Implantation of Capsular Tension Ring in Primary Angle Closure Patients With Zonular Laxity or Dialysis

Study Overview
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Brief Summary
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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.

Detailed Description
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Patients with PACD who are scheduled to have phacoemulsification and IOL implantation combined with goniosynechialysis are recruited. All recruited patients attended comprehensive eye examinations and interviews. Past history of ocular and systemic diseases, family and personal history, history of ocular trauma and surgery were interviewed. And the patients underwent ophthalmic examinations including visual acuity tests (presenting visual acuity [PVA] and best-corrected visual acuity [BCVA]), subjective refraction, intraocular pressure (IOP) measurements, slit-lamp examination, fundus photography, gonioscopy, ocular biometry using IOL Master 700, ultrasound biomicroscopy, anterior segment optical coherence tomography (ASOCT) imaging. All patients provide informed consent for inclusion in the study. All surgery procedures were performed by the same surgeons (CYQ) using the same standard operation procedure. All patients use the same type of foldable IOL calculated using SRK/T formula. During the surgery, patients with wrinkling of the anterior capsule (multiple sinusoidal folds were formed) during continuous curvilineal capsulorhexis (CCC) at the needle or forceps tip but without infolding of peripheral capsule or visualisation of the capsular equator during the cortical or nuclear removal, or, wrinkling of the anterior capsule during CCC with infolding of peripheral capsule and visualisation of the capsular equator ≤ 4 clocks of range during the cortical or nuclear removal, were finally included in the study and randomly assigned (using a random-number table generated by SAS) with equal probability to either CTR group (with CTR implantation during the surgery) and control group (without CTR implantation during the surgery). All patients included in the CTR group use the same type of CTR. The investigators recorded the complications during the surgery including vitreous prolapse, hyphema, vitreous hemorrhage, damage of iris and lens capsule, et al. Postoperatively, all patients received similar routine medication comprising topical prednisolone acetate (six times a day for 1 week and tapered down by 1 time every week), topical levofloxacin hydrochloride (four times a day for 1 month), and Tobramycin and Dexamethasone Eye Ointment (1 time every night for 1 month). Postoperative examinations were performed at 1 day, 1 week, 1 months, 3 months, 6 months and 12 months. During the follow-up visits, a complete ophthalmic examination was performed including PVA, BCVA, subjective refraction, non-contact IOP measurement, slit-lamp examination, slit-lamp photography after pupil dilation, ASOCT, gonioscopy, and fundus imaging.

Official Title
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Implantation of Capsular Tension Ring in Primary Angle Closure Patients With Zonular Laxity or Dialysis

Conditions
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Glaucoma, Angle-Closure

Intervention / Treatment
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* Procedure: Capsular tension ring implantation
* Procedure: No capsular tension ring implantation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 45-79 years old Continuous cases diagnosed with AACC, PACS, PAC and PACG in glaucoma department of Beijing Tongren Hospital from October 1st, 2022 to December 31th, 2024 and undergo phacoemulsification lens extraction and intraocular lens implantation combined with goniosynechialysis Wrinkling of the anterior capsule during manual continuous circular capsulorhexis (CCC) but without infolding of peripheral capsule or visualization of the capsular equator, or, wrinkling of the anterior capsule during manual capsulorhexis and combined with visualization of capsular equator and infolding of peripheral capsule ≤ 4 clocks (lens subluxation) The eye of each subject that meet the inclusion criteria is included and if both eyes meet the inclusion criteria, the first eye that undergo the surgery is included Exclusion Criteria: Past history of intraocular surgeries including trabeculectomy, peripheral iridotomy, glaucoma valve implantation, vitrectomy, and so on Past history of laser peripheral iridotomy or iridoplasty Past history of ocular trauma or signs referring to ocular trauma Ocular diseases that may cause zonulopathy, including choroidal detachment, retinal detachment, ciliary body detachment, intraocular tumor and so on Lens related secondary glaucoma, including spherophakia, Marfan syndrome, homocystinuria and son on Other secondary angle closure glaucoma, including neovascular glaucoma, iritis related secondary glaucoma and so on Visualization of capsular equator and infolding of peripheral capsule > 4 clocks during the surgery Anterior or posterior capsule rupture during the surgery which makes it impossible for CTR implantation

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 79 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: With capsular tension ring implantation<br>We performed phacoemulsification lens extraction and intraocular lens implantation with capsular tension ring implantation combined with goniosynechialysis. | Procedure: Capsular tension ring implantation<br>* Capsular tension ring implantation during phacoemulsification lens extraction and intraocular lens implantation combined with goniosynechialysis in included angle closure patients.<br>|
