Comparison of AC and PC Lenses After Vitreous Loss During ECCE

2014-08-27 03:39:25 | BioPortfolio


Objective: The standard definition of failure in cataract surgery is best corrected visual acuity of less than 20/40 at one year. The specific aim of this cooperative study was to compare the failure rate for those patients with vitreous loss in whom an PC IOL is placed to the failure rate for those in whom an AC IOL is placed after vitreous loss.

Design: A total of 437 patients in 15 centers were randomized to AC or PC IOL over a 45-month period and were followed for a minimum of one year. The null hypothesis is that the rate of failure is the same in the two groups.

All patients who were about to undergo cataract surgery in the participating centers and who did not meet an exclusion criterion were eligible for the study. At the time of surgery, if there was vitreous loss, and if in the opinion of the surgeon there was sufficient capsular support for a posterior chamber lens to be placed, then the patient was randomized into one of either the anterior or posterior chamber lens groups. The patients were then followed for complications (e.g., retinal detachment, cystoid macular edema, uveitis, glaucoma, hyphema) and for the primary end point of visual acuity of 20/40 or better at one postoperative year.

An "Index Group" of about 500 patients without vitreous loss also were followed according to study protocol. These patients were compared to those in the PC and AC IOL groups with respect to outcome and baseline characteristics in order to assess the effect of vitreous loss on complication rates.

All patients were followed at annual intervals until the termination of the study. This allowed the study to obtain long-term information with regard to visual acuity and complication rates.


Primary Hypothesis: There is no difference in failure rate between patients receiving anterior chamber or posterior chamber intraocular lenses following vitreous loss in extracapsular cataract extraction (ECCE).

Secondary Hypothesis: None

Intervention: 1) Anterior chamber intraocular lens, 2) Posterior chamber intraocular lens.

Primary Outcome: Failure defined as best corrected visual acuity less than 20/40 one year following ECCE.

Study Abstract: Extracapsular cataract surgery with posterior chamber intraocular lens implantation is one of the most common and most successful of surgical procedures. In the United States alone approximately 1.4 million cataract extractions were performed in 1990. Of these the overwhelming majority do well. However, the principal complication, vitreous loss, occurs in about 5% of cases. It is often sight-limiting.

Placement of an intraocular lens in the presence of vitreous loss is controversial. The standard approach following anterior vitrectomy usually involves placement of an anterior chamber intraocular lens (AC IOL). However, it has been suggested that implantation of a posterior chamber intraocular lens (PC IOL) in many of these patients is not only possible, but preferable.

In this study, eligible patients were VA patients who had vitreous loss during attempted ECCE. At each occurrence of vitreous loss, the patients were randomly assigned to have an AC IOL or PC IOL. Patient recruitment was terminated early with 438 patients enrolled in 15 centers. Patients were followed to the completion of at least one-year follow-up.

An ?Index Group?of 500 patients without vitreous loss also was followed according to study protocol. These patients will be compared to those in the PC and AC IOL groups with respect to outcome and baseline characteristics in order to assess the effect of vitreous loss on complication rates.

Results: More PC IOL patients (91%) achieved visual acuity of 20/40 or better at one year than AC IOL patients (79%). A highly significant difference (p=0.003). There was no significant difference between the two groups for patients' rating of vison or adverse events. Over 84% of the PC IOL patients and over 77% of the AC IOL patients rated their vision as good or better at one year as opposed to only 7% giving such ratings prior to surgery. For at least one rating period during the first year, 13.2% of the combined study patients had cystoid macular edema, 8.5% had posterior capsule opacification, 5.7% had glaucoma, and 3.7% had retinal detachment.

Conclusion: In the presence of sufficient capsular support, a PC IOL should be implanted after vitreous presentation during ECCE.

Collins JF, Krol WF, Gaster RN, Colling CL, Kirk GF, Smith TJ - A Comparison of Anterior Chamber and Posterior Chamber IOL's after Vitreous Loss during Cataract Surgery. The VA Cooperative Cataract Study. American Journal of Ophthalmology. 136:1-9, 2003

Collins JF, Krol WF, Kirk GF, Gaster, RN - The Effect of Vitreous Presentation During Extracapsular Cataract Surgery on the Postoperative Visual Acuity at One Year. American Journal of Ophthalmology. 138:536-542, 2004

Collins, JF, Gaster,RN, Krol,WF and the VA Cooperative Cataract Study Group. Outcomes in Patients Having Vitreous Presentation During Cataract Surgery Who Lack Capsular Support for a Nonsutured PC IOL. American Journal of Ophthalmology, Vol 141:71-78, 2006

Study Design

Allocation: Randomized, Control: Active Control, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind, Primary Purpose: Treatment




posterior chamber intraocular lens, anterior chamber intraocular lens




Department of Veterans Affairs

Results (where available)

View Results


Published on BioPortfolio: 2014-08-27T03:39:25-0400

Clinical Trials [1835 Associated Clinical Trials listed on BioPortfolio]

Lenstec Softec HD Posterior Chamber Intraocular Lens Clinical Investigational Protocol

The objectives of this multi-center clinical investigation are to determine the safety and effectiveness of the Lenstec Softec HD Posterior Chamber intraocular lens (IOL) following one yea...

