there have also been at least 5 reports of a creamy stromal corneal opac- ity. 3 To our knowledge, on the basis of a MEDLINE search performed in December 2004 using the terms tri- somy 8 mosaicism, retinitis pigmentosa, Leber congenital amaurosis, and retinal dystrophy, this is the first report of a congenital retinal dystrophy with an extinguished elec- troretinogram (ERG) in association with this syndrome, as well as the first report of spontaneous improvement of a characteristic corneal opacity. CASE REPORT A 5 month-old white male infant was referred for evalua- tion of a corneal opacity in his left eye. Significant medical history included incarcerated abdominal hernia, hypospa- dias, cryptorchidism, and tethered spinal cord; trisomy 8 mosaicism was established by cytogenetics. The patient’s serum titers were negative for toxoplasmosis, rubella, cy- tomegalovirus, and herpes virus. Ophthalmologic exami- nation demonstrated ability to fix and follow with each eye, orthophoria, no nystagmus, and grossly full versions and visual fields as assessed by visually directed eye move- ments to targets in each hemifield. Examination under anesthesia revealed intraocular pressures of 12 mm Hg OD and 16 mm Hg OS. The anterior segment was normal in the right eye by portable slit-lamp examination. The left cornea had a dense paracentral creamy white geographic stromal opacity with a well-demarcated margin and clear surrounding stroma. It measured approximately 3 mm in diameter and was temporal to but not involving the visual axis. An iridocorneal adhesion was noted from approxi- mately 12:00 to 1:30. Gonioscopy was normal in the right eye, but the view was limited OS. Dilated fundus exami- nation revealed normal vasculature, normal appearing op- tic nerves with a cup to disk ratio of 0.2 and mild pigmen- tary mottling in the macula and far periphery bilaterally. A standard ERG performed under conscious sedation showed no measurable a or b waves under photopic or scotopic conditions in either eye. The patient was subsequently lost to follow-up until age 14 years. Snellen visual acuity was 20/50 with a cycloplegic refraction of –3.75 sphere in the right eye and 20/400 with –5.00 sphere in the left. Intraocular pressure was 10 mm Hg OD and 12 mm Hg OS by applanation. Motility was normal, and the eyes were grossly well aligned. Slit-lamp examination of the right eye revealed a normal anterior segment. The left eye demonstrated an iridocorneal adhesion superiorly, but marked improvement was found in the corneal opacity when compared with previous drawings, with a faint mid-stromal haze visible temporally (Figure 1). Dilated fundus examina- tion revealed normal optic nerves and retinal vasculature. There was retinal pigment epithelial mottling and atrophy in the macula of both eyes with diffuse RPE drop-out in the mid and far periphery. Figure 2 represents the right eye (posterior pole); the left fundus appeared similar, but was difficult to photograph secondary to poor dilation. The patient’s family refused a repeat ERG. DISCUSSION Trisomy 8 mosaicism is characterized by mental retardation, a prominent forehead with deep-set eyes, cupped ears, and a variety of orthopedic, genitourinary, and cardiovascular ab- normalities. 1 In addition to strabismus, there have been re- ports of optic atrophy, chronic uveitis, hypertelorism, blepha- rophimosis, microphthalmia, ptosis, heterochromia, cataract, bilateral Duane syndrome, congenital pendular nystagmus, abnormal ERG with decreased cone function, and foveal hypoplasia. 2,3 One histopathological evaluation of a charac- teristic corneal opacity found a richly vascularized yellow– white fibrous tissue in the anterior stroma. 4 A more recent From the Department of Ophthalmology, Dean A. McGee Eye Institute, University of Oklahoma, Oklahoma City, Oklahoma. Supported in part by an unrestricted grant from Research to Prevent Blindness Inc, New York, New York. Submitted February 9, 2004. Revision accepted December 7, 2004. Reprint requests: R. Michael Siatkowski, MD, Dean A. McGee Eye Institute, 608 S.L. Young Boulevard, Oklahoma City, OK 73104. J AAPOS 2005;9:290-291. Copyright © 2005 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2005/$35.00 + 0 doi:10.1016/j.jaapos.2004.12.021 Journal of AAPOS 290 June 2005