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 (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 mm2.8 mm2.6 mm2.2 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 OuterInner 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