Screening for amblyopia in childhood.

BACKGROUND: Amblyopia is a reversible deficit of vision that has to be treated within the sensitive period for visual development. Screening programmes have been set up to detect this largely asymptomatic condition and refer children for treatment while an improvement in vision is still possible. The value of such programmes and the optimum protocol for administering them remain controversial. OBJECTIVES: The objective of this review was to evaluate the effectiveness of vision screening in reducing the prevalence of amblyopia. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Group Trials Register, on The Cochrane Library Issue 2, 2005, MEDLINE (1966 to May 2005 week 1) and EMBASE (1980 to 2005 week 19). No language restrictions were placed on these searches. No handsearching was done. SELECTION CRITERIA: We planned to analyse data from randomised controlled trials and cluster-randomised trials comparing the prevalence of amblyopia in screened versus unscreened populations. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study abstracts identified by the electronic searches. Full text copies of appropriate studies were obtained and, where necessary, authors were contacted. No data were available for analysis and no meta-analysis was performed. MAIN RESULTS: Despite the large amount of literature available regarding vision screening no trials designed to compare the prevalence of amblyopia in screened versus unscreened populations were found. Data currently under preparation may be available for updates to the review. AUTHORS' CONCLUSIONS: The lack of data from randomised controlled trials makes it difficult to analyse the impact of existing screening programmes on the prevalence of amblyopia. The absence of such evidence cannot be taken to mean that vision screening is not beneficial; simply that this intervention has not yet been tested in robust trials. To facilitate such trials normative data on age-appropriate vision tests need to be available and a consensus reached regarding the definition of amblyopia. In addition, the consequences of living with untreated amblyopia have yet to be quantified and a cost-benefit analysis carried out

Calcification of a Rayner Centerflex 570H hydrophilic acrylic intraocular lens following vitrectomy for retinal detachment: a clinicopathologic report.

PURPOSE: The case of a 71-year-old man who complained of progressive, unilateral visual blurring following vitrectomy for retinal detachment due to opacification of his Rayner Centerflex 570H intraocular lens (IOL) implant is reported. Intraocular lens exchange was carried out and the explanted lens analyzed. The same model lens in his fellow eye has remained clear. METHOD: Clinicopathologic case report. RESULTS: Scanning electron microscopy and energy-dispersive x-ray analysis confirmed the presence of hydroxyapatite deposits within the anterior surface of the IOL. CONCLUSIONS: To our knowledge, this is the first clinicopathologic case report of calcification of this model IOL in an adult patient. The sequence of events, unilaterality, and pathologic findings suggest secondary calcification, which could have been related to severe postoperative inflammation and associated blood-aqueous barrier breakdown

Light scattering characteristics of explanted opacified Aquasense TM intraocular lenses.

AIM: To study forward light-scattering characteristics of calcified explanted intraocular lenses (IOLs) (Aquasense, Ophthalmic Innovation International Ontario). METHODS: The amount of light scattered by the opacified IOLs was measured using a validated in vitro set-up for angles from 1.7 degrees to 22 degrees . This set-up gives results directly comparable with straylight values as valid for the in vivo situation. RESULTS: Straylight is highest at large angles and declines steeply approaching 0 degrees angle. This corresponds to the in vivo findings that opacified IOLs cause important visual complaints but have little effect on visual acuity. At 7.5 degrees , log (s) is around 1.8 and 2.9 for the two lenses respectively. This corresponds to 8 x and 100 x increases in straylight values compared with values in young, normal eyes. CONCLUSION: High straylight values caused by opacified IOLs can explain subjective complaints of reduced quality of vision in patients with opacified implants, despite good visual acuit

Calcification of hydrophilic acrylic intraocular lenses in combined phacovitrectomy surgery.

UNLABELLED: Two cases of postoperative intraocular lens (IOL) calcification in patients implanted with the Akreos Adapt IOL at the time of combined phacovitrectomy are described, along with clinical review of all patients implanted with this IOL type at our institution between November 2006 and September 2008. The IOLs explanted from the 2 cases were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The SEM of the explanted IOLs showed crystalline anterior surface and subsurface deposits; by EDX, the deposits showed high concentrations of calcium and phosphorous, consistent with calcium apatite. Twenty patients (20 eyes) attended for cohort review, and none showed IOL opacification. The reason calcification occurred in the 2 cases remains unknown, but clinicians should be aware of this potential complication. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned

Temporal Excitation Patterns on the Cerebral Cortex as a Result of Migraine Modeling

The complex, highly individual, geometry of the cerebral cortex in humans presents a major challenge in studying the spreading of spontaneous neuronal activity. Recent computational advances [1] allow to simulate the propagation of depolarization waves on the macroscale and for individual geometries, reconstructed from accurate medical imaging as MRI, with high levels of detail. In this paper we take advantage of such technique to study the temporal excitation patterns that follow the passage of a depolarization wave on the cerebral cortex