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recovery. We report a case of asymmetric disease in which there was full visual recovery after many months of visual ... temporal disc pallor in the right eye. (Fig.

Acta Ophthalmologica 2012

Letters to the Editor Leber’s optic neuropathy – visual return on alcohol cessation Brid Morris1 and Marcela Votruba1,2 (A) 1

Eye Department, University Hospital of Wales, Cardiff, UK 2 School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK doi: 10.1111/j.1755-3768.2012.02387.x

Editor,

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itochondrially inherited Leber’s hereditary optic neuropathy (LHON) presents with rapid unilateral visual loss. The second eye is affected within weeks. The visual loss is often profound, but the prognosis is highly mutation dependent, with the 14484 mutation having the best chance of some visual recovery. We report a case of asymmetric disease in which there was full visual recovery after many months of visual impairment after abrupt alcohol cessation. A 34-year-old male attended with a 5-month history of visual loss. He had no family history of note. He had been a smoker (20 per day) since age 17 years and had been drinking 60 units of alcohol weekly for a period of 18 months. His best corrected vision was 6 ⁄ 60 OD and 6 ⁄ 9 OS. He identified 3 ⁄ 13 Ishihara plates OD and 10 ⁄ 13 OS. A right relative afferent pupillary defect was present. Anterior segments and intraocular pressures were normal. Discs showed mild temporal disc pallor in the right eye (Fig. 1). Fluorescein angiography was normal. Humphrey FF-120 revealed small central scotomas in both eyes. VEPs were abnormal, with asymmetry in amplitude and delay on the right. There was evidence of N95 reduction on the pattern ERG from the right eye. Investigations including a full blood count, erythrocyte sedimentation rate, C-reactive protein, vitamin B12, folate, syphilis serology and an autoimmune screen were normal. Gamma glutamyltransferase (GGT) was elevated at 156 (normal 5–48) in keeping with excess alcohol ingestion. Genetic testing for Leber’s mutation 14484T >C was positive.

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may be protective (Ramos Cdo et al. 2009). This patient had the 14484T>C mutation, which is associated with the best visual recovery (approximately 50%) of all three of the primary mutations associated with LHON. Although recovery may have occurred spontaneously, the chronology is highly suggestive that alcohol cessation had a beneficial role. The key importance of environmental factors and mitochondrial dysfunction, whether or not a primary LHON mutation is detected, should be emphasized (Abdu Amero & Bosley 2006). This unusual case highlights the importance of environmental factors in precipitating visual loss. Patients with a known predisposition to optic nerve disease should be cautioned not to drink alcohol and smoke, although it may be difficult to distinguish nutritional or toxic amblyopia in such a case on clinical grounds alone.

(B) Fig. 1. Colour fundus photographs taken at the time of presentation, revealing mild temporal disc pallor in the right eye (A). Left eye (B).

The patient was counselled about his visual prognosis, the genetics underlying the disease and advised to refrain from alcohol and tobacco. Ten months after presentation, the patient stopped drinking all alcohol, although he continued to smoke around five cigarettes per day. Within 8 weeks, his vision had improved to 6 ⁄ 6 OD, 6 ⁄ 6 OS. Pupil examination and colour vision were also normal. The GGT had fallen to 37. This case illustrates the possibility of significantly asymmetric involvement in LHON, as well as the potential role for alcohol in precipitating LHON in a genetically predisposed individual. It also highlights that visual recovery may occur after many months of visual dysfunction (Johns et al. 1993). It is known that environmental factors can precipitate visual failure in LHON. Increased visual loss has been reported with heavy alcohol intake, and a clinical penetrance of 93% has been shown in male smokers with Leber’s mutations (Kirkman et al. 2009). Alcohol excess and smoking may increase stress on already compromised oxidative pathways within the optic nerve. Visual recovery has been reported in LHON and is more likely in younger patients. A thicker retinal nerve fibre layer (Barboni et al. 2005) or larger anatomical disc

References Abdu Amero KK & Bosley TM (2006): Mitochondrial abnormalities in patients with LHON-like optic neuropathies. Invest Ophthalmol Vis Sci 47: 4211–4220. Barboni P, Savini G, Valentino ML et al. (2005): Retinal nerve fiber layer evaluation by optical coherence tomography in Leber’s hereditary optic neuropathy. Ophthalmology 112: 120– 126. Johns DR, Heher KL, Miller NR & Smith KH (1993): Leber’s hereditary optic neuropathy. Clinical manifestations of the 14484 mutation. Arch Ophthalmol 111: 495–498. Kirkman MA, Yu-Wai-Man P, Korsten A, Leonhardt M, Dimitriadis K, De Coo IF et al. (2009): Gene-environment interactions in Leber hereditary optic neuropathy. Brain 132: 2306– 2308. Ramos Cdo V, Bellusci C, Savini G, Carbonelli M, Berezovsky A, Tamaki C et al. (2009): Association of optic disc size with development and prognosis of Leber’s hereditary optic neuropathy. Invest Ophthalmol Vis Sci 50: 1666– 1674.

Correspondence: Prof. Marcela Votruba, PhD, FRCOphth Cardiff School of Optometry and Vision Sciences Maindy Road Cardiff CF24 4LU UK Tel: + 44 29 2087 0134 Fax: + 44 29 2087 4859 Email: [email protected]

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