The Intrastromal Corneal Ring: Two Cases in Rabbits

Abstract

The intrastromal corneal ring (ICR) is a refractive device with the potential to correct both myopia and hyperopia. The ring is inserted in the peripheral corneal stroma at about two-thirds depth. Mechanical expansion of the ring flattens the central cornea, while constriction of the ring steepens it. Two rabbits underwent ICR surgery. The rabbit with ring expansion showed central corneal flattening 6 months postoperatively. The rabbit with ring constriction showed central corneal steepening 6 months postoperatively. In both cases, the central cornea remained clear.

Clinical and pathological effects of different acrylic intracorneal ring segments in corneal additive surgery

“…Intracorneal ring segments which were proposed originally for the correction of low degrees of myopia [24] have been recently investigated as an additive surgical procedure to treat patients with ectatic corneal diseases [3,4,13]. This additive method presents the advantages of being a safe, efficient and reversible surgery [25][26][27].…”

“…Previous studies have explored the effects of intracorneal ring segments on a variety of alternative animal models, selecting rabbits as the animal more suitable for evaluating the safety of the intracorneal rings effects [14,24,43]. However, in this study we chose the hen as the experimental animal since, histologically, its cornea resembles human cornea in size and structure: it is thinnest centrally and it thickens toward the periphery.…”

Cross-linking e segmento de anel corneano intraestromal

“…(22)(23) . Em 1987, Fleming et al (24) descreveram um implante feito de polimetilmetacrilato (PMMA) chamado de anel corneano intraestromal (ACI), baseado em um original conceito desenvolvido por Reynolds (24) . As primeiras cirurgias usando os anéis corneanos intraestromais foram realizadas no Brasil em olhos não funcionais por Nosé (25) , e nos Estados Unidos por Assil (26) …”

Treatment of Pellucid Marginal Degeneration

“…Then to decrease the rate of incision-related complications and make it surgically easier, the rings were changed to the C-shape range, and they were renamed as ICRS. [21][22][23] The ICRS is used in early-to-moderate PMD for deferring corneal transplant and improving tolerance of contact lens. The principle of using this originated from what was demonstrated by the addition of extramaterial at the normal corneal midperiphery, which results in a forward displacement of the anterior surface at this area.…”