Biomedical subjects
Publications and source records attributed to Rohit Saxena.
Pontine cavernous hemangioma presenting as horizontal gaze palsy is extremely rare. A 32-years-old patient presented with left horizontal gaze palsy with left esotropia. A large pontine mass was present which was removed in-toto using a sub-occipital craniotomy. Post- operatively, the gaze palsy showed recovery and the diplopia decreased. Follow-up MRI showed no residual mass.
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.
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.
OBJECTIVE: To compare latanoprost and timolol maleate as primary therapy in 60 eyes with chronic primary angle-closure glaucoma after a laser iridotomy. METHODS: We performed a prospective, randomized, crossover study of 60 eyes of 30 patients with chronic primary angle-closure glaucoma after laser iridotomy. Patients were randomized to 2 groups: those taking latanoprost once daily or those taking timolol twice daily. Three months after treatment with the first drug, the second drug was substituted. The circadian rhythm of intraocular pressure (IOP) was recorded before the start of therapy, at 3 months, and at 7 months. The fourth month was the washout period for the first drug. RESULTS: The mean baseline IOP was 23.5 +/- 2.1 mm Hg, which decreased by 8.2 +/- 2.0 mm Hg with latanoprost (P<.001) and by 6.1 +/- 1.7 mm Hg with timolol (P =.01). The decrease in IOP was greater for patients taking latanoprost (P<.001). Latanoprost was significantly more effective in eyes having morning and afternoon peaks of IOP. A total of 43 eyes (72%) of patients taking latanoprost and 26 (43%) on timolol achieved a reduction of more than 30% from baseline IOP. CONCLUSION: There were greater mean and peak IOP reductions achieved with 0.005% latanoprost once daily compared with 0.5% timolol twice daily.
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.
A field experiment was conducted to study the effect of different amendments of tannery sludge on physiological and biochemical parameters of tomato plant (Lycopersicon esculentum L. Mill). The accumulation of metals (Cr, Fe) in different parts of tomato plants grown on tannery sludge amended soil increased in a concentration and duration-dependent manner. The accumulation of both the metals was found lowest in the fruits of the plant. The statistical analysis of the results showed an increase in chlorophyll and protein contents in lower sludge amendment ratio at all exposures followed by a decrease at highest (100%) sludge amendment ratio. Lipid peroxidation enhanced in both root and leaves of sludge grown plants of tomato at all the sludge amendments and exposure periods, which is evidenced by increased malondialdehyde content, however the maximum increase was found in the roots (43.63%) and leaves (56.66%) of the plant grown on 100% tannery sludge at 60 d, over respective controls. The level of antioxidants, cysteine, non-protein thiol and ascorbic acid increased in the sludge grown plants of tomato to cope up with stress induced by the excess amount of the heavy metals present in the tannery sludge. The maximum increase was found in cysteine content (75.53% in the leaves), non-protein thiol content (92.68% in the roots) and ascorbic acid content (29.66% in the roots) of the plant at 75% tannery sludge after 30 d. The tomato plants were found well adopted for minimizing damage induced by reactive oxygen species, when grown on tannery sludge amendments in the present study.
The interaction of metals present in tannery waste and their tolerance in the plants of sunflower (Helianthus annuus L.) was studied in the present paper under field conditions. Effects of 100% tannery sludge and various amendments of tannery sludge (10%, 25%, 35%, 50%, 75%) along with one set of control were studied on the physiological and biochemical parameters of the plant along with their metal accumulation potential after 30, 60 and 90d after sowing. The plants of H. annuus were found effective in the accumulation of metals (Cr, Fe, Zn and Mn) in roots, shoots and leaves, however, the level of toxic metal, Cr was found below detection limit in the seeds of the plant. The oil was extracted from the seeds of the plant and the level of oil content was increased up to 35% tannery sludge as compared to control followed by decrease at higher tannery sludge ratio. An increase in the chlorophyll, protein, cysteine, non-protein thiol and sugar contents was observed at the lower amendment of tannery sludge at initial exposure periods followed by decrease than their respective controls. Malondialdehyde content in the roots and leaves was increased beyond 50% sludge amendments at all the exposure periods as compared to control. However, proline and ascorbic acid contents of the roots and leaves of the plant increased at all the exposure periods and sludge amendments, compared to their respective controls.
