Long-term outcomes and causes of intrastromal corneal ring segment explantation in a tertiary eye hospital.

PURPOSE: To evaluate the causes and long-term outcomes after intrastromal corneal ring segment (ICRS) explantation in the King Khaled Eye Specialist Hospital.

METHODS

This was retrospective cohort study. Two groups were analyzed: Group one, ICRS surgery done in our hospital (n = 41) and group two, surgery done outside but removed in our hospital (n = 29). Causes and postoperative management after ICRS removal were analyzed. For statistical analysis, groups were analyzed into two subgroups of causes of ICRS removal: Visual disturbance versus extrusion/infection/neovascularization (NV) subgroups; and two subgroups of postoperative treatment: Corneal transplant (CT) versus Contact lens (CL)/eyeglasses subgroups.

RESULTS

The most common cause of ICRS removal in group one was visual disturbance (45.2%) while in group two was extrusion (41.2%). CL is the preferable management after explantation. 76% of ICRS removal occurred during the first 4 years. In group 1, there was significant worse preimplantation visual acuity (P = 0.02) in CT subgroup versus CL/eyeglasses. CT subgroup had lower pachymetry of 437.4 μm (P = 0.04) and higher myopia of 8.05 (P = 0.03) than CL/eyeglasses subgroup. For group two, there was a significant improvement in uncorrected visual acuity in visual disturbances subgroup after explantation (P = 0.004). After explantation, visual disturbances subgroup had higher myopia -4.4 than extrusion subgroup -1.15 (P = 0.004).

CONCLUSION

Seventy-six percent of ICRS removal occurred during the first 4 years. High myopia and pachymetry lower than 437 um were associated with visual disturbances and further management with corneal transplantation. High myopia was also associated with visual disturbances in surgeries done outside our hospital.