TY - JOUR
T1 - Wavefront aberrations associated with the ferrara intrastromal corneal ring in a keratoconic eye
AU - Chalita, Maria Regina
AU - Krueger, Ronald R.
PY - 2004
Y1 - 2004
N2 - PURPOSE: To describe the optical implications of the aberration pattern of a keratoconic eye implanted with an intrastromal corneal ring (Ferrara ring). METHODS: A 32-year-old man with bilateral keratoconus had a Ferrara intrastromal corneal ring implanted in his right eye. Surgery was uneventful and both uncorrected (UCVA) and best spectacle-corrected (BSCVA) visual acuity improved. Corneal topography was performed before and after surgery. Wavefront measurements were performed 1 month after the procedure in both eyes for comparison. The point spread function, modulation transfer function (MTF), and convolved acuity chart were analyzed. RESULTS: The right eye-implanted with the intrastromal Ferrara ring-had high root-mean-square (RMS) values for higher order aberrations. The left eye-keratoconus without an intrastromal ring-had moderate values. Point spread function, MTF, and convolution acuity charts are presented for each eye, with the latter two showing improved visual function in the implanted eye, despite a higher aberration value. CONCLUSION: The wavefront measurement device captured aberrations even in a highly aberrated eye. Despite better UCVA and BSCVA, the Ferrara ring notably increased higher order aberrations compared to the fellow eye, but with a more uniform central pattern. In this case, the larger RMS value was a poor predictor of good visual function; other metrics better predicted the patient's subjective response. Metrics other than RMS error may be necessary to better correlate aberration value with visual satisfaction in some eyes.
AB - PURPOSE: To describe the optical implications of the aberration pattern of a keratoconic eye implanted with an intrastromal corneal ring (Ferrara ring). METHODS: A 32-year-old man with bilateral keratoconus had a Ferrara intrastromal corneal ring implanted in his right eye. Surgery was uneventful and both uncorrected (UCVA) and best spectacle-corrected (BSCVA) visual acuity improved. Corneal topography was performed before and after surgery. Wavefront measurements were performed 1 month after the procedure in both eyes for comparison. The point spread function, modulation transfer function (MTF), and convolved acuity chart were analyzed. RESULTS: The right eye-implanted with the intrastromal Ferrara ring-had high root-mean-square (RMS) values for higher order aberrations. The left eye-keratoconus without an intrastromal ring-had moderate values. Point spread function, MTF, and convolution acuity charts are presented for each eye, with the latter two showing improved visual function in the implanted eye, despite a higher aberration value. CONCLUSION: The wavefront measurement device captured aberrations even in a highly aberrated eye. Despite better UCVA and BSCVA, the Ferrara ring notably increased higher order aberrations compared to the fellow eye, but with a more uniform central pattern. In this case, the larger RMS value was a poor predictor of good visual function; other metrics better predicted the patient's subjective response. Metrics other than RMS error may be necessary to better correlate aberration value with visual satisfaction in some eyes.
UR - http://www.scopus.com/inward/record.url?scp=9144223367&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=9144223367&partnerID=8YFLogxK
U2 - 10.3928/1081-597x-20041101-11
DO - 10.3928/1081-597x-20041101-11
M3 - Article
C2 - 15586766
AN - SCOPUS:9144223367
VL - 20
SP - 823
EP - 830
JO - Journal of Refractive Surgery
JF - Journal of Refractive Surgery
SN - 0883-0444
IS - 6
ER -