Acute retinal necrosis following cataract surgery: a case of VZV reactivation and successful management

Abstract

Background

Acute retinal necrosis triggered by routine cataract surgery is a rare condition, which may be overlooked by the clinicians. We report a case of unilateral acute retinal necrosis (ARN) with the onset 4 days after uncomplicated cataract surgery. The patient demonstrates satisfactory outcomes following anti-virus therapy.

Case presentation

A 73-year-old male presenting with 1-day history of floaters, eye redness, pain and vision loss in his right eye was referred to our clinic. He had just completed uncomplicated phacoemulsification and posterior chamber intraocular lens implantation in the right eye 5 days ago. He had a history of cutaneous herpes zoster infection at the age of 40. The visual acuity was counting fingers in the right eye at presentation with marked anterior and posterior segment inflammation. ARN was suspected based on fundus findings, including retinal hemorrhage, vessel attenuation and retinal whitening. Following anti-virus therapy, the inflammation and visual acuity improved. Aqueous humor for viral DNA testing using polymerase chain reaction showed positivity to varicella zoster virus (VZV), confirming the diagnosis of VZV associated ARN. The visual acuity improved to 18/20 at one month follow-up examination with no recurrence of inflammation.

Conclusions

Clinicians should be aware of the possibility of cataract surgery as a triggering event for reactivation of VZV and subsequent ARN. Anti-virus therapy initiated at early phase of the disease may yield satisfactory visual outcomes for the patient. Careful preoperative screening and postoperative monitoring in patients with a history of herpes infection is important.

Background

Acute retinal necrosis (ARN) was initially reported by Urayama and colleagues in 1971 [1] which referred to a vision-threatening disease associated with viral necrotizing retinitis. The triggering factors for ARN have been reported with variety in previous reports. Here, we report a case of unilateral ARN onset on the fourth day after cataract surgery.

Case presentation

A 73 years old male was referred to our clinic with 1-day history of floaters, eye redness, pain and rapid vision loss in the right eye. The patient underwent uncomplicated phacoemulsification and posterior chamber intraocular lens implantation for the left and right eye at 15 and 5 days ago, respectively. He had undergone radiofrequency cardiac ablation for arrhythmia 15 years ago, and had a history of cutaneous herpes zoster infection at the age of 40.

At presentation, the visual acuity was counting fingers and 18/20 in the right and left eye, respectively. Intraocular pressure was 10mmHg in the right eye. The slit-lamp examination of the right eye revealed 3 + anterior chamber cells with conjunctival congestion. Before the cataract surgery, the vitreous body and the fundus of the right eye were not remarkable (Fig. 1a, b). While fundus examination at examination revealed haze and debris in the vitreous body and multiple retinal hemorrhage and peripheral attenuated retinal vessels with retinal whitening (Fig. 1c, d). No sign of inflammation was noted in the left eye.

Fig. 1

a: No abnormalities were found before the operation in the fundus photography. b: B ultrasonography revealed that the vitreous body was clean before the operation. c: One days after disease onset, the fundus photography revealed multiple retinal hemorrhage and peripheral retinal vessel attenuation with retinal whitening in the corresponding area. The optic disk could hardly be seen. d: B ultrasonography revealed dense vitreous haze in the posterior segment one day after disease onset

Laboratory examination including tests for complete blood count, comprehensive metabolic panel, syphilis, toxoplasmosis antibody, HIV antibody, and tuberculosis interferon-gamma release were negative. This patient was managed as presumed acute retinal necrosis and intravitreal ganciclovir 2 mg/0.1 ml was administered for the right eye, as well as intravenous acyclovir 750 mg/q8h. Three days later, improvement of inflammation was achieved (Fig. 2a) and the visual acuity increased to 2/20 in the right eye. Then aspirin and oral prednisolone were started, followed by a slow tapering of prednisolone.

Fig. 2

a: Three days after initiation of anti-virus therapy, the optic disk could be seen on the fundus photography. Multiple focal retinal hemorrhage but no obvious attenuation of retinal vessels was presented. b: One month after treatment, the fundus could be clearly seen with no retinal hemorrhage or vessel attenuation presented

Before the intravitreal injection, samples of aqueous humor were obtained. The viral DNA testing using polymerase chain reaction revealed positive varicella zoster virus (VZV), confirming the diagnosis of VZV associated ARN.

Visual acuity of the right eye increased to 18/20 at one month follow-up examination with no obvious signs of active inflammation. Retinal hemorrhage and vessel attenuation were not noted in the fundus examination (Fig. 2b). However, haze persisted in the vitreous body and the patient still complained about floaters in the right eye.

After a 10-day course of intravenous acyclovir, this patient started oral acyclovir for a total of 14 weeks. The patient was followed up for 3 months with no recurrence of inflammation after discontinuing oral acyclovir.

Discussion and conclusions

ARN is a rare but rapid-developing and vision-threatening disease associated with virus infection. In clinical practice, postoperative exogenous endophthalmitis was always considered one of the possible causative factors for vision loss with active inflammation within the anterior and posterior segment after recent intraocular surgery. However, in this case report, based on the medical history, characteristic clinical presentation, quick and positive reaction to anti-viral therapy, and confirmation with viral DNA test, we were able to make the diagnosis of ARN.

Previous reported triggering events for ARN include trauma [2], intraocular or periocular corticosteroid administration [3], vaccine injection [4] and alemtuzumab use [5]. ARN can affect both immunocompetent and immunosuppressed individuals [6, 7].

The patient has a history of previous cutaneous herpes zoster infection, which may be the source of infection. Varicella-associated ARN reflects a reactivation of latent virus. It has been reported that the time interval between cutaneous eruption and ARN ranges from 5 days to 3 months. However, this patient presented a history of cutaneous eruption at more than 30 years ago.

Chun and colleagues [7] reported a case of bilateral varicella-associated ARN at 4 weeks after routine cataract surgery in an elderly immunocompromised patient. They attributed this to surgical incision and intraocular lens implantation as a form of trauma similar to an intraocular foreign body injury, which have caused virus infection.

In our case, the interval of disease onset and operation was only 4 days and the disease was ipsilateral to the operation side. This has enhanced the hypothesis that cataract surgery was a triggering factor for virus reactivation in ARN. However, this case report is unable to definitively prove causality between cataract surgery and VZV reactivation and further studies with larger sample size is needed.

The prognosis of our patient has also proved that early initiation of anti-virus therapy is effective for ARN treatment and may help patients regain good visual acuity. Patient education is very important in clinical practice, especially for rapidly progressive vision-threatening diseases like ARN.

In conclusion, we have presented a rare case of VZV-associated ARN following cataract surgery. The initiation of anti-virus therapy at early stage of the disease resulted in satisfactory visual outcomes with rapid decrease of inflammation. Clinicians should be aware that cataract surgery could serve as a triggering event for virus reactivation in the eye and subsequent ARN, so careful preoperative screening and postoperative monitoring in patients with a history of herpes infection are recommended.