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Aims/background: Geographical variations in health care are common. There is, however, no simple explanation for why they arise. Variations in rates of ophthalmic surgery in the population aged 65 and over were investigated, with the aim of determining their cause., Methods: Routine data sources were used to obtain the 1991-2 age and sex standardised rates for English health districts with an ophthalmic unit. Weighted least squares regression was used to study the relation between these rates and various factors describing the population and the provision of care., Results: Surgery rates varied more than threefold. High rates of surgery were associated with high throughput and bed numbers (both p < 0.001), high proportions of day case surgery (p < 0.001), long waiting lists (p < 0.001), and a high number of theatre sessions (p = 0.002). Conversely, a high percentage of emergency admissions was associated with lower rates of surgery (p = 0.004). These six variables accounted for 58% of the variation., Conclusion: Geographical variations were found to exist, less than two thirds being explained by differences in the provision of care. The remaining variation may partly be attributed to private practice and the lack of consensus for many ophthalmic procedures (the 'surgical signature'), including a lowering of the threshold for surgery. These findings have implications for the planning of ophthalmic services.

Delayed visual maturation (DVM) can present as an isolated anomaly (type 1A), but can be compounded by perinatal problems (type 1B), severe neurodevelopmental delay (type 2), or ocular anomalies/nystagmus (type 3), in which group the common feature appears to be nystagmus. The neurodevelopmental and ophthalmic aspects of 26 infants with DVM were studied. Onset of visual improvement, rate of acquisition of normal vision and eventual outcome were studied quantitatively, using an adaptation of the acuity card procedure. Neurodevelopmental assessment was performed after visual improvement. The results support the long-held clinical impression that if blindness is the presenting feature, neurodevelopmental outlook is excellent. DVM could represent a defect in the extrageniculostriate visual system, and the onset of vision in all types--and the development of nystagmus in type 3--could herald the emergence of geniculostriate function.

Patients with Angelman's syndrome have been reported to have ocular hypopigmentation and a number are now known to have a microdeletion of chromosome 15q 11----13. Detailed ocular examination of eight new cases revealed normal visual acuity and foveal reflexes, but a pigmentary deficiency which is limited to the choroid and iris stroma--both of neural crest origin. Patients with Prader-Willi syndrome have similar ocular features and many have a microdeletion of chromosome 15q 11----13. It is therefore possible that this region may influence neural crest development.

Corneal arcus presents many puzzling features. The correlation between its incidence and serum lipid levels is poor and, using immunoelectrophoresis, we have only been able to identify low-density lipoprotein inconsistently in corneae containing this deposition. Infrared thermography has shown us that arcus commences in the warmest regions of the cornea. We have considered the possible relevance of our biochemical and thermographic findings to other problems with corneal arcus such as its irreversibility, anatomical distribution, and clear zone.

Extracts of fresh senile human peripheral cornea with varying degrees of arcus were prepared by soaking minced tissue in buffered saline/EDTA. Apolipoprotein B was, at most, an occasional feature of these extracts; interactions involving glycosaminoglycans were not evident; and the lipid composition, particularly of the cholesterol ester fraction, was also not consistent with a recent origin from plasma components and particularly form low density lipoprotein. Assuming this origin, substantial secondary changes must follow insudation, involving protein loss and lipid reesterification, as is described for lipid deposits forming intracellularly at other sites. The manner of these changes in deposit forming extracellularly in the avascular peripheral cornea is not clear.

