[Severe and reversible optic neuropathy by ethambutol and isoniazid]

Ethambutol and isoniazid are antimicrobial agents used to treat multi-drug-resistant tuberculosis. The most commonly recognized toxic effect of these drugs is optic neuropathy, usually manifesting as a decrease in visual acuity, deficits in colour vision and cecocentral scotomas. This study presents the case of a 59-year-old Nigerian woman diagnosed of multi-drug-resistant tuberculosis who developed a severe bilateral optic neuropathy induced by ethambutol and isoniazid. Ophthalmologic examination revealed normal intraocular pressure, normal funduscopic examination and normal biomicroscopy. Automated visual field revealed 360º peripheral constriction and central scotoma. Magnetic resonance images of the brain and orbits were normal. Ten months after suspending treatment, the patient recovered complete visual function. Visual loss is a rare complication that can be related to ethambutol and isoniazid toxicity. Both eyes are usually symmetrically affected with deficits in colour vision and cecocentral scotoma. For successful treatment of visual loss, it is important to make a differential diagnosis between infection and adverse effects of anti-TB drugs. Ophthalmological examination is thus important before and after treatment.

[Whole body PET/CT imaging for detection of metastatic choroidal melanoma]

Choroidal melanoma is the most common primary intraocular cancer in adults. Metastases are most commonly found in the liver and are rapidly fatal despite aggressive therapy. These metastases have been reported in the follow-up to 50 % of uveal melanoma. However, recent reports have shown that liver ultrasonography and liver function tests have low sensitivity in the diagnosis of metastatic uveal melanoma. The study reports on a patient with a history of choroidal melanoma. Preoperative medical evaluation, including CT imaging of the abdomen, complete blood count and liver enzymes proved negative. A PET/CT was requested and showed lesions in the liver and lungs. Whole-body PET/CT revealed melanoma metastases. The PET/CT is a sensitive tool for the detection and localization of hepatic and extrahepatic metastatic choroidal melanoma.

[Optical coherence tomography and macular phototoxicity]

CASE REPORT

Ocular examinations and optical coherence tomography (OCT) were performed in three patients with retinal phototoxicity lesions. Fluorescein angiography depicted a window defect. OCT exhibited hyporeflectivity at the outer foveal retina and fragmentation of the inner reflective layers, corresponding to the junction between the inner and outer photoreceptor segments.

DISCUSSION

Retinal damage after light exposure has a rapid onset and shows different patterns in OCT examination. OCT findings suggest that decreased visual acuity may be associated with full-thickness photoreceptors and retinal pigment epithelium (RPE) involvement. OCT is a useful tool for objective assessment of retinal pathology in phototoxicity cases where fundus changes may be minimal or absent.

[Proptosis as the first sign of recurrent scirrhous breast carcinoma]

OBJECTIVE

To inform clinicians of a metastatic orbital neoplasm that frequently masquerades as an orbital inflammatory syndrome.

CASE REPORT

The case of a 61-year-old woman, diagnosed and treated seven years ago for a scirrhous breast carcinoma is presented. She complained of blurred vision and proptosis of the left eye and these symptoms were the first manifestation of tumor relapse.

DISCUSSION

When orbital inflammation is detected in an adult female patient, a full medical history must be obtained and physical examination performed, as orbital metastases have been reported to be the initial manifestation of malignancy in 30 to 50% of cases.

[Primary orbital mucocele: exophthalmos and optic atrophy]

OBJECTIVE

Primary intraorbital mucoceles arising from the optic canal are extremely rare. We describe a patient with compressive optic neuropathy caused by an intraorbital mucocele.

CLINICAL CASE

A 51-year-old woman presented with proptosis and reduced vision. Magnetic resonance imaging showed a mass compressing the optic nerve. There was no direct connection between any paranasal sinus and the mass cavity, as assessed in imaging studies and intraoperatively confirmed. The pathological diagnosis after the operation indicated a mucocele.

DISCUSSION

Considering the absence of air pockets in the orbit, the mucocele might have originated from ectopic mucinous tissue that appeared during the development of the optic canal.