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OBJECTIVE: Ascertainment of an appropriate strategy of iron chelation for multi-transfused thalassemic children in developing countries. DESIGN: Prospective study from May 2000 to April 2001. SETTING: Urban tertiary care center. METHODS: Thirty thalassemic children having received more than 20 blood transfusions and a serum ferritin greater than 1500 ng/ml were enrolled and randomized into three groups. Group I received desferrioxamine (DFX) at a dose of 40 mg/kg subcutaneously, 5 days/week. Children in group II received oral deferiprone (L1) at a dose of 75 mg/kg/day daily and group III received a combination of daily L1 at a dose of 75 mg/kg/day and DFX at a dose of 40 mg/kg/day two times per week. The assessment of chelation was done by 24-hr urinary iron excretion (UIE) and measurement of serum ferritin levels at start and after 6 months of follow up. Statistical difference of serum ferritin levels between the three groups was assessed by applying analysis of variance. Analysis of covariance was applied to find out the urinary iron excretion keeping serum ferritin values same in each groups. RESULTS: Ferritin levels after 6 months of intervention were maximally decreased in group I. There was a significant difference between groups I and II however, no difference was noted between groups I and group III. There was no statistically significant difference in mean urinary iron excretion by keeping the initial serum ferritin levels equal though it was found to be more in group III as compared to other groups. CONCLUSIONS: DFX is the most effective chelating drug in iron overloaded multi-transfused thalassemic patients. In view of cost and unacceptability of daily DFX injections, combination therapy is an effective method of chelation thus increasing the compliance and cost effectiveness. Deferiprone (L1) alone is not an effective mode of chelation when used for a short period.
We report 4 cases that presented with intractable glaucoma after complicated phacoemulsification during which sodium hyaluronate 1.0% (Healon) was used to tamponade a central posterior capsule rupture. The postoperative intraocular pressure (IOP) was uncontrolled on maximal medical therapy. In 2 patients, the IOP took 8 to 10 weeks to resolve and simultaneous ultrasound B-scans showed the presence of clear globules in the anterior and midvitreous that became smaller with conservative therapy. An early pars plana vitrectomy in 2 cases immediately controlled the IOP. The presence of globules presumed to be sodium hyaluronate in the vitreous cavity of the patients while the IOP was elevated suggests a causal relationship with the refractory secondary glaucoma.
PURPOSE: To study the effect of environmental toxins on the ocular surface in persons travelling through highly polluted areas of the metropolis of Delhi. METHODS: A total of 500 apparently healthy volunteers recruited from the metropolis of Delhi were examined to establish the frequency of ocular surface disorders. All subjects underwent a slit-lamp examination, tear break-up time (BUT) test, Rose Bengal test, Schirmer's test and tear lysozyme level test. RESULTS: Subjects in the study group had significantly higher levels of ophthalmic symptoms compared to the control group. In all, 105 (42%) and 125 (50%) subjects in the study group compared to 50 (20%) and 65 (26%) in the control group complained of redness and irritation (p < 0.05). There was no significant difference in visual acuity (VA) between the two groups, with best corrected VA being 6/9 or better in 92% of the study group and 96% of the control group. The average (+/-standard deviation) Schirmer's test result was 13.42+/-6.67 mm in the study group compared to 15.95+/-6.14 mm in the control group. This difference was statistically significant. The BUT was also significantly lower in the study group (12.97+/-6.12 seconds) compared to the control group (19.23+/-5.70 seconds) (p < 0.001). The Rose Bengal test and tear lysozyme activity did not show any significant difference between the two groups. CONCLUSION: According to our study, environmental conditions appear to have a very significant effect on the ocular surface. There were very high levels of subclinical ocular surface changes among persons travelling in highly polluted areas.
