Visual, keratometric and corneal biomechanical changes after intacs SK implantation for moderate to severe keratoconus
Purpose: To report visual outcomes and corneal biomechanical changes after femtosecond-assisted Intacs SK implantation in keratoconic eyes. Methods: This prospective interventional case series is comprised of 32 keratoconic eyes of 25 patients with mean age of 23.8 ± 5.4 years. Uncorrected (UDVA) an...
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| Format: | Article |
| Language: | English |
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Knowledge E
2016-01-01
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| Series: | Journal of Ophthalmic & Vision Research |
| Subjects: | |
| Online Access: | http://www.jovr.org/article.asp?issn=2008-322X;year=2016;volume=11;issue=1;spage=17;epage=25;aulast=Zare |
| _version_ | 1797990405036310528 |
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| author | Mohammad Ali Zare Hadi Z Mehrjardi Mohsen Afarideh Hooman Bahrmandy Seyed-Farzad Mohammadi |
| author_facet | Mohammad Ali Zare Hadi Z Mehrjardi Mohsen Afarideh Hooman Bahrmandy Seyed-Farzad Mohammadi |
| author_sort | Mohammad Ali Zare |
| collection | DOAJ |
| description | Purpose: To report visual outcomes and corneal biomechanical changes after femtosecond-assisted Intacs SK implantation in keratoconic eyes.
Methods: This prospective interventional case series is comprised of 32 keratoconic eyes of 25 patients with mean age of 23.8 ± 5.4 years. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, refraction, manifest refraction spherical equivalent (MRSE), keratometry, central corneal thickness (CCT), corneal hysteresis (CH) and corneal resistance factor (CRF) were measured preoperatively, and 1, 3 and 6 months postoperatively.
Results: Mean UDVA improved from 0.81 ± 0.3 LogMAR preoperatively to 0.53 ± 0.2 LogMAR six months postoperatively (P < 0.001). At 6 months, MRSE was significantly reduced only in eyes with moderate KCN (mean change, +2.61 ± 0.54 diopter [D]; P< 0.001). A significant improvement in sphere (mean change, +1.92 ± 0.37 D; P< 0.001) and mean keratometry (mean change, -3.34 ± 0.47D; P< 0.001) were observed. CCT increased from 446.1 ± 38 μm preoperatively to 462.2 ± 50 μm at six months (P < .001). CRF decreased from 6.5 ± 1.6 mmHg to 5.9 ± 1.1 mmHg six months after surgery (P = 0.02). CDVA, refractive cylinder and CH did not change significantly (P = 0.48, 0.203 and 0.55, respectively). Linear regression analysis disclosed that a decrease in CCT and moderate KCN are associated with higher CRF (standardized B,-0.513 and 0.314;P= 0.004 and 0.024, respectively; Adjusted R square = 0.353).
Conclusion: Visual, refractive and keratometric indices remarkably improved in a parallel fashion. CRF was inversely associated with CCT. Changes in CRF represent the trend of changes in corneal biomechanics and thickness during the early postoperative months. |
| first_indexed | 2024-04-11T08:35:49Z |
| format | Article |
| id | doaj.art-b9ead060cd9a48e48d37d61ed8d71060 |
| institution | Directory Open Access Journal |
| issn | 2008-322X |
| language | English |
| last_indexed | 2024-04-11T08:35:49Z |
| publishDate | 2016-01-01 |
| publisher | Knowledge E |
| record_format | Article |
| series | Journal of Ophthalmic & Vision Research |
| spelling | doaj.art-b9ead060cd9a48e48d37d61ed8d710602022-12-22T04:34:20ZengKnowledge EJournal of Ophthalmic & Vision Research2008-322X2016-01-01111172510.4103/2008-322X.180698Visual, keratometric and corneal biomechanical changes after intacs SK implantation for moderate to severe keratoconusMohammad Ali ZareHadi Z MehrjardiMohsen AfaridehHooman BahrmandySeyed-Farzad MohammadiPurpose: To report visual outcomes and corneal biomechanical changes after femtosecond-assisted Intacs SK implantation in keratoconic eyes. Methods: This prospective interventional case series is comprised of 32 keratoconic eyes of 25 patients with mean age of 23.8 ± 5.4 years. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, refraction, manifest refraction spherical equivalent (MRSE), keratometry, central corneal thickness (CCT), corneal hysteresis (CH) and corneal resistance factor (CRF) were measured preoperatively, and 1, 3 and 6 months postoperatively. Results: Mean UDVA improved from 0.81 ± 0.3 LogMAR preoperatively to 0.53 ± 0.2 LogMAR six months postoperatively (P < 0.001). At 6 months, MRSE was significantly reduced only in eyes with moderate KCN (mean change, +2.61 ± 0.54 diopter [D]; P< 0.001). A significant improvement in sphere (mean change, +1.92 ± 0.37 D; P< 0.001) and mean keratometry (mean change, -3.34 ± 0.47D; P< 0.001) were observed. CCT increased from 446.1 ± 38 μm preoperatively to 462.2 ± 50 μm at six months (P < .001). CRF decreased from 6.5 ± 1.6 mmHg to 5.9 ± 1.1 mmHg six months after surgery (P = 0.02). CDVA, refractive cylinder and CH did not change significantly (P = 0.48, 0.203 and 0.55, respectively). Linear regression analysis disclosed that a decrease in CCT and moderate KCN are associated with higher CRF (standardized B,-0.513 and 0.314;P= 0.004 and 0.024, respectively; Adjusted R square = 0.353). Conclusion: Visual, refractive and keratometric indices remarkably improved in a parallel fashion. CRF was inversely associated with CCT. Changes in CRF represent the trend of changes in corneal biomechanics and thickness during the early postoperative months.http://www.jovr.org/article.asp?issn=2008-322X;year=2016;volume=11;issue=1;spage=17;epage=25;aulast=ZareCorneal Biomechanic; Corneal Hysteresis; Corneal Resistance Factor; Femtosecond Laser; Intacs SK; Intracorneal Ring Segment; Keratoconus |
| spellingShingle | Mohammad Ali Zare Hadi Z Mehrjardi Mohsen Afarideh Hooman Bahrmandy Seyed-Farzad Mohammadi Visual, keratometric and corneal biomechanical changes after intacs SK implantation for moderate to severe keratoconus Journal of Ophthalmic & Vision Research Corneal Biomechanic; Corneal Hysteresis; Corneal Resistance Factor; Femtosecond Laser; Intacs SK; Intracorneal Ring Segment; Keratoconus |
| title | Visual, keratometric and corneal biomechanical changes after intacs SK implantation for moderate to severe keratoconus |
| title_full | Visual, keratometric and corneal biomechanical changes after intacs SK implantation for moderate to severe keratoconus |
| title_fullStr | Visual, keratometric and corneal biomechanical changes after intacs SK implantation for moderate to severe keratoconus |
| title_full_unstemmed | Visual, keratometric and corneal biomechanical changes after intacs SK implantation for moderate to severe keratoconus |
| title_short | Visual, keratometric and corneal biomechanical changes after intacs SK implantation for moderate to severe keratoconus |
| title_sort | visual keratometric and corneal biomechanical changes after intacs sk implantation for moderate to severe keratoconus |
| topic | Corneal Biomechanic; Corneal Hysteresis; Corneal Resistance Factor; Femtosecond Laser; Intacs SK; Intracorneal Ring Segment; Keratoconus |
| url | http://www.jovr.org/article.asp?issn=2008-322X;year=2016;volume=11;issue=1;spage=17;epage=25;aulast=Zare |
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