0.3% ciprofloxacin ophthalmic ointment in the treatment of bacterial keratitis. The Ciprofloxacin Ointment/Bacterial Keratitis Study Group.

OBJECTIVE: To determine the efficacy and safety of topical 0.3% ciprofloxacin hydrochloride ophthalmic ointment in the treatment of bacterial keratitis. DESIGN: Prospective case series with a nonrandomized comparison of culture-positive, evaluable cases (ciprofloxacin ointment group) with culture-positive, concurrent patients (nonenrolled group) treated with conventional therapy. SETTING: Multicenter clinical study. PATIENTS: After informed consent was obtained, 253 eligible patients underwent corneal scrapings and received topical ciprofloxacin ointment; 145 (57%) had positive cultures and completed the follow-up schedule. Forty (70%) of 57 apparently eligible patients had culture-positive bacterial keratitis but were not enrolled in the ciprofloxacin ointment study during the same period. INTERVENTION: Ciprofloxacin ophthalmic ointment instilled every 1 to 2 hours for 2 days, then every 4 hours for 12 days. MAIN OUTCOME MEASURES: Clinical evaluation of signs at 1, 3, 7, and 14 days of treatment and the overall condition classified as clinical success (cured or improved) or failure (unchanged or worse) during and after therapy. RESULTS: Clinical success with the initial treatment occurred in 135 patients (93%) in the ciprofloxacin ointment group and in 28 patients (70%) in the nonenrolled group. Of the 10 ciprofloxacin clinical failures, seven were staphylococcal; two, pneumococcal; and one, polybacterial. The 90% minimum inhibitory concentration of ciprofloxacin was 3 mg/L or less for corneal bacterial isolates. No serious adverse event attributable to ciprofloxacin ointment occurred, although 32 (13%) of 253 patients developed a transient white crystalline corneal precipitate shown with liquid chromatography in two cases to be ciprofloxacin. CONCLUSION: Ciprofloxacin ophthalmic ointment is an effective and safe topical antimicrobial agent for the treatment of bacterial keratitis caused by susceptible microorganisms.

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 less than 0.05). There were no patient-to-patient 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 less than 0.05). It was concluded that Quantum aspheric design lenses need only be trial fitted in 0.10-mm base curve steps.

Multiple applications of the NCT: an assessment of the instrument's effect on IOP.

The feasibility of the American Optical Non-Contact Tonometer as an instrument for tonography was assessed. It was found that after 20 measurements in quick succession, there was a statistically insignificant change in IOP. Multiple intraocular pressure (IOP) readings with this instrument are helpful in determining an abnormally high IOP from an aberrant recording.

Deswelling of the cornea after hypoxia.

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 less than 0.0001).

Clinical prediction of postsurgical aphakic refractive correction.

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.

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

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 micron 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 micron in patients corrected with CR-39 optical plastic and for patients corrected with high-index optical glass, it was between 56 and 78 microns.

Retrolental fibroplasia and vitamin E in the preterm infant--comparison of oral versus intramuscular:oral administration.

To evaluate the efficacy of four early intramuscular injections of vitamin E given in addition to continuous minimal oral vitamin E supplementation, 168 very low-birth-weight infants (less than or equal to 1,500 g) have enrolled in a randomized, double-masked, clinical study. All infants received vitamin E orally, 100 mg/kg/d. In addition, on days 1, 2, 4, and 6, seventy-nine infants received vitamin E intramuscularly, 15, 10, 10, and 10 mg/kg, respectively. On the same days, 89 control infants received placebo intramuscular injections. Multivariate analysis of the 135 infants who survived greater than or equal to 10 weeks showed no significant difference in the development of severe retrolental fibroplasia between these two supplementation schedules (P = .86). Plasma vitamin E levels never exceeded a mean of 3.3 mg/100 mL, and no toxicity was observed. Ultrastructural analyses of seven pairs of whole eye donations from infants receiving IM vitamin E demonstrated identical kinetics of gap junction formation between adjacent spindle cells as compared with 13 pairs of whole eye donations from control infants (P greater than .3). Therefore, oral vitamin E supplementation affords retinal protection against the development of severe retrolental fibroplasia when initiated on the first day of life and maintained continuously until retinal vascularization is complete.

