Preterm-associated visual impairment and estimates of retinopathy of prematurity at regional and global levels for 2010.

BACKGROUND: Retinopathy of prematurity (ROP) is a leading cause of potentially avoidable childhood blindness worldwide. We estimated ROP burden at the global and regional levels to inform screening and treatment programs, research, and data priorities. METHODS: Systematic reviews and meta-analyses were undertaken to estimate the risk of ROP and subsequent visual impairment for surviving preterm babies by level of neonatal care, access to ROP screening, and treatment. A compartmental model was used to estimate ROP cases and numbers of visually impaired survivors. RESULTS: In 2010, an estimated 184,700 (uncertainty range: 169,600-214,500) preterm babies developed any stage of ROP, 20,000 (15,500-27,200) of whom became blind or severely visually impaired from ROP, and a further 12,300 (8,300-18,400) developed mild/moderate visual impairment. Sixty-five percent of those visually impaired from ROP were born in middle-income regions; 6.2% (4.3-8.9%) of all ROP visually impaired infants were born at >32-wk gestation. Visual impairment from other conditions associated with preterm birth will affect larger numbers of survivors. CONCLUSION: Improved care, including oxygen delivery and monitoring, for preterm babies in all facility settings would reduce the number of babies affected with ROP. Improved data tracking and coverage of locally adapted screening/treatment programs are urgently required

Personalized versus standardized dosing strategies for the treatment of childhood amblyopia: study protocol for a randomized controlled trial

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

The effect of amblyopia treatment on stereoacuity

Purpose: To explore how stereoacuity changes in patients while they are being treated for amblyopia. Methods: The Monitored Occlusion Treatment for Amblyopia Study (MOTAS) comprised 3 distinct phases. In the first phase, baseline, assessments of visual function were made to confirm the initial visual and binocular visual deficit. The second phase, refractive adaptation, now commonly termed “optical treatment,” was an 18-week period of spectacle wear with measurements of logMAR visual acuity and stereoacuity with the Frisby test at weeks 0, 6, 12, and 18. In the third phase, occlusion, participants were prescribed 6 hours of patching per day. Results: A total of 85 children were enrolled (mean age, 5.1 ± 1.5 years). In 21 children amblyopia was associated with anisometropia; in 29, with strabismus; and in 35, with both. At study entry, poor stereoacuity was associated with poor visual acuity (P < 0.001) in the amblyopic eye and greater angle of strabismus (P < 0.001). Of 66 participants, 25 (38%) who received refractive adaptation and 19 (29%) who received occlusion improved by at least one octave in stereoacuity, exceeding test–retest variability. Overall, 38 (45%) improved one or more octaves across both treatment phases. Unmeasureable stereoacuity was observed in 56 participants (66%) at study entry and in 37 (43%) at study exit. Conclusions: Stereoacuity improved for almost one half of the study participants. Improvement was observed in both treatment phases. Factors associated with poor or nil stereoacuity at study entry and exit were poor visual acuity of the amblyopic eye and large-angle strabismus

The further refinement of ROP treatment. Commentary on the Early Treatment of Retinopathy of Prematurity study: structural findings at 2 years of age

Reaching the goal of early ROP treatment by recent advances in ROP managemen

Impact of retinopathy of prematurity on ocular structures and visual functions.

The preterm baby may develop ophthalmic sequelae which can be due to prematurity per se, due to retinopathy of prematurity (ROP) or due to neurological damage. Focusing on the former two, we discuss how in high-income countries the risk of sight-threatening ROP is largely confined to babies <1000 g birth weight (BW), whereas in low-income or middle-income countries babies exceeding 2500 g BW can be blinded. The effects of prematurity and ROP are presented as regional and global estimates of acute-phase ROP and the consequent mild/moderate and severe visual impairment. We discuss sequelae and how they affect the eye and its shape, strabismus and finally consider their impact on visual functions, including visual acuity, the visual field, colour vision and contrast sensitivity