Alteration in pattern reversal visual evoked potential in pediatric population with amblyopia and spherical refractive errors

Purpose: To study the effect of refractive errors on pattern visual evoked potential (VEP) recordings in the pediatric population. Methods: This cross?sectional observational study assessed 240 eyes of 120 participants attending the outpatient department of a tertiary care center in North India. Participants were between 8 and 18 years of age; 30 participants each were recruited into four groups, namely emmetropia, myopia, hypermetropia, and amblyopia. They were then subjected to pattern reversal VEP, with P?100 amplitude and latency recorded for each participant. Results: The emmetropic group in this study provided normal values of P?100 parameters, namely P?100 latency and P?100 amplitude with readings of 115.78 ± 10.19 ms and 11.11 ± 4.08 ?V, respectively. P?100 amplitude was significant compared to P?100 latency in detecting the presence or absence of a specific type of refractive error. It was found that there was a significant association between severity of myopia and P?100 latency (both unaided and aided) with P < 0.05. The severity of hypermetropia showed a significant association with P?100 amplitude (unaided) (P < 0.05). Receiver operating characteristics analysis revealed P?100 amplitude to be a good predictor of refractive error and the cut?offs were calculated. Conclusion: The P?100 parameters of the pediatric Indian population were comparatively higher than conventional values. P?100 latency seemed to better correlate with myopia, while hypermetropia correlated with P?100 amplitude. P?100 amplitude appears to be the most significant predictor of the presence of refractive error in an individual.

Burden of ocular morbidities and color blindness among school-attending children in a foothill town of Uttarakhand State

Purpose: To estimate prevalence of common ocular morbidities including color blindness among school?attending children of an urban foothill town of Uttarakhand State in Northern India. Methods: A cross?sectional study was conducted among school?going children of age group 6–16 years of standard I– XII. Schools were selected using population proportionate to the size sampling technique. Detailed ocular examination including color vision and unaided or aided visual acuity for various ocular morbidities was done. Data was entered into MS excel with statistical analysis using SPSS version 23 with significant P value <0.05. Results: In total, 13,492 students (mean age 10.9 ± 2.7 years) with almost equal male to female ratio were screened. Overall prevalence of ocular morbidity was 23.2%, with refractive error (18.5%) on top, followed by color blindness (2.2%). The later was observed more among males (3.0%) as compared to females (1.4%) with significantly higher odds, OR = 2.3 (1.7–2.9) (P < 0.001). Conclusion: Refractive error has been the most common ocular morbidity, followed by color blindness. Earliest detection can prevent permanent disability and disappointment among youngsters when rejected from entering certain professions due to color vision defect

Gender Preference for Auditory Versus Visual Routes for Memorization.

Objective: Memory is formed on the basis of sensory stimuli perceived. Vision and Auditory sense are the most common modes to form visual and auditory memory. This study was planned to find the preferred sense route for the formation of memory, between the two genders. Method: In the present cross sectional experimental study, 40 male and 40 female subjects between 18- 20 years of age were tested for visual & auditory memory. Results: The results suggested statistically significant higher scores of ‘Memory Test’ in women in comparison to men (F479 3.312, p=<0.001). The mean score for memory subtests was best for black & white pictures followed by colored pictures, visual words, visual digits, auditory digits and auditory words in that order in men, whereas in women, mean score was best for colored pictures followed by black & white pictures, auditory words, auditory digits, visual words and visual digits. Conclusion: It may be concluded that in men visual sense and in women auditory sense are more effectual for the formation of memory.

Gender based alteration in color perception.

Human beings are able to perceive hundreds of shades of color which depends on the three types of cone system and various ratios of stimulation in response to different wavelengths. Perceptually and cognitively, men and women may experience appearance of color differently. Therefore, this study was planned to assess and compare color vision in male and female subjects. This study was carried out in the department of Physiology, SGRRIM&HS, Dehradun on 60 ocular healthy subjects (equal number of males and females) of 17–22 years of age group. The task was to match 22 test color strips with 2 shade charts of different colors. Total number of correct answers and total time taken in matching all the test color strips with the shade charts was recorded in both the sexes and analyzed. The results of this study showed that overall, females gave more correct responses (P<0.001) and also took less time (P<0.01) than males. Color wise also, females gave more correct responses especially for red (P<.001) and green color (P<0.01). The conclusion states that the females can see more shades of colors than males.

Effect of '61-points relaxation technique' on stress parameters in premenstrual syndrome.

