Acute retinal necrosis: the effects of intravitreal foscarnet and virus type on outcome

Abstract

Purpose: To study the effects of intravitreal foscarnet and the clinical differences between varicella zoster virus (VZV) and herpes simplex virus (HSV) induced acute retinal necrosis (ARN).

Design: Retrospective comparative case series.

Participants: Eighty-one eyes of 74 patients.

Methods: A retrospective case note analysis was performed in 2 tertiary referral centers.

Main outcome measures: Presenting and final visual acuity, and progression to retinal detachment.

Results: Thirty-three eyes had HSV-ARN and 48 had VZV-ARN. The average age for HSV-ARN was 34 years and 51 for VZV-ARN (P<0.001). Visual acuity on presentation was similar (P = 0.48), but a larger proportion had better vision (> or =20/60) in the HSV-ARN group (52%) than the VZV-ARN group (35%). A greater proportion of eyes with poor vision (< or =20/200) was found at the 12-month follow-up in the VZV-ARN group (60%) compared with the HSV-ARN group (35%). A greater degree of visual loss in the VZV-ARN group (0.4 logarithm of the minimum angle of resolution [logMAR]) compared with the HSV-ARN group (0.04 logMAR) was detected (P = 0.016). Retinal detachment was 2.5-fold more common in VZV-ARN (62%) compared with HSV-ARN (24%). When comparing eyes treated with (n = 56) and without (n = 25) intravitreal foscarnet, there was a 40% lower rate in retinal detachment (53.6% vs 75.0%) for VZV-ARN (P = 0.23). The numbers with HSV-ARN were too small for analysis.

Conclusions: The results support the difference of outcome in HSV-ARN and VZV-ARN. Therefore, viral identification serves as a key to predicting outcome in these patients. Intravitreal foscarnet seems to be a useful adjunct for the treatment of ARN in that it reduced rate of retinal detachment.