a 32-year - old female was diagnosed with chronic hepatitis c ( grade 3/4 , stage 2/4 , genotype 2a / c ) in february of 2007 . she underwent treatment with pegylated interferon-2b 80 micrograms and ribavirin combination therapy for 5 months ( from february of 2007 until july of 2007 ) . she was also treated with subcutaneous insulin injections for a previous condition of pregnant diabetic mellitus diagnosed seven years before . she was first referred to ophthalmology in february of 2007 for a diabetic retinopathy examination . her vision was 0.6 in both eyes , and intraocular pressure was 11 mmhg in the right eye and 12 mmhg in the left eye . fundus examination found moderate nonproliferative diabetic retinopathy ( npdr ) in the right eye and mild npdr in the left eye . accordingly , a follow - up visit to check her eyes was scheduled for six months later . she felt visual blurring two months later , and we referred to a past ophthalmologic exam in june of 2007 . at that time , previous fundoscopy revealed retinal hemorrhages , cotton wool spots , macular edema , and new vessels elsewhere ( nve ) in both eyes ( fig . the pegylated interferon and ribavirin combination therapy was stopped , and the patient was treated with intravitreal 0.05 ml bevacizumab ( avastin ) injections . after completion of treatment , the patient 's retinal hemorrhages , cotton wool spots , and macular edema improved ( fig . 2 ) . the retinal non - perfusion areas ( figs . 3 and 4 ) and the best corrected visual acuity of the patient did not improve . as of june standard interferon therapy in chronic hepatitis c patients causes various ocular complications , including branch retinal vein occlusion , subconjunctival hemorrhages , visual blurring , papilledema , neovascular glaucoma , and retinal detachment , among others . the most common among the ocular complications are retinopathy - parapapillary retinal hemorrhages at the posterior pole , and cotton wool spots . these features of retinopathy occur in approximately 18% to 86% of alpha interferon - treated chronic hepatitis c patients . a study by jain et al . has reported that these features of retinopathy may occur between 4 to 12 weeks after the start of interferon and ribavirin combination therapy , and will regress within 4 to 12 weeks after therapy stops . the pathogenesis of these features of retinopathy is unknown , however , the hypothesis that interferon interferes with retinal microcirculations is persuasive . in this respect , interferon treatment for patients with abnormal microcirculation diseases , such as diabetic mellitus or hypertension , has a very high risk of causing interferon - associated ocular complications . the patient in this case , due to previous diagnosis of diabetic mellitus , belonged to a high - risk group for interferon - associated ocular complications . the patient presented with retinal hemorrhages , cotton wool spots , macular edema , and retinal ischemic changes in both of her eyes . these ocular complications progress more acutely and severely than the progression of complications in a state of pre - pegylated interferon treatment , and the patient 's vision decreased irreversibly . usually , interferon - treated patients have reversible interferon - associated retinopathy [ 1 - 7 ] . chronic hepatitis c patients must undergo examination of their eyes before interferon treatment begins , and they must follow up with a second exam within three months of starting treatment . particularly for high - risk patients with hypertension or diabetes mellitus , not only are regular follow - up examinations very important , but also stopping the interferon treatment at the right time is critical . this report shows that patients treated with pegylated interferon combined with ribavirin may have irreversible and severe ocular complications . this study proposes that chronic hepatitis c patients treated with pharmacokinetically improved pegylated interferon must also be managed with regular and exact ophthalmic examinations on an ongoing basis .
this paper reports a case of pegylated interferon - associated retinopathy in a patient with chronic hepatitis c. a 32-year - old female with chronic hepatitis c undergoing pegylated interferon and ribavirin combination therapy complained of visual blurring . features of interferon - associated retinopathy , including ocular complications such as cotton wool spots , retinal hemorrhages , macular edema , and branch retinal vein occlusion , were found in the fundus of both of her eyes . 
 pegylated interferon combination therapy was stopped , and the retinopathy of the patient was treated with intravitreal bevacizumab injections and panretinal photocoagulations . 
 this case shows that pharmacokinetically improved pegylated interferon has ocular complications for patients with chronic hepatitis c. accordingly , patients undergoing pegylated interferon treatment for hepatitis c need regular eye examinations for protection of their vision .