Rahul Bhola

Hang-back recession of inferior oblique muscle in V-pattern strabismus with inferior oblique overaction

INTRODUCTION Although hang-back recession has widely been used as a weakening procedure on extraocular muscles, its effectiveness has mostly been studied for rectus muscles. We report a surgical technique for recessing the inferior oblique muscle and evaluate its effectiveness in V-pattern strabismus with inferior oblique overaction (IOOA). METHODS Fifteen patients with V-pattern strabismus and IOOA, 7 with V exotropia, and 8 with V esotropia underwent hang-back recession of inferior oblique muscle in addition to horizontal muscle surgery when required. The surgical technique consisted of free suspension of one or both inferior oblique muscles 10 mm along their physiological path using 6-0 polyglactin 910 sutures bridging the cut ends of muscle. RESULTS The mean preoperative V pattern in the V-exotropia group was 22(Delta) +/- 6(Delta) and 25(Delta) +/- 7(Delta) in V-esotropia group. The mean correction of V pattern after a mean follow-up period of 8 +/- 1 months was 19(Delta) +/- 2(Delta) for the V-exotropia group and 22(Delta) +/- 7(Delta) months for the V-esotropia group. Mean correction of IOOA in the V-exotropia group was 18(Delta) +/- 5(Delta); in the V-esotropia group, mean correction was 20(Delta) +/- 6(Delta) in the right eye and 18(Delta) +/- 2(Delta) in the left eye. CONCLUSIONS Hang-back recession of inferior oblique is another surgical procedure for correction of both V pattern and IOOA in V-pattern strabismus.

Pilot study of the influence of eyeliner cosmetics on the molecular structure of human meibum.

Background/Aims: It has been suggested that eye makeup could interact with human meibum causing a decrease in the stability of the tear film. The aim of this pilot study was to measure makeup-human meibum interactions in vitro. Methods: Human meibum-makeup interactions were quantified by measuring order-to-disorder lipid phase transitions using infrared spectroscopy. Results: Makeup products exhibited lipid phase transition temperatures that were much higher than those for meibum. One product increased the lipid phase transition temperature by 4.2°C when combined with human meibum causing a large increase (from 30 to 49%) in the order of the meibum-lipid hydrocarbon chains and significantly decreased the minimum frequency, enthalpy and entropy of the phase transition of human meibum. Another eyeliner caused no significant (p < 0.05) change in the phase transition parameters of human meibum. Conclusion: Infrared spectroscopy may be used to measure interactions between human meibum and makeup. One makeup product increased the lipid order (viscosity) which could have adverse effects on tear film stability. Modern cosmetics are highly regulated and relatively safe to use; however, it could be beneficial to design makeup products that do not interact with meibum, especially since women have a higher prevalence of dry eye symptoms.

Effect of granulocyte colony-stimulating factor on the incidence of threshold retinopathy of prematurity

PURPOSE To study the effect of granulocyte colony-stimulating factor (GCSF) on the incidence of threshold retinopathy of prematurity (ROP). METHODS A retrospective chart review of all neonates who received GCSF at our neonatal intensive care unit over a period ranging from January 2003 to September 2007 was performed. Of the 213 patients identified, 50 patients with birth weight <1,500 g and gestational age <32 weeks were included in this study. The incidence of threshold ROP in this subset was compared to a control group (n = 161) obtained from Vermont Oxford Network ROP database over the same time period. The two data sets were cross-referenced to exclude any patient receiving GCSF from the control data. RESULTS The average birth weight was 913 g in GCSF patients and 847 g in controls. The average dose of GCSF was 10.4 microg (range, 1.2-21.6 microg). The average age at administration of GCSF was 12 days after birth (range, 0-34 days). Out of 50 patients in the GCSF group, 5 (10%) required laser treatment, whereas in the contol group, 30 (18.6 %) required laser treatment; this difference was not statistically significant. CONCLUSIONS There was a suggestion of a decreased incidence of threshold ROP, leading to reduced need for laser treatment, in patients who received GCSF, but the observed differences were not statistically significant. The authors anticipate that these findings will lead to further study of the upstream regulators of neovascularization.

Human Meibum Age, Lipid–Lipid Interactions and Lipid Saturation in Meibum from Infants

Tear stability decreases with increasing age and the same signs of instability are exacerbated with dry eye. Meibum lipid compositional changes with age provide insights into the biomolecules responsible for tear film instability. Meibum was collected from 69 normal donors ranging in age from 0.6 to 68 years of age. Infrared spectroscopy was used to measure meibum lipid phase transition parameters. Nuclear magnetic resonance spectroscopy was used to measure lipid saturation. Increasing human meibum lipid hydrocarbon chain unsaturation with age was related to a decrease in hydrocarbon chain order, cooperativity, and in the phase transition temperature. The change in these parameters was most dramatic between 1 and 20 years of age. Meibum was catalytically saturated to determine the effect of saturation on meibum lipid phase transition parameters. Hydrocarbon chain saturation was directly related to lipid order, phase transition temperature, cooperativity, changes in enthalpy and entropy, and could account for the changes in the lipid phase transition parameters observed with age. Unsaturation could contribute to decreased tear film stability with age.