Microperimetry as a diagnostic tool for the detection of early, subclinical retinal damage and visual impairment in multiple sclerosis.

BACKGROUND: A majority of multiple sclerosis patients experience visual impairment, often as the initial presenting symptom of the disease. While structural changes in the retinal nerve fiber layer and optic nerve have demonstrated correlations with brain atrophy in multiple sclerosis using magnetic resonance imaging, a non-invasive, cost-effective, and clinically efficacious modality to identify early damage and facilitate prompt therapeutic intervention to slow the progression of multiple sclerosis and its ocular manifestations, is still urgently needed. In this study, we sought to determine the role of macular sensitivity measured by microperimetry in the detection of subclinical multiple sclerosis-related retinal damage and visual dysfunction. METHODS: This cross-sectional observational case-control study involved population-based samples of multiple sclerosis patients and age-, race-, and gender-matched healthy control subjects. Among the key criteria for the multiple sclerosis patients were diagnosis by the McDonald criteria, visual acuity greater than 20/25, and no history of optic neuritis. Macular sensitivity and average macular thickness were measured in all subjects using microperimetry and spectral-domain optical coherence tomography, respectively. Pearson correlation coefficients were measured using bivariate correlations. Sample means, mean differences, and 95% confidence intervals were calculated using independent sample t-tests. RESULTS: Twenty-eight eyes from 14 MS patients and 18 eyes from 9 control subjects were included. Mean macular sensitivity of control subjects and multiple sclerosis patients in decibels was 18.2 ± 0.4 and 16.5 ± 0.4, respectively, corresponding to a mean difference of 1.7 (95% CI, 1.1-2.4; P < 0.001). Macular sensitivity was positively correlated with macular thickness in multiple sclerosis patients (r = 0.49, P = 0.01) but not control subjects (r = 0.15, P = 0.55). CONCLUSIONS: Macular sensitivity as measured by microperimetry was decreased in multiple sclerosis patients with normal visual acuity and no history of optic neuritis. Furthermore, macular sensitivity demonstrated a positive correlation with macular thickness as measured by optical coherence tomography. As such, microperimetry may represent a non-invasive and efficient method to identify signs of subclinical visual dysfunction that correspond with early macular architectural changes characteristic of multiple sclerosis.

A rare case of odontogenic parainfectious intraorbital optic neuritis with the absence of clinical manifestation of orbital cellulitis.

PURPOSE: To report the case of a 67-year-old male patient with odontogenic maxillary sinusitis who presented with unilateral parainfectious intraorbital optic neuritis without clinical signs and symptoms suggestive of orbital cellulitis. Despite the absence of clinical signs, taking a thorough history and obtaining the appropriate neuroimaging study raised the suspicion for an infectious etiology as the cause of optic neuropathy and stopped the continuation of corticosteroid treatment. METHODS: Retrospective case report. RESULTS: The only abnormal findings in the ophthalmic examination were acute decrease visual acuity, inferior visual field loss, and the presence of a relative afferent pupillary defect. A gadolinium contrast-enhanced magnetic resonance imaging scan showed ill-defined diffuse enhancement of the left intraorbital optic nerve and sheath with mild perineural fat stranding and enlargement of the inferior rectus muscle. There was also complete opacification of the ipsilateral maxillary sinus with peripheral enhancement, suggestive of a sinus abscess. CONCLUSION: Prompt arrival to the diagnosis led to expedient implementation of treatment comprising of broad-spectrum intravenous antibiotics and maxillary sinus irrigation by otolaryngology ultimately resulted in restoring the patient's vision back to baseline with complete resolution of the relative afferent pupillary defect.