ESCRS - FP23.14 - Structural Diversity In High Myopia: Three Anatomical Phenotypes Identified By Anatomical Equivalent Refraction With Different Risks Of Visual Impairment And Implications For Refractive Surgery

Structural Diversity In High Myopia: Three Anatomical Phenotypes Identified By Anatomical Equivalent Refraction With Different Risks Of Visual Impairment And Implications For Refractive Surgery

Published 2026 - 44th Congress of the ESCRS

Reference: FP23.14 | Type: Free paper | DOI: 10.82333/x7qm-zz26

Authors: Mr Clement Kangombe* 1 , Prof. James Loughman 1 , Dr Pan Wei 2 , Dr Lan Weizhong 2 , Prof. Ian Flitcroft 1

1Centre for Eye Research Ireland,Technological University Dublin,Dublin,Ireland, 2Aier Optometry & Vision Science,Changsha City ,China

Purpose

To characterise structural determinants of refractive error and visual function in high myopia using Anatomical Equivalent Refraction (AER), the expected refraction based solely on ocular anatomy, and to identify distinct anatomical subtypes with differing risks of visual impairment. A secondary aim was to explore how these phenotypes might inform risk stratification and counselling in refractive surgery candidates.

Setting

This study utilised data from the UK Biobank, a large population-based cohort study comprising multimodal ophthalmic imaging and biometric measurements. The analysis included eyes with highly myopic refractive errors (subset SER ≤ −6.0 D, n = 460; SER = spherical equivalent refraction) that had available fundus imaging, OCT-derived choroidal thickness (CHT; derived from OCT using a novel, objective AI algorithm) measurements, axial length (AXL) measurements, and visual function assessments.

Methods

Following AI model training for AER on 40,068 eyes from the UK Biobank, we analysed an independent cohort of 460 highly myopic eyes  in adults in the typical refractive-surgery age range (range, 29–72). Structural and functional parameters included fundus AER, AXL, CHT, SER, fundus deviation (fundus AER − SER), and visual acuity (logMAR). Multivariable linear regression was used to identify the structural determinants of SER (AXL, CHT, fundus AER, fundus deviation, age, and sex) and to assess the associations between structural metrics and visual acuity, adjusted for age and sex. Unsupervised k-means clustering on structural features (AXL, CHT, fundus AER and fundus deviation) was used to identify anatomical subtypes.

 

 

Results

In 460 eyes (mean age 41.0 ± 6.3 years, mean SER −7.81D), unsupervised clustering identified three distinct structural phenotypes:

  • Cluster 1 – “Advanced structural” high myopia: marked axial elongation (mean AXL 30.4mm), very high myopia (SER~ −17.4D) and poorest visual acuity.
  • Cluster 2 – “Disproportionately elongated” phenotype: longer AXL, thinner choroid, fundal appearance worse than expected for SER,  and reduced visual acuity compared with Cluster 3.
  • Cluster 3 – “Structurally mild” high myopia: relatively shorter AXL, thicker choroid, less negative SER (mean~ -7.4D) and preserved visual function.

Visual acuity differed across clusters (p < 0.001). Fundus AER and AXL were independently associated with SER (β=0.40 and −0.51; both p<0.001).

Conclusions

High myopia in adults can be partitioned into three reproducible anatomical phenotypes with distinct visual prognoses. For refractive surgeons, AER-based phenotyping may provide a practical framework to:

  • distinguish “structurally mild” from high-risk high myopia,
  • identify eyes in which refractive error underestimates structural damage, and
  • refine patient selection, choice of procedure, and visual prognosis counselling in high myopia.