Primary angle closure glaucoma (PACG) is the main type of glaucoma in China, which includes acute and chronic PACG. According to the International Society of Geographical and Epidemiological Ophthalmology (ISGEO), this spectrum of disease is divided into acute angle closure crisis (AACC), primary angle closure suspect (PACS), primary angle closure (PAC) and PACG. Previous researchers have reported that with the wider use of lens extraction and intraocular lens (IOL) implantation combined with anti-glaucoma surgery in the treatment of PAC and PACG, the prevalence of zonular laxity or dialysis in primary angle closure disease (PACD) was found to be relatively high. In one of the studies performed by the investigators, the proportion of zonular laxity or dialysis was 46.2%, significantly higher than that in the age-related cataract patients (control group), which was 6.0%. In PACD patients with zonular laxity or dialysis, whether or not should the investigators implant capsular tension ring (CTR), the efficacy and safety of CTR implantation, and if there is any difference in the prevalence of complications during and after surgery between patients with and without CTR implantation remain unclear. The purpose of this study was to investigate the efficacy and safety of CTR implantation in PACD patients with zonular laxity and zonular dialysis ≤ 4 clocks.