The optimum time to employ telephotoscreening to detect retinopathy of prematurity. (33/577)

PURPOSE: Labor-intensive screening of infants in the neonatal intensive care units is the only way to detect retinopathy of prematurity (ROP). Our purpose is to determine if RetCam 120 photos, acquired by a neonatal nurse, can be used to screen for ROP by performing 2 screening examinations, at 32 to 34 weeks (exam 1) and at 38 to 40 weeks (exam 2) post-conceptional age. METHODS: RetCam examinations are performed by a nurse on infants at exam 1 and exam 2 intervals. At the same time, an examination is performed by an experienced ophthalmologist. Masked readers evaluate the photos for ROP and determine if each eye will progress to prethreshold or threshold disease. The data are compared to the clinical course of the eyes. RESULTS: Forty-six eyes were photographed at exam 1 and 50 eyes at exam 2 from July 1, 1999, to December 15, 1999. Sensitivity and specificity of detecting ROP were 76% and 100% for exam 2 and 46% and 100% for exam 1. Sensitivity and specificity of predicting prethreshold disease were 64% and 97% for exam 2 and 33% and 100% for exam 1. Sensitivity and specificity of predicting threshold were both 100% at exam 2 and 0% (one photo in category) and 95% at exam 1. CONCLUSION: A potential reason for low sensitivity is technical limitations of the Retcam, such as the difficulty in capturing peripheral retina in small eyes and the need for a better lid speculum.  (+info)

Early diagnosis of Usher syndrome in children. (34/577)

PURPOSE: To screen severe to profound, preverbal hearing-impaired children for Usher syndrome by ophthalmologic examinations, including electroretinographic testing. These patients are especially good candidates for early cochlear implants, which will improve listening and spoken language skills. METHODS: Consecutive patients over 2 years of age, given a diagnosis of severe to profound, preverbal hearing loss, were screened for Usher syndrome by a complete ophthalmologic examination including an electroretinogram. RESULTS: Five of 48 patients screened (10.4%) were diagnosed with Usher syndrome and received cochlear implants. CONCLUSION: All children with severe to profound, preverbal sensorineural hearing loss should be screened for Usher syndrome by ophthalmologic examination including electroretinogram.  (+info)

Eduard Jaeger's Test-Types (Schrift-Scalen) and the historical development of vision tests. (35/577)

PURPOSE: Eduard Jaeger's original Test-Types were carefully evaluated: (1) to determine whether Jaeger had maintained a consistent standard, (2) to establish the correct Snellen equivalent for Jaeger's Test-Types, (3) to answer the question of why and how the standard was lost, and (4) to compare the visual angle of optotypes to lines of continuous text. METHODS: All original Viennese editions of Jaeger's Test-Types, as well as first generation United Kingdom (UK) and United States (US) versions, were evaluated. Data were collected objectively using a microruler with a 20X loupe and subjectively using a laser distance-measuring device. The data were analyzed using Microsoft Excel. All previous measurements of Jaeger's Test-Types, objective and subjective, collected over the past 133 years were compared to the current data and to each other. RESULTS: The correct Snellen equivalent of Jaeger's Test-Types was determined. The visual angle created from the measurement of the height of lowercase letters, without ascenders or descenders, provides an accurate method of assigning a visual angle of a line of continuous text. Comparing the typefaces used in printing first generation UK and US versions of Jaeger's Test-Types to the Viennese editions provided an explanation for the absence of a consistent standard for Jaeger's Test-Types today. CONCLUSIONS: All 10 versions of Jaeger's original Test-Types are virtually identical and established a gold standard for reading vision tests. Jaeger's standard was lost when his Test-Types were first printed in the UK and the US using local typefaces. The Jaeger standard has been re-established. Visual angles determined using continuous text are comparable to those obtained by using optotypes.  (+info)

The impact of information technology on the practice of ophthalmology. (36/577)

Information technology has had a tremendous impact on the outlook of our professional lives. The Internet has revolutionised the speed of access to information with touch of a button. This article discusses the various aspects of information technology which are changing and enhancing our professional lives. It provides tips to enable the busy practising clinician to use the available resources effectively. Problems such as reliability of information on the web and how to assess the quality of such matter are also discussed.  (+info)

Sample size for ophthalmology studies. (37/577)

Knowledge and the usage of actual sample size formulae are a necessity as validity of the inferences from research studies is often dependent on this. This paper explains how sample sizes are calculated. The concept of sampling variation is explained to emphasize the need for its proper calculation. Sample size formulae are explained with examples to provide researchers with a means of calculating the sample sizes for the commonly used study designs. Ophthalmic data are used as examples. It is perceived that this will improve the quality of inferences drawn from ophthalmic research studies.  (+info)

