Intrastromal Corneal Ring Segment with and without Collagen Corneal Crosslinking vs Penetrating Keratoplasty for the Treatment of Keratoconus

ABSTRACT Keratoconus (KC) is a noninflammatory progressive corneal degeneration that cause irregular astigmatism especially in moderate and advanced cases, the irregular astigmatism can not be corrected by glasses, contact lenses are the only optical way for improving the visual acuity (VA) in these patients. In this retrospective study, we shall present the results of eight patients suffering from KC who were treated by PKP in one eye (PKP group) and ICRS (ICRS group) with or without CXL in the second eye. All the ICRS surgeries, the CXL and the PRK were performed at the I Vision, Refractive Surgery and Keratoconus Treatment Center in Haifa, Israel, by the same surgeon (AB), the PKPs were performed elsewhere, because they were treated in our medical center after the PKP. How to cite this article Barbara R, Barbara A. Intrastromal Corneal Ring Segment with and without Collagen Corneal Crosslinking vs Penetrating Keratoplasty for the Treatment of Keratoconus. Int J Kerat Ect Cor Dis 2014;3(2):88-94.

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Influence of scleral lenses on visual acuity and aberrations in patients with irregular cornea

The Eye ◽

10.33791/2222-4408-2019-2-32-39 ◽

2019 ◽

Vol 126 (2019-2) ◽

pp. 32-39

Author(s):

Olga Tikhonova ◽

Nikolai Pashtaev ◽

Nadezhda Pozdeyeva ◽

Alexander Myagkov ◽

Svetlana Bodrova ◽

...

Keyword(s):

Visual Acuity ◽

Laser Surgery ◽

Contact Lenses ◽

Lens Space ◽

Astigmatism Correction ◽

Intrastromal Corneal Ring ◽

Stable Vision ◽

Ring Segment ◽

Ophthalmologic Examination ◽

Fitting In

Purpose: To analyze changes of functional parame¬ters and aberrations before fitting and after using rigid gas-permeable scleral lenses (RGPSCL) in patients with irregular cornea. Material and methods. 21 patients (29 eyes) with irregular astigmatism of various etiology were enrolled in this study. The patients could not achieve good visual aсuity in glasses, standard soft or rigid corneal contact lenses. Complex ophthalmologic examination was per¬formed: autorefractometry, visometry, biomicroscopy, computer corneal topography, aberrometry on “OPD-Scan II” (“Nidek”, Japan) before fitting scleral lenses and during the period of their wearing. Results and discussion. The results demonstrat¬ed significant visual acuity improvement after RGP¬SCL fitting in all observed patients. UCVA amounted to 0.1±0.18, BCVA in glasses amounted to 0.4±0.26, BCVA in RGPSCL amounted to 0.7±0.1. An increase of best-corrected visual acuity in RGPSCL was statistically significant in patients after keratoplasty, after intra-stromal corneal ring segments (ICRS) implantation, af¬ter refractive laser surgery (RLS) and in cases of mixed astigmatism. We have found that the correction of ker¬atoconus with the use of RGPSCL resulted in a decrease of the root mean square value (RMS), measured in the 3 mm and 5 mm zones by 2.5 times and 4 times, re¬spectively. In patients wearing RGPSCL after kerato¬plasty, statistically significant decrease in RMS was observed in the 3 mm zone (by 3.85 times) and in the 5 mm zone (by 2.99 times). In patients wearing RGPSCL after implantation of intrastromal corneal ring segment (ICRS), RMS in the 3 mm zone decreased by 1.5 times. In patients wearing RGPSCL after refractive laser surgery (RLS) RMS was 2.5 times lower in the 3 mm zone and 2.8 times lower in the 5 mm zone. In case of mixed astigmatism correction with RGPSCL, RMS increased by 1.6 times in the 3 mm zone and practically did not change in the 5 mm zone. Conclusion. The results obtained demonstrated significant visual acuity improvement in all observed patients. The sub-lens-space filled with tear forms a unified “cornea-tear-scleral contact lens” optic system that corrects unevenness of cornea, decreases amount of high-order aberrations (HOA) and provides a clear stable vision.

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Intrastromal corneal ring segment implantation to correct astigmatism after penetrating keratoplasty

Journal of Cataract & Refractive Surgery ◽

10.1016/j.jcrs.2011.12.037 ◽

2012 ◽

Vol 38 (6) ◽

pp. 1006-1013 ◽

Cited By ~ 10

Author(s):

Sandro Coscarelli ◽

Guilherme Ferrara ◽

Jose F. Alfonso ◽

Paulo Ferrara ◽

Jesús Merayo-Lloves ◽

...

Keyword(s):

Penetrating Keratoplasty ◽

Intrastromal Corneal Ring ◽

Ring Segment

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Intrastromal Corneal Ring Segments for Astigmatism Correction after Deep Anterior Lamellar Keratoplasty

Journal of Ophthalmology ◽

10.1155/2017/8689017 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Júlio C. D. Arantes ◽

Sandro Coscarelli ◽

Paulo Ferrara ◽

Luana P. N. Araújo ◽

Marcos Ávila ◽

...

Keyword(s):

Contact Lenses ◽

Corneal Astigmatism ◽

Lamellar Keratoplasty ◽

Deep Anterior Lamellar Keratoplasty ◽

Spherical Equivalent ◽

Astigmatism Correction ◽

Intrastromal Corneal Ring ◽

Anterior Lamellar Keratoplasty ◽

Corrected Distance Visual Acuity ◽

Ring Segment

Background. To evaluate the change in corneal astigmatism after intrastromal corneal ring segment (ICRS) implantation in keratoconus patients with previous deep anterior lamellar keratoplasty (DALK). Design was a longitudinal, retrospective, interventional study. The study included 25 eyes of 24 patients with keratoconus who had DALK performed at least two years prior to ICRS implantation. All patients had a clear corneal graft with up to 8.00 D of corneal astigmatism and intolerance to contact lenses. The studied parameters were age, sex, corrected distance visual acuity (CDVA), maximum keratometry (K1), minimum keratometry (K2), spherical equivalent, and astigmatism. There was a statistically significant decrease in the postintervention analysis as follows: 3.5 D reduction in K1 (p<0.001); 1.53 D in K2 (p=0.005); and 2.52 D (p<0.001) in the average K. The spherical equivalent reduced from −3.67 D (±2.74) to −0.71 D (±2.35) (p<0.001). The topographic astigmatism reduced from 3.87 D preoperatively to 1.90 D postoperatively (p<0.001). The CDVA improved from 0.33 (±0.10) to 0.20 (±0.09, p<0.001). ICRS implantation is a useful option for the correction of astigmatism after DALK as it yields significant visual, topographic, and refractive results.

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