The American Academy of Ophthalmology (AAO) Preferred Practice Pattern defines high refractive errors as +3.00 D or more of hyperopia (with low-to-moderate hyperopia being less than +3.00 D).[1] However, many clinical studies use a higher threshold:

- ≥+5.00 D is the most widely used cutoff for “high hyperopia” in pediatric amblyopia and strabismus research.[2][3] - ≥+4.00 D is used in some epidemiologic studies as the threshold for “moderate to high hyperopia”.[4][5] - ≥+7.00 D is often used to define the extreme end of the spectrum, particularly in the context of structural conditions such as nanophthalmos and posterior microphthalmos.[6][7]

Amblyopia — The most strongly associated condition. Among preschoolers with hyperopia >+3.25 D, amblyopia prevalence was 34.5% compared to 2.8% in non-hyperopic children, rising to 51.5% in those with ≥+5.00 D. Both unilateral (anisometropic) and bilateral (isoametropic) amblyopia occur; isoametropic amblyopia was found in approximately 8.6% of children with ≥+4.5 D of hyperopia.[1][2]

Strabismus (especially accommodative esotropia) — Prevalence of strabismus was 17% in hyperopic children (>+3.25 D) versus 2.2% in non-hyperopic children, increasing to 32.9% in those with ≥+5.00 D. The risk of esotropia rises with increasing hyperopia.[1][3]

Angle-closure glaucoma — Hyperopic eyes have shorter axial lengths, shallower anterior chambers, and thicker, more anteriorly positioned lenses, all of which predispose to primary angle-closure disease (PACD). The risk of PACD rises rapidly with greater hyperopia (OR 1.41 per diopter). This is particularly prominent in nanophthalmos, where angle-closure glaucoma occurs in up to 67% of affected individuals.[4][5][6]

Reduced stereoacuity — Even in non-strabismic, non-amblyopic hyperopic children, stereoacuity is significantly worse (median 120 arcsec vs. 60 arcsec in non-hyperopic children), worsening with higher degrees of hyperopia.[1]

Anisometropia and astigmatism — Both are significantly more prevalent in children with high hyperopia (26.9% and 29.4%, respectively, vs. 5.1% and 10.3% in non-hyperopic children).[1]

Diabetic retinopathy — Hyperopia has been associated with progressive retinopathy in patients with type 1 diabetes.[7]

• Nanophthalmos — Extreme hyperopia (+8 to +25 D) due to a very short axial length with normal cornea and lens size. Associated with angle-closure glaucoma, thickened sclera, and uveal effusion.[5][8]
• Posterior microphthalmos — Short axial length with normal anterior segment dimensions. Associated with macular folds (papillomacular folds) and high hyperopia, but lower rates of angle-closure glaucoma compared to nanophthalmos.[5]

Several genetic conditions include high hyperopia as a characteristic feature:[9][10][11]

• [Down syndrome](https://www.openevidence.com/rare-disease/down-syndrome) (trisomy 21)
• [Fragile X syndrome](https://www.openevidence.com/rare-disease/fragile-x-syndrome)
• 22q11.2 deletion syndrome
• Leber congenital amaurosis
• Achromatopsia
• Aniridia
• X-linked juvenile retinoschisis
• Senior-Loken syndrome (renal-retinal dystrophy)[12]
• Gorlin-Chaudhry-Moss syndrome
• Bardet-Biedl syndrome

Mutations in MYRF (myelin regulatory factor) have been identified as a cause of autosomal dominant high hyperopia, with some affected individuals also developing angle-closure glaucoma.[13] Mutations in MFRP cause autosomal recessive nanophthalmos (NNO2).[8]

1. Kulp MT, Ying GS, Huang J, et al. Associations Between Hyperopia and Other Vision and Refractive Error Characteristics. Optom Vis Sci. 2014. https://pubmed.ncbi.nlm.nih.gov/24445716/
2. Klimek DL, Cruz OA, Scott WE, Davitt BV. Isoametropic Amblyopia Due to High Hyperopia in Children. J AAPOS. 2004. https://pubmed.ncbi.nlm.nih.gov/15226727/
3. Sprunger DT, Lambert SR, Hercinovic A, et al. Esotropia and Exotropia Preferred Practice Pattern. Ophthalmology. 2023. https://pubmed.ncbi.nlm.nih.gov/37839895/
4. Zhou S, Pardeshi AA, Burkemper B, et al. Refractive Error and Anterior Chamber Depth as Risk Factors in Primary Angle Closure Disease: The Chinese American Eye Study. J Glaucoma. 2023. https://pubmed.ncbi.nlm.nih.gov/36728083/
5. Relhan N, Jalali S, Pehre N, et al. High-Hyperopia Database, Part I: Clinical Characterisation Including Morphometric (Biometric) Differentiation of Posterior Microphthalmos From Nanophthalmos. Eye (Lond). 2016. https://pubmed.ncbi.nlm.nih.gov/26493039/
6. Jonas JB, Aung T, Bourne RR, et al. Glaucoma. Lancet. 2017. https://pubmed.ncbi.nlm.nih.gov/28577860/
7. Jacobs DS, Afshari NA, Bishop RJ, et al. Refractive Errors Preferred Practice Pattern. Ophthalmology. 2023. https://pubmed.ncbi.nlm.nih.gov/37839893/
8. Young TL, Metlapally R, Shay AE. Complex Trait Genetics of Refractive Error. Arch Ophthalmol. 2007. https://pubmed.ncbi.nlm.nih.gov/17210847/
9. National Library of Medicine (MedlinePlus). Farsightedness. 2018. https://medlineplus.gov/farsightedness.html
10. Pinazo-Duran MD, Zanon-Moreno V, Garcia-Medina JJ, et al. Eclectic Ocular Comorbidities and Systemic Diseases with Eye Involvement: A Review. Biomed Res Int. 2015. https://pubmed.ncbi.nlm.nih.gov/26583104/
11. von Scheibler ENMM, van der Valk Bouman ES, Nuijts MA, et al. Ocular findings in 22q11.2 deletion syndrome: A systematic literature review and results of a Dutch multicenter study. Am J Med Genet A. 2022. https://pubmed.ncbi.nlm.nih.gov/35274463/
12. Wen S, Min X, Zhu Y, Zhou X. Genetic analysis Assists Diagnosis of Clinical Systemic Disease in Children With Excessive Hyperopia. BMC Pediatr. 2022. https://pubmed.ncbi.nlm.nih.gov/35590282/
13. Xiao X, Sun W, Ouyang J, et al. Novel Truncation Mutations in MYRF Cause Autosomal Dominant High Hyperopia Mapped to 11p12-Q13.3. Hum Genet. 2019. https://pubmed.ncbi.nlm.nih.gov/31049660/