A novel classification of high myopia into anterior and posterior pathologic subtypes.

PURPOSE: High myopia and pathologic myopia are common causes of visual morbidity. Myopic pathology can affect all regions of the retina, though there is currently no classification system to distinguish anterior (peripheral) and posterior (macular) pathology. We hypothesize that these classifications are characterized by distinct demographic and refractive features, highlighting the disparity in types of pathologic myopia. METHODS: Institutional retrospective cohort study. The Stanford University Medical Center Clinical Data Warehouse was used to identify patients with high myopia by ICD-9 and ICD-10 codes. Predetermined ICD diagnoses were then used to classify patients with high myopia into isolated high myopia (IHM), anterior pathologic myopia (APM), posterior pathologic myopia (PPM), and combined pathologic myopia (CPM). A cohort of this population was then manually reviewed to gather refractive data and confirm accuracy of ICD coding. RESULTS: Patients (3274) were identified with high myopia. Overall, 22.1% individuals met criteria for APM, 10.7% for PPM, 17.0% for CPM, and 50.2% for IHM. We identified a significantly higher frequency of females with PPM compared to APM (62.3 vs. 48.3%; OR, 1.73; 95% CI, 1.34 to 2.25), Asian patients with PPM as compared to APM (42.9 vs. 33.3%; OR, 1.50; 95% CI, 1.16 to 1.95), and younger patients with APM compared to PPM (median 45.3 vs. 63.4 years). The refractive error was significantly more myopic in the CPM (median - 9.8D; interquartile range, IQR 6.7) and PPM (median - 10.5D; IQR 9.8) subgroups as compared to the APM (median - 8.1D; IQR 3.5), and IHM (median - 8.2D; IQR 4.1) subgroups (p = 0.003). CONCLUSIONS: High myopia may be divided into four distinct subgroups based on presence and location of pathology, which is associated with differences in age, gender, race, and refractive error.

Biometric Variations in High Myopia Associated with Different Underlying Ocular and Genetic Conditions.

Purpose: To report different biometric measurements in high myopia associated with different underlying ocular and genetic conditions. Design: Retrospective study. Subjects: Patients with high myopia. Methods: We searched the Stanford Research Repository tool to identify patients with the diagnosis of high myopia who were seen by a single provider at Byers Eye Institute at Stanford from January 2019 to March 2022. We performed a chart review and included eyes that had high myopia and ocular biometric measurements at any time point after January 2019. We divided our cohort into 5 different groups: (1) isolated high myopia (IHM) (control group); (2) retinopathy of prematurity (ROP); (3) familial exudative vitreoretinopathy; (4) Marfan syndrome; and (5) Stickler syndrome. Main Outcome Measures: Biometric measurements. Results: A total of 246 patients (432 eyes) were included as follows: 202 patients (359 eyes) in the IHM group, 17 patients (27 eyes) in the ROP group, 7 patients (12 eyes) in the familial exudative vitreoretinopathy group, 8 patients (14 eyes) in the Marfan group, and 12 patients (20 eyes) in the Stickler group. The ROP group showed significantly shorter axial lengths, shallower anterior chambers, and thicker lenses compared with the IHM group. The Marfan group showed significantly flatter corneas and thicker lenses compared with the IHM group. The Stickler group showed significantly longer axial lengths compared with the IHM group. Conclusions: High myopia is associated with variable biometric measurements according to underlying ocular or genetic conditions. Retinopathy of prematurity-associated high myopia is primarily lenticular, while Stickler syndrome-associated high myopia is axial. Marfan syndrome-associated high myopia is derived from both axial and lenticular mechanisms.