Comparison of the Quality of Vision Provided by AMO Tecnis Z9000 and Alcon Laboratories MA60 Acrysof Posterior Chamber Intraocular Lenses

This study is a comparison of the quality of vision provided by AMO Tecnis Z9000 three-piece silicone posterior chamber intraocular lens and Alcon Laboratories MA60 three-piece acrylic pos...

Comparison of the Hoya Surgical Optics (HSO) iSert 251 Posterior Chamber Aspheric Aphakic Intraocular Lens to Historical / Literature Controls.

The purpose of this multi-center clinical trail is to determine the safety and efficacy of the iSert 251 for the correction of aphakia.

Anterior Chamber Depth Variability Between Two Lenses With Different Materials

Compare the change of the Anterior chamber depth (ACD) variability between the Clareon and the AcrySof Intraocular lens (IOL) after implantation over 6 months.

Combined Phacotube vs Phacotrabeculectomy:A Randomized Controlled Trial

The aim of this study is to compare the effectiveness and safety of combined phacoemulsification, posterior chamber intraocular lens implantation , trabeculectomy (phacotrabeculectomy) wit...

PubMed Articles [3755 Associated PubMed Articles listed on BioPortfolio]

Computational simulation of aqueous humour dynamics in the presence of a posterior-chamber versus iris-fixed phakic intraocular lens.

To compare aqueous humour (AH) dynamics in the presence of a precrystalline (Implantable Collamer Lens®; ICL) or iris-fixed (Artiflex®) phakic intraocular lens (PIOL).

Intraoperative optical coherence tomography measurements of aphakic eyes to predict postoperative position of 2 intraocular lens designs.

To evaluate intraoperative anterior chamber depth (ACD) measurements of the aphakic eye to predict the postoperative ACD and compare 2 intraocular lens (IOL) designs.

Relationship between effective lens position and axial position of a thick intraocular lens.

To discuss the impact of intraocular lens-(IOL)-power, IOL-thickness, IOL-shape, corneal power and effective lens position (ELP) on the distance between the anterior IOL vertex (ALP) of a thick IOL an...

Long-Term Clinical Observation of Posterior Chamber Phakic Intraocular Lens Implantation in Young Population.

To compare the clinical outcomes and vision-related quality of life after implantable collamer lens (ICL) implantation for younger patients (17 years ≤ age ≤21 years) and for older patients (age >...

Iridociliary cysts do not impact on posterior phakic intraocular lens implantation for high myopia correction: A prospective cohort study in 1569 eyes.

To investigate the clinical characters and effect of iridociliary cysts among patients who had undergone posterior phakic intraocular lens implantation.

Medical and Biotech [MESH] Definitions

Inflammation of the anterior uvea comprising the iris, angle structures, and the ciliary body. Manifestations of this disorder include ciliary injection, exudation into the anterior chamber, iris changes, and adhesions between the iris and lens (posterior synechiae). Intraocular pressure may be increased or reduced.

Insertion of an artificial lens to replace the natural CRYSTALLINE LENS after CATARACT EXTRACTION or to supplement the natural lens which is left in place.

Incomplete rupture of the zonule with the displaced lens remaining behind the pupil. In dislocation, or complete rupture, the lens is displaced forward into the anterior chamber or backward into the vitreous body. When congenital, this condition is known as ECTOPIA LENTIS.

A form of glaucoma in which the intraocular pressure increases because the angle of the anterior chamber is blocked and the aqueous humor cannot drain from the anterior chamber.

Lenses, generally made of plastic or silicone, that are implanted into the eye in front of the natural EYE LENS, by the IRIS, to improve VISION, OCULAR. These intraocular lenses are used to supplement the natural lens instead of replacing it.

More From BioPortfolio on "Comparison of AC and PC Lenses After Vitreous Loss During ECCE"

Quick Search


Relevant Topics

Ophthalmology is the branch of medicine that is devoted to the study and treatment of eye diseases. As well as mild visual defects correctable by lenses, ophthalmology is concerned with glaucoma, uveitis and other serious conditions affecting the eye, ...

Surgical treatments
Surgery is a technology consisting of a physical intervention on tissues. All forms of surgery are considered invasive procedures; so-called "noninvasive surgery" usually refers to an excision that does not penetrate the structure being exci...

Searches Linking to this Trial