in august 2008 , a 63-year - old man presented with gradual onset blurry vision in both eyes . he had initially developed the visual disturbance one year prior at that time , his best corrected visual acuity was 20/30 in both eyes . on slit lamp examination , the anterior and posterior segments of both eyes showed no significant findings and further ophthalmologic exam was not performed . he had a history of liver transplantation for chronic hepatitis b - related cirrhosis , 2 years prior to presentation . he denied any other significant medical history , including hypertension , diabetes mellitus , and trauma . he also had no significant family history and no clinical or laboratory signs of a graft versus host reaction . he had been taking tacrolimus ( prograf ) for 30 months ( 6 mg for 2 years and 3 mg for 6 months ) and had noted the gradual onset of the visual disturbance in conjunction with the immunosuppressive therapy . he had also been taking multiple other drugs , including digestives , antihistamines , expectorants , and cellcept ( syntex puerto rico inc . , humacao , puerto rico ) . both pupils were reactive to light , and no relative afferent pupillary defect was noted . the intraocular pressure was 9 mmhg in the right eye and 10 mmhg in the left eye . no swelling or pallor was noted in either optic disc . although the foveal reflex was slightly decreased , no bulls eye phenomenon was noted . fluorescein angiography revealed non - specific signs , with only a window defect caused by retinal pigment epithelium ( rpe ) atrophy ( fig . 1 ) . optical coherence tomography also revealed non - specific finding in the fovea ( fig . 2 ) . electroretinography ( erg ) demonstrated a delayed a wave and b wave latency during the photopic response ; the response amplitude was slightly decreased in the left eye . multifocal erg showed decreased amplitude in the central ring one in both eyes ( fig . , san leandro , ca , usa ) static visual field with central 10 - 2 threshold test revealed a central scotoma ( fig . visual evoked potential ( vep ) testing demonstrated a p100 delay in both eyes ( fig . a coagulation factor deficiency was not found and the platelet count was within the normal range on serologic testing . the patient 's best corrected visual acuity was maintained at 20/200 in both eyes , some rpe changes were observed on fundus examination . although vep testing demonstrated a mild p100 delay , the present patient did not exhibit disc swelling or disc pallor . a mild , focal , central scotoma therefore , maculopathy was considered a more likely source of the visual disturbance than optic neuropathy . cortical blindness is another possible cause of symptoms in patients such as the one described in this report . magnetic resonance imaging easily demonstrates the white matter lesions attendant to tacrolimus and cyclosporine toxicity . although magnetic resonance imaging was not performed in this patient because of claustrophobia , brain computed tomography revealed no abnormalities . therefore , this patient 's visual disturbance was unlikely to have been associated with cortical blindness . tacrolimus may have a direct neurotoxic effect on the rpe , cone cells , or rod cells . furthermore , vasoconstriction may be induced along with the maculopathy , resulting in neural tissue damage and tissue ischemia . furthermore , another possible mechanism for the development of maculopathy could involve focal proliferation and loss of the rpe , predominantly in the fovea , similar to that seen with cyclophosphamide and cytarabine in a patient with central nervous system lymphoma . in conclusion
a 63-year - old man with a history of liver transplantation presented to our clinic complaining of visual disturbance . 
 he had been receiving tacrolimus ( fk 506 ) for 30 months ( 6 mg / day for 2 years and 3 mg / day for 6 months ) ; he reported that the visual disturbance began while taking tacrolimus . 
 a full ophthalmologic examination and electrophysiologic and imaging studies were performed . 
 the best corrected visual acuity was 0.1 in both eyes . 
 there were no abnormal finding in the anterior segment , pupillary reflexes were normal and , there was no swelling in either optic disc . although the foveal reflex was slightly decreased , fluorescein angiography revealed non - specific signs , with the exception of a window defect . a multifocal electro - retinogram revealed decreased amplitude of the central ring . a swedish interactive threshold algorithm - standard 
 10 - 2 visual field test revealed a central scotoma . 
 these findings suggest that tacrolimus may result in maculopathy . 
 therefore , careful ophthalmologic examination is necessary in the patients taking tacrolimus .