Diffuse unilateral subacute neuroretinitis in a young boy: a case report

Abstract

We report a case of diffuse unilateral subacute neuroretinitis in a young boy with no clinical visualization of nematode. The diagnosis was made based on clinical findings and detection of Toxocara immunoglobulin G by Western blot test. An 11-year-old Malay boy presented with progressive blurring of vision in the left eye for a duration of 1 year. It was associated with intermittent floaters. Visual acuity in the left eye was 6/45 and improved to 6/24 with pinhole. There was positive relative afferent pupillary defect, impaired color vision, and presence of red desaturation in the left eye. There were occasional cells in the anterior chamber with no conjunctiva injection. Posterior segment examination revealed mild-to-moderate vitritis and generalized pigmentary changes of the retina with attenuated vessels. The optic disk was slightly hyperemic with mild edema. There was presence of multiple, focal, gray-white subretinal lesions at the inferior part of the retina. Full blood picture results showed eosinophilia with detection of Toxocara immunoglobulin G by Western blot test. Investigations for other infective causes and connective tissue diseases were negative. The diagnosis of diffuse unilateral subacute neuroretinitis secondary to Toxocara was made based on clinical findings and laboratory results. He was treated with oral albendazole 400 mg daily for 5 days and oral prednisolone 1 mg/kg with tapering doses over 6 weeks. At 1 month follow-up, the inflammation had reduced, and multiple, focal, gray-white subretinal lesions were resolved; however there was no improvement of vision.

Neuroretinitis with dual infections

“…Oral treatment with albendazole may be an alternative for patients in whom the worm is not identified and in whom photocoagulation cannot be performed. 19 , 20 Early and prompt treatment in this patient resulted in excellent recovery of vision.…”

Short-term oral albendazole therapy for diffuse unilateral subacute neuroretinitis: A case report

“…The presence of a parasite in the retina, the release of toxic products by that parasite, and the host's immune response to the organism generate an inflammatory response. 1 , 4 , 6 , 11 This inflammation is associated with the unilateral loss of visual acuity that characterizes the disease. 9 …”

“…Corticosteroids appear to both decrease inflammation and prevent the worsening of visual acuity in DUSN. 6 , 11 , 15 , 19 Their use is linked to the suppression of inflammation that occurs after the death of the nematode (secondary to treatment with photocoagulation or systemic medications such as albendazole). 11 Further research is needed to clarify whether or not corticosteroids should be used as adjunctive therapy in the treatment of DUSN.…”

“… 1 , 5 However, in many cases, the parasite cannot be identified, making the diagnosis (in those cases) of DUSN a challenge. 2 , 6 Maintaining a high index of suspicion for this condition is crucial, as early detection and treatment have been associated with better patient outcomes. 5 , 7 , 8 , 9 …”

“…When the parasite is visualized, the first-line treatment of DUSN consists of laser photocoagulation. 1 , 6 In cases in which the parasite cannot be detected, albendazole has proven to be a valuable second option. 3 , 10 However, there is no consensus about the specific regimen that should be used to treat DUSN.…”