Photoscreening for amblyogenic factors by public health personnel: the Eyecor Camera System.

OBJECTIVES: This pilot study was designed to assess the ability of a photoscreening camera to detect amblyogenic factors such as high refractive error, anisometropia, media opacities and strabismus in children, compared to the standard vision screening techniques employed by the local state public health screening personnel. METHODS: Public health personnel in Illinois used the Eyecor prototype to the current commercially available MTI PS-100 photoscreening camera (manufactured by Medical Technology Inc.) to screen 127 non-dilated subjects, ages 7 months to 20 years (mean age, 6 years), for amblyogenic factors. All participants were concurrently subjected to the "standard" vision screening employed routinely by state public health personnel. The study participants included a group of normal inner-city children and one group of special-needs children. The normal children came from both a public school and a private school. The special-needs children included a group of children from a state-run school for the deaf and hard-of-hearing and a separate group of children attending a multi-disciplinary Easter Seals clinic. RESULTS: In the population of normal children, the mean sensitivity and specificity for the observers using the Eyecor Camera system was 81% and 83% with a mean positive predictive value of 83%, and a mean negative predictive value of 55%. Standard vision screening techniques employed by public health service certified vision screeners had a sensitivity of 88%, a specificity of 91%, a positive predictive value of 67% and a negative predictive value of 97% in the same subjects. In the population of special-needs children with hearing impairment and developmental delay, the mean sensitivity and specificity for the observers using the Eyecor Camera system was 74% and 82% with a mean positive predictive value of 69% and a mean negative predictive value of 85%. Standard vision screening techniques employed by public health service certified vision screeners had a sensitivity of 100%, a specificity of 55%, a positive predictive value of 62% and a negative predictive value of 100% in the same subjects. (See Table 1) CONCLUSIONS: This study shows that the Eyecor Photoscreening Camera is useful in screening normal children for amblyogenic factors. Photoscreening was at least as effective as standard screening methodologies performed by certified vision screeners as required by state public health policy. In addition, photoscreening is particularly useful in testing those children "unscreenable" by conventional vision screening procedures.

Residual ethanol content of donor sclera after storage in 95% ethanol and saline rinse of various durations.

PURPOSE: Some surgeons are wary of using alcohol-preserved sclera for allografts because they fear a toxic effect on surrounding tissue after placement. We set out to determine the amount of ethanol remaining in scleral allograft material after storage in 95% ethanol. METHODS: Sixty half scleras from 30 donors were preserved in 95% ethanol for an average of 31+/-14 days (range, 11 to 50 days). Rehydration was performed by soaking each half sclera in 4 ounces of balanced salt solution. Half scleras were randomly assigned to six groups of 10 each. Assays for ethanol were performed on the following groups: no balanced salt solution soak and balanced salt solution soak for 10 minutes, 20 minutes, 30 minutes, 40 minutes, and 50 minutes. Ethanol assay was performed by Headspace Gas Space Chromatography at ChemaTox Laboratory, Inc, Boulder, Colorado. RESULTS: The 10 half scleras without balanced salt solution soak had a mean ( SD) ethanol level of 175+/-14.1 mg per g of sclera. After 10 minutes of balanced salt solution s oak, the level decreased to 7.57+/-1.56 mg per g, then 3.77+/-3.02 mg per g at 20 minutes, 1.59+/-0.61 mg per g at 30 minutes, 1.07+/-0.30 mg per g at 40 minutes, and 0.96+/-0.26 mg per g at 50 minutes. Approximately 96% of the ethanol is leeched out of the half sclera by 10 minutes and 98% by 20 minutes. CONCLUSIONS: For sclera preserved in 95% ethanol, soaking in balanced salt solution for 20 minutes or longer leeches approximately 98% of the ethanol from the preserved donor sclera.

Measuring quality in pediatric ophthalmology.

Pediatric ophthalmologists should respond to quality expectations inherent in all disciplines of medicine. The specialists must be able to collect data to document and prove the quality of their work if it anticipates continued reimbursement for services. Quality of medical practice is assessed by outcomes research, which is different from clinical research. All specialists are systemically measuring individual and group outcomes across the spectrum of American health care systems. Pediatric ophthalmologists, both in private practice and at academic centers, must concentrate their research efforts on the assessment of cost, quality, utilization, and patient-centered health-related quality of life for the most common pathologies in pediatric ophthalmology practice.

Case report: unilateral mydriasis from topical Opcon-A and soft contact lens.

The use of topical ocular antihistamine/decongestant combinations to treat symptoms associated with allergic conjunctivitis is widespread, effective, and generally without adverse effects. Recently, these medications have become available without a prescription, possibly leading patients to the erroneous assumption that they are void of side effects. Likewise, patients may use these drugs for many ocular therapies for which they are unintended, possibly resulting in ocular complications. One significant adverse effect of these antihistamine/decongestant combinations when used inappropriately is pupillary dilation with associated blurry vision. Continued emphasis of the possible deleterious side effects by the clinician is recommended to circumvent these problems.

A southern Illinois eyecare provider survey.

