Purpose: To assess the impact of uncorrected hyperopia and hyperopic spectacle correction on children's academic performance. Design: Systematic review and meta-analysis Methods: We searched 9 electronic databases from inception to July 26, 2021, for studies assessing associations between hyperopia and academic performance. There were no restrictions on language, publication date, or geographic location. A quality checklist was applied. Random-effects models estimated pooled effect size as a standardized mean difference (SMD) in 4 outcome domains: cognitive skills, educational performance, reading skills, and reading speed. (PROSPERO registration: CRD-42021268972). Results: Twenty-five studies (21 observational and 4 interventional) out of 3415 met the inclusion criteria. No full-scale randomized trials were identified. Meta-analyses of the 5 studies revealed a small but significant adverse effect on educational performance in uncorrected hyperopic compared to emmetropic children {SMD À0.18 [95% confidence interval (CI), À0.27 to À0.09]; P < 0.001, 4 studies} and a moderate negative effect on reading skills in uncorrected hyperopic compared to emmetropic children [SMD À0.46 (95% CI, À0.90 to À0.03); P ¼ 0.036, 3 studies]. Reading skills were significantly worse in hyperopic than myopic children [SMD À0.29 (95% CI, À0.43 to À0.15); P < 0.001, 1 study]. Qualitative analysis on 10 (52.6%) of 19 studies excluded from metaanalysis found a significant (P < 0.05) association between uncorrected hyperopia and impaired academic performance. Two interventional studies found hyperopic spectacle correction significantly improved reading speed (P < 0.05). Conclusions: Evidence indicates that uncorrected hyperopia is associated with poor academic performance. Given the limitations of current methodologies, further research is needed to evaluate the impact on academic performance of providing hyperopic correction.

Background Keratoconus (KC) is a corneal ectasia characterised by steepening corneal curvature, changes in refractive error and corneal thickness that result in visual impairment. Early signs of KC include displacement of the thinnest part of the cornea from the central position, changes in the corneal epithelial layer cell distribution, variations in the anterior corneal astigmatism/posterior corneal astigmatism relationship and a variation in corneal thickness. It is important that we review the corneal imaging methods for the diagnosis of preclinical KC. Method An online literature search was carried out on PubMed. Only publications detailing corneal assessment procedures were considered for this review and any publication on instruments that did not generate KC predictability indices were also excluded from the review. The 308 publications were reviewed. Discussion Corneal assessment techniques, with the ability to characterise both the anterior and posterior corneal surfaces, are invaluable in the diagnosis of pre-clinical KC. Reflection based and elevation based corneal imaging systems should be used in conjunction with other assessments such as higher order aberration measuring systems to improve sensitivity and reliability in the diagnosis of pre-clinical KC. Ultra high resolution ultrasound can detect pre-clinical KC. The ability to asses both the epithelium and endothelium makes anterior surface optical coherence tomography a superior technique for pre-clinical KC diagnosis. There is a positive correlation between central corneal thickness and corneal hysteresis. Corneal biomechanics should be considered in conjunction with other corneal assessments in the diagnosis of pre-clinical KC.