AIM:To evaluate the characteristics of ocular biometric parameters and the distribution of corneal astigmatism(CA)in patients with high myopia before cataract surgery.METHODS:A prospective cross-sectional study was conducted, and 695 cataract patients(695 eyes)with high myopia [defined as an axial length(AL)≥26.00 mm] scheduled to undergo cataract surgery at our hospital from January 2022 to December 2024 were consecutively enrolled, another 695 cataract patients(695 eyes)with normal ALs(22.00 mm ≤AL≤25.00 mm)who underwent cataract surgery at our hospital during the same period were included in the control group. For patients with both eyes eligible, the right eye was used for analysis. Before cataract surgery, IOL Master 700 was used to measure the ocular biometric parameters of both eyes for each patient in the two groups. The medical records and ocular biometric data in the two groups were recorded and collected.RESULTS:There were no statistically significant differences between the two groups in genger, age, corneal diameter, and central corneal thickness(all P>0.05). In the high myopia group, the mean AL was 29.20±2.61 mm, and 252 eyes(34.1%)had AL ≥30.00 mm(extremely high myopia). The mean anterior chamber depth(ACD), lens thickness, vitreous chamber depth(VCD), CA, AL/corneal radius of curvature and VCD/AL in the high myopia group were 3.45±0.40, 4.41±0.47, 21.34±2.60 mm, 1.18±0.78 D, 3.79±0.38, and 0.73±0.03, respectively, which were all greater than those in the control group(all P<0.01). In the high myopia group, 350 eyes(50.4%)had CA ≥1.00 D, 192 eyes(27.6%)had CA ≥1.50 D, and 94 eyes(13.5%)had CA ≥2.00 D, which were all higher than those in the control group(32.8%, 15.1%, and 6.6%, respectively; all P<0.001). In the high myopia group, 87 eyes(12.5%)had flat corneas, 424 eyes(61.0%)had moderate CA, and 40 eyes(5.8%)had high CA. These proportions were all higher than those in the control group(6.0%, 46.9%, and 2.9%, respectively; all P<0.001). In the high myopia group, ACD and ACD/AL were negatively correlated with AL(r=-0.162 and -0.661, respectively; all P<0.001), while both ACD and ACD/AL in the control group were positively correlated with AL(r=0.338 and 0.105, respectively; both P<0.01). In the high myopia group, CA increased with age when the patient's age was ≥50 years(r=0.197, P<0.001), which was consistent with the control group.CONCLUSION: The standardized ocular biometric data of cataract patients with high myopia before cataract surgery are helpful for ophthalmologists to accurately calculate the intraocular lens(IOLs)power and select the appropriate IOL type. The majority of high myopia patients need simultaneous correction of CA during cataract surgery.

Objective To evaluate the characteristics of preoperative corneal astigmatism in cataract surgery candi-dates with high myopia.Methods In this observational study,medical records of consecutive patients who underwent cataract surgery in our hospital between January 2014 and December 2023 were reviewed retrospectively.Biometric param-eters of eyes were measured preoperatively by IOL-Master optical biometry.The cataract patients were classified into a high myopia group[defined as axial length(AL)≥26.00 mm]and a control group(normal ALs,22.00 mm ≤ AL ≤25.00 mm).The characteristics of corneal astigmatism were compared between the two groups.Results Among 17 325 cataract pa-tients(17 325 eyes),2 206 patients(2 206 eyes)had high myopia and 13 429 patients(13 429 eyes)had no high myopia.In the high myopia group,1 822 eyes(82.6％)had corneal astigmatism ≥0.50 D,1 138 eyes(51.6％)had corneal astig-matism ≥1.00 D,623 eyes(28.2％)had corneal astigmatism ≥1.50 D and 314 eyes(14.2％)had corneal astigmatism ≥2.00 D.These proportions were significantly higher than those in the control group(71.9％,35.9％,15.9％and 7.3％,re-spectively;all P＜0.001).In the high myopia group,1 340 eyes(60.7％)had moderate astigmatism,147 eyes(6.7％)had high astigmatism and 922 eyes(41.8％)had with-the-rule(WTR)astigmatism.These 3 proportions were all significantly higher than those in the control group(48.9％,3.3％and 