Vision screening for children: current trends, technology, and legislative issues

PURPOSE OF REVIEW: The purpose of this review is to examine current trends in vision screening for children. RECENT FINDINGS: Literature within the past year regarding children's vision screening has been dominated by clinical validation studies of autorefractors or photoscreeners that allow the detection of amblyogenic refractive errors, misalignment of the eyes, or media opacities. New technologies reported include wave-front analysis for amblyogenic factors and a visual evoked potentials-based screening tool for the preverbal child. Studies evaluating the goals of the screening program, the target population, and the physical limitations of the screening environment have prompted multipronged or hybrid studies designed to more accurately detect vision problems, particularly in the preschool child, in whom cooperation and cognitive development affect reliability of results. State and federal legislation in the United States has been proposed or adopted to regulate and partially fund pediatric vision screening and comprehensive examinations. SUMMARY: Through improvements and new developments in technology, study design, the efforts of organized medicine, and legislative initiatives, vision screening for children continues toward the goal of bringing all children with eye disease or vision problems to treatment in a timely fashion.     

青光眼的基因治疗:问题与挑战

青光眼基因治疗的靶目标包括眼前节的小梁网和睫状体、眼后节的视网膜神经节细胞等。青光眼基因治疗的策略包括降眼压、视神经保护及抑制滤过术后瘢痕形成等方面。将目的基因导入小梁组织使房水排出阻力增加是一种理想的造模方法。目前虽在青光眼基因治疗领域取得较大进展,但在组织特异性启动子、长时基因表达及副作用等方面尚存在着问题和挑战。     

Glaucoma screening: analysis of conventional and telemedicine-friendly devices

PURPOSE: Portable, telemedicine-friendly devices offer novel opportunity for screening and monitoring glaucoma in the remote and rural regions of the world. This study examines the effective combination of telemedicine-friendly screening devices for detection of glaucoma in relation with conventional, hospital-based devices. METHODS: A total of 399 eyes were screened with telemedicine-friendly devices and conventional, hospital-based devices such as ophthalmoscope, tonometer and perimeter. RESULTS: Combination of age and family history of glaucoma alone has a sensitivity of 35.6% (specificity 94.2%, area under the curve 0.81, correctly classified 81.1%) and an addition of telemedicine-friendly or conventional visual field tests optimized the sensitivity to 91.1% (specificity 93.6%, area under the curve 0.95, correctly classified 93%). Analysis indicates good agreement between vertical cup-to-disc ratio by ophthalmoscopy and digital image reading. An addition of intraocular pressure test does not change sensitivity (35.6%) and specificity (94.2%). CONCLUSION: This study indicates that evaluations of cup-to-disc ratio and visual field, using telemedicine-friendly devices, are most useful tools in screening for glaucoma. When used together these devices may be an alternative for conventional glaucoma screenings.     

Glaucoma management trends in Australia and New Zealand

BACKGROUND: To describe self-reported patterns of care for glaucoma of ophthalmologists in Australia and New Zealand and summarize current practice styles and patterns associated with glaucoma management. METHODS: A questionnaire of glaucoma management practices was mailed to all ophthalmologists registered with the Royal Australian and New Zealand College of Ophthalmologists in June 2003. The questionnaire assessed practice preferences for medical management, examination techniques and indications for surgery. The results were cross-tabulated by age, country and subspecialty training in glaucoma. RESULTS: Fifty-one per cent of 761 surveys were returned, 14% being from glaucoma specialists. New Zealand ophthalmologists proceeded to surgical management of glaucoma earlier than did their Australian colleagues. Australian ophthalmologists tended to use argon laser trabeculoplasty more frequently. Ninety-six per cent of ophthalmologists routinely use gonioscopy in diagnosing glaucoma. Disc drawings and recording cup:disc ratios were the most commonly used methods of documenting disc morphology; glaucoma specialists were more likely to use imaging technologies. SITA-Standard 24-2 was the most commonly used modality of perimetry, and was favoured by glaucoma specialists. CONCLUSIONS: This survey represents the first Australian and New Zealand effort to identify glaucoma management practices. Although a substantial consensus was found in most areas of treatment, a few areas showed diversity. The information gathered will enable ophthalmologists to compare their own practices with those of their colleagues. In addition, this survey provides a baseline allowing future trends in management to be determined.     