The assessment of lens opacities in clinical practice: results of a national survey. (38/577)

AIM: To investigate the examination of lens opacities in routine ophthalmic clinical practice. METHOD: A questionnaire survey was mailed to 703 consultant ophthalmologists in the UK. The surgeons were asked which lens feature(s) they assessed in their clinics when deciding whether to offer cataract surgery. RESULTS: 489 replies were received. A broad range of lens opacities was assessed, with differences between surgeons for some opacities with high prevalences in the population, particularly cortical opacities. Many (74% of 467) surgeons assessed one or more lens opacities (anterior subcapsular cataract, vacuoles, water clefts, coronary flakes, focal dots, retrodots, fibre folds) which may be visually important but which have received relatively little attention by researchers. CONCLUSIONS: Some classes of lens opacity which are traditionally measured by researchers may be ignored in clinical practice and opacities which are traditionally ignored by some researchers are regarded as clinically important by a substantial number of surgeons.  (+info)

Patterns of prescription and drug use in ophthalmology in a tertiary hospital in Delhi. (39/577)

AIMS: The present study was carried out to describe the patterns of prescription and drug use in Ophthalmology in out-patients at Dr Rajendra Prasad (R.P.) Centre for Ophthalmic Sciences of All India Institute of Medical Sciences (A.I.I.M.S.), New Delhi. METHODS: Prescriptions of 1017 out-patients were audited through a specially designed form and analysed for the following: average number of drugs per prescription, duration of treatment (recorded or not), dosage forms prescribed, frequency of administration (recorded or not), number of encounters with antibiotics and percentage of drugs prescribed by generic name. RESULTS: Prescription analysis showed that the average number of drugs per prescription was 3.03. Duration of treatment was recorded for only 26.4% of the drugs prescribed. The maximum number of drugs prescribed were in the form of eye drops (76%), followed by tablets (10.9%), ointments (6.4%), syrups (1%), capsules (0.7%), lotions (0.3%) and injections (0.1%). No dosage form was recorded for 4.6% of the drugs prescribed. The frequency of administration was recorded for only 77.9% of the drugs prescribed. The number of antibiotics prescribed was 1059 which constitutes 34.2% of the total number of drugs prescribed. The percentage of drugs prescribed by generic name was only 35%. CONCLUSIONS: The results obtained in this study indicated an awareness of polypharmacy but a high incidence of common prescription writing errors such as not recording the duration of therapy, frequency of administration and dosage form. Moreover prescribing by generic name was also low.  (+info)

Tritan colour contrast sensitivity function in refractive multifocal intraocular lenses. (40/577)

AIMS: To compare tritan colour contrast sensitivity (CCS), without and with glare, in patients with refractive multifocal intraocular lenses (IOLs) and with monofocal intraocular lenses. METHODS: Tritan CCS was determined (Moorfields Vision System, CH Electronics) in 15 eyes (14 patients, 75.7 (+/-6.6) years) with a refractive multifocal IOL (Allergan SA 40N) and in 11 eyes (10 patients, 73.7 (+/-6.4) years) with a monofocal IOL (Allergan SI 40 NB). Measurements were made monocularly under mesopic conditions at a distance of 2 metres from the monitor with best distance refraction plus 0.5 D at 0.5, 1, 3, 6, 11.4, and 22.8 cycles per degree (cpd). The test was then repeated for the multifocal IOLs, adding minus 2.5 D to the best distance refraction to force the patient to use the near focus. Both lenses were also investigated under glare conditions with the same set-up and using the brightness acuity tester (BAT). RESULTS: The tritan CCS function without glare in multifocal lenses through the distance focus was nearly identical to that through the near focus. The following statistically significant differences were measured: the CCS function without glare for the multifocal lens was worse at 0.5 cpd and 1.0 cpd than that of the monofocal lens. In CCS testing of the multifocal group with glare at 6 cpd, the results through the distance focus were better than the results through the near focus. For the CCS function with glare, the values for the distance focus in the multifocal lens were worse than the values for the monofocal lens at 0.5 cpd and 1 cpd. In CCS testing with glare through the near focus and CCS testing through the monofocal lens, the monofocal lens performed better at 0.5 cpd, 1 cpd, 3 cpd, and 6 cpd. CONCLUSION: Refractive multifocal intraocular lenses influence tritan CCS function compared to monofocal lenses.  (+info)