Ethambutol Optic Neuropathy: Vigilance and Screening, the Keys to Prevent Blindness with the Revised Anti-tuberculous Therapy Regimen.

There has been change in the guidelines for the management of tuberculosis in India. The new guidelines advocate the daily use of Ethambutol for both intensive and continuation phase of the treatment. This may be a matter of concern as increased cumulative dose may lead to increase in incidence of toxic optic neuropathy due to ethambutol. Indian Neuro-Ophthalmology Society has taken cognizance of the issue and has come-up with guidelines for prevention and early detection of the toxic optic neuropathy.

Spectacle Coverage among Urban Schoolchildren with Refractive Error Provided Subsidized Spectacles in North India.

SIGNIFICANCE: Provision of subsidized spectacles to schoolchildren with refractive error in Delhi was associated with increased spectacle coverage. PURPOSE: Studies involving free spectacle distribution and self-purchase of spectacles often report poor compliance. We assessed 1-year spectacle coverage among schoolchildren with refractive error who were provided subsidized spectacles. METHODS: This was a study of a prospective cohort of 10,114 students from 20 randomly selected schools of Delhi. Children were presumed to have refractive error when unaided visual acuity was worse than or equal to 6/12 in either eye and a best-corrected visual acuity better than or equal to 6/9.5 in both eyes (n = 1503). Children with unmet need of spectacles (presenting with a visual acuity worse than 6/9.5 in the worse eye) were provided subsidized spectacles (n = 1191). Coverage was established by direct observation at baseline and after 1 year through unannounced visits. RESULTS: Mean age of cohort was 12.0 ± 2.0 years, and 566 (37.7%) were girls. Baseline spectacle coverage was 29.3% (95% confidence interval [CI], 27.1 to 31.7%), which improved to 65.9% (95% CI, 56.0 to 61.6%) among all children (n = 1470) and 58.8% (95% CI, 56.0 to 61.6%) among children with unmet need (n = 1163) at 1 year. Uptake of the subsidized spectacles was 98.6%. On multivariate regression, the odds of spectacle use were greatest when unaided vision was poor: 55.5% when visual acuity was better than or equal to 6/9.5, 74.8% when visual acuity was 6/19 to 6/60 (adjusted odds ratio, 2.5; 95% CI, 1.7 to 3.5), and 91.5% when visual acuity was worse than 6/60 (adjusted odds ratio, 3.1; 95% CI, 1.0 to 9.5). Sex (boys, 66.3%; girls, 65.3%) and socioeconomic status (lower, 58.6%; middle, 61.8%; upper middle, 70.7%) were not associated with coverage. Increasing maternal education and baseline spectacle use were associated with coverage. However, 38.0% were wearing spectacles prescribed by the project, and 61.9% of the spectacles being used at 1 year were purchased in the open market. CONCLUSIONS: Spectacle coverage after 1 year increased through a subsidized spectacle scheme, particularly for children with poor uncorrected vision.

Steroids versus No Steroids in Nonarteritic Anterior Ischemic Optic Neuropathy: A Randomized Controlled Trial.

PURPOSE: To examine the role of oral steroid therapy in the treatment of nondiabetic cases of acute nonarteritic anterior ischemic optic neuropathy (NAAION). DESIGN: Randomized double-blind clinical trial. PARTICIPANTS: Thirty-eight patients with acute nondiabetic NAAION divided into 2 arms of 19 patients each. One arm constituted the cases and the other constituted the controls. METHODS: Cases received oral steroid therapy and were designated the steroid group, whereas controls received placebo and were designated the nonsteroid group. Best-corrected visual acuity (BCVA), visual evoked response (VER), and OCT were performed at baseline, 1 month, 3 months, and 6 months after recruitment into the trial. MAIN OUTCOME MEASURES: Best-corrected visual acuity, VER, and retinal nerve fiber layer changes on OCT. RESULTS: Both groups showed significant improvement in BCVA, VER latency, and resolution of disc edema on OCT parameters over 6 months. Final outcome showed no statistically significant difference with regard to visual acuity, although VER was better in the steroid group (P = 0.011). Best-corrected visual acuity, VER amplitude, and VER latency (P = 0.02, P = 0.02, and P = 0.04, respectively) showed a greater percentage improvement in the steroid group, which also saw a faster resolution of disc edema on OCT (1-month follow-up). CONCLUSIONS: Oral steroids in acute NAAION did not improve the visual acuity significantly at 6 months. However, they improved resolution of disc edema significantly and enabled a greater improvement in VER parameters. This subtle benefit of oral steroids in NAAION is clinically unimportant and does not provide support for its use.