Glaucoma prescribing trends in Australia and New Zealand

PURPOSE: To summarize current practice styles and patterns associated with glaucoma management in ophthalmologists of Australia and New Zealand as derived from a survey. METHOD: A questionnaire was sent to all Australian and New Zealand ophthalmologists, which anonymously assessed demographic characteristics and prescribing patterns for each major class of glaucoma medication. RESULTS: A total of 761 questionnaires were sent with a response rate of 51%. Of respondents 14% were glaucoma subspecialists. In 69%, the first-line drug-class of choice was a prostaglandin analogue. New Zealand ophthalmologists favoured beta-blockers as their first-line agent because of cost, government restrictions and familiarity. Most respondents stated "hypotensive efficacy" as the most important factor in class choice. Alpha-2-agonists, carbonic anhydrase inhibitors and miotics were considered second-line agents, because of side-effects and lack of hypotensive potency. CONCLUSIONS: The choice of first-line agent for the treatment of glaucoma differed between Australian and New Zealand ophthalmologists, in part as the result of government restriction of prostaglandin-class drugs. Practice patterns seen in Australasia parallel the current evidence base reported in peer-reviewed literature.     

Bleaching desensitization: background and current challenges

"Bleaching desensitization" in rod photoreceptors refers to the prolonged depression of phototransduction sensitivity exhibited by rods after their exposure to bright light, i.e., after photolysis (bleaching) of a substantial fraction of rhodopsin in the outer segments. Rod recovery from bleaching desensitization depends critically on operation of the retinoid visual cycle: in particular, on the removal of all-trans retinal bleaching product from opsin and on the delivery of 11-cis retinal to opsin's chromophore binding site. The present paper summarizes representative findings that address the mechanism of bleaching desensitization.     

Patient-centred care in ophthalmology: current practices,effectiveness and challenges

Graefe's Archive for Clinical and Experimental Ophthalmology - To summarise different patient-centred care approaches that can be used in ophthalmology and review their effectiveness. An Entrez...     

Glaucoma screening by primary care physicians in southern Alberta: patterns,methods and deficiencies

BACKGROUND: This study was undertaken to determine the proportion of primary care physicians who routinely assess their patients for risk factors associated with glaucoma as well as the elements that underlie whether these physicians screen for glaucoma. METHODS: A brief, confidential questionnaire was distributed to primary care physicians on 3 occasions. The survey asked about the physicians' background, their glaucoma screening habits, reasons for not doing routine screening and measures that would help the physician begin to do screening. Responses were categorized and percentages calculated. RESULTS: Of the 161 questionnaires distributed, 49 (30.4%) were returned. Of the respondents, 53% claimed that they routinely screened for glaucoma; more urban than rural physicians did so (57% vs. 44%). Some of the screening methods documented were inappropriate. The reasons most often given for not screening were lack of equipment and skills, cited by 48% and 30%, respectively, of the physicians who claimed not to be currently screening. Most (85%) of the respondents who claimed to routinely screen for glaucoma said they would refer the patient to an ophthalmologist or optometrist if they suspected the condition. Among the measures that would help physicians currently not screening to begin doing so, training and access to equipment and facilities were most often suggested by those not currently screening as well as those routinely doing so. INTERPRETATION: If family physicians are an appropriate group to screen for glaucoma, and if mass screening for this condition is worth while, education and access to equipment are critical.     

Glaucoma drainage devices: a systematic literature review and current controversies

Glaucoma drainage devices create alternate aqueous pathways by channeling aqueous from the anterior chamber through a long tube to an equatorial plate that promotes bleb formation. Glaucoma drainage devices are being used more frequently in the treatment of glaucoma that does not respond to medications or trabeculectomy operations. In certain conditions, such as neovascular glaucoma, iridio-corneal syndrome, penetrating keratoplasty with glaucoma, glaucoma following retinal detachment surgery, and so on, it is becoming the primary operation. This review provides a systematic review of the literature and outlines the current controversies involving different glaucoma drainage devices and their design, overall surgical success, and complications following glaucoma drainage device insertion.     

Glaucoma screening: the importance of combining test data.