Zone of zero-associated phoria in patients with convergence insufficiency.

The zone of zero-associated phoria (ZZAP) was determined for patients with convergence insufficiency. The ZZAP for these patients differs from that of asymptomatic patients. It is concluded that the ZZAP may be used as a supplemental test to help the clinician detect convergence insufficiency and possibly other binocular deficiencies.

Common clinical configuration of zone of zero-associated phoria.

The four common configurations of the zone of zero-associated phoria are presented based on the results of a clinical study of 156 asymptomatic patients. These configurations and the relative frequencies, constitute normative data against which we can compare similar zones and frequencies in patient populations having certain binocular defects.

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.

Retrolental fibroplasia: further clinical evidence and ultrastructural support for efficacy of vitamin E in the preterm infant.

To further evaluate the efficacy of oral vitamin E in preventing the development of severe retrolental fibroplasia (RLF) in very low-birth-weight infants, 100 infants treated with 100 mg/kg/d of vitamin E (dl-alpha-tocopheryl acetate) were compared with 75 infants treated with 5 mg/kg/d of vitamin E (dl-alpha-tocopherol) in the same nursery during the previous year. All 175 infants weighed less than or equal to 1,500 g at birth and required supplemental oxygen. A total of 120 infants (69 treatment; 51 control) survived greater than or equal to 10 weeks. Multivariate analysis of the control population identified five risk factors (P less than or equal to .10): gestational age, level and duration of oxygen administration, intraventricular hemorrhage, sepsis, and birth weight. When multivariate analysis was applied to both control and treatment groups, the severity of RLF was found to be significantly reduced in infants given the treatment dose of vitamin E (P = .003). Ultrastructural analyses of 58 pairs of whole-eye donations from high-risk infants surviving less than 10 weeks suggest that the initial morphologic event is gap junction increases between the plasma membranes of adjacent spindle cells of the van-guard retina. Such extensively gap junction-linked spindle cells are apparently removed from the vasoformative process as early as 4 days of life, forming a barrier to further normal vascular development and triggering retinal and vitreal neovascularizations approximately 8 weeks later. These events are maximally suppressed by elevated plasma vitamin E levels in infants greater than or equal to 27 weeks gestational age.

Clinical comparison of the zone of clear single binocular vision with the zone of zero-associated phoria.

Normative data comparing the zone of zero-associated phoria (ZZAP) with the zone of clear single binocular vision (ZCSBV) are presented based on a clinical study of 156 asymptomatic patients. No statistically significant relations were found between zone difference and patient age, sex, and amount of near lens addition in the case of presbyopes.

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).

The range of zero-associated phoria in an asymptomatic clinical population.

The clinical concept of the range of zero-associated phoria is developed, and normative data for this range are presented based on a clinical study of 201 asymptomatic patients. The relation of patient age, sex, and amount of near lens addition to this range is examined. The range at far is not related to patient age or sex. The range at near appears to bae independent of patient age, sex, and the amount of near addition required by presbyopes.

The ratio of the size of the optic cup (as determined by the place where the vessels deviate) to size of the disc.

The vessel deviation to disc ratio (VDR) of the optic nerve head can be defined for a given meridian as the ratio of the size of the cup as indicated by small blood vessel deviation in that meridian to the size of the disc. Thus, VDR is a relative measure similar to cup/disc ratio. The difference between VDR and other methods of measuring cup/disc ratio is that the former identifies the rim of the cup with the deviation or bending of the small blood vessels as they fan out over the disc, whereas the latter determine the location by the other criteria which vary from examiner to examiner. The purpose of this study is to quantify the variation in VDR and its relation to age, refractive error, and sex.