Evaluation of the Protective Effect of NMDA/Non-NMDA Receptor Antagonists Against Ethambutol Induced Retinal Toxicity Using ERG in Wistar Rats.

To study the protective effect of NMDA and non-NMDA receptor antagonists against ethambutol (EMB) induced retinal toxicity in Wistar rats using flash electroretinogram (ERG). Rats were randomized into four groups: Group-1 received vehicle. Group-2 received oral EMB (200 mg/kg/day). Group-3 and 4 were fed with oral EMB along with memantine (MEM) (1 mg/kg, ip) and trimetazidine (TMZ) (3mg/kg, ip) respectively. All treatments were continued up to 28 days. ERG was recorded at 0 and 21st day using green and white lights. Ethambutol and 2, 2' ethylene diimino dibutyric acid (EDBA) levels were quantified in rat body fluids and tissues using LC-MS/MS. A higher rate of rat mortality was observed between 21st and 28th day, 21st day considered for ERG recording among groups. Ethambutol did not cause any significant change in 'a'-wave amplitude of rat ERG but caused a predictable decrease in 'b'-wave amplitude of the rat ERG on the 21st day. Memantine treatment showed a significant (P=0.029) protection against the fall of 'b'-wave amplitude on 21st day. Interestingly, we found that plasma levels of EMB in memantine treated rats were significantly reduced when compared to the positive control group. Memantine reversed the effects of EMB on 'b'-wave of rat ERG suggests its protective role. We suggest MEM may be considered as a possible preventive treatment modality for EMB induced vision toxicity warranting further clinical investigations.

Fabrication and Validation of Gyro-Dot-Optomotor Response Device using Gold Fish to Study Drugs Affecting Visual Perception.

An appropriate model to predict the effect of xenobiotics on the vision perception in neuropsychoharmacological studies is of great importance in drug development and toxicity studies. The present study valuated the effect of CNS stimulant, depressant and therapeutic agents known to have ocular toxicity on ptomotor response (OMR) using goldfish in a newly developed device. A digital light processing aided gyrating poly-chromatic dotted pattern-OMR (Gyro-dot-OMR) analyzer was developed and standardized for this study in our laboratory. Goldfishes were exposed to varying concentrations of caffeine and pentobarbitone sodium to evaluate the effect of CNS stimulation and depression on OMR in white light. Ethambutol induced ocular toxicity was evaluated by intravitreal injection into both eyes of goldfishes. They were subjected for polychromatic Gyro-dot-OMR in both clock and anticlockwise directions. At the low concentration (5, 10 and 20 ng/mL) caffeine exposed animals showed significant (p<0.05) stimulant effect and the EC(50) of caffeine in goldfish was found to be 4.806 ng/mL. In contrast, pentbbarbitone sodium treated fishes showed significant (p<0.05) depressant effect with increasing the concentration. Ethambutol toxicity was reflected by the color iscrimination in the Gyro-dot-OMR pattern. For the first time, this model proved the possibility of running Irwin profile test on goldfish using Gyro-dot-OMR. This model successfully predicted ethambutol induced toxicity with poor discrimination of red-green color. This model can be used for predicting toxicity of drugs affecting vision perception.

Correlation Between Structural and Functional Retinal Changes in Parkinson Disease.

