TY - JOUR
T1 - Hyperopia correction by noncontact holmium:YAG laser thermal keratoplasty
T2 - U.S. Phase IIA clinical study with 2-year follow-up
AU - Koch, D. D.
AU - Kohnen, T.
AU - McDonnell, P. J.
AU - Menefee, R.
AU - Berry, M.
N1 - Funding Information:
Originally received: October 27, 1996. Revision accepted: May 12, 1997. 1 Cullen Eye Institute, Baylor College of Medicine, Department of Ophthalmology, Houston, Texas. 2 Doheny Eye Institute, Department of Ophthalmology, University of Southern California, Los Angeles, California. 3 Sunrise Technologies, Inc., Fremont, California. Supported in part by an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York, by Deutsche Forschungsgemeinschaft (DFG) Postdoctoral Research Grants Ko 159511-1 and 1-2, and by core grant EY03040 from the National Eye Institute, Bethesda, Maryland.
PY - 1997
Y1 - 1997
N2 - Purpose: This study was performed to determine the long-term efficacy, safety, and stability of noncontact holmium:yttrium aluminum garnet (Ho:YAG) laser thermal keratoplasty (LTK) for correction of low-to-moderate hyperopia. Methods: The authors treated 1 eye each of 28 patients for correction of low- tomoderate hyperopia (up to +3.88 diopters [D] refractive error) using the Sun 1000 Corneal Shaping System (Sunrise Technologies, Inc., Fremont, CA). Treatments were performed with one or two rings of eight spots per ring with centerline diameters of 6 mm (one ring) or 6 and 7 mm (two rings), ten pulses of laser light at 5-Hz pulse repetition frequency, and pulse energies ranging from 208 to 242 mJ. Follow-up was 2 years. Results: At 2 years after surgery, uncorrected distance visual acuity was improved by 1 or more lines of Snellen visual acuity in 19 (73%) of 26 of the treated eyes. The mean lines gained was 2.5 ± 2.2/3.3 ± 2.7 for one- and two-ring treatment groups, respectively. The mean change in spherical equivalent of the subjective manifest refraction was -0.53 ± 0.33 D/-1.48 ± 0.58 D for one- and two- ring treatment groups. Regression between 1 and 2 years was 0.01 D and 0.16 D, respectively. In the one-ring treatment group (18 eyes), 13 eyes (72%) had refractive corrections (range, -0.38 to -1.13 D), and 5 eyes (29%) were unchanged (within ±0.25 D) relative to their preoperative measurements. In the two-ring treatment group, all eight eyes (100%) had reductions in their hyperopia (range of corrections, -0.38 to -2.25 D). None of the eyes lost two or more lines of spectacle-corrected distance visual acuity. There were no sight-threatening complications. Conclusions: This initial U.S. clinical study indicates that noncontact laser thermal keratoplasty treatment of low hyperopia is safe and produces modest but persistent corrections with 2-year follow-up. Expanded studies of this treatment method are warranted.
AB - Purpose: This study was performed to determine the long-term efficacy, safety, and stability of noncontact holmium:yttrium aluminum garnet (Ho:YAG) laser thermal keratoplasty (LTK) for correction of low-to-moderate hyperopia. Methods: The authors treated 1 eye each of 28 patients for correction of low- tomoderate hyperopia (up to +3.88 diopters [D] refractive error) using the Sun 1000 Corneal Shaping System (Sunrise Technologies, Inc., Fremont, CA). Treatments were performed with one or two rings of eight spots per ring with centerline diameters of 6 mm (one ring) or 6 and 7 mm (two rings), ten pulses of laser light at 5-Hz pulse repetition frequency, and pulse energies ranging from 208 to 242 mJ. Follow-up was 2 years. Results: At 2 years after surgery, uncorrected distance visual acuity was improved by 1 or more lines of Snellen visual acuity in 19 (73%) of 26 of the treated eyes. The mean lines gained was 2.5 ± 2.2/3.3 ± 2.7 for one- and two-ring treatment groups, respectively. The mean change in spherical equivalent of the subjective manifest refraction was -0.53 ± 0.33 D/-1.48 ± 0.58 D for one- and two- ring treatment groups. Regression between 1 and 2 years was 0.01 D and 0.16 D, respectively. In the one-ring treatment group (18 eyes), 13 eyes (72%) had refractive corrections (range, -0.38 to -1.13 D), and 5 eyes (29%) were unchanged (within ±0.25 D) relative to their preoperative measurements. In the two-ring treatment group, all eight eyes (100%) had reductions in their hyperopia (range of corrections, -0.38 to -2.25 D). None of the eyes lost two or more lines of spectacle-corrected distance visual acuity. There were no sight-threatening complications. Conclusions: This initial U.S. clinical study indicates that noncontact laser thermal keratoplasty treatment of low hyperopia is safe and produces modest but persistent corrections with 2-year follow-up. Expanded studies of this treatment method are warranted.
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U2 - 10.1016/S0161-6420(97)30003-7
DO - 10.1016/S0161-6420(97)30003-7
M3 - Article
C2 - 9373130
AN - SCOPUS:0031416403
SN - 0161-6420
VL - 104
SP - 1938
EP - 1947
JO - Ophthalmology
JF - Ophthalmology
IS - 11
ER -