Table 2.
Incidence of interferon-associated retinopathy in observational studies during which more than half of the patients were treated with pegylated interferon-α based regimens for chronic hepatitis C
| Study | IAR incidence | Country | Timing of examinations | Comments |
| Mousa et al[27] | 8 of 98 (8%) | Egypt | Baseline, 2, 4, 8, 12 and 24 wk then every 3 mo | IAR: seven of 8 patients with IAR had no reduction in VA. No dose reduction for management of IAR. Combined DM and HTN gave relative risk of 6.5 of developing IAR. Atypical adverse events: vitreous hemorrhage from retinal tears with retinal detachment requiring vitrectomy in 1 patient, final visual outcomes were not described. |
| Fouad et al[28] | 22 of 84 (26%) | Egypt | Baseline, 12, 24 and 48 wk and 1 mo after completing treatment | IAR: no reduced VA in eyes that developed IAR. Three patients with IAR developed retinal hemorrhages and treatment was ceased. Logistic regression found HTN (9 of 12) and DM (13 of 16) to be predictors of developing IAR. Atypical adverse events: NAION in 2 patients and optic neuritis in 1 patient, final visual outcomes for these patients were not described. |
| Vujosevic et al[29] | 21 of 97 (22%)1 | Canada | Baseline, 3 and 6 mo and 3 mo after completing treatment | IAR: all patients with pre-existing retinopathy, 9 patients, had worsening of retinopathy during treatment. Factors associated with developing IAR were age, metabolic syndrome, HTN, cryoglobulinemia and pre-existing intraocular lesions. Using multivariate analysis only HTN was a significant predictor of developing IAR. Insufficient number of patients with DM (n = 5). Atypical adverse events: bilateral BRVO in one patient with a background of HTN resulting in irreversible vision loss in the left eye only. |
| Lim et al[30] | 5 of 10 (50%)2 | Korea | Baseline and then 3 weekly for 6 mo | IAR: no reduced VA in eyes that developed IAR. No dose reduction for management of IAR. Atypical adverse events: unilateral CRVO in 1 patient with a background of DM resulting in irreversible vision loss. |
| Mehta et al[31] | 18 of 64 (28%)3 | United States | Baseline, 3 and 6 mo | IAR: no reduced VA in eyes that developed IAR. 1 of 88 ceased treatment for asymptomatic IAR. Male only cohort. HTN and DM not significant predictor of developing IAR. Poor follow up rates - 69% had an eye exam within the first 12 weeks of starting treatment. Atypical adverse events: nil reported. |
| Kim et al[32] | 11 of 32 (34%) | Korea | Baseline, 4, 8, 12, 16, 24, 36 wk | IAR: no reduced VA in eyes that developed IAR alone. No dose reduction for management of IAR. All retinal lesions spontaneously resolved. 91% of retinopathy developed within 2 mo, but 1 occurred at 4 mo. HTN significantly associated with development of IAR (6 of 10), T2DM not (1 of 2). Atypical adverse events: unilateral BRVO in 1 patient with background of HTN resulting in irreversible vision loss. |
| Panetta et al[33] | 7 of 183 (4%) | United States | Baseline and repeat examination when visually symptomatic | IAR: three patients ceased treatment. Two with visual symptoms associated with IAR. 46% of patients had HTN and 16% had DM - neither predictive of developing IAR. Atypical adverse events: nil reported. |
| Malik et al[34] | 3 or 38 (8%) | United Kingdom | Baseline, 3 and 6 mo. Low follow up rates | IAR: no reduced VA in eyes that developed IAR. No dose reduction for management of IAR. Atypical adverse events: nil reported. |
| Andrade et al[35] | 5 of 34 (15%) | Spain | Baseline, at cessation of treatment and when visually symptomatic | IAR: no reduced VA in eyes that developed IAR. No dose reduction for management of IAR. Higher serum VEGF in patients with retinopathy and/or subconjunctival hemorrhage. Atypical adverse events: cystoid macular edema in 1 patient, final visual outcomes were not described. |
| Ogata et al[36] | 25 of 69 (36%) | Japan | Baseline and then regularly for 6 months | IAR: no reduced VA in eyes that developed IAR. No dose reduction for management of IAR. 46% (13 of 28) treated with IFNα developed IAR compared to 29% (12 of 41) treated with PEG-IFNα. Atypical adverse events: no details. |
| Chisholm et al[37] | 5 of 10 (50%) | United Kingdom | Baseline, 2, 4, 8, 12 and 24 wk and 12 wk after completing treatment | IAR: no dose reduction for management of IAR. Atypical adverse events: nil reported. |
| Cuthbertson et al[38] | 4 of 25 (16%) | United Kingdom | 3 mo after starting treatment or when visually symptomatic | IAR: no reduced VA in eyes that developed IAR. No dose reduction for management of IAR. Atypical adverse events: nil reported. |
1
Nine patients that had baseline retinopathy were excluded from the incidence data shown. All 9 had progression of retinopathy;
2
Thirty-six of the 46 patients treated for chronic hepatitis B infection were excluded from the incidence data shown;
3
Ten patients that had baseline diabetic retinopathy were excluded from the incidence data shown. Five of these had resolution of retinopathy on subsequent eye exams. BRVO: Branch retinal vein occlusion; CRVO: Central retinal vein occlusion; DM: Diabetes; HTN: Hypertension; IAR: Interferon-associated retinopathy; NAION: Non-arteritic anterior ischemic optic neuropathy; PEG: Pegylated; IFN: Interferon; RBV: Ribavirin; VA: Visual acuity; VEGF: Vascular endothelial growth factor.