Impact of Incision Size and Architecture on Wound Stability and Astigmatism in Cataract Surgery: an Exploratory Study

Study Overview
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Brief Summary
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One of the most recent advances in cataract surgery is microincisional phacoemulsification (MICS). Through small incisions of 2.0 mm and less the lens material is emulsified either bimanually or with a thin single coaxial hand-piece. The possible advantages are lower induced corneal astigmatism1, 2, possibly a lower incidence of infection due to higher resistance of the wound to deformation3 and a lower risk of complications such as iris prolapse during surgery in patients at risk such as with intraoperative floppy iris syndrome (IFIS). Additional factors that have to be taken into account are the construction and the position of the incision and the influence of the extraocular force on the wound morphology.4 Another effect that may influence the wound architecture is stromal hydration at the end of surgery.5 Wound architecture has recently been assessed6-9 using optical coherence tomography. Elkady et al.10 observed the wound architecture in MICS cases focusing on corneal thickness and the incision angle. However, none of these studies observed the effect of the wound architecture on post-operative astigmatism. Furthermore, all observations in the past have been performed in the post-operative period only and information concerning the wound architecture intra-operatively is missing. A recently launched CE-marked intra-operative OCT allows observing the wound architecture intra-operatively. One aim of the study is to assess the influence of the intra-operative wound architecture using a similar grading system as used by Calladine and Packard (2007)7 on the resistance to deformation of the wound and the surgically induced astigmatism in MICS and small incision cataract surgery (SICS). In a second part of this exploratory study the effect of a hinged incision with a pre-cut should be assessed along the same line

Official Title
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Impact of Incision Size and Architecture on Wound Stability and Astigmatism in Cataract Surgery: an Exploratory Study

Conditions
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Cataract

Intervention / Treatment
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* Procedure: MICS-group
* Procedure: SICS-group
* Procedure: SICS pre-cut
* Procedure: SICS stab-incision


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age-related cataract Age 21 and older written informed consent prior to recruitment Exclusion Criteria: Pregnancy (pregnancy test will be taken pre-operatively in women of reproductive age) Any ophthalmic abnormality that could compromise the measurements

Ages Eligible for Study
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Minimum Age: 21 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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: MICS-group<br> | Procedure: MICS-group<br>* Micro incision cataract surgery is done<br>|
| Active Comparator: SICS-group<br> | Procedure: SICS-group<br>* small incision cataract surgery is done<br>|
| Active Comparator: SICS pre-cut<br> | Procedure: SICS pre-cut<br>* Small incision cataract surgery with pre-cut is done<br>|
| Active Comparator: SICS stab-incision<br> | Procedure: SICS stab-incision<br>* Small incision cataract surgery with stab-incision is done<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| o Correlation between a wound architecture score (developed during the study) and the post-operative astigmatism for the MICS, the SICS, the SICS pre-cut and the SICS stab-incision group |  | pre-operatively to one day post-operativly | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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OCT, incision, pre-cut, wound architecture