[A case of secondary retinal detachment caused by ocular toxocariasis].

PURPOSE: We report a case with bullous retinal detachment secondary to ocular toxocariasis. CASE: A 68-year-old man, who was a professional dog breeder, visited an ophthalmologist because of visual field defect in the left eye, and was referred to our clinic. The patient had bilateral cataract and bullous retinal detachment in the left eye. Fundus examinations after cataract surgery revealed no break but a white mass in the temporal lower peripheral retina of the left eye. Initial treatment with systemic corticosteroids was ineffective. Retinal detachment was treated by retinal cryocoagulation, scleral buckling, and subretinal fluid drainage. Subretinal fluid obtained during the operation showed high antibody titer for Toxocara canis. CONCLUSION: Ocular toxocariasis can cause bullous retinal detachment. To confirm the diagnosis, examination of the antibody titer of Toxocara canis in the subretinal fluid is useful.

The rarity of Charles Bonnet syndrome.

Charles Bonnet syndrome (CBS) is characterized by complex visual hallucinations in otherwise psychologically normal people. Estimates of the prevalence of CBS in different samples vary from a small percentage (around 1%), to a relatively large percentage (about 10%). The purpose of the present study is to determine whether CBS is rare or not. One-thousand ophthalmologic and optometric outpatients at a university hospital were consecutively screened by a questionnaire to identify patients possibly experiencing visual hallucinations. The mean corrected visual acuity in the best eye was 1.1. Those who positively responded to the questionnaire were further investigated to determine whether their symptoms were consistent with CBS. As a result, the prevalence of CBS was 0.5% (5/1000). In subclass analyses, the prevalence was 3 of 372 (0.8%) in the low vision group, 2 of 346 (0.6%) in the elderly, and 1 of 120 (0.8%) in both conditions. These were not significantly different from each other or from the overall prevalence (0.5%). This low prevalence of CBS in our subjects may be due to their relatively good visual acuity because previous studies with high prevalence of CBS investigated patients with a visual acuity of less than 0.3. The prevalence of CBS may be low in patients with these particular characteristics, and this syndrome seems to be rare in even ophthalmologic and optometric patients if they do not have seriously low vision. Further studies are needed to investigate the prevalence of CBS in general population.

[A case of optic nerve drusen associated with Grönblad-Strandberg syndrome].

PURPOSE: We report a rare case of optic nerve drusen associated with Grönblad-Strandberg syndrome. CASE: The patient was a 29-year-old woman who had pseudoxanthoma elasticum on her neck. OBSERVATIONS: On eye examination, there were no abnormal findings in the anterior segment or ocular media. Ophthalmoscopic examination revealed milky white granular lesions on the optic nerve disc, and angioid streaks around the disc in both eyes. Orbital computerized tomography(CT), B-scan echography and photography with a fluorescein angiography filter identified the granular lesions as optic nerve drusen. With a scanning laser ophthalmoscope(SLO), poorly-visible drusen buried below the nerve head could be detected. The optic nerve drusen could be seen more clearly by infrared laser than by helium-neon laser. CONCLUSIONS: SLO using infrared laser is useful for evaluation of superficial and buried drusen.

Charles Bonnet syndrome and visual acuity--the involvement of dynamic or acute sensory deprivation.

A 61-year-old patient suffered from Charles Bonnet syndrome (CBS) while his visual acuity declined, whereas CBS subsided after he became blind. These findings suggest that reduction of visual acuity (dynamic or acute impairment) has a greater impact on the onset of CBS than low visual acuity (static or chronic impairment) per se in some patients. They may also explain why patients with low visual acuity do not always suffer from CBS. Although further studies are required, the present case highlights the importance of the differentiation between lowering and low visual acuity in the etiology of CBS.