BACKGROUND: To evaluate structural changes in the retina and correlate those with visual function measurements in patients with Parkinson disease (PD). METHODS: A cross-sectional comparative study of 20 patients with PD and 20 age-matched healthy controls was conducted. Visual acuity, color vision, contrast sensitivity, visual fields, pattern visual-evoked response (VER), and multifocal electroretinogram were recorded to determine functional change, whereas structural changes were evaluated with retinal nerve fiber layer (RNFL) thickness, macular thickness, macular volume, and ganglion cell-inner plexiform layer complex (GCL-IPL) thickness using spectral domain ocular coherence tomography (SD-OCT). RESULTS: PD patients ranged from Stage 1-3, with median Stage 2 (Hoehn and Yahr Classification) with mean Unified Parkinson Disease Rating Scale III score of 19 ± 10.42, and average disease duration of 5.8 ± 2.78 years. Visual acuity, color vision, and visual fields were unaffected but contrast sensitivity was significantly worse than controls (P < 0.001). Multifocal electroretinogram values in the central 2° field revealed decreased foveal electrical activity, with increased pattern VER amplitude and latency. Significant RNFL thinning was observed in the average RNFL (P = 0.033), superior (P = 0.018), and temporal (P = 0.036) quadrants. Significant ganglion cell layer loss was captured on SD-OCT with average, minimum GCL-IPL, and all 6 sectors showing thinning (P ≤ 0.003). The functional changes correlated significantly with structural changes, disease duration, and severity. There was no correlation between structural changes in the retina and disease duration or severity. CONCLUSIONS: Subclinical visual dysfunction was observed in patients with PD with good structural-functional correlation. GCL-IPL thinning may be a more reliable parameter than RNFL thickness for structural alterations of the retina in patients with PD.

Ethambutol toxicity: Expert panel consensus for the primary prevention, diagnosis and management of ethambutol-induced optic neuropathy.

Ethambutol use may lead to permanent vision loss by inducing a dose- and duration-dependent optic neuropathy. This has been of concern to ophthalmologists and physicians both; however, ethambutol continues to be used because of its anti-mycobacterial action with relative systemic safety. Recently, the guidelines of the Revised National Tuberculosis Control Programme of India have been revised to allow for fixed dose and longer duration of ethambutol use; this is likely to result in an increase in vision-threatening adverse effects. Taking cognizance of this, neuro-ophthalmologists, infectious disease specialists, and scientists met under the aegis of the Indian Neuro-Ophthalmology Society to deliberate on prevention, early diagnosis, and management of ethambutol-related toxic optic neuropathy. The recommendations made by the expert group focus on early suspicion of ethambutol toxicity through screening at the physician's office and opportunistic screening by the ophthalmologist. Further, they focus on an early diagnosis through identification of specific clinical biomarkers and on management in way of early stoppage of the drug and supportive therapy. This statement also describes the mechanism of reporting a case of toxic optic neuropathy through the Pharmacovigilance Programme of India and emphasizes the need for spreading awareness regarding vision-threatening adverse effects among patients and healthcare workers.

Comparative study of unilateral and bilateral surgery in moderate exotropia.

PURPOSE: To evaluate the surgical outcome of unilateral versus bilateral rectus recession for the correction of moderate exotropia. METHODS: This was a prospective study of 20 consecutive cases of intermittent exotropia ranging from 15 to 25 prism diopters (PD) randomized into two groups and operated on by a single surgeon. In the unilateral group, a recession of 7.0 to 7.5 and 8.0 to 8.5 was done for 15 to 20 PD and 21 to 25 PD of exotropia, respectively. In the bilateral group, a recession of 5.0 to 5.5 and 6.0 to 6.5 mm was done for 15 to 20 PD and 21 to 25 PD of exotropia, respectively. Surgical results of both groups were compared 3 months postoperatively. RESULTS: The mean age of patients was 8.5 years in the unilateral group and 11 years in the bilateral group. The mean preoperative exotropia was 21.0 ± 3.77 PD in the unilateral group and 22.9 ± 3.03 PD in the bilateral group. The mean postoperative deviation at 3 months was 5.5 ± 4.03 PD in the unilateral group and 2.8 ± 3.91 PD in the bilateral group. Consecutive persistent small-angle esotropia was seen in one patient in the bilateral group. There was no significant incomitance at 3 months in either group. CONCLUSION: Unilateral and bilateral rectus recession are equally effective in mild to moderate exotropia.

Evaluation of distance and near stereoacuity and fusional vergence in intermittent exotropia.

