Results The thickness of the entire retina, retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retinal pigment epithelium layer (RPE), inner retinal layer (IRL), and outer retinal layer (ORL) in patients were measured. The AL<26.5 mm group was (258.9±20.0)μm, (10.1±2.9) μm, (13.1±5.0) μm, (18.5±4.0) μm, (15.4±4.4) μm, (24.8±5.5) μm, (87.6±9.4) μm, (17.2±1.7) μm, (169.2±20.1) μm and (89.7±3.5) μm, respectively. The groups with 26.5 mm ≤AL<27.5 mm were (266.6±26.1) μm, (10.8±2.9) μm, (15.2±8.6) μm, (19.6±5.3) μm, (17.7±5.4) μm, (26.2±6.8) μm, (87.5±12.2) μm, (17.1±2.4) μm, (176.5±27.6) μm and (90.1±4.5) μm, respectively. The AL≥27.5 mm groups were (271.0±24.1) μm, (11.6±2.8) μm, (17.3±7.6) μm, (21.3±5.1) μm, (18.9±5.8) μm, (28.4±7.3) μm, (86.5±9.3) μm, (16.7±2.5) μm, (184.2±23.6) μm and (86.9±4.5) μm, respectively. The age groups ≤ 30 years old were (263.3±23.0)μm, (10.8±3.2) μm, (14.7±7.6) μm, (19.5±5.1) μm, (17.0±4.2) μm, (26.0±4.1) μm, (86.7±9.7) μm, (17.0±1.9) μm, (173.9±22.8) μm and (89.5±3.5) μm, respectively. The age group of 31 to 39 years old was (263.8±26.1)μm, (10.7±3.1) μm, (15.2±7.3) μm, (19.7±5.0) μm, (17.0±5.4) μm, (25.5±6.1) μm, (87.0±11.8) μm, (17.1±2.1) μm, (174.8±26.8) μm and (89.1±4.3) μm, respectively. The age group ≥40 years old was (272.0±21.4)μm, (11.3±2.3) μm, (16.0±8.4) μm, (20.3±5.2) μm, (18.8±6.2) μm, (28.7±9.0) μm, (87.9±9.3) μm, (16.8±2.7) μm, (183.4±23.2) μm and (88.5±5.4) μm, respectively. The male groups were (277.7±22.1) μm, (11.8±2.4) μm, (16.9±6.3) μm, (21.3±4.3) μm, (19.3±5.3) μm, (27.9±7.7) μm, (91.4±11.5) μm, (17.1±2.1) μm, (188.7±22.3) μm and (89.0±3.7) μm, respectively. The female groups were (259.3±23.0) μm, (10.4±3.0) μm, (14.4±8.2) μm, (19.0±5.2) μm, (16.5±5.2) μm, (25.7±6.0) μm, (84.8±9.4) μm, (17.0±2.3) μm, (170.4±24.3) μm and (89.0±4.8) μm, respectively. The longer the AL, the thicker the thickness of IPL, INL, IRL, and ORL in the AL<26.5 mm group, 26.5 mm ≤AL<27.5 mm, and AL≥27.5 mm group, and the differences were statistically significant (F=3.09, 4.06, 3.37, 6.97; P<0.05). Further pairwise comparison revealed that patients with AL≥27.5 mm had thicker IPL, INL, and IRL compared to those with AL<26.5 mm, and the differences were statistically significant (t=2.58, 2.87, 2.90; P<0.05). The thickness of ORL in the AL≥27.5 mm group was thinner than that in the AL<26.5 mm group, and the AL≥27.5 mm group was thinner than that in the 26.5≤AL<27.5 group, with statistical significance (t=2.94, 3.30; P<0.05). However, there were no statistically significant differences in the retinal full thickness, RNFL, GCL, OPL, ONL, and RPE thickness among patients in different AL groups (F=2.33, 2.60, 2.88, 2.76, 0.13, 0.46; P>0.05). There were no statistically significant differences in the thickness of the entire retinal layer, RNLF, GCL, IPL, INL, OPL, ONL, RPE, IRL, and ORL among patients aged ≤30 years, 30-39 years, and ≥40 years (F=1.54, 0.63, 0.26, 0.22, 1.50, 2.68, 0.11, 0.24, 1.62, 0.45; P>0.05). The thickness of the entire retina, RNFL, IPL, INL, ONL, and IRL in the female group was thinner than that in the male group, and the differences were statistically significant (t=4.44, 2.97, 2.66, 2.88, 3.28, 4.32; P<0.05). Single factor linear regression was used to screen for factors related to the thickness of each layer of the retina, including patient′s age, gender, systolic and diastolic blood pressure, BMI, initial age of myopia, intraocular pressure, AL, and SFCT. The final multiple regression analysis found that the thickness of the full retinal layer, RNFL, INL, ONL, and IRL in the male group was thicker than that in the female group, and the correlation was statistically significant (β=- 15.40, -1.27, -2.57, -6.16, -16.77; P<0.05). The thickness of the entire retinal layer and IPL increases with increasing systolic blood pressure, and their correlation was statistically significant (β= 0.29, 0.06; P<0.05). The thickness of ORL decreases with increasing diastolic blood pressure, and its correlation was statistically significant (β=- 0.09, P<0.05). The thickness of RNFL, GCL, IPL, INL, OPL, and IRL increases with AL, and their correlation was statistically significant (β=0.49, 1.55, 0.80, 0.88, 1.21, 4.13; P<0.05).