| Other: Without capsular tension ring implantation<br>We performed phacoemulsification lens extraction and intraocular lens implantation without capsular tension ring implantation combined with goniosynechialysis. | Procedure: No capsular tension ring implantation<br>* No capsular tension ring implantation during phacoemulsification lens extraction and intraocular lens implantation combined with goniosynechialysis in included angle closure patients.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Spherical equivalent | Sphere +1/2 cylinder obtained from subjective refraction | baseline | 
| Spherical equivalent | Sphere +1/2 cylinder obtained from subjective refraction | 1 month after the surgery | 
| Spherical equivalent | Sphere +1/2 cylinder obtained from subjective refraction | 3 months after the surgery | 
| Spherical equivalent | Sphere +1/2 cylinder obtained from subjective refraction | 6 months after the surgery | 
| Spherical equivalent | Sphere +1/2 cylinder obtained from subjective refraction | 12 months after the surgery | 
| Area of anterior capsulorhexis | Area of anterior capsulorhexis measured using slit-lamp photography | 1 week after the surgery | 
| Area of anterior capsulorhexis | Area of anterior capsulorhexis measured using slit-lamp photography | 1 month after the surgery | 
| Area of anterior capsulorhexis | Area of anterior capsulorhexis measured using slit-lamp photography | 3 months after the surgery | 
| Area of anterior capsulorhexis | Area of anterior capsulorhexis measured using slit-lamp photography | 6 months after the surgery | 
| Area of anterior capsulorhexis | Area of anterior capsulorhexis measured using slit-lamp photography | 12 months after the surgery | 
| Assessment of posterior capsular opacification | Assessment of posterior capsular opacification using slit-lamp photography | 1 week after the surgery | 
| Assessment of posterior capsular opacification | Assessment of posterior capsular opacification using slit-lamp photography | 1 month after the surgery | 
| Assessment of posterior capsular opacification | Assessment of posterior capsular opacification using slit-lamp photography | 3 months after the surgery | 
| Assessment of posterior capsular opacification | Assessment of posterior capsular opacification using slit-lamp photography | 6 months after the surgery | 
| Assessment of posterior capsular opacification | Assessment of posterior capsular opacification using slit-lamp photography | 12 months after the surgery | 
| The extent of iris-trabecular contact | The extent of iris-trabecular contact assessed by gonioscopy | baseline | 
| The extent of iris-trabecular contact | The extent of iris-trabecular contact assessed by gonioscopy | 1 month after the surgery | 
| The extent of iris-trabecular contact | The extent of iris-trabecular contact assessed by gonioscopy | 3 months after the surgery | 
| The extent of iris-trabecular contact | The extent of iris-trabecular contact assessed by gonioscopy | 6 months after the surgery | 
| The extent of iris-trabecular contact | The extent of iris-trabecular contact assessed by gonioscopy | 12 months after the surgery | 
| The extent of peripheral anterior synechia | The extent of peripheral anterior synechia assessed by gonioscopy | baseline | 
| The extent of peripheral anterior synechia | The extent of peripheral anterior synechia assessed by gonioscopy | 1 month after the surgery | 
| The extent of peripheral anterior synechia | The extent of peripheral anterior synechia assessed by gonioscopy | 3 months after the surgery | 
| The extent of peripheral anterior synechia | The extent of peripheral anterior synechia assessed by gonioscopy | 6 months after the surgery | 
| The extent of peripheral anterior synechia | The extent of peripheral anterior synechia assessed by gonioscopy | 12 months after the surgery | 
| Corneal thickness | Corneal thickness obtained by IOL Master 700 | baseline | 
| Central anterior chamber depth | Central anterior chamber depth obtained by IOL Master 700 | baseline | 
| Lens thickness | Lens thickness obtained by IOL Master 700 | baseline | 
| Axial Length | Axial Length obtained by IOL Master 700 | baseline | 
| Refractive prediction error | Refractive prediction error obtained by IOL Master 700 | baseline | 
| Anterior chamber depth | Anterior chamber depth obtained by anterior segment optical coherence tomography | baseline | 
| Anterior chamber depth | Anterior chamber depth obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Anterior chamber depth | Anterior chamber depth obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Anterior chamber depth | Anterior chamber depth obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Anterior chamber depth | Anterior chamber depth obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Anterior chamber depth | Anterior chamber depth obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| Angle opening distance | Angle opening distance obtained by anterior segment optical coherence tomography | baseline | 
| Angle opening distance | Angle opening distance obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Angle opening distance | Angle opening distance obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Angle opening distance | Angle opening distance obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Angle opening distance | Angle opening distance obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Angle opening distance | Angle opening distance obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| Trabecular-iris space area | Trabecular-iris space area obtained by anterior segment optical coherence tomography | baseline | 
| Trabecular-iris space area | Trabecular-iris space area obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Trabecular-iris space area | Trabecular-iris space area obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Trabecular-iris space area | Trabecular-iris space area obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Trabecular-iris space area | Trabecular-iris space area obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Trabecular-iris space area | Trabecular-iris space area obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| Trabecular-iris angle | Trabecular-iris angle obtained by anterior segment optical coherence tomography | baseline | 