AIM: To evaluate the role of distance and near stereoacuity and fusional vergence in patients with intermittent exotropia [X(T)] and their change after surgery. MATERIALS AND METHODS: This prospective interventional institution-based clinical study included 31 cases of X(T) requiring surgery and 33 age, sex-matched controls. All subjects underwent complete orthoptic assessment including near stereopsis (Randot stereogram) and distance stereopsis by polaroid stereo-projector apparatus using special paired slides and fusional vergence assessment at distance and near prism bar at baseline and one week, one month, three months and six months after surgery in X(T). RESULTS: The successful surgical alignment rate was 74.2%. Preoperatively, cases demonstrated significantly poor distance and near stereoacuity, compared to controls ( P < 0.001). Mean distance stereoacuity (sec of arc) in normals, (X)T preoperatively and postoperatively was 344.8 +/- 139.5, 1149.2 +/- 789.4 and 450.1 +/- 259 while mean near stereoacuity was 34.7 +/- 9.5, 68.7 +/- 31.1 and 47.4 +/- 22.6 respectively. Postoperatively at six months, significant improvement in stereoacuity was observed both at near and distance ( P < 0.05). Mean distance fusional convergence (in prism diopter) in normals, X(T) preoperatively and postoperatively was 20.7 +/- 4.7, 18.0 +/- 3.3 and 21.4 +/- 3.6 respectively, mean near fusional convergence was 27.8 +/- 6.3, 24.1 +/- 5.5 and 29.1 +/- 5.5 respectively. There was good correlation between fusional vergence amplitudes for distance and near indicating any one would suffice. CONCLUSION: Early detection of abnormal stereoacuity (near and if possible distance) and near fusional vergence amplitudes may help to decide proper timing of surgery in X(T).

Retinal nerve fiber layer and ganglion cell layer changes on optical coherence tomography in early multiple sclerosis and optic neuritis cases.

PURPOSE: To study the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) changes on optical coherence tomography in early multiple sclerosis (MS) patients. METHODS: A prospective cohort study was conducted at a tertiary care center. Patients of early MS (expanded disability status scale <3) with or without optic neuritis (ON) and idiopathic ON were included. Twenty age-matched individuals were taken as controls. Changes in RNFL and GCL thickness were evaluated along with the correlation with visual function parameters such as visual acuity, contrast sensitivity, and visual evoked response at first visit and again at six months. RESULTS: Forty-four patients of MS with or without ON (24 and 20 patients respectively), 29 patients with idiopathic ON, and 20 healthy controls constituted the cohorts. Mean LogMAR best-corrected visual acuity was found to be significantly reduced in all groups except fellow eyes (FE) of ON group. Mean values of average RNFL thickness and values in superior, temporal, and inferior quadrant were significantly reduced. Similarly, overall mean values of average GCL-inner plexiform layer (IPL) thickness and values in superior, superonasal, superotemporal, inferonasal, and inferotemporal quadrant were significantly reduced in all groups except FE of ON group (P < 0.05). All the visual parameters significantly correlated with GCL + IPL thickness. CONCLUSION: GCL + IPL thickness is a more sensitive clinical structural marker than RNFL in early MS with/without ON and ON patients and correlates with all the visual parameters better than RNFL thickness.

Trypan blue-assisted posterior tenectomy of the superior oblique.

Posterior tenectomy of the superior oblique tendon can be difficult, particularly for inexperienced surgeons, due to problems in visualization and anatomic peculiarities. Trypan blue can be used to stain the superior oblique tendon for easy identification and delineation of it at its insertion, making the current surgical technique less difficult.

Visual outcome after intravenous dexamethasone therapy for idiopathic optic neuritis in an Indian population: a clinical case series.

PURPOSE: To evaluate the clinical profile, response to dexamethasone treatment and visual function outcome in Indian patients with acute optic neuritis. MATERIALS AND METHODS: We conducted an observational study of patients with acute optic neuritis who were treated with intravenous dexamethasone (100 mg in 250 ml of 5% dextrose over 1-2 hours daily, for three consecutive days) and had completed at least two years of follow-up. Parameters assessed included visual acuity, contrast sensitivity, color vision, visual fields, relative afferent pupillary defect (RAPD) and visually evoked potentials. Out of 40 patients studied, 26 patients (33 eyes) had all visual function parameters assessed. Twenty three patients (28 eyes) had completed two years of follow-up and were included for statistical analysis. RESULTS: Improvement in visual acuity was statistically significant for distance after 24 hours of the first dose (P = < 0.001) and for near vision after 24 hours of the second dose (P = 0.006); improvement in color and contrast sensitivity was statistically significant 24 hours after the third dose (P = < 0.001 for color vision and P = 0.013 for contrast sensitivity). Significant improvement in RAPD and visual fields were seen by 1 month (P = 0.005). Recurrence was seen in 4 eyes of 4 patients. No serious side effects were observed. At two years, 82.14% (23 out of 28) eyes had visual acuity > 20/40. CONCLUSION: Treatment with intravenous pulsed dexamethasone led to rapid recovery of vision in acute optic neuritis, without any serious side effects.

