Risk factors for self-reported visual symptoms with Intacs inserts for myopia.
OBJECTIVE
Potential risk factors and visual performance measures were evaluated for relationship to self-report of clinical visual symptoms after the refractive procedure for placement of Intacs microthin prescription inserts for myopia.


METHODS
Retrospective nonrandomized comparative study.


METHODS
Patients were participants in the U.S. Food and Drug Administration phase III KeraVision prospective clinical trials.


METHODS
Study participants (n = 263) were retrospectively classified into one of three outcome groups on the basis of postoperative self-reported visual symptoms and/or request for Intacs inserts removal through month 24. Differences between outcome groups in visual acuity, refractive error, corneal geometry, corneal topography, type of preoperative corrective lens wear, and demographic variables were evaluated with multivariate logistic regression.


RESULTS
Clinical trial participants who had preoperative mean keratometry >45 diopters (D) (adjusted odds ratio [OR], 0.43; 95% confidence interval [CI], 0.21, 0.85, P = 0.02), manifest refractive astigmatism of 0.75 D or 1.00 D (adjusted OR, 0.52; 95% CI, 0.25, 1.08, P = 0.08), measured uncorrected visual acuity > or =2 lines better than that predicted by their respective cycloplegic refractive error (adjusted OR, 0.39; 95% CI, 0.14, 1.12, P = 0.08) and/or had worn soft contact lenses (adjusted OR, 0.58; 95% CI, 0.32, 1.04, P = 0.07) tended to be less likely to report postoperative clinical visual symptoms with Intacs inserts. Risk of clinical visual symptoms and request for Intacs inserts removal approximately doubled for each 0.50 D of additional postoperative defocus equivalent (crude OR, 1.86; 95% CI, 1.39, 2.48, P = 0.00). Controlling for postoperative defocus and important preoperative risk factors, subjects who reported significant clinical visual symptoms were more likely to have had preoperative uncorrected visual acuity that was worse than that predicted by their respective cycloplegic refractive error (adjusted OR, 1.84; 95% CI, 0.98, 3.42, P = 0.06). Risk of reporting clinical visual symptoms was increased with mesopic pupil diameter > or =6.5 mm (adjusted OR, 1.76; 95% CI, 0.96, 3.24, P = 0.07). Within the group of patients who reported postoperative clinical visual symptoms, 71 of 122 (58%) had ceased reporting them by month 24.


CONCLUSIONS
Adjusting for important risk factors simultaneously, this study suggested that certain preoperative characteristics may increase or decrease the likelihood, depending on the characteristic, of refractive surgery candidates to report significant clinical visual symptoms with Intacs inserts.
Holmes-Higgin
Debby K
DK
Northwest Corneal Services, Corneal Topography Research Center, 6950 SW Hampton, Suite 150, Portland, OR 97223, USA.
Burris
Terry E
TE
Lapidus
Jodi A
JA
Greenlick
Merwyn R
MR
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003315:Cornea / Q000601:surgery*; D019781:Corneal Topography; D020878:Device Removal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D019904:Polymethyl Methacrylate; D011446:Prospective Studies; D019736:Prostheses and Implants / Q000009:adverse effects*; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D012307:Risk Factors; D012650:Self Disclosure; D014786:Vision Disorders / Q000175:diagnosis / Q000209:etiology*; D014792:Visual Acuity
D019904:Polymethyl Methacrylate