Toxocaral chorio-retinitis. Treatment of early cases with photocoagulation.

Since Wilder (I950) described nematode endophthalmitis in patients previously diagnosed as cases of pseudoglioma, and Nichols (1956) identified the nematode as Toxocara canis, it has been recognized that this organism, which is very common in puppies all over the world, is liable to infect the human eye, particularly in young children. Ashton (I960) demonstrated the pathology of the condition. Ocular toxocariasis manifests itself clinically as a granuloma at the posterior pole or as a chronic endophthalmitis. Duguid (i96i) suggested that the granuloma occurred when a previous infection had conferred high resistance and low tissue sensitivity, while chronic endophthalmitis developed when sensitivity was high and resistance low. Perkins (I966) showed that chronic endophthalmitis was more common than granuloma. However, as more cases of toxocariasis are diagnosed, other manifestations also appear to be quite cQmmon. A lesion resembling macular degeneration was recently described by Rubin, Kaufman, Tierney, and Lucas (i968) as being due to an intraretinal Larva migrans, most probably Toxocara, which produced a localized haemorrhage. Smith and Greer (I97I) reported a case of acute anterior uveitis with subsequent development of a retinal mass at the ora serrata, which progressed to endophthalmitis and was found histologically to be toxocaral. This peripheral chorio-retinitis was also thought by Perkins (i 966) to be due to Toxocara in a number of cases in children. Peripheral retinitis and chronic cyclitis in children were also reported by Hogan, Kimura, and O'Connor (i965) as being due to nematode infestation. Granulomatous lesions in the macula in the three cases reported below were suggestive of toxocariasis on clinical and serological grounds; two were very early granulomatous lesions in adolescents. We have tried a new form of treatment, namely photocoagulation, in these two early cases with satisfactory results.