PURPOSE: To determine opinions and knowledge of southern illinois eyecare patients about the different types of eyecare providers and the services they perform. METHODS: A two page survey (Appendix) was presented to 500 consecutive patients registering at the Southern Illinois University Eye Center in April, 1995. Patients were asked to respond to questions which tested their knowledge of the type of provider they were to visit, i.e., ophthalmologist, optometrist, or optician and the services provided. RESULTS: There was pronounced confusion and uncertainty especially with regard to the terms "ophthalmologist" and "optometrist." Approximately one-quarter of those polled believed an optometrist to be a physician, and another one-quarter was unsure. Only one-third of those surveyed reported that "OD" referred to "optometrist." Approximately one-third were unsure if an optician was a physician. Over eighty percent felt there was confusion concerning the different types of eyecare providers and only 49% felt they were well informed with regard to providers and their services. CONCLUSION: The public, even among eyecare patients, is poorly informed with regard to the different types of eyecare providers and their services.

5-Fluorouracil reduces scarring after strabismus surgery.

PURPOSE: To examine the effect of topically administered 5-fluorouracil during strabismus surgery on post-operative scarring and the strength of the tendon-muscle union. METHODS: Bilateral superior and inferior rectus muscle recessions were performed on 10 Stauffland white rabbits. The operated muscles in one eye received a 5-min topical application of 50 mg/mL solution of 5-fluorouracil (5-FU). The fellow eye received placebo treatment with a 5-min application of balanced sterile saline. Both eyes were enucleated 29 days postoperatively and examined for evidence of scarring. The tensile strength of both treated and untreated muscles was measured. Two additional rabbits received no surgery but had their eyes enucleated to serve as controls for tensile strength measurements. RESULTS: A significant reduction (P = 0.0001) in the amount of scarring was noted in eyes treated with 5-FU. A reduction in the tensile strength of both operated groups compared with the unoperated groups (P = 2.72 x 10(-12)) was noted, with a small but significant difference between the two operated groups (P = 0.0423). CONCLUSION: This study suggests that 5-FU may be a useful adjunctive therapy in strabismus surgery, especially when extensive postoperative scarring is expected.

Unilateral surgery for exotropia with convergence weakness.

We prospectively studied 14 patients whom we treated surgically for exotropia (XT) with convergence weakness measuring at least 8 delta for distance (6 m) that increased at least 8 delta at near (1/3 m). Surgery involved lateral rectus recessions and medial rectus strengthenings (advancements or resections) to eliminate distance and near deviations and simultaneously collapse near-distance differences. The medial rectus was strengthened more than the lateral rectus was recessed; amounts were based on the near deviation. Minimum follow-up was 6 months after surgery. Preoperatively, the mean XT at distance was 18.3 delta (range, 8 to 35 delta) and at near 30.1 delta (range, 16 to 50 delta). At latest follow-up evaluations the mean distance deviation was 0.1 delta XT and at near 1.8 delta XT. The near-distance differences were reduced by a mean of 10.2 delta; the mean postoperative difference was 1.7 delta. Unilateral surgery for XT with convergence weakness biased to medial rectus strengthening and geared to near deviation can successfully collapse the near-distance differences while satisfactorily aligning both distance and near fixation. This surgery has low risk of creating long-term postoperative esodeviations at distance.

Wound strength comparison of a 5.1-millimeter no-stitch with a 7.0-millimeter sutured incision in human cadaver globes.

We compared the wound strength of 5.1-millimeter no-stitch incisions with that of 7.0-millimeter sutured incisions in cadaver eyes. Each incision was performed on seven cadaver eyes. Wound integrity was evaluated by subjecting each globe to increasing intraocular pressure (IOP), increasing external pressure, and sudden external pressure. Wound leaks occurred in the 7.0-millimeter-incision globes at consistently lower IOPs and with less external pressure than they did in the 5.1-millimeter-incision globes. We conclude that the 5.1-millimeter no-stitch flap incision has greater wound integrity than the 7.0-millimeter sutured incision when subjected to either internal or external pressures.

Screening for ocular toxicity in asymptomatic patients treated with tamoxifen.

Tamoxifen is an antiestrogen drug used in the treatment of patients with breast cancer that is being studied for use in patients at high risk for developing breast cancer. Case reports have documented ocular toxicity caused by tamoxifen in patients with visual symptoms. We attempted to determine the prevalence of ocular toxicity in visually asymptomatic tamoxifen-treated patients. We performed extensive ocular examinations on 135 visually asymptomatic tamoxifen-treated patients. Two patients (1.5%) had intraretinal refractile crystals consistent with tamoxifen retinopathy. Both patients were without visual symptoms or visual loss. Corneal crystals, macular edema, and optic nerve changes were absent. The cumulative tamoxifen doses of these two patients were 10.9 and 21.9 g, respectively. For the 135 patients studied, the mean cumulative dose was 17.2 g, with a standard deviation of 13.0. We do not believe the relatively uncommon finding of tamoxifen-related ocular toxicity merits special screening for such disease.