Intraocular Lens-shell Technique in Phacoemulsification

Study Overview
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Brief Summary
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In this study, the investigators introduce a surgical procedure called IOL-shell technique in the purpose of reduce complications of surgeries for dense cataract, and report a prospective randomized controlled study aiming at assessing efficacy and safety of the IOL-shell technique, which showed that the new procedure offered a safer way for hard cataract surgery over the conventional phacoemulsification procedure without compromise in efficacy.

Detailed Description
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A Prospective, randomized controlled study of 80 eyes with dense nucleus were enrolled. Patients were assigned to two groups: Group I: IOL was traditionally implanted after all nuclear fragments were completely removed, while in Group II, IOL was innovatively implanted in the bag before last residual nuclear fragment was removed. This novel adjusted surgical procedure, featured by using IOL as a protective barrier (named IOL-shell technique), not just as a refractive alternative, was conceptual different from the traditional step-by-step procedure. Clinical examinations including uncorrected visual acuity, central corneal thickness (CCT), temporal clear corneal thickness and the corneal endothelial cell density were carried out.

Official Title
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Intraocular Lens-Shell Technique: An Adjustment of Surgical Procedure Makes Differences in Treating Dense Nucleus Cataract

Conditions
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Cataract, Pseudoaphakia

Intervention / Treatment
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* Procedure: IOL-shell technique
* Procedure: Conventional procedure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 50 years or above Dense cataract cases were defined as eyes in which the nuclear color was graded IV or V according to the Lens Opacities Classification System III (LOCS III). Special attention was paid in selecting cases without apparent posterior cortical layer. No central corneal opacification Pupil diameter >= 7 mm after full pharmacological dilation in preoperative assessment A preoperative central endothelial cell count of >= 1500 cells/mm2. Exclusion Criteria: Participants with previous intraocular surgery Abnormal lens zonules Glaucoma High myopia (>-6.0 Diopters) Pseudoexfoliation Uveitis Diabetes mellitus Those who were not able to come for follow-up visits.

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 90 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: IOL-shell technique<br>In this group, before the emulsification of the last nuclear fragment, cohesive viscoelastic material was injected below the nuclear fragment and a foldable IOL was implanted into the well inflated capsular bag posterior to the nuclear fragment. The remaining last piece of nuclear fragment was then emulsified and removed within the capsular bag. | Procedure: IOL-shell technique<br>* Phacoemulsification was performed with the same device and handpieces, using the same phaco chop technique as in the conventional procedure group. What was different was that before the emulsification of the last nuclear fragment, cohesive viscoelastic material was injected below the nuclear fragment and a foldable IOL was implanted into the well inflated capsular bag posterior to the nuclear fragment. The remaining last piece of nuclear fragment was then emulsified and removed within the capsular bag.<br>|
| Active Comparator: Conventional procedure<br>In this group, a Sensar IOL (AMO Laboratories) was implanted in the capsular bag with the injector system after the lens material was completely removed. The nuclear fragmentation was performed using the Phaco-chop technique, which was then followed by ultrasound emulsification of the nuclear fragments piece by piece. Due to lack of cortical shell within the capsular bag, special care was taken to carry out the emulsification of the last nuclear fragment at a relatively more anterior anatomical position between the iris plan and the anterior chamber. | Procedure: Conventional procedure<br>* In this procedure, a IOL was not implanted until all the nuclear fragments were removed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Central corneal endothelial cell loss | Central corneal endothelial cell loss was calculated by subtracting postoperative corneal endothelial cell density from the preoperative baseline level. | one month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| central cornea thickness | The temporal corneal thickness and central corneal thickness were measured using the manual measurement scale in the scanning pictures of anterior segment optical coherence tomography preoperatively and at each postoperative visit. | one month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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dense cataract, phacoemulsification, lens-shell technique, intraocular lens