Corneal Wound: Architecture and Integrity

Luis E. Fernández de Castro, M.D.1

Helga P. Sandoval, M.D., M.S.C.R.1

Kerry D. Solomon, M.D.1

1 Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA

Disclosure: L.E. Fernández de Castro-D: Alcon, Allergan, AMO; H.P. Sandoval-D: Alcon, Allergan, AMO; K.D. Solomon–A,C,D: Alcon, Allergan, AMO, Advanced Medical Research, B&L, InSite Vision,

Eyemaginations

Supported in part by NIH/NEI EY-014793 (vision core) and an unrestricted grant to MUSC-SEI from Research to Prevent Blindness, New York, NY, USA

Introduction

• Surgeons transitioning from larger to smaller micro-incisions

• Incision construction is key for preventing hypotony, wound leaks, and ingress of microorganisms (endophthalmitis)

Purpose

• To compare different incision sizes on clear corneal incision (CCIs) and to determine which incision width creates a square or nearly square arquitecture

Materials and Methods

• A prospective study of 4 human cadaver eyes using different incisions (4) were analyzed– Particular attention was given to ensure that the

wound had a square or near square configuration– Scanning electron microscopy was used to

evaluate wound architecture in each group

3.2 mm 2.8 mm 2.6 mm 2.2 mm

Materials and Methods

• After the CCIs– Corneas were fixed in 2% Cacodylate

Glutaraldehyde– Processed and examined using SEM at the Medical

University of South Carolina, Charleston, SC• Imaging was performed using a magnification factor of

50x, 100x, and 200x• Each specimen was examined and then photographed

according to a standard protocol• The outer and inner corneal wound surface were

evaluated

Results

• Qualitative observations– On the epithelial side• All incisions were

adequately apposed– Large incision width• Rectangle

configuration – Small incision width• Square configuration

3.2 mm Incision

Outer Inner

Epithelial cell loss Apposed Tear of Descemet membrane

Gapping

2.8 mm Incision

Outer Inner

Epithelial cell loss Apposed Gapping

2.6 mm Incision

Outer Inner

Epithelial cell loss Gapping Apposed Tear at the edge

2.2 mm Incision

Outer Inner

Apposed Gapping

3.2 mm

2.8 mm

2.6 mm

2.2 mm

3.2 mm

2.8 mm

2.6 mm

2.2 mm

Larger incision widths prevent a square configuration

Smaller incision widths permit a nearly squared or squared configuration

Conclusion• Larger incision widths often preclude a square

construction due to infringement on the visual axis• Smaller incision width permit a nearly square or square

construction– Square incisions can be more stable than rectangular

• Reducing risk of hypotony• Reducing risk of wound leakage• Reducing ingress of microorganisms

• Irregular apposition and minimal gapping in endothelial edges due to direct mechanical trauma– Clinically shown to improve over time

• Ongoing study to determine wound integrity