Sudden unilateral visual loss in a healthy adult female.

A 45-year-old Indian female presented with sudden diminution of vision in the left eye of 10-day duration. She had no systemic illness of note. Investigations done elsewhere showed low hemoglobin (10.5g/dl), total count 12200, erythrocyte sedimentation rate (ESR)-57 mm/ 1sthr, Human immunodeficiency virus (HIV)/Veneral disease research laboratory (VDRL) -non-reactive, Mantoux negative, serum angiotensin converting enzyme (ACE)/chest X-ray normal. Before presentation to our hospital she had been treated with 60 mg of oral steroids for a week with no improvement in the visual acuity. Her right eye (OD) examination was within normal limits. Left eye (OS) showed normal anterior segment with vitreous haze 2+, vitreous cells 1+ and retinal opacification and hemorrhages with occlusive vasculitis. Figure 1a

Figure 1

(a) Wide angle color fundus photograph of the left eye showing vitreous haze1+, peripheral retinal opacification, occluded vessels, and hemorrhages in all the quadrants; (b) wide angle color fundus photograph of the left eye showing (one week after initiation of antiviral treatment) pale optic disc, occlusive vasculitis with hemorrhages and extensive area of retinal opacification. Vitreous haze has reduced.

What is your call?

Give intra-vitreal steroids along with systemic steroids

Start on empirical antibiotics treatment orally and discontinue oral steroids.

Consider doing anterior chamber paracentesis for polymerase chain reaction (PCR) for Herpes Simplex Virus (HSV I and II), Varicella Zoster Virus (VZV), Cytomegalovirus (CMV) and start on systemic antiviral therapy.

Increase the dose of oral steroids.

Answer is 3

Well-demarcated areas of peripheral retinal whitening suggesting retinitis or retinal necrosis with occlusive arteritis and prominent inflammatory reaction in the vitreous suggests acute retinal necrosis (ARN). The infiltration of retina with viral particles and mono nuclear cells causes retinal opacification. Additionally with retinal arteriolar inflammation causes vaso-occlusion which leads to retinal tissue necrosis and may also contribute to retinal opacification. The treating ophthalmologist should do a complete blood count with differential, baseline liver and renal function test, HIV testing, FTA-ABS (fluorescent treponemal antibody absorption) erythrocyte sedimentation rate and toxoplasmosis titers. Mantoux test and chest radiograph were done to rule out tuberculosis in the present patient.

An anterior chamber paracentesis or vitreous tap for doing PCR for herpes viruses (VZV, HSV I and II, CMV, Epstein Barr Virus (EBV)); and toxoplasmosis (if clinical suspicion is present) is helpful.

Treatment should not be delayed for want of PCR results. PCR for VZV or HSV in the aqueous or vitreous humor of suspected ARN is positive in 79–100% of cases.[1]

The treatment should be on a priority basis. There is a great chance of the fellow eye being affected. The goal is to decrease the incidence in the fellow eye. Seventy-five percent of acyclovir treated patients remained unaffected in the other eye at 2 years compared to 35% patients not treated with acyclovir.[2] Occurrence of retinal detachment in the affected eye is not affected by the treatment.

Our patient was started with intravenous acyclovir 1500 mg thrice daily for 7 days [Figure 1b] followed by oral valacyclovir 1000 mg thrice daily. Nested PCR was positive for VZV. Since the ARN was sight threatening she was given intravitreal ganciclovir 2 mg/0.1ml 3 doses in 3-day intervals. Oral steroids were re started 48 hours after initiation of IV acyclovir. There was resolution of hemorrhages and retinitis over 2 months. The patient was informed about the possible causes of severe visual impairment secondary to retinal detachment, optic neuritis, and severe vaso-occlusion. She subsequently developed retinal detachment. Surgery was offered with guarded visual prognosis due to pale optic disc and extensively occluded vessels. Patient declined to proceed with the surgery.

Acyclovir should be started at 10-13 mg/kg every 8 hours or 1500 mg/m2/day intravenously (IV) for 5-10 days.[3] This should be followed by acyclovir 800 mg five times daily orally for 6 weeks to 3 months. Blumenkranz et al.[4] in their study of 12 patients with ARN treated them with intravenous acyclovir 1500 mg/m2/day, oral aspirin or coumadin, and oral steroids (in 9 patients) after the initiation of acyclovir. Retinitis lesions regressed on an average after 3.9 days after starting the IV acyclovir and completely in 32.5 days on average.[4] They also noted that the treatment did not reduce the risk of retinal detachment (occurring in 11 of 13 eyes after an average of 59 days of initiation of therapy) or vitritis.[4]

Alternative to IV injections include valacyclovir (1000-2000 mg orally every 8 hours) which has good bioavailability and avoids the need for intravenous access. Other options include famciclovir (500 mg orally every 8 hours), valganciclovir started at 900 mg twice daily orally for 3 weeks induction, followed by 900 mg once daily orally for maintenance. Valganciclovir has been successfully used for CMV retinitis. It has known activity against HSV, VZV, and CMV.

Sight threatening retinitis or macular or optic disc involvement can be treated with intravitreal injections. Ganciclovir can be given at 2 mg per 0.1 mL, and foscarnet can be given 1.2 mg to 2.4 mg per 0.1 mL.

Oral steroids (0.5-2.0 mg/kg/day) can be given upto 6 to 8 weeks and it should be started 24-48 hours after the start of antiviral therapy or once regression of necrosis sets in. Triamcinolone 40 mg/1 mL as sub-tenon injection can be considered after antiviral therapy. Periocular or oral steroids should not be started in active retinitis before the initiation of antiviral therapy, as it may worsen the retinitis as it happened in the present patient prior to being referred to our center.

The diagnosis and management of ARN is complex and only a prompt diagnosis can help save vision. Immediate treatment of the patient is required and can be done in either the inpatient or outpatient setting. The goal is to decrease the incidence in the fellow eye.

The visual prognosis of ARN is poor and 64% of affected eyes achieve a final acuity of worse than Snellen visual acuity 20/200 due to multiple complications including retinal detachment, optic neuropathy, macular abnormality, and retinal ischemia.[5]

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Conflicts of interest

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