Stanley M Chan1, Hamza N Khan. 1. Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada.
Abstract
PURPOSE: To evaluate the effect of removal and/or exchange of intrastromal corneal ring segments (ICRS, Intacs); specifically the risk factors, degree of reversibility, and visual outcomes. SETTING: Gimbel Eye Centres, Calgary, Edmonton, and Vancouver, Canada. METHODS: Prospective cohort data were collected on 71 eyes that had ICRS placement by 3 surgeons at the Gimbel Eye Centres between August 1998 and July 1999. Data included patient symptoms, best spectacle-corrected visual acuity, uncorrected visual acuity (UCVA), manifest refraction, reason for removal or replacement, keratometry, corneal topography, and complications. RESULTS: Twenty-four eyes (33.8%) had exchange or removal procedures because of underresponse, 20 eyes; overresponse, 2 eyes; and induced astigmatism and shallow placement, 1 eye each. Secondary procedures were removal and replacement, removal with subsequent laser in situ keratomileusis, and segment repositioning. Two risk factors for secondary surgery were identified: high preoperative refractive astigmatism and postoperative spherical equivalent greater than +/-0.5 diopter (D). The 6 eyes that had ICRS removal stabilized to within +/-0.25 D of the original refractive error with no surgically induced astigmatism within 1 to 7 weeks (mean 4 weeks) and had a final UCVA of 20/20 or better. In the 15 eyes that had ICRS exchange procedures, the UCVA improved by at least 1 line and median UCVA improved from 20/40 to 20/20. CONCLUSION: Preliminary data from this study indicate that removal of segments resulted in reversal of the refractive effect.
PURPOSE: To evaluate the effect of removal and/or exchange of intrastromal corneal ring segments (ICRS, Intacs); specifically the risk factors, degree of reversibility, and visual outcomes. SETTING: Gimbel Eye Centres, Calgary, Edmonton, and Vancouver, Canada. METHODS: Prospective cohort data were collected on 71 eyes that had ICRS placement by 3 surgeons at the Gimbel Eye Centres between August 1998 and July 1999. Data included patient symptoms, best spectacle-corrected visual acuity, uncorrected visual acuity (UCVA), manifest refraction, reason for removal or replacement, keratometry, corneal topography, and complications. RESULTS: Twenty-four eyes (33.8%) had exchange or removal procedures because of underresponse, 20 eyes; overresponse, 2 eyes; and induced astigmatism and shallow placement, 1 eye each. Secondary procedures were removal and replacement, removal with subsequent laser in situ keratomileusis, and segment repositioning. Two risk factors for secondary surgery were identified: high preoperative refractive astigmatism and postoperative spherical equivalent greater than +/-0.5 diopter (D). The 6 eyes that had ICRS removal stabilized to within +/-0.25 D of the original refractive error with no surgically induced astigmatism within 1 to 7 weeks (mean 4 weeks) and had a final UCVA of 20/20 or better. In the 15 eyes that had ICRS exchange procedures, the UCVA improved by at least 1 line and median UCVA improved from 20/40 to 20/20. CONCLUSION: Preliminary data from this study indicate that removal of segments resulted in reversal of the refractive effect.
Authors: Michael M Lai; Maolong Tang; Eduardo M M Andrade; Yan Li; Rahul N Khurana; Jonathan C Song; David Huang Journal: J Cataract Refract Surg Date: 2006-11 Impact factor: 3.351
Authors: Hussain F Al-Habboubi; Hernan Martinez-Osorio; Azza M Y Maktabi; Abdulrahman H Badawi; Faisal N Aldosari; Rajiv Khandekar; Samar A Al-Swailem Journal: Saudi J Ophthalmol Date: 2022-07-11