Background Amblyopia screening can target reduced visual acuity (VA), its refractive risk factors, or both. VA testing is imprecise under 4 years of age, so automated risk-factor photoscreening appears an attractive option. This review considers photoscreening used in community services, focusing on costs, cost-effectiveness and scope of use, compared with EUSCREEN project Country Reports describing how photo- and automated screening is used internationally. Methods A systematic narrative review was carried out of all English language photoscreening literature to September 10th 2018, using publicly available search terms. Where costs were considered, a CASP economic evaluation checklist was used to assess data quality. Results Of 370 abstracts reviewed, 55 reported large-scale community photoscreening projects. Five addressed cost-effectiveness specifically, without original data. Photoscreening was a stand-alone, single, test event in 71% of projects. In contrast, 25 of 45 EUSCREEN Country Reports showed that if adopted, photoscreening often supplements other tests in established programmes and is rarely used as a stand-alone test. Reported costs varied widely and evidence of cost-effectiveness was sparse in the literature, or in international practice. Only eight (13%) papers compared the diagnostic accuracy or cost-effectiveness of photoscreening and VA testing, and when they did, cost-effectiveness of photoscreening compared unfavourably. Discussion Evidence that photoscreening reduces amblyopia or strabismus prevalence or improves overall outcomes is weak, as is evidence of cost-effectiveness, compared to later VA screening. Currently, the most cost-effective option seems to be a later, expert VA screening with the opportunity for a re-test before referral.

Aim: To establish whether the contrast sensitivity threshold obtained with the computerised Test Chart 2000 Xpert is comparable with the printed Pelli-Robson chart. Methods: Healthy volunteers from a student population were recruited. The inclusion criteria included: monocular visual acuity of at least 0.2 logMAR, no history of any ocular abnormalities and amblyopia, no sign of any manifest strabismus and a Frisby stereo-acuity threshold of at least 85 seconds of arc. Visual acuity was assessed at 1 m to allow the contrast sensitivity to be directly comparable. The results were statistically analysed using a two-factor ANOVA and a paired t-test. Results: Twenty participants (7 male, 13 female) were recruited with a mean age of 20.9 Ô 6.0 years. The average visual acuity tested at 1 m was À0.05 Ô 0.12 logMAR for the right eye, À0.07 Ô 0.11 logMAR for the left eye and À0.11 Ô 0.12 logMAR tested binocularly. The average contrast sensitivity using the Pelli-Robson chart was 1.63 Ô 0.02 log unit for the right eye, 1.62 Ô 0.04 log unit for the left eye and 1.70 Ô 0.05 log unit when tested with both eyes open. The average contrast sensitivity using the computerised Test Chart 2000 Xpert was 1.84 Ô 0.13 log unit for the right eye, 1.85 Ô 0.15 log unit for the left eye and 2.02 Ô 0.20 log unit when tested with both eyes open. A significant difference was found in contrast sensitivity scores between the two tests (p < 0.001, paired t-tests). The Test Chart 2000 Xpert also consistently gave higher contrast sensitivity scores when compared with the Pelli-Robson. Weak correlations were noted between visual acuity and both contrast sensitivity tests testing right eye, left eye and with both eyes open, with Pearson's correlation coefficient values ranging between r = 0.40 and r = 0.11. Conclusion: The study was carried out to determine whether the contrast sensitivity threshold values obtained with the computerised Test Chart 2000 Xpert are comparable with those obtained with the Pelli-Robson chart. A significant difference was found between the scores from the two tests and the Test Chart 2000 Xpert consistently generated a higher contrast sensitivity threshold. This study did not assess test-retest variability. It is acknowledged that further studies with a larger sample size and repeat testing on two visits are required to assess repeatability.