Persistent Hypotony and Annular Ciliochoroidal Detachment After Microhook Ab Interno Trabeculotomy

Area of Science:

• Ophthalmology
• Glaucoma Surgery
• Ocular Anatomy

Background:

• Microhook ab interno trabeculotomy (μLOT) is a minimally invasive glaucoma surgery (MIGS).
• Persistent hypotony is a potential complication following glaucoma surgery.
• Ciliochoroidal detachment (CCD) can lead to hypotony.

Purpose of the Study:

• To report persistent hypotony after μLOT.
• To investigate the mechanism of persistent hypotony following μLOT.
• To identify risk factors associated with persistent hypotony after μLOT.

Main Methods:

• Observational case series of 4 consecutive patients with persistent hypotony after μLOT.
• Data collected from medical charts, including surgical history and postoperative outcomes.
• Ultrasound biomicroscopy used to assess ciliochoroidal detachment and anterior chamber communication.

Main Results:

• Four patients developed persistent hypotony (<5 mmHg) after μLOT.
• Ultrasound biomicroscopy revealed annular CCD in all cases; suprachoroidal space communication in 3/4.
• Hypotony resolved in 3/4 patients spontaneously or with intervention; incidence was 0.7%.

Conclusions:

• Persistent hypotony after MIGS, while rare, can be caused by CCD, potentially due to cyclodialysis cleft formation.
• Increased uveoscleral outflow or cyclodialysis cleft formation are proposed mechanisms for CCD.
• Young age and myopia may increase the risk of cyclodialysis cleft formation and subsequent hypotony maculopathy after MIGS.