In a cross-sectional study of 50 consecutive primary open-angle glaucoma cases, full threshold 30-2 visual fields on Humphrey Visual Field Analyser were correlated to stereometric parameters obtained using a scanning laser ophthalmoscope (HRT II). The strength of linear correlation between the stereometric parameters and visual thresholds was used to generate a correspondence map between the optic disc and the visual field. Rim/disc area ratio and cup/disc area ratio correlated with the visual thresholds at the highest number of points in the visual fields. Thresholds at superior hemifield locations correlated best with the rim/disc area ratio and cup/disc area ratio in the inferonasal sector and the ones in the inferior hemifield correlated best with the rim/disc area ratio and cup/disc area ratio in the superotemporal sector. Optic disc parameters correlated better with inferior field locations and non-edge points than superior field locations and edge points. The data indicate that rim/disc area ratio and cup/disc area ratio measurements on HRT II have a good correlation with visual field damage seen on automated visual fields.
PURPOSE: To compare and evaluate Teller Acuity Cards (TAC) and Cardiff Acuity Cards (CAC) to assess vision in children below the age of two. METHODS: The study evaluated TAC and CAC to assess visual acuity in 90 normal children divided into three age groups, 0-6 months (group I), 6-12 months (group II) and 12-24 months (group III). 30 cases of unilateral amblyopiogenic conditions, 10 cases each of unilateral refractive error, unilateral esotropia, and unilateral cataract, were also examined. Trained optometrists carried out binocular testing followed by monocular testing, and recorded the test time in each case. RESULTS: The mean visual acuity (in Snellen units) and standard deviation (in octaves) in the three age groups of normal children, I, II, III respectively were 6/44 +/- 0.54, 6/21 +/- 0.37 and 6/21 +/- 0.41 (binocularly by TAC) and 6/46 +/- 0.80, 6/21 +/- 0.59 and 6/14.5 +/- 0.84 (binocularly by CAC). Although the time taken for testing with CAC was less, its coefficient of variance was greater for all age groups as compared to TAC. Diminution of visual acuity could be assessed correctly by both the tests in cases of strabismus and cataract, but not in some cases of refractive error. CONCLUSION: CAC is a useful and child-friendly test. It can be used clinically but may miss some cases of visually significant refractive errors. TAC is a more dependable test to assess amblyopiogenic conditions despite the use of gratings.
OBJECTIVE: The aim of the study is to identify the causes, demographic and clinical profile and evaluate final visual outcome of pediatric ocular injuries. METHODS: Two hundred and four children aged fourteen years or less presenting to the emergency services of a tertiary care centre with ocular injury were included. Demographic data, nature and cause of injury, duration between injury and presentation to an ophthalmologist and the diagnosis were recorded. Evaluation of visual acuity, anterior segment and fundus were done. All patients were appropriately managed and followed up on days 1, 7, 1 month, 3 and 6 months. RESULT: Majority of injuries occurred in children of 5 years and older (87.7%). There were 133 (65.1%) boys and 71 (34.9%) girls. Forty-nine (24%) cases presented within 6 hours of injury while 70 (34.3%) presented after more than 24 hours after trauma. Most common cause of injury was bow and arrow (15.2%) followed by household appliances(14.3%). Closed globe injuries accounted for 42.2% injuries, open globe for 53.9% and 3.9% were chemical injuries. Best corrected visual acuity of 6/12 or better was achieved in 79 eyes (91.86%) in closed globe group. However, only 17 eyes (15.45%) in open globe group could achieve this. CONCLUSION: Most ocular injuries in children are preventable and occur from unsupervised games like bow and arrow and firecracker, which can lead to significant visual loss.
