AB Interno Canaloplasty in the Treatment of Glaucoma after Corneal Transplant Surgery
Abstract:
Introduction: Secondary glaucoma is one of the most common complications after corneal transplant surgery, which can lead to the rejection of the graft and irreversible damage to the optic nerve, leading to loss of visual potential in the eye. Therefore, early detection, control of intraocular pressure, and timely treatment are essential to promote graft survival and protect patients' vision. In recent years, glaucoma surgery has undergone a great revolution. Minimally invasive glaucoma surgeries (MIGS) unlike traditional ones, offer a rapid recovery process, less postoperative complications, safety, and effectiveness. MIGS should be considered as a new option in treating secondary glaucoma after keratoplasty given that it allows better protection of the graft and an increased survival rate.
Methods: This study is a retrospective review of patient data from consecutive patients with penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK), who underwent ab interno canaloplasty as a stand-alone procedure. Patients were followed up for 6 months: regarding vision, intraocular pressure (IOP), and the number of medications. Endothelial cell density (ECD), coefficient of variation, and hexagonality were calculated using specular microscopy preoperative and postoperatively to evaluate the security of the procedure in these types of patients.
Results: 10 patients were included. All canaloplasty surgeries were performed by the same surgeon. Preoperative mean IOP was 33.7 ± 14.7; the number of preoperative glaucoma medications was 4 ± 0.92, after surgery the mean IOP was 12.2 ± 1.50 mmHg (p<0.001) on 1.9 ± 0.88 medications (p<0.001). The preoperative mean endothelial cell density (ECD) was 1813 ± 687.4 cells/ mm2. Following surgery was 1473 ± 549.0 cells/mm2 (p = 0.005). No significant endothelial cell loss was detected. No serious adverse events were recorded. No failure graft was reported after surgery.
Conclusion: Ab interno canaloplasty is an effective and safe procedure that successfully achieves a lower IOP in patients with glaucoma after corneal transplant surgery. In this study survival of the corneal grafts was high, therefore it should be considered as an alternative prior to drainage surgery. Further prospective studies with larger patient populations are needed to elucidate the utility of canaloplasty in this population.
