Abstract:

Objective

The aim of this study is to observe the long-term clinical effect of laser peripheral iridotomy（LPI）combined with capsule tension ring（CTR）implantation in cataract patients with primary angle closure glaucoma（PACG）.

Methods

A total of 100 patients（100 eyes）with senile cataract complicated with PACG were retrospectively collected from Cataract Glaucoma Department of Shanghai Xinshijie Eye Hospital from June to December 2019.There were 52 males（52 eyes）and 48 females（48 eyes）with an average age of（71.7±8.3）years（ranged from 54 to 90 years）.Patients were divided into study group and control group according to with or without CTR.Both groups of patients underwent LPI combined with cataract surgery，and CTR was implanted in the study group，while not implanted in the control group.The visual acuity，intraocular pressure（IOP），corneal endothelial cell density，and anterior chamber depth of two groups of patients before surgery，after LPI treatment，and after cataract surgery for 1 day，1 month，and 4 years were compared.Gender and ocular data were presented as cases and percentage and used for comparison between groups by chi-square test.Count data such as visual acuity，IOP，corneal endothelial cell count，and anterior chamber depth were described as for data consistent with normal distribution.Independent sample t test was used for inter-group comparison，and paired t test was used for intra-group comparison.Data that did not conform to normal distribution were described by M（Q1，Q3），and used for inter-group comparison by Mann-Whitney U test，and for intra-group comparison was used by Wilcoxon signed rank test.

Results

There were 54 patients（54 eyes）in the study group.Among them，there were 26 males（26 eyes）and 28 females（28 eyes）with an average of（71.3±8.5）years old（ranged from 54 to 90 years old）；there were 31 cases（31 eyes）in the right eye and 23 cases（23 eyes）in the left eye.The phacoemulsification surgery time for cataracts was 17.00 to 39.00 seconds，with an average of（27.76±5.30）seconds.The refractive error of artificial intraocular lens（IOL）ranged from 9.00 to 30.00 D，with an average of（21.25±4.13）D.There were 46 patients（46 eyes）in the control group.Among of them，there were 26 males（26 eyes）and 20 females（20 eyes）；there were 23 cases（23 eyes）in the right eye and 23 cases（23 eyes）in the left eye.The age range was 54 to 87 years old，with an average of（72.1±8.0）years old.The phacoemulsification surgery time for cataracts was 21.00 to 43.00 seconds，with an average of（29.72±4.99）seconds.The IOL refractive power was 10.00 to 30.00 D，with an average of（21.43±4.20）D.There was no statistically significant difference in gender and eye distribution between the study group and the control group（χ²=0.70，0.55；P＞0.05）.There was no statistically significant difference in age and phacoemulsification surgery time between the study group and the control group（t=-0.45，-1.89；P＞0.05）.There was no statistically significant difference in IOL refractive power comparison（Z=-0.052，P＞0.05）.The uncorrected distance visual acuity of the study group and the control group after surgery for 1 day and 4 years was0.20（0.10，0.30）logarithm of the minimum angle of resolution（logMAR），0.20（0.10，0.30）logMAR，0.30（0.20，0.30）logMAR，0.30（0.20，0.40）logMAR，respectively.The differences were statistically significant（Z=-2.672，-3.562；P＜0.05）.At 4 years after surgery，uncorrected distance visual acuity in both groups was better than the baseline，and the differences were statistically significant（Z=-6.359，-5.829；P＜0.05）.The IOPof the study group and the control group at 4 years after surgery was 16.50（13.75，18.00）mmHg（1 mmHg=0.133 kPa）and 18.00（15.00，20.00）mmHg，respectively，and the difference was statistically significant（Z=-2.873，P＜0.05）.At 4 years after surgery，IOP of both groups was lower than the baseline，and the differences were statistically significant（Z=-5.893，-4.512；P＜0.05）.The IOP of the study group at 4 years after cataract surgery was significantly lower than that after LPI treatment，and the difference was statistically significant（Z=-4.124，P＜0.05）.The anterior chamber depth was（2.75±0.28）mm and（2.65±0.22）mm respectively in the study group and the control group after cataract surgery for 4 years，and the difference was not statistically significant（t=1.955，P＞0.05）.After surgery for 4 years，the anterior chamber depth in both groups was greater than the baseline，with statistical significance（t=-28.106，-29.694；P＜0.05）.Compared with LPI treatment，there were significant differences in anterior chamber depth between the study group and the control group at 4 years after cataract surgery（t=-25.933，-26.930；P＜0.05）.The corneal endothelial cell count after cataract operation for 4 years was（2095.50±312.81）/mm² and（1977.15±251.12）/mm²，respectively，and the difference was statistically significant（t=2.061，P＜0.05）.The corneal endothelial cell count in the study group after cataract surgery for 4 years was lower 10.79% than the baseline，and the difference was statistically significant（Z=-6.393，P＜0.05）. The control group reduction was 15.57%， and the difference was statistically significant（t=13.959，P＜0.05）.There were no abnormal IOL between the study group and the control group after cataract surgery for 4 years in two groups，and the long-term safety of IOL between the study group and the control group was good.

Conclusions

LPI combined with phacoemulsification and IOL the study group and the control group implantation for cataracts patients with PACG can significantly improve the visual acuity，reduce IOP，increase anterior chamber depth，and have good corneal safety.At the same time，the application of CTR in cataract surgery can significantly reduce the IOP，and has less impact on corneal endothelial cells.

Key words: Capsule tension ring, Primary angle closure glaucoma, Laser peripheral iridotomy, Cataract, Intraocular lens