The present study demonstrates comparison of Cr accumulating potential by the plants of Najas indica Cham. (submerged), Vallisneria spiralis L. (rooted submerged) and Alternanthera sessilis R. Br. (rooted emergent) under repeated metal exposure and its effect on chlorophyll and protein concentrations. These plants were treated with different concentrations of Cr under repeated exposure in controlled laboratory conditions to assess the maximum metal accumulation potential. The plants of V. spiralis accumulated significantly high amount of Cr under laboratory conditions in comparison to N. indica and A. sessilis. The maximum accumulation of 1378, 458 and 201 microg (-1) dw Cr was found in the leaves of V. spiralis. N. indica and A. sessilis, respectively at 8 mg (-1) after 9 day of Cr exposure. These plants have shown a decrease in chlorophyll and protein concentrations with increase in Cr concentrations. In view of high accumulation of Cr in V. spiralis, the plants were treated with different concentrations of tannery effluent collected from Common Effluent Treatment Plant, Unnao (UP). The plants of V. spiralis treated with 100% tannery wastewater showed the maximum accumulation (57.5 microg g(-1) dw) of Cr in the roots after 10 days of exposure. The plants were found effective in removing Cr from solution and tannery effluent.
PURPOSE: To study the test-retest variability of stereometric parameters on the Heidelberg Retina Tomograph II, a new clinical instrument for glaucoma management. METHODS: In a cross-sectional study of 24 consecutive cases of glaucoma and 26 healthy subjects, Heidelberg Retina Tomograph II stereometric parameters from five consecutive images were obtained for one randomly selected eye of each subject. Test-retest variability was studied using three different statistical methods (coefficient of variance, intraclass correlation coefficient, and Cronbach alpha). The effect of age, diagnosis, linear cup/disc ratio, visual acuity, and refractive error on test-retest variability on HRT II was analyzed. The repeatability of Moorfields regression analysis and the baseline variability in the progression analysis software was also studied. RESULTS: Using coefficient of variance, intraclass correlation coefficient, and Cronbach alpha, the test-retest variability was found to be lowest for mean cup depth, cup area, cup/disc area ratio, vertical cup/disc ratio and rim/disc area ratio, in that order. Test-retest variability had a significant correlation with age (r = 0.33, P = 0.019) and visual acuity (r = -0.46, P = 0.005). Compared with eyes with astigmatism less than 1 D (mean coefficient of variance = 6.4 +/- 4.9), the test-retest variability was higher (P = 0.044) in eyes with astigmatism more than 1D (mean coefficient of variance = 20.0 +/- 22.6). Moorfields regression analysis was inconsistent in 52% cases. The average baseline change in progression analysis software was 0.076 +/- 0.081. CONCLUSION: The test-retest variability of Heidelberg Retina Tomograph II stereometric parameters is comparable to that reported for the Heidelberg Retina Tomograph. Eyes with uncorrected astigmatism more than 1 D and poor visual acuity may have a higher variability of Heidelberg Retina Tomograph II stereometric parameters.
This prospective study compared intraocular pressure (IOP) control, cardiorespiratory function, and adverse effects in 50 patients with glaucoma and ocular hypertension. Patients on topical combination timolol-latanoprost therapy were recruited. After they had used this combination for at least 2 months, they were switched to bimatoprost monotherapy. Full ocular examination and spirometric testing were performed; a questionnaire concerned with ocular symptoms was completed, and pulse rate was recorded. Two months later, mean IOP was similar with the combination (17.2 mm Hg) and with bimatoprost (16.4 mm Hg), but mean peak expiratory flow rate, ratio of forced expiratory volume in 1 second to forced vital capacity, and heart rate had increased significantly after the switch was made to bimatoprost. Adverse effects generally were similar with these regimens; however, the incidence of hyperemia doubled after the switch had been made. Bimatoprost and the timolol-latanoprost combination were equally efficacious in lowering IOP; bimatoprost had less of an effect on cardiorespiratory function.