Indications and visual outcomes of intrastromal corneal ring segment implantation in a large patient series

Abstract

OBJECTIVES:To describe the indications for and visual outcomes of intrastromal corneal ring segment implantation.METHODS:A large retrospective case-series chart-review study was conducted using Sorocaba Ophthalmological Hospital medical records. This study included 1222 eyes (1196 patients) that were surgically treated between November 2009 and December 2012. The following preoperative data were collected: age, gender, type of medical care and funding source, surgical technique, best-corrected visual acuity, manifest sphere and cylinder refractive error, maximum and minimum central keratometry, and pachymetry measurements of the cornea at the thinnest point and at the ring channel. The postoperative best-corrected visual acuity and patient satisfaction were also determined. The cases were classified into six groups: four keratoconus groups (severe, advanced, moderate and mild), a pellucid marginal degeneration group and a post-graft irregular astigmatism group. This study was approved by the Brazilian Registry of Clinical Trials (UTN number 1111-1182-6181, TRIAL RBR-6S72RF).RESULTS:The age (mean±standard deviation) of the patients was 31.0±10.0 years. The most prevalent pathology was keratoconus (1147 eyes, 93.8%). A correlation was found between ectasia severity and medical assistance (p<0.001), and the most serious cases was treated by the Brazilian public health system. No complications were found in a total of 1155 surgeries, and after surgery, 959 patients were satisfied. Among the 164 dissatisfied patients, the majority failed to show improved best-corrected visual acuity.CONCLUSION:Patients in the public health system underwent surgical intervention for keratoconus later than those with private sources of funding. In the vast majority of operated cases, the patients reported improvements in vision.

Intracorneal Stromal Ring Can Affect the Biomechanics of Ectatic Cornea

“…Among the patients with definite KCN, inclusion criteria for ICRS implantation were intolerance to spectacles or rigid gas permeable contact lenses (RGP), a transparent cornea with no scarring in the central part, corneal thickness greater than 450 microns in the incision region, keratometry between 48 and 52 diopters (D), and no therapeutic option other than corneal transplantation to improve their functional vision. The contraindications of ICRS implantation in KCN patients were keratometry over 70 D, central corneal opacity (in the vision axis), existence of an irregular scar in the cornea, patients with atopic and chronic itching, consumption of immunomodulatory drugs, ocular infections, rheumatologic diseases, and corneal dystrophia [ 9 ]. Patients with spherical equivalents greater than 5 were selected for MyoRing implantation, while patients with astigmatism dominancy with a lower spherical equivalent were selected for KeraRing implantation.…”

One-year visual outcome of secondary piggyback pinhole device implantation in pseudophakic eyes with irregular corneal astigmatism and iris trauma

“…Treatment aims at rearranging the orientation of the astigmatism so that it is more regular and amenable to sphero-cylindrical correction. Current management options include contact lens wear such as rigid gas-permeable [ 1 ], hybrid [ 2 ] or scleral lens [ 3 ], topography-guided laser refractive surgery [ 4 ], or intrastromal corneal ring segments (ICRS) [ 5 , 6 ]. However, there are pros and cons with each of these treatments and may not be suitable for patients with poor ocular surface, those with contact lens intolerance or corneas too thin for the laser refractive surgery or ICRS to be performed safely.…”

Toric Artisan after transepithelial topography-guided photorefractive keratectomy for higher-order aberrations following intrastromal corneal ring segments in keratoconus – Trioptics

“…[ 2 3 ] However, many patients remain unsatisfied with their CDVA after ICRS implantation. [ 4 ] Therefore, we describe a surgical alternative for those challenging cases.…”