Factors influencing visual rehabilitation after occlusion therapy in unilateral amblyopia in children.

BACKGROUND & OBJECTIVE: Amblyopia is one of the most common causes of visual impairment in adults and children, and visual loss may be permanent if not treated in time. Though many studies have been done on occlusion therapy which is the mainstay in the treatment of unilateral amblyopia, discrepancies exist in literature about quantification of treatment and follow up measures. The present study was undertaken to evaluate the factors responsible for the successful outcome of treatment and the optimum time required for the same in children with unilateral amblyopia. METHODS: Baseline characteristics of 63 verbal patients with unilateral amblyopia (strabismic, anisometropic, mixed) referred to the Strabismus and Amblyopia Clinic at the Dr Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi between September 2001 to December 2002 who improved to the desired level of visual acuity after treatment for amblyopia in the mentioned time period, were analyzed to assess for factors that directly or indirectly influenced the optimum visual rehabilitation and the average duration of therapy required for the same. The evaluation included assessment of the baseline best-corrected visual acuity (BCVA) and refractive status in both eyes, the age at presentation, the type of amblyopia present, fixation pattern in the amblyopic eye, inter-eye visual acuity difference, and evaluation of compliance through a parental diary system. RESULTS: Baseline BCVA in the amblyopic eye was similar in all the three groups. Patients with anisometropic amblyopia showed a quicker response to therapy. Compliance to treatment was the major factor affecting the overall time required for a successful outcome in most cases. The overall time required for the treatment to be successful (including the period of maintenance) was about 1,089 h. INTERPRETATION & CONCLUSION: This hospital-based study showed that the average duration of occlusion therapy to achieve stable isoacuity was 7.2 months with an average occlusion of 6-7 h/day. Compliance to therapy was the most important factor affecting the duration of therapy. With increasing emphasis on paediatric eye diseases, amblyopia is at last getting its due importance as a cause of treatable correctable paediatric visual impairment which can have lifelong repercussions, both in terms of individual disability and financial burden to the society if not treated in time. As the therapy is simple and effective if started early, mass awareness, visual screening, and counselling would go a long way in treating the patients, thus decreasing the prevalence of amblyopia in the country.

Bilateral neuro-retinitis following chick embryo cell anti-rabies vaccination--a case report.

BACKGROUND: The Optic nerve is rarely involved after sheep brain anti-rabies vaccination in the form of retrobulbar neuritis or papillitis. Bilateral neuroretinitis after chick embryo cell antirabies vaccination has not been reported. CASE PRESENTATION: We report the case of a 56 year old male who developed bilateral neuro-retinitis following three injections of antirabies vaccine prepared from the chick embryo. CONCLUSION: The chick embryo cell antirabies vaccine can cause bilateral neuroretinits which has not been reported previously.

Profile of amblyopia in a hospital referral practice.

OBJECTIVE: Evaluation of the clinical profile and distribution of different sub-types of amblyopia in a referral eye hospital in India. METHODS: This was a prospective hospital-based observational study, evaluating the clinical profile of patients with amblyopia presenting to a referral strabismology practice. The examination included assessment of the visual acuity, the refractive status, the fixation pattern, the grade of binocularity, and evaluation of the associated strabismus, if any before treatment was started. RESULTS: The average age of the patients at presentation was 7.97?6.18 years with 81 out of 683 patients (11.8%) presenting above the age of 20 years. The best-corrected visual acuity (BCVA) was less than 6/60 in the amblyopic eye in 121 out of 733 eyes (16.5%). Strabismic amblyopia was the most common sub-type of amblyopia seen (274/733 eyes, 37.38%). Though patients with anisometropic amblyopia presented at a later age (average of 10.03+/-6.92 years), they had better visual acuity, binocular functions, and centricity of fixation at all ages, relative to other sub-types of amblyopia. The BCVA did not show any co-relation with the age of presentation [co-relation co-efficient (CF) of 0.074], refractive status of the amblyopic eye (CF of 0.078), the type of amblyopia (CF of 0.196), or the type of strabismus present (CF of 0.079). However, a very significant co-relation was seen between the BCVA and the fixation pattern of the amblyopic eye (CF of 0.817). CONCLUSIONS: Lack of knowledge and awareness about amblyopia and its appropriate timely management has been the main cause for the late presentations and significant visual impairment associated with the condition.

