Abstract
Photorefractive keratectomy (PRK) using an argon fluoride excimer laser for photoablation of the cornea shows potential for the precise correction of refractive errors in patients. Usually, the epithelium is mechanically removed, and Bowman's layer and stromal tissue are photoablated to precomputed depths and shapes that are based on known ablation rates for these tissues. After four day's time, the epithelium has regrown. Assuming the epithelium to be preoperatively uniform in thickness across the central optical zone, and assuming that it regrows to the same thickness, a theoretical precision of ±0.05 diopters is achievable with PRK. Keratometric measurements of the epithelium and of Bowman's layer were made at the 2.0 and 3.6mm optical zones on 10 fresh cadaver eyes (<21 hours postmortem). In the eyes studied, the epithelium thickness was found to vary across the central optical zone, accounting for the measured refractive differences of 0.5 to 1.8 diopters. Bowman's layer was found to be more prolated than the epithelial surface (ratios: 1.005 compared to 1.033). In addition, the surface of Bowman's layer had a larger degree of astigmatism.
| Original language | English (US) |
|---|---|
| Title of host publication | Proceedings of SPIE - The International Society for Optical Engineering |
| Editors | Carmen A. Puliafito |
| Publisher | Publ by Int Soc for Optical Engineering |
| Pages | 154-156 |
| Number of pages | 3 |
| Volume | 1423 |
| State | Published - 1991 |
| Event | Proceedings of Ophthalmic Technologies - Los Angeles, CA, USA Duration: Jan 21 1991 → Jan 22 1991 |
Other
| Other | Proceedings of Ophthalmic Technologies |
|---|---|
| City | Los Angeles, CA, USA |
| Period | 1/21/91 → 1/22/91 |
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ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Condensed Matter Physics
Cite this
Corneal epithelium, visual acuity and laser refractive keratectomy. / Simon, Gabriel; Parel, Jean-Marie A; Kervick, Gerard; Rol, Pascal; Hanna, Khalil; Thompson, Keith.
Proceedings of SPIE - The International Society for Optical Engineering. ed. / Carmen A. Puliafito. Vol. 1423 Publ by Int Soc for Optical Engineering, 1991. p. 154-156.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Corneal epithelium, visual acuity and laser refractive keratectomy
AU - Simon, Gabriel
AU - Parel, Jean-Marie A
AU - Kervick, Gerard
AU - Rol, Pascal
AU - Hanna, Khalil
AU - Thompson, Keith
PY - 1991
Y1 - 1991
N2 - Photorefractive keratectomy (PRK) using an argon fluoride excimer laser for photoablation of the cornea shows potential for the precise correction of refractive errors in patients. Usually, the epithelium is mechanically removed, and Bowman's layer and stromal tissue are photoablated to precomputed depths and shapes that are based on known ablation rates for these tissues. After four day's time, the epithelium has regrown. Assuming the epithelium to be preoperatively uniform in thickness across the central optical zone, and assuming that it regrows to the same thickness, a theoretical precision of ±0.05 diopters is achievable with PRK. Keratometric measurements of the epithelium and of Bowman's layer were made at the 2.0 and 3.6mm optical zones on 10 fresh cadaver eyes (<21 hours postmortem). In the eyes studied, the epithelium thickness was found to vary across the central optical zone, accounting for the measured refractive differences of 0.5 to 1.8 diopters. Bowman's layer was found to be more prolated than the epithelial surface (ratios: 1.005 compared to 1.033). In addition, the surface of Bowman's layer had a larger degree of astigmatism.
AB - Photorefractive keratectomy (PRK) using an argon fluoride excimer laser for photoablation of the cornea shows potential for the precise correction of refractive errors in patients. Usually, the epithelium is mechanically removed, and Bowman's layer and stromal tissue are photoablated to precomputed depths and shapes that are based on known ablation rates for these tissues. After four day's time, the epithelium has regrown. Assuming the epithelium to be preoperatively uniform in thickness across the central optical zone, and assuming that it regrows to the same thickness, a theoretical precision of ±0.05 diopters is achievable with PRK. Keratometric measurements of the epithelium and of Bowman's layer were made at the 2.0 and 3.6mm optical zones on 10 fresh cadaver eyes (<21 hours postmortem). In the eyes studied, the epithelium thickness was found to vary across the central optical zone, accounting for the measured refractive differences of 0.5 to 1.8 diopters. Bowman's layer was found to be more prolated than the epithelial surface (ratios: 1.005 compared to 1.033). In addition, the surface of Bowman's layer had a larger degree of astigmatism.
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M3 - Conference contribution
VL - 1423
SP - 154
EP - 156
BT - Proceedings of SPIE - The International Society for Optical Engineering
A2 - Puliafito, Carmen A.
PB - Publ by Int Soc for Optical Engineering
ER -