Background: Amblyopia is the commonest visual disorder of childhood in Western societies, affecting, predominantly, spatial visual function. Treatment typically requires a period of refractive correction ('optical treatment') followed by occlusion: covering the nonamblyopic eye with a fabric patch for varying daily durations. Recent studies have provided insight into the optimal amount of patching ('dose'), leading to the adoption of standardized dosing strategies, which, though an advance on previous ad-hoc regimens, take little account of individual patient characteristics. This trial compares the effectiveness of a standardized dosing strategy (that is, a fixed daily occlusion dose based on disease severity) with a personalized dosing strategy (derived from known treatment dose-response functions), in which an initially prescribed occlusion dose is modulated, in a systematic manner, dependent on treatment compliance. Methods/design: A total of 120 children aged between 3 and 8 years of age diagnosed with amblyopia in association with either anisometropia or strabismus, or both, will be randomized to receive either a standardized or a personalized occlusion dose regimen. To avoid confounding by the known benefits of refractive correction, participants will not be randomized until they have completed an optical treatment phase. The primary study objective is to determine whether, at trial endpoint, participants receiving a personalized dosing strategy require fewer hours of occlusion than those in receipt of a standardized dosing strategy. Secondary objectives are to quantify the relationship between observed changes in visual acuity (logMAR, logarithm of the Minimum Angle of Resolution) with age, amblyopia type, and severity of amblyopic visual acuity deficit. Discussion: This is the first randomized controlled trial of occlusion therapy for amblyopia to compare a treatment arm representative of current best practice with an arm representative of an entirely novel treatment regimen based on statistical modelling of previous trial outcome data. Should the personalized dosing strategy demonstrate superiority over the standardized dosing strategy, then its adoption into routine practice could bring practical benefits in reducing the duration of treatment needed to achieve an optimal outcome. Trial registration: ISRCTN ISRCTN12292232. [ABSTRACT FROM AUTHOR]

Purpose: To describe the rate of change in retinal vessel width and tortuosity in eyes that develop treatment-requiring, or type 1, retinopathy of prematurity (ROP) versus eyes that do not develop type 1 ROP. Methods: Posterior poles of eyes of 41 infants at risk for ROP were imaged longitudinally with a 30° fundus camera. Retinal vessel width and tortuosity were measured with computer-assisted image analysis. The rate of change per day in width and tortuosity up to the development of most severe ROP was calculated from linear regression and eyes with (n = 10) and without type 1 ROP (n = 31) were compared. Results: Eyes that developed type 1 ROP had a greater rate of change in width for venules and 3 widest vessels (P < 0.0001), and a greater rate of change in tortuosity for arterioles and 3 most tortuous vessels (P < 0.0001) than eyes that did not develop type 1 ROP. These vessel parameters discriminate the 2 groups well (area under the ROC curve, 0.79-0.90). A combination of venular width and arteriolar tortuosity had the best discriminative ability (area under the ROC curve, 0.96). Conclusions: In this pilot study, eyes that eventually developed type 1 ROP demonstrated a faster increase in width and tortuosity of retinal vessels compared with those that did not. Further study of the kinetics of retinal vascular change in a larger sample may allow for the earlier identification of vision-threatening ROP. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives To compare visual outcome in response to two prescribed rates of occlusion (six hours a day and 12 hours a day). Design Unmasked randomised trial. Setting Research clinics in two London hospitals. Participants 97 children with a confirmed diagnosis of amblyopia associated with strabismus, anisometropia, or both. Interventions 18 week period of wearing glasses (refractive adaptation) followed by occlusion prescribed ("patching") for six or 12 hours a day. Main outcome measures Visual acuity measured by logMAR letter recognition; objectively monitored rate of occlusion (hours a day). Results The mean age of children at study entry was 5.6 (SD 1.5) years. Ninety were eligible for occlusion but 10 dropped out in this phase, leaving 80 children who were randomised to a prescribed dose rate of six (n=40) or 12 (n=40) hours a day. The mean change in visual acuity of the amblyopic eye was not significantly different (P=0.64) between the two groups (0.26 (95% confidence interval 0.21 to 0.31) log units in six hour group; 0.24 (0.19 to 0.29) log units in 12 hour group). The mean dose rates (hours a day) actually received, however, were also not significantly different (4.2 (3.7 to 4.7) in six hour group v 6.2 (5.1 to 7.3) in 12 hour group; P=0.06). The visual outcome was similar for those children who received three to six hours a day or more than six to 12 hours a day, but significantly better than that in children who received less than three hours a day. Children aged under 4 required significantly less occlusion than older children. Visual outcome was not influenced by type of amblyopia. Conclusions Substantial (six hours a day) and maximal (12 hours a day) prescribed occlusion results in similar visual outcome. On average, the occlusion dose received in the maximal group was only 50% more than in the substantial group and in both groups was much less than that prescribed. Younger children required the least occlusion. Trials registration Clinical Tria [ABSTRACT FROM AUTHOR]

Presents a review of research data on the long-term ophthalmic morbidity of low birth weight children. Extent of visual acuity deficits; Prevalence of strabismus; Reduction in stereopsis.