28.2％,respectively;all P＜0.001).Among high-myopia pa-tients,the corneal astigmatism was statistically greater in women than that in men(P=0.001),and the proportion of ob-lique astigmatism was higher in women than that in men(19.3％vs.15.8％,P=0.034).The proportion of against-the-rule(ATR)astigmatism increased significantly with age.In the high myopia group,the corneal astigmatism of eyes with WTR,ATR and oblique astigmatism was(1.26±0.85)D,(1.28±0.81)D and(0.89±0.71)D,respectively.They were signifi-cantly greater than those in the control group[(0.82±0.71)D,(1.06±0.68)D and(0.67±0.53)D,respectively;all P＜0.001].In the high myopia group,there were 31.8％,12.3％and 4.1％of eyes with corneal astigmatism ≥1.00 D,≥1.50 D and ≥2.00 D,respectively.All of these 3 proportions were significantly lower than those of eyes with WTR or ATR astig-matism(all P＜0.05).This finding is consistent with the tendency in the control group.Conclusion A significant bur-den of preoperative corneal astigmatism is observed in cataract surgery candidates with high myopia,with more than 50％of the patients having corneal astigmatism ≥1.00 D.The corneal astigmatism of patients with high myopia is significantly greater than that of patients with normal ALs.The proportion of moderate-to-high astigmatism is significantly higher in high-myopia patients than that in patients with normal ALs.

Objective To evaluate the characteristics of preoperative corneal astigmatism in cataract surgery candi-dates with high myopia.Methods In this observational study,medical records of consecutive patients who underwent cataract surgery in our hospital between January 2014 and December 2023 were reviewed retrospectively.Biometric param-eters of eyes were measured preoperatively by IOL-Master optical biometry.The cataract patients were classified into a high myopia group[defined as axial length(AL)≥26.00 mm]and a control group(normal ALs,22.00 mm ≤ AL ≤25.00 mm).The characteristics of corneal astigmatism were compared between the two groups.Results Among 17 325 cataract pa-tients(17 325 eyes),2 206 patients(2 206 eyes)had high myopia and 13 429 patients(13 429 eyes)had no high myopia.In the high myopia group,1 822 eyes(82.6％)had corneal astigmatism ≥0.50 D,1 138 eyes(51.6％)had corneal astig-matism ≥1.00 D,623 eyes(28.2％)had corneal astigmatism ≥1.50 D and 314 eyes(14.2％)had corneal astigmatism ≥2.00 D.These proportions were significantly higher than those in the control group(71.9％,35.9％,15.9％and 7.3％,re-spectively;all P＜0.001).In the high myopia group,1 340 eyes(60.7％)had moderate astigmatism,147 eyes(6.7％)had high astigmatism and 922 eyes(41.8％)had with-the-rule(WTR)astigmatism.These 3 proportions were all significantly higher than those in the control group(48.9％,3.3％and 28.2％,respectively;all P＜0.001).Among high-myopia pa-tients,the corneal astigmatism was statistically greater in women than that in men(P=0.001),and the proportion of ob-lique astigmatism was higher in women than that in men(19.3％vs.15.8％,P=0.034).The proportion of against-the-rule(ATR)astigmatism increased significantly with age.In the high myopia group,the corneal astigmatism of eyes with WTR,ATR and oblique astigmatism was(1.26±0.85)D,(1.28±0.81)D and(0.89±0.71)D,respectively.They were signifi-cantly greater than those in the control group[(0.82±0.71)D,(1.06±0.68)D and(0.67±0.53)D,respectively;all P＜0.001].In the high myopia group,there were 31.8％,12.3％and 4.1％of eyes with corneal astigmatism ≥1.00 D,≥1.50 D and ≥2.00 D,respectively.All of these 3 proportions were significantly lower than those of eyes with WTR or ATR astig-matism(all P＜0.05).This finding is consistent with the tendency in the control group.Conclusion A significant bur-den of preoperative corneal astigmatism is observed in cataract surgery candidates with high myopia,with more than 50％of the patients having corneal astigmatism ≥1.00 D.The corneal astigmatism of patients with high myopia is significantly greater than that of patients with normal ALs.The proportion of moderate-to-high astigmatism is significantly higher in high-myopia patients than that in patients with normal ALs.