Premenstrual Syndrome is a psychoneuroendocrine stress related disorder and more than 300 treatment modalities for PMS show that the existing remedies have not provided satisfactory help to relieve PMS. 61-points relaxation exercise (61-PR), a relatively less known hatha yoga technique, is a successful means of stress relaxation and is expected to relieve PMS as well. The present study was conducted on 50 clinically healthy women volunteers who were in their reproductive age group and in their premenstrual period, from which a control group (n = 20) and a PMS group (n = 30) based on the symptoms were identified. In both groups basal heart rate (HR/min), systolic (SBP; mmHg) and diastolic blood pressure (DBP; mmHg), electromyogram (EMG; mV), electrodermal galvanic activity (EDG; microv), respiratory rate (RR/min) and peripheral temperature (T; degrees F) were recorded and the subjects were taken through a guided 61-PR. The symptoms and parameters were re-recorded after the 61-PR. In control group, the basal HR was 82.06 +/- 8.07, SBP 111.95 +/- 8.23, DBP 76.8 +/- 6.42, EMG 4.08 +/- 2.99, EDG 9.77 +/- 3.29, RR 15.60 +/- 3.77 and T was 97.86 +/- 0.63. After 10 minutes of 61-PR, HR (77.27 +/-10.85, P < 0.05), SBP (107.35 +/- 7.41, P < 0.05), DBP (75.25 +/-7.57, P < 0.05), EMG (2.07 +/- 1.90, P < 0.05), EDG (8.06 +/- 2.87, P < 0.05), RR (16.00 +/- 4.12, P < 0.05) fell significantly and T (97.97 +/- 0.64, P > 0.05) rose significantly. In the PMS group, the basal HR was 90.61 +/- 8.46, SBP 122.5 +/- 11.52, DBP 83.53 +/- 8.26, EMG 5.79 +/-2.75, EDG 13.14 +/- 6.54, RR 19.13 +/- 3.76 and T was 93.43 -/+ 5.29. After 10 minutes of 61-PR, HR (75.58 +/- 10.11, P < 0.0001), SBP (114.53 +/- 9.70, p < 0.0001), DBP (77.46 +/- 8.68, P < 0.0001), EMG (2.56 +/- 1.77, P < 0.0001), EDG (10.64 +/- 5.72, P < 0.0001), and RR (16.13 +/- 3.76, P < 0.0001) declined to a much greater extent and T (93.49 +/- 5.28, P < 0.0001) rose more significantly. These results suggest a reduction in sympathetic activity by 61-PR, also the high basal sympathetic tone present in subjects of PMS group due to stress is considerably reduced by relaxation. 61-PR is effective in providing relief from PMS and may be a useful adjuvant to medical therapy of PMS and other stress disorders.

Salt preference: age and sex related variability.

Salt preference was assessed in 60 adults of 18-21 yrs of age (30 males and 30 females) and in 60 children of 7-12 yrs of age (30 boys and 30 girls). Subjects rated the preference on Likert scale for popcorns of five salt concentrations (OM, 1M, 2M, 3M and +3M). Statistical analysis using Two way ANOVA revealed statistically significant effect of age and sex on salt preference (F4,100 = 15.027, P < 0.01) and One Way ANOVA revealed statistically significant sex difference in salt preference of adults (F4,50 = 16.26, P < 0.01) but no statistically significant sex difference in salt preference of children (F4,50 = 4.08, P > 0.05). Dietary experiences during development and more physical activity in children may be responsible for higher salt preference in children while finding no sex variability in children favours the role of sex hormones in salt preference of male and females.

Role of Ca++ gradient in functional dilatation in the microvessels of rat skeletal muscle.

During skeletal muscle contraction functional dilatation (FD) is a well established phenomenon, which is usually linked to the accumulation of various vasodilator metabolites. The present study aimed to establish the role of calcium ions (Ca++) in the functional dilatation of skeletal muscle microvessels especially during single & few twitches. The FD was studied in urethane anaesthetized rats whose spinotrapezius muscle was prepared for intravital microscopy. After stimulating the muscle with few twitch (1 & 3 Hz) and tetanic frequency (40 Hz), muscle contracted and showed dilatation. However the dilator response was quickest (1 Hz : 10 +/- 0.40, 3 Hz : 02 +/- 0.47 sec and 40 Hz : 02 +/- 0.10 sec) and maximum in magnitude (1 Hz : 25 +/- 0.30%, 3 Hz : 35 +/- 0.49% and 40 Hz : 55 +/- 0.39%) in terminal arteriole and with tetanic frequency. Calcium channel blockade by Diltiazem abolished the FD response except for tetanic stimulation contraction. Findings suggested possible involvement of Ca++ movement in functional dilatation which was initiated by passive efflux of Ca++ from smooth muscle of vessel and then maintained during higher frequency stimulation by release of local metabolities.

Salt preference across different phases of menstrual cycle.

It is well established that women experience food craving for particular foods and gain weight in relation to phases of menstrual cycle. In this study, the preference for different concentrations of salt sprayed on bland popcorn was assessed in 55 healthy women (age 18 to 22 yrs). Salt solutions of 0, 1, 2, 3 and +3 molar strength were used. Samples of sprayed popcorn were consumed in random order and preference marked on a Likert scale. It was observed that women preferred unsalted popcorn in the menstrual phase more than in the luteal phase. The preference for salted popcorn was most during the luteal phase and was proportionate to the strength of the salt solution used. Statistical analysis revealed significant differences in the preference rating between the menstrual phase and the other two phases. There was no significant difference in preference between the luteal and follicular phases.