Male aged one year and five months, referred by his paediatrician for strabismus. He had endotropia (15 degrees) and small hypertropia in the right eye (OD), the left eye (OI) was dominant. The visual acuity (VA) is low in the right eye (the eye is disturbed by occluding the left eye) and acceptable in the left eye (the eye fixes the gaze and picks up small objects). The light reflex on the cornea leads us to suspect eccentric fixation in both eyes.
The child had suffered from febrile convulsions. Among the family history, the mother had chickenpox while pregnant (between 16 and 18 weeks), and a maternal uncle has Alport syndrome. The anterior pole is normal. On schiascopy the neutral point is +2 in both eyes.
Indirect ophthalmoscopy shows oval lesions in both maculae, predominantly in the temporal half, suggestive of old retinochoroiditis, with normal periphery. In the OD the macula is larger, highly pigmented and with whitish glial tissue in the centre; the temporal arches are curved towards the pathological area, and there is temporal parapapillary atrophy. In the OI there is well-defined chorioretinal atrophy with pigmented borders, normal retinal vessels and some choroidal vessels over the sclera with pigment clusters; scleral ectasia is seen under the retina. The child has no nystagmus, no other ocular or systemic lesions. The skull X-ray is normal.
Suspecting intrauterine ocular infection, serology for TORCH (Toxoplasma, Rubella, Cytomegalovirus and Herpes), syphilis and lymphocytic choriomeningitis virus is requested for the child and the mother. Both are negative for toxoplasma (both IgG 0.14 IU/ml, by enzyme immunoassay, EIA). Cytomegalovirus, child negative, mother positive with low titres (Ig G 2.1 Index, by EIA). Herpes type I, child negative, mother positive with low titres (IgG 2 Index, by EIA). Herpes type II, child negative, mother positive with low titres (IgG 2.39 Index, by EIA). Varicella-zoster virus, child negative, mother positive with high titres (IgG 2.68 Index and IgM negative, by EIA). Syphilis, mother and child RPR negative. Rubella, both positive as vaccinated (boy IgG 59.3 IU/ml, mother IgG 113.7 IU/ml, by EIA). Lymphocytic choriomeningitis virus, both positive, but with low titres that are not significant (IgG 1/32, by indirect immunofluorescence).
This rules out an infectious aetiology, as the child's antibodies are not elevated, and suggests that it is a bilateral atypical macular coloboma. As there are hereditary cases (1), the fundus examination of the child's parents and siblings was performed, and all were normal. It can also be associated with hypercalciuria and hypomagnesaemia (2), but in this case the calcium/creatinine index and magnesaemia are within normal limits.
Subsequently we have followed the evolution until the age of three years, the VA in the OD is light perception and projection, and in the OI it is 0.2. In the visual evoked potentials, by stimulation with luminous glasses and checkerboard, there is a clear asymmetry, with a detriment in OD.
Penalisation with patching was not considered due to the large size of the coloboma in the OD. It would be interesting to carry out an ocular ultrasound scan, but it was decided to wait until the patient was older and cooperated in carrying it out.