| Trabecular-iris angle | Trabecular-iris angle obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Trabecular-iris angle | Trabecular-iris angle obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Trabecular-iris angle | Trabecular-iris angle obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Trabecular-iris angle | Trabecular-iris angle obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Trabecular-iris angle | Trabecular-iris angle obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| Anterior chamber width | Anterior chamber width obtained by anterior segment optical coherence tomography | baseline | 
| Anterior chamber width | Anterior chamber width obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Anterior chamber width | Anterior chamber width obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Anterior chamber width | Anterior chamber width obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Anterior chamber width | Anterior chamber width obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Anterior chamber width | Anterior chamber width obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| Iris thickness | Iris thickness obtained by anterior segment optical coherence tomography | baseline | 
| Iris thickness | Iris thickness obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Iris thickness | Iris thickness obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Iris thickness | Iris thickness obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Iris thickness | Iris thickness obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Iris thickness | Iris thickness obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| Iris cross-sectional area | Iris cross-sectional area obtained by anterior segment optical coherence tomography | baseline | 
| Iris cross-sectional area | Iris cross-sectional area obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Iris cross-sectional area | Iris cross-sectional area obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Iris cross-sectional area | Iris cross-sectional area obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Iris cross-sectional area | Iris cross-sectional area obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Iris cross-sectional area | Iris cross-sectional area obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| Iris curvature | Iris curvature obtained by anterior segment optical coherence tomography | baseline | 
| Iris curvature | Iris curvature obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Iris curvature | Iris curvature obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Iris curvature | Iris curvature obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Iris curvature | Iris curvature obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Iris curvature | Iris curvature obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| Lens thickness | Lens thickness obtained by anterior segment optical coherence tomography | baseline | 
| Lens thickness | Lens thickness obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Lens thickness | Lens thickness obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Lens thickness | Lens thickness obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Lens thickness | Lens thickness obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Lens thickness | Lens thickness obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| Lens vault | Lens vault obtained by anterior segment optical coherence tomography | baseline | 
| Lens vault | Lens vault obtained by anterior segment optical coherence tomography | 1 week after the surgery | 
| Lens vault | Lens vault obtained by anterior segment optical coherence tomography | 1 month after the surgery | 
| Lens vault | Lens vault obtained by anterior segment optical coherence tomography | 3 months after the surgery | 
| Lens vault | Lens vault obtained by anterior segment optical coherence tomography | 6 months after the surgery | 
| Lens vault | Lens vault obtained by anterior segment optical coherence tomography | 12 months after the surgery | 
| The distance between intraocular lens and the posterior capsular | The distance between intraocular lens and the posterior capsular obtained by CASIA2 anterior segment optical coherence tomography | 1 week after the surgery | 
| The distance between intraocular lens and the posterior capsular | The distance between intraocular lens and the posterior capsular obtained by CASIA2 anterior segment optical coherence tomography | 1 month after the surgery | 
| The distance between intraocular lens and the posterior capsular | The distance between intraocular lens and the posterior capsular obtained by CASIA2 anterior segment optical coherence tomography | 3 months after the surgery | 
| The distance between intraocular lens and the posterior capsular | The distance between intraocular lens and the posterior capsular obtained by CASIA2 anterior segment optical coherence tomography | 6 months after the surgery | 
| The distance between intraocular lens and the posterior capsular | The distance between intraocular lens and the posterior capsular obtained by CASIA2 anterior segment optical coherence tomography | 12 months after the surgery | 
| Intraocular lens inclination angle | Intraocular lens inclination angle obtained by CASIA2 anterior segment optical coherence tomography | 1 week after the surgery | 
| Intraocular lens inclination angle | Intraocular lens inclination angle obtained by CASIA2 anterior segment optical coherence tomography | 1 month after the surgery | 
| Intraocular lens inclination angle | Intraocular lens inclination angle obtained by CASIA2 anterior segment optical coherence tomography | 3 months after the surgery | 