The objective of this study was to evaluate the effectiveness of screening tests for primary open angle glaucoma, both singly and in combination, using a decision analysis approach. A range of screening tests were carried out on 145 nonglaucomatous patients and 67 cases of previously undiagnosed glaucoma. Receiver operator characteristic curves were constructed for single test data to show the trade-off between sensitivity and specificity for varying cut-off criteria. The best discriminators of glaucoma were, in rank order: (1) a multiple stimulus static visual field screening test, (2) optic disc cupping, and (3) intraocular pressure. Decision curves were also constructed for various combinations of screening tests, where the inclusion of the tests were based on discriminant analyses. Sensitivities and specificities of more than 0.90 were obtained when visual field screening, optic disc cupping, and intraocular pressure were combined. Data from other tests when combined with these three variables failed to provide a significant improvement in discrimination.     

Glaucoma screening during regular optician visits: the feasibility and specificity of screening in real life

Purpose: To determine the feasibility and specificity of glaucoma screening during regular optician visits. Methods: In four optician shops, glaucoma screening was offered to 400 consecutive visitors aged 45?years or above. If the visitor agreed to participate, an intraocular pressure measurement and - in those with a pressure below 25?mmHg - a frequency-doubling perimeter (FDT) C20-1 visual field screening test were performed. Those with an elevated pressure or at least one reproducibly abnormal test location on FDT were referred to our hospital. Results: Three-hundred and fifty-two of 400 consecutive visitors (88%) were screened. Fifteen of the unscreened visitors were not screened because they were already regularly checked by an ophthalmologist related to glaucoma. Forty-two of 352 screened participants (12%) were referred. Of these 42 referrals, seven were diagnosed with glaucoma, 10 were diagnosed with ocular hypertension (OHT), 12 did not have any eye disease, seven had an eye disease other than glaucoma or OHT that was diagnosed previously and six were newly diagnosed with an eye disease other than glaucoma or OHT. The specificity of the screening protocol was 91% (95% confidence interval 88-94%). Conclusions: Glaucoma screening at the optician shop was feasible, but the specificity of the screening protocol was rather low. With more stringent cut-off points (30?mmHg; at least two reproducibly abnormal test locations), the specificity could be improved to 96% (94-98%), apparently without a significant loss of sensitivity. This suggests that screening during regular optician visits might be a viable approach.     

The Carmarthenshire Glaucoma Referral Refinement Scheme, a safe and efficient screening service

Aim

It has been previously shown that community refinement of glaucoma referrals is an efficient way to investigate and treat glaucoma suspects. The potential for false negatives has not been explored previously and we describe a scheme in which effort has been made to both assess and control for this, and report on its success.

Methods

Trained optometrists were recruited to examine and investigate the patients referred with suspected glaucoma, with a view to decreasing false-positive rates in accordance with an agreed protocol. The randomly selected notes of 100 patients referred onward to the Hospital Eye Service (HES) by trained, accredited optometrists, and the notes and optic disc images of 100 randomly selected patients retained in the community were examined in order to determine the efficiency and safety of the scheme.

Results

The scheme resulted in a 53% reduction in the total number of referrals to HES with a cost saving of £117 per patient. Analysis of patients referred resulted in a diagnosis of glaucoma or retention of patients in HES with suspected glaucoma in 83% and a good correlation between the hospital and optometric measurements. Analysis of notes and optic nerve images of patients not referred indicated no compromise on patient safety.

Conclusion

This study suggests that suspected glaucoma can be successfully refined in the community with benefits to both the patient and the hospital. We also suggest that such a scheme may be safe as well as cost-effective, a conclusion that has not as yet been reached by any other study.     

Diabetes mellitus: pathophysiology and current trends in management

Diabetes mellitus is a group of disorders that have in common abnormal insulin function resulting in disordered carbohydrate, protein and fat metabolism, the cardinal feature being elevated blood glucose levels. Acute complications include diabetic ketoacidosis, hyperosmolar non-ketotic "coma" and hypoglycemia. Long-term complications develop over several years and cause more morbidity and mortality than the acute complications. Although the pathogenesis of long-term complications is still unknown, it is likely that it relates to the abnormal metabolic state that occurs in diabetes. Current techniques of monitoring diabetes include blood glucose self-monitoring and the measurement of glycosylated hemoglobin. Management focuses on dietary adjustments (caloric amount, timing and composition), exercise and medications. Patients are encouraged to participate in comprehensive diabetes education programs to learn about new aspects of treatment and prevention of complications.