Visual outcomes of toxic optic neuropathy secondary to Ethambutol: A retrospective observational study from India, an endemic country

Purpose: Ethambutol (EMB) is one of the first?line drugs used for treating tuberculosis. Vision loss due to optic nerve toxicity is a well?known potential side effect of the drug. Our aim was to evaluate the clinical features and visual outcomes of patients with EMB optic neuropathy (EON). Methods: A retrospective, observational, single?center study of all patients who were diagnosed to have EON during January 2017–December 2019 was done. All these patients were screened in the Department of Neuro?ophthalmology at a referral tertiary eye care institution in India. Clinical features, visual outcomes, and neuroimaging findings of these patients were analyzed. Results: Two hundred and fifty?six eyes of 128 patients were included. Of these, 73 were male and 55 were female. Mean age was 50.55 ± 15 years. Mean visual acuity at presentation was 1.12 ± 0.45 logarithm of the minimum angle of resolution (logMAR). One hundred and forty three eyes had normal optic disk on presentation, 111 had disk pallor, and two eyes had disk edema. The most common field defect was central/paracentral scotoma (26.2%) followed by temporal defects (24.6%). Magnetic resonance imaging (MRI) brain and orbit showed optic nerve signals in 19.6% and chiasmal signals in 5.2%. At the final follow?up, a ?2?line vision improvement was noted in 161 eyes (62.9%), which was statistically significant. Conclusion: Multiple prognostic factors were analyzed to predict the visual recovery of EON. We observed that patients presenting with visual acuity worse than 6/60 had poor visual outcome and long duration of follow?up showed better visual recovery, proving the possibility of a gradual recovery pattern of EON. Interestingly, we found in our study that the chances of favorable visual outcome were directly proportionate to early diagnosis and cessation of EMB.

Ocular features of patients with Parkinson’s disease examined at a Neuro-Optometry Clinic in a tertiary eye care center

Purpose: To report the ocular features of patients with PD who presented with visual complaints to a tertiary eye care center. Methods: This was a retrospective study carried out between January 2015 and March 2020 at the Neuro?Optometry clinic of a tertiary eye care center in Southern India. All PD patients with ocular complaints examined by the neuro? ophthalmologists were referred to Neuro? Optometry Clinic for detailed evaluation. Patients with other neurodegenerative disorders, brain injury, and other causes of vision loss or extraocular motility disorders were excluded. Results: A total of 43 patients (7 females, 36 males) between 50 and 86 years of age (mean: 70 ± 8.9 years) with a mean duration of PD of 4.5 ± 4.5 years were studied. Decreased vision associated with reading difficulty (40%) was common in PD patients. In terms of gaze restriction, vertical gaze involvement (35%) was more than horizontal involvement (7%). Convergence insufficiency (CI) was the most common binocular vision dysfunction (30%), followed by CI with oculomotor dysfunction (14%) and vertical gaze palsy (18%). Ground prisms were recommended for 26 patients (61%) and home vision therapy for 5 patients (12%) as corrective measures. Conclusion: Binocular vision dysfunction is highly prevalent among PD patients. This could potentially contribute to the reading difficulties and double vision encountered by these patients. Assessment of binocular vision and oculomotor parameters thus becomes important to understand and manage the reading difficulties in patients with PD

Clinical profile, imaging features and short term visual outcomes of Indian optic neuritis patients with and without seromarkers for myelin oligodendrocyte glycoprotein and neuromyelitis optica

Purpose: To analyze clinical profile, imaging features, and short?term visual outcomes of optic neuritis patients in Indian population with and without seromarkers for myelin oligodendrocyte glycoprotein (MOG)/neuromyelitis optica (NMO). Methods: Electronic medical records of 203 optic neuritis patients who presented between June 2018 and December 2019 to the Neuro?ophthalmology services of a tertiary care center in India were retrospectively analyzed. Results: Of 203 patients, 57 patients (28.08%) were positive for MOG?antibody and 20 patients (9.85%) were positive for NMO antibody. 114 patients (56.16%) were double?negative (negative for both antibodies) and 12 patients (5.91%) were diagnosed as multiple sclerosis (MS). None of the patients had both antibodies. Mean age of presentation was 31.29 ± 1.035 years. There was female preponderance in NMO?optic neuritis (NMO?ON) and MS?optic neuritis (MS?ON) groups (1:5). Mean vision on presentation was worse (logMAR 1.570 ± 0.863) in NMO?ON group. The mean visual acuity showed statistically significant recovery (logMAR 0.338 ± 0.639) in the final follow?up in MOG?optic neuritis (MOG?ON) group. Multivariate logistic regression analysis revealed poor visual outcome in patients presenting with retrobulbar neuritis, optic disc pallor, bilateral sequential optic nerve involvement, and with positive NMO antibody. Optic neuritis patients presenting with disc edema associated with pain and positive for MOG antibody were found to have a better visual outcome. Conclusion: In this Indian optic neuritis cohort, the prevalence of MOG?ON was higher than NMO?ON. MOG?ON had a better visual outcome than NMO?ON. The incidence of MS?ON was less compared to the western literature. A significant number of patients (114 patients, 56.16%) were double negative for both seromarkers and yet had presented with optic neuritis with no clinical or imaging features suggestive of MS/MOG associated disease (MOG AD)/NMO spectrum disorder (NMO SD).

The diagnostic yield of neuroimaging in sixth nerve palsy - Sankara Nethralaya Abducens Palsy Study (SNAPS): Report 1.

Aims: The aim was to assess the etiology of sixth nerve palsy and on the basis of our data, to formulate a diagnostic algorithm for the management in sixth nerve palsy. Design: Retrospective chart review. Results: Of the 104 neurologically isolated cases, 9 cases were attributable to trauma, and 95 (86.36%) cases were classified as nontraumatic, neurologically isolated cases. Of the 95 nontraumatic, isolated cases of sixth nerve palsy, 52 cases were associated with vasculopathic risk factors, namely diabetes and hypertension and were classified as vasculopathic sixth nerve palsy (54.7%), and those with a history of sixth nerve palsy from birth (6 cases) were classified as congenital sixth nerve palsy (6.3%). Of the rest, neuroimaging alone yielded a cause in 18 of the 37 cases (48.64%). Of the other 19 cases where neuroimaging did not yield a cause, 6 cases were attributed to preceding history of infection (3 upper respiratory tract infection and 3 viral illnesses), 2 cases of sixth nerve palsy were found to be a false localizing sign in idiopathic intracranial hypertension and in 11 cases, the cause was undetermined. In these idiopathic cases of isolated sixth nerve palsy, neuroimaging yielded no positive findings. Conclusions: In the absence of risk factors, a suggestive history, or positive laboratory and clinical findings, neuroimaging can serve as a useful diagnostic tool in identifying the exact cause of sixth nerve palsy. Furthermore, we recommend an algorithm to assess the need for neuroimaging in sixth nerve palsy.