Louis B. Godio

Retrolental Fibroplasia: Efficacy of Vitamin E in a Double-Blind Clinical Study of Preterm Infants

We performed a double-blind study in 101 preterm infants who weighed less than or equal to 1500 g at birth, who had respiratory distress, and who survived for at least four weeks, to evaluate the efficacy of oral vitamin E in preventing the development of retrolental fibroplasia. Weekly indirect ophthalmologic examinations begun when the infants were three weeks old revealed a significant decrease in the incidence of retrolental fibroplasia greater than or equal to Grade III (P less than 0.03) and greater than or equal to Grade II (P less than 0.05) (McCormick classification) in the 50 infants given 100 mg of vitamin E per kilogram of body weight per day as compared with 51 given 5 mg per kilogram per day (controls). When multivariate analysis was applied to the controls, five risk factors were identified: gestational age, level and duration of administration oxygen, intraventricular hemorrhage, sepsis, and birth weight. When multivariate analysis was applied to both control and treatment groups, the severity of retrolental fibroplasia was found to be significantly reduced in infants given 100 mg of vitamin E (P = 0.012).

Deswelling of the cornea after hypoxia

ABSTRACT Central corneal thickness changes were monitored in nine subjects who wore low water content hydrogel lenses of varying thickness for 3 h in the open and closed eye conditions. At the end of 3 h of lens wear, corneal deswelling to prelens thickness for the different levels of hypoxia was determined by pachometry performed every 5 min for the first 30 min, every 10 min for the next 40 min, and every 15 min thereafter. Examination of the individual deswelling profiles indicates (1) a biphasic response in those with corneal edema greater than 14%, and (2) a large portion of the deswelling occurred during the first 30 min, followed by a more gradual rate until baseline was reached. Small amounts of corneal edema (less than 5%) required up to 25 min to return to baseline, whereas 6 to 15% required 30 to 70 min, and 20% required 95 min. The time taken for the cornea to deswell to baseline was linearly related to the amount of corneal swelling (r = 0.88; p < 0.0001).

Aspheric rigid gas permeable contact lenses: practitioner discrimination of base curve increments using fluorescein pattern evaluation.

Evaluation of the fluorescein pattern is the main clinical indicator of the fit of a rigid gas permeable (RGP) contact lens to the cornea. Traditionally, manufacturers inventory RGP lenses in 0.05-mm base curve increments. The objective of this study was to test the hypothesis that experienced practitioners are not able to discern base curve/cornea relations of aspheric design lenses correctly to within ±0.05 mm. Eleven clinicians with expertise in fitting rigid lenses were asked to interpret fluorescein patterns and lens fittings of the Bausch & Lomb Quantum aspheric RGP lens on five adapted rigid lens wearers. The results showed that the experienced practitioners used in this study were not able to discriminate cornea/base curve relations of Quantum aspheric lenses within ± 0.05 mm more than 67% of the time (p < 0.05). There were no patient-topatient differences based on type of lens fit (interpalpebral or lid attachment) or degree of corneal toricity. Lenses fitted in 0.10-mm base curve steps were judged as being as acceptable as lenses fitted in 0.05 mm steps (p < 0.05). It was concluded that Quantum aspheric design lenses need only be trial fitted in 0.10-mm base curve steps.

Factors influencing vision with rigid gas permeable alternating bifocals

This study assessed the fitting and visual performance of a rigid, gas permeable (RGP), monocentric, alternating bifocal. Fourteen presbyopic eyes each wore 24 different lenses consisting of all combinations of 2 diameters, 2 segment heights, 2 prism ballasts, and 3 fitting relations. The influence of parameter selection on visual performance and the usefulness of clinical measurements in predicting visual performance were determined statistically by multivariate logistic regression. Our results showed that prism, segment height, and the fitting relation can influence distance and near visual performance. Lens movement, postblink segment positioning, and return time were the most useful measured predictors of visual performance.

Retinal images and astigmatic distortions in the individual corrected aphakic eye

For paraxial objects viewed at finite distances from the correction plane, retinal image size and retinal distortions due to astigmatism are obtained for spectacle- or contact-lens-corrected aphakic individuals with astigmatism. Our methods are based not on the analysis of schematic or reduced eyes but on clinical measurements (corneal, refractive, pachometer, and correction parameters) that correspond to the individual patient.

Clinical determination of the corrected retinal image size in spectacle-corrected aphakes.

ABSTRACT For individual spectacle‐corrected aphakic patients, a method of estimating the size of the corrected retinal image corresponding to distant objects smaller than Snellen 6/360 (20/1200) is developed. Our results indicate that an estimate of the corrected retinal image size corresponding to a distant Snellen 6/12 (20/40) object in an individual spectacle‐corrected aphake can be obtained to within plus or minus 1.0 &mgr;m of error using a multivariate regression model based on the measurement of six patient factors: axial length, anterior corneal power, spectacle lens back vertex power, lens thickness, lens back curve, and lens vertex distance. Clinical application of these results are discussed along with comparisons to other results based on traditional spectacle magnification formulas. The size of the corrected retinal image corresponding to a Snellen 6/12 (20/40) object was found to vary between 60 and 84 &mgr;m in patients corrected with CR‐39 optical plastic and for patients corrected with high‐index optical glass, it was between 56 and 78 &mgr;m.

Clinical prediction of postsurgical aphakic refractive correction.

ABSTRACT A simple clinical predictor of the amount of spectacle convex lens power that will be needed to correct the refractive error of an aphakic patient after cataract surgery is developed based on clinical measures of anterior corneal surface power (keratometer measurements) and axial length. This predictor derived from matrix optics is compared to previous ones developed by Binkhorst and Sanders et al. using different methodologies.

1328 RETINOPATHY OF PREMATURITY: ADMINISTRATION OF VITAMIN E TO MITIGATE AGAINST SEVERE DISEASE

One-hundred infants admitted to Texas Childrens Hospital Neonatal Intensive Care Unit from Nov. 1979 to Nov. 1980 who weighed ≤1500 grams at birth and who developed respiratory distress were given orally either 5 mg/kg/day (control) or 100 mg/kg/day (experimental) of dl-α-tocopherol (vitamin E) beginning on their first day of life and continuing throughout their hospital stay on a randomized double-blind basis. Blood levels of vitamin E were found to average 6 ugm/ml in the controls and 12 ugm/ml in the experimentals after 7 days. Each infant had a weekly retinal evaluation beginning at the third week of life. The critical time for screening and treatment for retinopathy of prematurity (ROP) was found to be seven weeks post-delivery. The significant ROP risk factors identified in the controls were gestational age, birth weight, oxygen administration, intraventricular hemorrhage, and sepsis.There was no difference between the two groups in clinically insignificant ROP (grade II or less). However, the incidence of grade III ROP in the control population was 10% (5 of 50) while no grade III ROP developed in the experimental infants. The correlation between the development of grade III ROP and the lower level of vitamin E administration was found to be highly significant (p<.02).