Effect of expanding the treatment zone of the Nidek EC-5000 laser on laser in situ keratomileusis outcomes.
ABSTRACT To evaluate the effect of expanding the treatment zone of the Nidek EC-5000 laser on postoperative visual acuity as well as night glare and halos after laser in situ keratomileusis (LASIK) using 4 ablation zone diameters.
Division of Ophthalmology, Evanston Northwestern Healthcare and Northwestern University Medical School, Glenview, Illinois, USA.
This prospective study comprised 301 eyes of 154 consecutive patients who had LASIK in 1 or both eyes using the Nidek EC-5000 laser by 1 surgeon with experience in keratomileusis and excimer laser refractive surgery. A 6.5 mm optical zone was used with a transition zone 1.0 mm larger than the pupil under scotopic conditions (7.5, 8.0, 8.5, or 9.0 mm). Targeted correction was calculated according to a customized clinical nomogram. All patients were queried about glare and halos preoperatively and 3 months postoperatively using a questionnaire assigning numeric values to the degree of perceived visual disturbance (0 = no glare or halos, 1 = minimal, 2 = moderate, 3 = severe).
The baseline uncorrected visual acuity (UCVA) was 20/200 or worse in 293 eyes. The baseline best spectacle-corrected visual acuity was 20/20 or better. The mean preoperative refractive sphere was -6.33 diopters (D) +/- 2.80 (SD) (range -1.00 to -16.25 D) and the mean preoperative refractive cylinder, 0.86 +/- 0.83 D (range 0 to +3.25 D). Three months postoperatively, 78% of eyes had a UCVA of 20/20 and 99%, of 20/40 or better. Preoperatively, 94 eyes (31%) had glare and halos. At 3 months, glare, halos, or both were present in 19 eyes of 11 patients (6.3%) (P<.0001); in 14 eyes, patients reported less severe glare and halos postoperatively than preoperatively.
The use of a peripheral transition zone 1.0 mm larger than the pupil under scotopic conditions resulted in a low incidence of glare and halos postoperatively and did not adversely affect visual acuity. There was no increase in postoperative complications including corneal ectasia.
SourceAvailable from: Ruth Lapid-Gortzak[Show abstract] [Hide abstract]
ABSTRACT: To review the spectrum of disease, symptomatology, and management offered to patients referred for a second opinion after refractive surgery. A prospective cohort study was done on all patients referred from October 1, 2006, to September 30, 2011, to a tertiary eye clinic after refractive surgery of any kind (ie, corneal laser surgery, conductive keratoplasty, radial keratotomy, phakic implants, refractive lens exchanges, or any combination thereof). Data analysis was performed on all demographic and clinical aspects of this cohort, including the initial complaint, type of referral, number of complaints, procedure previously performed, diagnosis at our center, type of advice given, and rate and type of surgical intervention. One hundred thirty-one eyes (69 patients) were included. Corneal refractive surgery was performed in 82% (108 eyes), and 11% (14 eyes) were seen after phakic intraocular lens (PIOL) implantation and 7% (9 eyes) after refractive lens exchange. The most common diagnoses were tear film dysfunction (30 eyes, 23%), residual refractive error (25 eyes, 19%), and cataract (20 eyes, 15%). Most patients (42 patients, 61%) were treated conservatively. In 27 patients (39%), 36 eyes (28%) were managed surgically. Severe visual loss was seen in 1 eye. No major problems were found in most second opinions after refractive surgery referral. Dry eyes, small residual refractive error, or higher-order aberrations were the most common complaints. Surgical intervention was needed in 36 eyes (28%), almost half of which were cataract extractions. Severe visual loss was seen in 1 eye with a PIOL. There was no incidence of severe visual loss in keratorefractive and refractive lens exchange procedures. [J Refract Surg. 20XX;XX:XX-XX.].Journal of refractive surgery (Thorofare, N.J.: 1995) 10/2013; DOI:10.3928/1081597X-20131023-05 · 2.78 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: To detect possible differences in residual wavefront aberrations between standard and customized laser refractive surgery based onmathematical modeling, the residual optical aberrations after conventional and customized laser refractive surgery were compared accordingto the ablation profile with transition zone. The results indicated that ablation profile has a significant impact on the residual aberrations.The amount of residual aberrations for conventional correction is higher than that for customized correction. Additionally, the residualaberrations for high myopia eyes are markedly larger than those for moderate myopia eyes. For a 5 mm pupil, the main residual aberrationterm is coma and yet it is spherical aberration for a 7 mm pupil. When the pupil diameter is the same as optical zone or greater, themagnitudes of residual aberrations is obviously larger than that for a smaller pupil. In addition, the magnitudes of the residual fifth orsixth order aberrations are relatively large, especially secondary coma in a 6 mm pupil and secondary spherical aberration in a 7 mm pupil.Therefore, the customized ablation profile may be superior to the conventional correction even though the transition zone and treatmentdecentration are taken into account. However, the customized ablation profile will still induce significant amount of residual aberrations.Journal of the European Optical Society Rapid Publications 09/2013; 8:3061-. DOI:10.2971/jeos.2013.13061 · 1.15 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: To determine the relationship between low-light pupil size and patient-reported outcomes 1 month after wavefront-guided LASIK in young patients with myopia. Retrospective case series of 10,944 eyes of 5,563 young patients with myopia who underwent wavefront-guided LASIK (6.0-mm optical zone). Preoperative pupil size was measured under low-light conditions with an infrared pupillometer. Visual and refractive outcomes were evaluated at 1 month postoperatively. A questionnaire was administered to assess patient-reported outcomes including satisfaction with the procedure, night driving, and glare and halo visual symptoms. The average patient age was 29.8 years (range: 18 to 40 years). The mean preoperative manifest spherical equivalent of -3.49 diopters (D) (range: -0.50 to -11.75 D) was reduced to -0.04 ± 0.29 D at 1 month, with 94% of eyes achieving an uncorrected distance visual acuity of 20/20 or better. The mean low-light pupil diameter was 6.6 mm (range: 4 to 9 mm) and 1,514 patients (27.2%) had a diameter of 8 mm or larger. No correlation between pupil diameter and patient-reported outcomes was found (r range: -0.02 to 0.07). Logistic regression analysis identified postoperative uncorrected distance visual acuity and postoperative manifest refraction as significant predictors of night halo complaints after wavefront-guided LASIK (P < .01). In this large series of young patients with myopia treated with wavefront-guided LASIK, low-light pupil diameter was not predictive of surgery satisfaction, ability to perform activities, or visual symptoms at 1 month postoperatively. [J Refract Surg. 2014;30(3):159-165.].Journal of refractive surgery (Thorofare, N.J.: 1995) 03/2014; 30(3):159-65. DOI:10.3928/1081597X-20140217-02 · 2.78 Impact Factor