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

Vienna Institute for Research in Ocular Surgery

Status: Completed

Conditions: Cataract

Treatments: Procedure: SICS stab-incision; Procedure: SICS-group; Procedure: MICS-group; Procedure: SICS pre-cut

Study type: Interventional

Funder types: Other

Identifiers

NCT01778998

INCISIONS

Details and patient eligibility

About

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

Enrollment: 68 patients

Sex: All

Ages: 21+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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68 participants in 4 patient groups

MICS-group

Active Comparator group

Treatment:

Procedure: MICS-group

SICS-group

Active Comparator group

Treatment:

Procedure: SICS-group

SICS pre-cut

Active Comparator group

Treatment:

Procedure: SICS pre-cut

SICS stab-incision

Active Comparator group

Treatment:

Procedure: SICS stab-incision