Canon CP-TX1 camera - As a screening tool for amblyogenic risk factors.

Purpose: To evaluate the Canon CP-TX1 camera as a screening tool for ARFs in a pediatric population and estimate the prevalence of ARFs. Methods: In a pediatric outpatient space, largely in the immunization clinic, after obtaining parental consent, we encouraged children to be photographed from a distance of 5 feet in a dim room by using a CP-TX1 camera with the red-eye reduction feature off. Based on the captured red reflex, children were labeled as normal (symmetrical red reflexes in the two eyes, with no visible crescents); all others were considered as abnormal or positive for ARFs. All photographed children were assessed by an optometrist/refractionist for VA by age-appropriate methods. Data were entered into a 2 × 2 contingency table on statpages.org, and diagnostic indices were calculated with 95%CI. Results: With a sample of 262 children, we obtained a sensitivity of 0.82, a specificity of 0.98, a positive predictive value of 0.92, a negative predictive value of 0.94, a positive likelihood ratio of 41.06, a negative likelihood ratio of 0.17, and a prevalence of 0.24 for ARFs. Conclusion: CP-TX1 performed well as a screening tool to identify ARFs in children. Placing such a camera in an immunization clinic offers a chance to identify children with ARFs at a time when amblyopia is eminently reversible.

Half Minimally Invasive Strabismus Surgery (MISS): A single para-muscular approach to horizontal muscle strabismus surgery.

PURPOSE: Minimally invasive surgeries are gaining popularity. We compared two different approaches to rectus muscles: namely the standard para limbal (SPL) and the single para-muscular (SPM). METHODS: Thirty-six patients planned for monocular horizontal strabismus surgery were block randomized to SPL and SPM approach. SPM approach involved a single para-muscular 10-mm conjunctival incision levelled at the inferior border of rectus muscle. We compared the post-operative grades of redness, congestion, chemosis, foreign body sensation, and drop intolerance at day 1, 2 weeks, and 6-8 weeks; scar visibility and success rates at 6-8 weeks and operation duration in minutes. We compared the results using Mann-Whitney U-test for inflammatory grades, Fisher's exact test for proportions, and t-test for parametric measures. Significance was set at P < 0.05. RESULTS: On postoperative follow-up at any time point, no significant difference was found on comparing inflammatory grades, scar visibility, and success rates. In terms of duration, SPL approach was on an average 21.5 minutes quicker than SPM (P = <0.001). CONCLUSION: The SPM is comparable to the SPL approach in terms of postoperative comfort and appearance, but takes significantly longer to accomplish.

Single-snip paralimbal incision: A quick approach to rectus muscles.

INTRODUCTION: Less invasive and quicker surgeries have become common. We compared two conjunctival incisional approaches in strabismus, namely Follow standard paralimbal approach for (SPLA) and single-snip paralimbal (SSPLA). MATERIALS AND METHODS: Forty-four patients with horizontal strabismus qualifying for uniocular recession-resection surgeries were randomized to SPLA and SSPLA. SSPLA involved a single v-shaped incision, with the apex of the V near the limbus, and the limbs facing away: by pinching up the conjunctiva with a forceps and delivering the single snip with a spring scissors. We compared the postoperative grades of redness, congestion, chemosis, foreign body sensation, and drop intolerance at day 1, 2 weeks, and 6-8 weeks; scar visibility, as yes or no, at 6-8 weeks; success rates, considered to be within 10 prism diopters of orthophoria, at 6-8 weeks; and operation duration in minutes. STATISTICAL ANALYSIS: Statistical analysis was done using Mann-Whitney U-test, for inflammatory grades, Chi-square for proportions, and t-test for parametric measures. Statistical significance was set at P < 0.05. RESULTS: On postoperative day 1, congestion (P = 0.02), foreign-body sensation (P = 0.04), and total inflammatory score (P = 0.003) were statistically significantly favoring the SSPLA group. While at 2 weeks, only congestion (P = 0.02) was found to be significantly less in the SSPLA group. There were no significant differences in the proportions of scar visibility (5/22 in the SPLA vs. 3/22 in the SSPLA) and success rate: 20/22 vs. 18/22. The SSPLA was quicker on an average by 6 min (P < 0.001, 95% confidence interval: 3.2-8.7). CONCLUSION: Compared to the SPLA, the SSPLA is quicker and results in lesser inflammation in the immediate postoperative period.

