Evaluation of the effect of optic zone diameter selection on high-order aberrations in photorefractive keratectomy excimer laser treatment

AbstractTo evaluate the postoperative higher-order aberration (HOA) differences and visual quality outcomes of wavefront-optimised photorefractive keratectomy (PRK) surgery in 6.5-mm and 7.0-mm optic zones. The study included 136 eyes of 68 patients who underwent wavefront-optimised PRK surgery for myopia or myopia with astigmatism.Q values, third-order coma (Z [3, 1] andZ [3, − 1]), third-order trefoil (Z [3] andZ [3, − 3]), fourth-order spherical aberration (Z [4, 0]) and aberration coefficients were evaluated before surgery and 6  months after surgery. All patients underwent ophthalmic examinations that included visual acuity, central corneal thickness and intraocular pressure. The mean age of participants was 25.5 ± 6.7 (18–50 years). A total of 38 (55.88%) participants were male and 30 (44.12%) were female. In hal f of the eyes (n = 68), the 6.5-mm optic zone was selected (group 1), while the 7.0-mm optic zone was selected for other half (n = 68; group 2). No statistically significant difference was observed between the two groups in terms of preoperative best corrected visual acuity (BCVA) and postoperative uncorrected visual acuity (UCVA) (p = 0.45 andp = 0.22, respectively). The 7.0-mm optical zone was found to be associated with lower aberration coefficient values and lowerZ [4, 0] spherical aberrations of HOAs. Although the 6.5-mm optical zone was a...
Source: Lasers in Medical Science - Category: Laser Surgery Source Type: research

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CONCLUSIONS: SMILE has proven to be effective and safe for correcting myopia and astigmatism. We showed that SMILE did not induce spherical aberrations. A small increase in postoperative corneal higher order aberration may be associated with increase in coma and trefoil. PMID: 32037752 [PubMed - in process]
Source: Korean Journal of Ophthalmology : KJO - Category: Opthalmology Tags: Korean J Ophthalmol Source Type: research
Conclusion: The corneal elevation indices and thicknesses specific to the Saudi myopes were found to be comparable to the international databases in terms of the elevation and thickness in some of the parameters. PMID: 32020151 [PubMed - in process]
Source: Saudi Medical Journal - Category: Middle East Health Tags: Saudi Med J Source Type: research
This study aims to investigate symptoms of dry eye and signs of ocular surface disease in children with myopia during OK lens wear. METHODS: A total of 68 subjects were prospectively managed with OK lens correction. These subjects were 8-14 years of age with myopia -0.50 to -5.00 dioptres of sphere and astigmatism of≤1.00 dioptres of cylinder. Patients with any ocular disease were ruled out from this study. All subjects completed a dry eye symptom questionnaire for OSDI scoring, corneal fluorescein staining, tear film break up time (TBUT) test and Schirmer's test I during the follow-up period. The follow-up period i...
Source: Journal Francais d Ophtalmologie - Category: Opthalmology Tags: J Fr Ophtalmol Source Type: research
Conclusions for PracticeRefractive errors are more common in children born of mothers with GD. These conditions are easily managed, but if they are not detected, they can lead to amblyopia or accommodative strabismus, interfere with acquisition of fine motor skills, and lead to learning problems. Regular ocular examinations would be recommended in these patients.
Source: Maternal and Child Health Journal - Category: Health Management Source Type: research
ConclusionExcimer laser vision correction among ophthalmologists in Saudi is much higher than the market penetration in the general population reported in other countries. Most of the ophthalmologists who underwent the procedure were satisfied with the outcome.
Source: Saudi Journal of Ophthalmology - Category: Opthalmology Source Type: research
Authors: Qiu K, Zhang Y Abstract To assess eye axial length (AL), spherical equivalent (SE), astigmatic power, distance unaided visual acuity (UCVA), and their relationship in 7- and 8-year-old pupils in Kunming, Southwest China. Grade I and grade II pupils underwent measurement of AL, UCVA, and refraction. The associations of AL with SE, UCVA and astigmatic power were studied. 291 pupils enrolled with 50.2% girls. AL was 22.71 ± 0.61 mm in children with emmetropia (UCVA> 0.8, -0.50
Source: Strabismus - Category: Research Tags: Strabismus Source Type: research
Conditions:   Myopia;   Hyperopia;   Astigmatism;   Presbyopia Interventions:   Device: Vision R-800 Phoropter;   Device: Standard Phoropter Sponsor:   Pete Kollbaum, OD, PhD Recruiting
Source: ClinicalTrials.gov - Category: Research Source Type: clinical trials
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