The occurrence of postoperative PCO is considered as a wound healing outcome of the residual LECs [7, 8]. LECs play an essential role in the progression and development of capsular fibrosis and contraction [9, 10]. In our study, a polisher was used to polish the anterior capsule to eliminate the LECs. Theoretically, PCO could be reduced by the removal of these cells. Numerous clinical studies have compared PCO between eyes with capsule polishing and eyes without anterior capsule polishing. Nevertheless, no consensus has been reached on the effectiveness of polishing.
A three-year randomized trial revealed that ACP does not prevent the formation of PCO but allows for more regeneratory cataract . Similarly, herein, we established that the rate of Nd: YAG capsulotomy in non-polishing is higher than polishing 3 years postoperatively, but there is no significant difference. Another study showed that the incidence of PCO in the 360-degree polishing group is lower, although not markedly different during a one-year follow-up . Consistently, in a different study, the results revealed no apparent advantages of scraping on ACO development in a cohort of 120 eyes with a 6‑month follow‑up . Three years following a cataract operation, the ACO of the eyes with polished anterior capsule decreases significantly. However, polishing does not reduce the incidence of PCO when the sharp-edged IOL is implanted in the bag. Even though the results showed that ACP promotes the development of regenerative PCO, this trend is not statistically significant .
Another study explained why polishing the anterior capsule did not reduce the PCO rate . The surgical techniques, including ACP, have a crucial effect on the growth of residual cells in vitro. Notably, although the cells under the anterior capsule are almost entirely removed by polishing before culture, ACP significantly promotes the growth of pouch cells cultured in vitro during phacoemulsification in the human eyes. In the study, capsule polishing did not eliminate all the LECs, and that capsule polishing stimulated strong remaining cell proliferation in vitro, while numerous living cells in unpolished eyes tended to die, leading to less proliferation.
However, some studies indicated that ACP remarkably lessens the incidence of PCO. In one study, the results posited that lower anterior capsule opacification (ACO) and fibrotic PCO with both round‑edged silicone IOLs 3‑years postoperatively in eyes which the anterior capsule was extensively polished . A meta-analysis of studies for 1-year or longer follow-up showed that the PCO rate was reduced in the ACP group based on the summary odds ratio on the PCO rate (OR 0.42 95% CI 0.24–0.73) .
Besides, some studies show that ACP changes the position stability of IOL. A previous study indicated decreasing the polishing of anterior capsule enhances the rotational firmness of a toric IOL . However, a study involving 30 patients (60 eyes) revealed that the eyes that did not undergo intraoperative ACP had a likelihood for backward IOL movement by about 0.2mm, at two months after surgery . Another study posited that 360° ACP effectively reduces the incidence of the anterior capsule contraction and raises the firmness of IOL in cataract patients with high myopia .
In the present study, we primarily analyzed the rate of Nd: YAG capsulotomies between two groups using Kaplan-Meier survival curves. Based on the type of IOL implanted in the two groups, there were statistical differences between the two groups by different types of IOL. We found that diffractive MIOL (AT LISA tri 839MP) had a higher incidence of PCO than segmental refractive MIOL (SBL-3) in both the ACP and the non-ACP groups. The kind of intraocular lens could affect the occurrence of PCO. We analyzed the two types of MIOL with Kaplan-Meier survival to verify the effect of ACP on the incidence of PCO in the two kinds of MIOL. Consequently, there were no distinct differences between the two types of MIOL. Therefore, ACP did not affect diffractive MIOL (AT LISA tri 839MP) and segmental refractive MIOL (SBL-3).
We demonstrate that ACP shows no difference in terms of PCO formation in MIOL. A recent study recommended ACP for eyes only with a higher risk of anterior capsule contraction, such as myotonic dystrophy and high myopia, and for those who must undergo a peripheral retinal examination after surgery . Therefore, intraoperative ACP might not be a routine choice for ophthalmologists to reduce the incidence of PCO. However, the role of ACP in maintaining the stability of IOL cannot be ignored, especially for MIOL, because some studies have shown that it reduces the occurrence of ACO and the anterior capsule contraction [18–20].