Economizing strabismus surgery: Using half the double-armed suture for horizontal muscles.

In a developing country like India, both availability and affordability of medical care are obstacles, leading to delay in seeking timely treatment. To reduce the cost incurred to the patients for strabismus surgery, we used half of a 6-0 polyglactin suture for performing common muscle weakening and strengthening procedures: a fixed and hang back recessions with plication and resection. We cut the 45-cm-long double-armed 6-0 polyglactin sutures in two halves, and with a modified approach, used one-half in each of two patients planned for monocular two horizontal muscles surgeries: fixed recession-plication and hang back recession-resection. By devising an intuitive manner of threading a single armed 22.5 cm suture we successfully carried out horizontal extraocular muscle surgeries on each of two patients of exotropia. We believe in the long run, this will reduce the cost to individual patients and sponsoring groups, and suggest that strabismus surgeons consider adopting this option.

Saving space: Comparing mini - logMAR with standard logMAR visual acuity.

Purpose: Assessing visual acuity (VA) is the cornerstone of an ophthalmic workup and needs VA charts in a four or six meters space. The objective of this study was to compare the performance of distant VA (DVA) on one meter mini-logMAR (MLM) with a standard six meter logMAR (SLM) chart. Methods: We developed a MLM chart to be used at 1 m with +1.0 D spectacles, by reducing the SLM chart designed for 6 meters, to 1/6th its size, using AutoCAD version 2014. On an initial cohort, we obtained DVA on the two charts by optometrist trainees, masked to the outcomes on the different tests. We performed regression and checked agreement between the two measurements. Subsequently, on a new cohort, we validated the performance of the MLM. Results: Of the 56 initial subjects, mean DVA with SLM was 0.44 ± 0.13 and with MLM was 0.45 ± 0.13; mean difference of -0.01 ± 0.02, 95%CI: 0.007 to 0.018; P < 0.0001 on paired t-test. There was a significant correlation: r = 0.99; r2 = 0.98, P < 0.0001. On an average, DVA with MLM was less than a letter worse than with SLM. The regression formula obtained: SLM DVA = -0.1312 + 1.0014 x (MLM DVA). The validation study revealed no significant difference (P = 0.29) between the predicted standard DVA calculated by the regression formula and the actual standard. Conclusion: We suggest that we can deduce distance logMAR VA from a mini-logMAR chart as devised and used by us. This will take less space, be portable and allow congenial interaction with patients.

Do all children need a cycloplegic refraction? A comparison of Mohindra's versus cycloplegic refraction.

PURPOSE: In 1-12 years old children, we assessed correlation, regression, and agreement between spherical equivalents (SE) obtained on Mohindra's near retinoscopy (MNR) and the post cycloplegic refraction (PCRef), performed 72 h after a cycloplegic refraction (CRef) using cyclopentolate 1% drops. METHODS: In this prospective comparative study, Mohindra's near retinoscopy (MNR) was performed on 202 eyes of 101 children, from 50 cm with a streak retinoscope, in a dimly lit room, subtracting 1.25 from the trial lens used for neutralization, to obtain the final refraction. Subsequently we undertook CRef, half-hour after instilling 1% cyclopentolate, with a PCRef 72 h later. All refractive data were converted to SE for evaluation. We compared the SEs using correlation, linear regression, and agreement (Bland-Altman graphic analysis) and paired t-test. Significance was set at P ≤ 0.05. RESULTS: The mean SE on MNR was 1.71 ± 2.49 D compared to 1.43 ± 2.42 D on PCRef. A significant correlation with r = 0.97 (r2= 0.94, P < 0.001) existed. Agreement analysis suggested that MNR overestimates hypermetropia and underestimates myopia each by 0.3 D than the standard procedure of CRef-PCRef. The regression analysis suggested that SE on PCRef is 95% of that on MNR, less 0.20. CONCLUSION: Our study suggests that MNR offers single point refraction very similar to CRef-PCRef, and may be considered as a viable option more often.