Cairs At The Edge: Melt And Endothelial-Level Placement

To report two uncommon and previously underreported complications of Corneal Allogenic Intrastromal Ring Segment (CAIRS) implantation in keratoconus:

1. Postoperative corneal melt with early extrusion

2. Inadvertent pre-Descemet’s (ultra-deep) stromal implantation

and to discuss their management and clinical outcomes.

Department of Ophthalmology, King Salman Medical City and Ohud Hospital, Al-Madinah, Saudi Arabia.

Case 1 – Corneal Melt

A 19-year-old male with keratoconus underwent manual CAIRS implantation after contact lens intolerance.

One week postoperatively, following vigorous eye rubbing, localized stromal melt developed over the central segment with partial bulging.

Management included:

• Multilayer dehydrated amniotic membrane transplantation (AMT)

• Bandage contact lens (BCL)

• Topical corticosteroids and antibiotics

• Serial anterior segment OCT monitoring

A second AMT application was required.

Case 2 – Pre-Descemet’s Implantation

A 30-year-old female with advanced keratoconus and prior CXL underwent femtosecond laser-assisted CAIRS implantation.

Although intended depth was 250 µm, postoperative AS-OCT revealed unintended placement at the pre-Descemet’s level, posing theoretical endothelial risk.

The patient was managed conservatively with close monitoring.

These two cases highlight that:

• CAIRS, despite improved biocompatibility, can present with rare complications.

• Corneal melt can be successfully managed conservatively using multilayer AMT without segment removal.

• Ultra-deep (pre-Descemet’s) CAIRS placement may not necessarily compromise short-term outcomes, though endothelial monitoring remains essential.

• Surgical depth control remains critical; manual dissection and OCT-guided femtosecond platforms may enhance safety.

This report expands the current understanding of CAIRS safety profile and provides practical management strategies for atypical complications.