With the advent of the acuity card procedure, it is now possible to measure quantitatively the vision of infants and young children in a routine clinical setting. Over a 19 month period 1177 tests were performed on 586 patients; ages ranged from 0.5 weeks to 23 years. Overall 1102 (93%) were successful, as were 588 of the 627 (94%) tests performed on children under the age of two years when no conventional acuity test is possible. The results serve as a background on which the argument for and against the need to measure the vision of children is considered. [ABSTRACT FROM AUTHOR]

Multidisciplinary teams are generally viewed as beneficial in the management of the visually impaired child, yet little is known about them. Two teams were studied. Team A had well-defined functions relating to Identification of visually impaired children, coordination of services and liaison. Team B had a more general aim of sharing information on a range of ophthalmic issues other than visual impairment. By comparing the two teams, we conclude that a muitidisciplinary team is more likely to be effective if it draws its membership from a range of appropriate professions and its functions are focused. Benefits of teams include increased and earlier referral, improved interdisciplinary liaison and collaboration, and speedier and more appropriate implementation of services. Lack of time to participate, particularly by medical personnel, is a problem. [ABSTRACT FROM AUTHOR]

Plus disease is a major indicator for treatment in retinopathy of prematurity (ROP), and computer-assisted image analysis of vessel caliber and tortuosity in the posterior pole may indicate disease progression and severity. We sought to determine whether semiautomated digital analysis of posterior pole vessels using narrow field images with varying severity of ROP correlated with vessel width and tortuosity.▪ [Copyright &y& Elsevier]

Aim: To determine the temporal retinal vessel angle in babies and its relation to preterm birth. Methods: Digital images were obtained during routine screening for retinopathy of prematurity (ROP). The temporal retinal vessel angle was measured in 164 eyes of 82 babies born "very preterm" (24-27 weeks gestational age (GA)), "preterm" (28-31 weeks GA), and "near term" (⩾32 weeks GA). Results: Mean temporal vessel angle (TVA) for all three GA groups together is 80.0° (SD 17.0°) for the right eye and 80.5° (16.7°) for the left eye. The range is right eye 59-106°, left eye 69-97°, with 95% data above 67° for the right and 63° for the left eye. For babies born near term, WA is 82° in each eye. There is a high degree of interocular symmetry between right and left eyes and a statistically insignificant trend for increasing WA with increasing GA. The presence and stage of ROP affected one parameter of the left eye alone. Conclusions: These data provide normative data on the WA in babies and will facilitate, especially if there is interocular asymmetry, determining whether there is macular displacement. [ABSTRACT FROM AUTHOR]

Aim: To offer a critique of current methods of defining amblyopia treatment outcome and to examine alternative approaches. METHOD: Literature appraisal and descriptive case presentations. RESULTS: Currently, the outcome of amblyopia treatment is expressed as the number of acuity chart lines gained or, alternatively, achievement of an arbitrarily adopted level of visual acuity. As binocular vision is optimised with equal visual input from each eye the authors propose that the optimum outcome of amblyopia therapy is to achieve a visual acuity in the amblyopic eye equal to that of its fellow. In addition, improvement should be graded as the proportion of change in visual acuity with respect to the absolute potential for improvement (that is, that pertaining in the fellow eye at end of treatment). CONCLUSIONS: There are two methods of appropriately describing the outcome of amblyopia treatment: firstly, by the difference in final visual acuity of amblyopic and fellow eye (residual amblyopia); secondly, the proportion of the deficit corrected. [ABSTRACT FROM AUTHOR]

Eye (2003) 17, 117-118. doi:10.1038/sj.eye.6700297 [ABSTRACT FROM AUTHOR]