ObjectiveTo observe and analyze the spatial distribution and morphological characteristics of macular photoreceptor cones in eyes with high myopia (HM). MethodsA clinical cross-sectional study. A total of 98 eyes from 55 subjects (aged 20-61 years) with varying degrees of myopia, who visited Eye Center of Beijing Tongren Hospital, Capital Medical University from March to May 2024 were enrolled. All subjects underwent examinations including refractive error, color fundus photography, and axial length (AL) measurement. Confocal scanning laser ophthalmoscopy was utilized to measure the density and diameter of cone cells in the central macula and its superior-temporal, inferior-temporal, superior-nasal, and inferior-nasal regions. Based on the equivalent spherical refractive error (SE), 55 eyes from 98 eyes were divided into the emmetropic and low myopic groups (EM/LM group, SE +0.25 to ?3.00 D) and the HM group (SE≤?6.00 D), with 11 eyes from 18 eyes and 44 eyes from 80 eyes in each group. The differences in cone cell density and diameter between the two groups were compared. The qualitative data between the groups were compared using the χ2 test; linear regression analysis was used to analyze the correlations between refractive error, AL, cone cell density, and diameter. ResultsAmong the 44 cases and 80 eyes in the HM group, 7 were male; the age was (33.66±10.33) years; the AL was (27.51±1.53) mm, and the SE was (?9.09±2.95) D. In the EM/LM group, there were 11 cases and 18 eyes, with 4 being male; the age was (31.00±12.50) years; the AL was (22.86±0.69) mm, and the SE was (?0.68±0.52) D. Compared with the EM/LM group, the AL and SE of the HM group were higher, and the density of cone cells in the superior temporal, superior nasal, inferior nasal, and inferior temporal regions was significantly lower, and the diameters were significantly larger. The differences were statistically significant (P＜0.01). There were no statistically significant differences in age (t=0.73, P=0.47), the proportion of males (χ2=1.20, P=0.23), and the density and diameter of cone cells in the macular center region between the two groups (P＞0.05). After adjusting for age and gender, the linear regression analysis results showed that the density of cone cells in the macular center and surrounding regions was negatively correlated with AL (β=?0.53, ?0.58, ?0.90, ?0.79, ?0.92; P＜0.05), and the diameter was positively correlated with AL (β=0.52, 0.81, 0.92, 0.90, 0.96; P＜0.05); among them, the correlation of cone cell density and diameter in the inferior temporal region with AL was the strongest. ConclusionsIn eyes with HM, there is a decrease in cone density and an increase in cone diameter within the macular and paramacular regions. Regional changes in temporal macular cones are strongly associated with axial elongation.