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Autorefraction as an outcome measure of laser in situ keratomileusis.
J Cataract Refract Surg. 2004 Sep; 30(9):1921-8.JC

Abstract

PURPOSE

To determine the limits of agreement between subjective refraction and autorefraction before and after laser in situ keratomileusis (LASIK) to assess whether autorefraction is a valid refractive outcome measure of refractive surgery.

SETTING

Ultralase, Leeds, United Kingdom.

METHOD

The prospective study involved consecutive preoperative normal patients and post-LASIK patients who had autorefraction using the Nidek ARK 700A autorefractor and careful subjective refraction (masked to autorefraction). Inclusion criteria were age greater than 18 years and healthy eyes with a visual acuity better than 0.1 logMAR (6/7.5) with or without previous LASIK. Refractions were compared by spherical equivalent (SE) using Bland-Altman limits of agreement and astigmatic vector difference using the median and the 95th percentile. The effect of time after treatment and treatment strength were explored.

RESULTS

Data were collected from 208 preoperative patients and 237 post-LASIK patients. Preoperatively, the agreement between subjective refraction and autorefraction for the SE was -0.10 diopter (D) +/- 0.35 (SD) and the median difference for the astigmatic vector was 0.28 D with a 95th percentile of 0.72 D. Post-LASIK, the SE agreement was similar, -0.09 +/- 0.39 D, but the astigmatic vector agreement decreased slightly with a median of 0.31 D and a 95th percentile of 1.02 D. This decrease reflected poorer agreement in patients whose pre-LASIK refractive error was greater than +4.00 D. Removing this group brought the median astigmatic difference post-LASIK to 0.27 D with a 95th percentile of 0.87 D, similar to that in the preoperative normals. The percentage within +/-0.50 D and +/-1.00 D of the attempted correction was 56.1% and 78.5%, respectively, with subjective refraction and 51.2% and 78.1%, respectively, with autorefraction.

CONCLUSIONS

Autorefraction showed excellent agreement with subjective refraction and was unaffected by refractive surgery except after LASIK for high hyperopia. Most outcomes were correctly classified in the standard categories (+/-0.50 D, +/-1.00 D), illustrating that autorefraction is a valid outcome measure of refractive surgery.

Authors+Show Affiliations

Ultralase, Leeds, UK. k.pesudovs@bradford.ac.uk

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15342056

Citation

Pesudovs, Konrad. "Autorefraction as an Outcome Measure of Laser in Situ Keratomileusis." Journal of Cataract and Refractive Surgery, vol. 30, no. 9, 2004, pp. 1921-8.
Pesudovs K. Autorefraction as an outcome measure of laser in situ keratomileusis. J Cataract Refract Surg. 2004;30(9):1921-8.
Pesudovs, K. (2004). Autorefraction as an outcome measure of laser in situ keratomileusis. Journal of Cataract and Refractive Surgery, 30(9), 1921-8.
Pesudovs K. Autorefraction as an Outcome Measure of Laser in Situ Keratomileusis. J Cataract Refract Surg. 2004;30(9):1921-8. PubMed PMID: 15342056.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Autorefraction as an outcome measure of laser in situ keratomileusis. A1 - Pesudovs,Konrad, PY - 2004/01/22/accepted PY - 2004/9/3/pubmed PY - 2004/11/17/medline PY - 2004/9/3/entrez SP - 1921 EP - 8 JF - Journal of cataract and refractive surgery JO - J Cataract Refract Surg VL - 30 IS - 9 N2 - PURPOSE: To determine the limits of agreement between subjective refraction and autorefraction before and after laser in situ keratomileusis (LASIK) to assess whether autorefraction is a valid refractive outcome measure of refractive surgery. SETTING: Ultralase, Leeds, United Kingdom. METHOD: The prospective study involved consecutive preoperative normal patients and post-LASIK patients who had autorefraction using the Nidek ARK 700A autorefractor and careful subjective refraction (masked to autorefraction). Inclusion criteria were age greater than 18 years and healthy eyes with a visual acuity better than 0.1 logMAR (6/7.5) with or without previous LASIK. Refractions were compared by spherical equivalent (SE) using Bland-Altman limits of agreement and astigmatic vector difference using the median and the 95th percentile. The effect of time after treatment and treatment strength were explored. RESULTS: Data were collected from 208 preoperative patients and 237 post-LASIK patients. Preoperatively, the agreement between subjective refraction and autorefraction for the SE was -0.10 diopter (D) +/- 0.35 (SD) and the median difference for the astigmatic vector was 0.28 D with a 95th percentile of 0.72 D. Post-LASIK, the SE agreement was similar, -0.09 +/- 0.39 D, but the astigmatic vector agreement decreased slightly with a median of 0.31 D and a 95th percentile of 1.02 D. This decrease reflected poorer agreement in patients whose pre-LASIK refractive error was greater than +4.00 D. Removing this group brought the median astigmatic difference post-LASIK to 0.27 D with a 95th percentile of 0.87 D, similar to that in the preoperative normals. The percentage within +/-0.50 D and +/-1.00 D of the attempted correction was 56.1% and 78.5%, respectively, with subjective refraction and 51.2% and 78.1%, respectively, with autorefraction. CONCLUSIONS: Autorefraction showed excellent agreement with subjective refraction and was unaffected by refractive surgery except after LASIK for high hyperopia. Most outcomes were correctly classified in the standard categories (+/-0.50 D, +/-1.00 D), illustrating that autorefraction is a valid outcome measure of refractive surgery. SN - 0886-3350 UR - https://www.unboundmedicine.com/medline/citation/15342056/Autorefraction_as_an_outcome_measure_of_laser_in_situ_keratomileusis_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0886335004003451 DB - PRIME DP - Unbound Medicine ER -