Ocular and cardiovascular autonomic function in diabetic patients with varying severity of retinopathy.

The study was conducted to assess the ocular and cardiovascular autonomic function in diabetic patients with varying severity of diabetic retinopathy. Ocular and cardiovascular autonomic function tests were performed in 30 patients with type 2 Diabetes Mellitus (10 in each group of proliferative retinopathy, non-proliferative retinopathy and no retinopathy) of more than 5 years duration and 10 normal controls. Ocular autonomic function tests were done by measuring pupil cycle time and denervation hypersensitivity with 0.125% pilocarpine and 0.5% phenylephrine. Cardiovascular autonomic function was measured by a battery of standard tests. Denervation hypersensitivity to 0.125% pilocarpine and to 0.5% phenylephrine and pupil cycle time showed statistically significant differences (P value < 0.001) between controls and patients with proliferative retinopathy (PDR) and also between no retinopathy and PDR (P < 0.001). Systemic autonomic function tests namely expiration--inspiration ratio, difference in heart rate, 30th beat and 15th beat ratio in head up tilt and difference in diastolic blood pressure in head up tilt test also showed significant difference (P < 0.01) between controls and all 3 groups of diabetics. There was statistically significant difference found in para-sympathetic ocular autonomic dysfunction between NPDR and controls. Ocular and systemic autonomic dysfunctions are related to the severity of diabetic retinopathy.

Study of the psychosocial aspects of strabismus.

PURPOSE: To systematically evaluate the perception of psychosocial difficulties due to strabismus and the impact of corrective surgery in adolescents and young adults in India. METHODS: Patients 15 to 25 years of age with childhood onset (< or = 5 years of age) of constant concomitant squint (> or = 30 prism diopters of deviation for distance) were included in the study. After a detailed orthoptic evaluation, demographic data of the patients and their parents were recorded. Postgraduate Institute Health Questionnaire N-2 (standardized in India) was administered to rule out neuroticism in the patients. Psychosocial problems faced by the patients were evaluated with a semistructured interview schedule. Patients were evaluated 3 months after surgery using a similar interview schedule to assess the psychological impact of surgery. RESULTS: Eighty percent of both male and female patients had problems in their social life; 85% of the males and 75% of the females had personal problems due to squint. After surgery, a positive change in appearance was noticed by 97.5% and 95% noticed a change in self-esteem and self-confidence. CONCLUSION: These patients had difficulties with self-image and interpersonal relationships, faced ridicule at school and work, and generally avoided activities that brought attention to their defect. Substantial changes were noticed in them after corrective surgery, and the differences in their scores before and after surgery were statistically significant.

Isolated "one and a half syndrome" with brainstem tuberculoma.

A seldom reported causal association of two rare entities, an isolated brainstem tuberculoma and an isolated One and a half syndrome in a 12 year old girl is presented. MRI showed an isolated inflammatory granuloma in the brainstem which on empirical treatment with anti tubercular drugs resulted in complete restoration of ocular motility, along with resolution of the lesion on follow up MRI at 6 months. The diagnosis and management are discussed.

Controversies in neuro-ophthalmology: steroid therapy for traumatic optic neuropathy.

BACKGROUND: There is an increase in the incidence of traumatic optic neuropathy (TON) due to increasing urbanization and rapid spurt in the number of motor vehicles on the road. Despite early presentation and ease of diagnosis the visual outcomes in TON are still limited. There is also significant confusion about the timing, dose and efficacy of steroid treatment in its management. PURPOSE: To provide a clinical update of the pros and cons of steroid therapy for TON. DESIGN: The paper is a retrospective review of the currently available literature in the English language indexed in PubMed. METHODS: A PubMed search was conducted by the authors using the following terms: Traumatic optic neuropathy, megadose, steroids, methylprednisolone. Relevant original articles, review articles, and case reports related to the topic of discussion were evaluated and discussed in the paper. RESULTS: There is no prospective randomized control trial evaluating the effect of steroids in TON. There are varying reports on the effect of steroid therapy from significant improvement to no difference compared to observation. CONCLUSION: The decision to give steroids to patients with TON has to be on an individual case to case basis and must involve informed consent from the patient. There are documented advantages and disadvantages of steroid therapy and a prospective, randomized, controlled trial is necessary comparing steroids, surgery and observation before definitive management can be evolved.