Intrastromal Corneal Ring Implants Boost Keratoconus Vision,Quality of Life

Intrastromal corneal ring segment implantation can lead to significant improvements in psychological and psychosocial measures for teens and young adult patients with moderate keratoconus (KC), according to an analysis published in Cornea. Researchers attribute these scores to improved vision after surgery and suggest that intrastromal corneal ring segment implants may be a “first surgical option,” due to new techniques, including femtosecond laser tunnel and ring technologies, that provide more predictable outcomes.

This prospective, interventional study recruited 30 patients (60 eyes) with Amsler–Krumeich stage II or III KC and enantiomorphism, who were randomly assigned to receive intrastromal corneal ring segment implants or be placed in a control group. Patients ranged from 16 to 35 years of age. The surgeon performed same-day bilateral procedures at Federal University of São Paulo, Brazil during 2020 and 2021. Investigators used 2 questionnaires to assess quality of life (QOL).

In the experimental group, average best-corrected visual acuity (BCVA) increased from 0.32±0.2 logMAR before intrastromal corneal ring segment implantation to 0.14±0.11 after 1 year, and spherical equivalent of -7.24±3.47 improved to -4.13±2.41 (both P =.001). The Visual Function Questionnaire (VFQ-25) composite score increased from 55.1 at baseline to 80.4 after surgery (P =.001). Similarly, the Short Form Health Survey (SF-36) showed significant increases in all domains, along with physical and mental health summary scores — and results persisted after adjusting for sex and age.

Notably, a meaningful correlation emerged between visual acuity and the VFQ-25 composite score (r of -0.40, P =.001). Following intrastromal corneal ring segment implantation, patients with KC demonstrated improvements in psychological symptoms, psychosocial criteria, visual dependency, and quality of life, which the researchers attribute to corneal remodeling.

“With earlier interventions using less invasive, more predictable surgical technologies, we can significantly improve visual acuity and QOL, as shown by the statistically significant improvements in all items in both questionnaires,” according to the researchers. “The improvements in scores suggest that in these patients, surgery had a statistically significant, beneficial effect on social inclusion components, visual interference, mental health, and dependency on others.”

Previous research on intrastromal corneal ring segment implants using the National Eye Institute Refractive Error Quality of Life (NEI-RQL) has revealed postoperative improvements, as well as that in a multivariate model, QOL was related to sex, cylinder, and normal contrast sensitivity. Alternatively, corneal crosslinking (CXL) has been reported to reduce anxiety, improve QOL; and associated data indicates psychological impact from KC likely arises from both anxiety and actual physical deficiency.

Limitations of this investigation are a small sample size, and lack of subsequent therapeutic contact lens wear. The study is first to confirm identifiable characteristics of improvement in QOL after intrastromal corneal ring segment implantation for individuals with bilateral, symmetrical keratoconus.