| Intraocular lens inclination angle | Intraocular lens inclination angle obtained by CASIA2 anterior segment optical coherence tomography | 6 months after the surgery | 
| Intraocular lens inclination angle | Intraocular lens inclination angle obtained by CASIA2 anterior segment optical coherence tomography | 12 months after the surgery | 
| Effective intraocular lens position | Effective intraocular lens position obtained by CASIA2 anterior segment optical coherence tomography | 1 week after the surgery | 
| Effective intraocular lens position | Effective intraocular lens position obtained by CASIA2 anterior segment optical coherence tomography | 1 month after the surgery | 
| Effective intraocular lens position | Effective intraocular lens position obtained by CASIA2 anterior segment optical coherence tomography | 3 months after the surgery | 
| Effective intraocular lens position | Effective intraocular lens position obtained by CASIA2 anterior segment optical coherence tomography | 6 months after the surgery | 
| Effective intraocular lens position | Effective intraocular lens position obtained by CASIA2 anterior segment optical coherence tomography | 12 months after the surgery | 
| The distance between ciliary body and the equator of lens at 3 o'clock position | The distance between ciliary body and the equator of lens at 3 o'clock position obtained by ultrasound biomicroscopy | baseline | 
| The distance between ciliary body and the equator of lens at 6 o'clock position | The distance between ciliary body and the equator of lens at 6 o'clock position obtained by ultrasound biomicroscopy | baseline | 
| The distance between ciliary body and the equator of lens at 9 o'clock position | The distance between ciliary body and the equator of lens at 9 o'clock position obtained by ultrasound biomicroscopy | baseline | 
| The distance between ciliary body and the equator of lens at 12 o'clock position | The distance between ciliary body and the equator of lens at 12 o'clock position obtained by ultrasound biomicroscopy | baseline | 
| Incidence of complications | Incidence of complications including posterior capsular opacification (PCO), IOL tilt, capsule contraction syndrome, et al. | 1 month after the surgery | 
| Incidence of complications | Incidence of complications including PCO, IOL tilt, capsule contraction syndrome, et al. | 3 months after the surgery | 
| Incidence of complications | Incidence of complications including PCO, IOL tilt, capsule contraction syndrome, et al. | 6 months after the surgery | 
| Incidence of complications | Incidence of complications including PCO, IOL tilt, capsule contraction syndrome, et al. | 12 months after the surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Presenting visual acuity | Presenting visual acuity with or without glasses | baseline | 
| Presenting visual acuity | Presenting visual acuity with or without glasses | 1 day after the surgery | 
| Presenting visual acuity | Presenting visual acuity with or without glasses | 1 week after the surgery | 
| Presenting visual acuity | Presenting visual acuity with or without glasses | 1 month after the surgery | 
| Presenting visual acuity | Presenting visual acuity with or without glasses | 3 months after the surgery | 
| Presenting visual acuity | Presenting visual acuity with or without glasses | 6 months after the surgery | 
| Presenting visual acuity | Presenting visual acuity with or without glasses | 12 months after the surgery | 
| Best corrected visual acuity | Visual acuity with refractive correction | baseline | 
| Best corrected visual acuity | Visual acuity with refractive correction | 1 month after the surgery | 
| Best corrected visual acuity | Visual acuity with refractive correction | 3 months after the surgery | 
| Best corrected visual acuity | Visual acuity with refractive correction | 6 months after the surgery | 
| Best corrected visual acuity | Visual acuity with refractive correction | 12 months after the surgery | 
| Intraocular pressure | Intraocular pressure obtained by non-contact tonometer | baseline | 
| Intraocular pressure | Intraocular pressure obtained by non-contact tonometer | 1 day after the surgery | 
| Intraocular pressure | Intraocular pressure obtained by non-contact tonometer | 1 week after the surgery | 
| Intraocular pressure | Intraocular pressure obtained by non-contact tonometer | 1 month after the surgery | 
| Intraocular pressure | Intraocular pressure obtained by non-contact tonometer | 3 months after the surgery | 
| Intraocular pressure | Intraocular pressure obtained by non-contact tonometer | 6 months after the surgery | 
| Intraocular pressure | Intraocular pressure obtained by non-contact tonometer | 12 months after the surgery | 
| Number of anti-glaucoma medications | Number of anti-glaucoma medications | 1 week after the surgery | 
| Number of anti-glaucoma medications | Number of anti-glaucoma medications | 1 month after the surgery | 
| Number of anti-glaucoma medications | Number of anti-glaucoma medications | 3 months after the surgery | 
| Number of anti-glaucoma medications | Number of anti-glaucoma medications | 6 months after the surgery | 
| Number of anti-glaucoma medications | Number of anti-glaucoma medications | 12 months after the surgery | 
| Vertical cup-to-disc ratio | Vertical cup-to-disc ratio evaluated by fundus photography | baseline | 
| Vertical cup-to-disc ratio | Vertical cup-to-disc ratio evaluated by fundus photography | 1 month after the surgery | 
| Vertical cup-to-disc ratio | Vertical cup-to-disc ratio evaluated by fundus photography | 6 months after the surgery | 
| Vertical cup-to-disc ratio | Vertical cup-to-disc ratio evaluated by fundus photography | 12 months after the surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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angle closure, zonular laxity, zonular dialysis, lens subluxation, capsular tension ring, efficacy, safety