To explore the effects of vitrectomy (PPV) combined with phacoemulsification cataract extraction and posterior chamber intraocular lens (IOL) implantation on postoperative refractive status and effective position of the intraocular lens.

Prospective continuous recruitment of 100 patients (100 eyes) who visited Beijing Tongren Eye Center between September 2021 and October 2022. Among them, there were 38 males (38 eyes) and 62 females (62 eyes)with an average age of (67.7±6.2) years (ranging from 56 to 87 years old). According to the different surgical methods performed, patients were divided into cataract group and combination group. The cataract group patients underwent phacoemulsification cataract extraction and posterior chamber IOL implantation, while the combined group patients underwent PPV combined phacoemulsification cataract extraction and posterior chamber IOL implantation. The IOL diopter for two groups of patients were calculated using the Kane formula. The age and gender of the patient were recorded, the best corrected visual acuity (BCVA), axial length (AL), corneal curvature, anterior chamber depth (ACD), lens thickness, horizontal corneal diameter, and refractive error of the implanted IOL one month after surgery were measured, and the refractive error (PE), standard deviation (SD), mean absolute error (MAE), and median absolute error (MedAE) of the two groups of patients at one month after surgery were calculated. The percentage of PE within the range of ±0.25 D, ±0.50 D, ±0.75 D, and ±1.00 D were calculated. After testing, age, axial length, corneal curvature, anterior chamber depth, lens thickness, horizontal corneal diameter, and refractive index of implanted IOL all conform to normal distribution, expressed as ±s, and compared by independent sample t-test for inter group. BCVA did not follow a normal distribution and was described using median and interquartile intervals, and compared by Mann Whitney′s U test for inter group. Gender and eye type were described using examples and percentages, and compared bychi square tests test for inter group. The comparison between ME values and zero values was performed by a single sample t test.

The postoperative PE of patients in the cataract group and the combination group were (0.155±0.345) D and (-0.007±0.600) D, respectively. Compared with zero values, the cataract group showed hyperopia system error, with a statistically significant difference (t=3.176, P<0.05). However, the combined group had no statistically significant system error (t=-0.083, P>0.05). The postoperative ACD of patients in the cataract group and the combined group was deeper than before surgery, with values of (4.377±0.336) mm and (4.213±0.357) mm, respectively. However, the ACD of patients in the combined group was shallower than that of the cataract group, and the difference between the two groups was statistically significant (t=2.364, P<0.05). The accuracy of refractive prediction in the combined group was poor, with SD, MAE, and MedAE being higher than those in the white cataract group. The percentage of PE within the range of ±0.25 D, ±0.50 D, ±0.75 D, and ±1.00 D was lower than that of the cataract group, and the differences were statistically significant (χ²=4.026, 5.877, 10.698, 6.383; P<0.05).

After surgery for one month, the effective position of IOL in the combined group was moved forward compared to the cataract group. PPV surgery and filling the vitreous cavity with air or perfluoropropane did not produce errors in hyperopia or myopia, but the accuracy of refractive prediction in the combined group was poorer compared to the cataract group.