Orthoptic Changes following Photorefractive Keratectomy (original) (raw)
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Orthoptic Changes following Photorefractive
2013
Methods: This interventional case series included 297 eyes of 150 patients scheduled for PRK. Complete ophthalmologic evaluations focusing on orthoptic examinations were performed before and 3 months after PRK. Results: Before PRK, 2 (1.3%) patients had esotropia which remained unchanged; 3 (2%) patients had far exotropia which improved after the procedure. Of 12 cases (8%) with initial exotropia at near, 3 (2%) cases became orthophoric, however 6 patients (4%) developed new near exotropia. A significant reduction in convergence and divergence amplitudes (P < 0.001) and a significant increase in near point of convergence (NPC) (P < 0.006) were noticed after PRK. A reduction ≥ 10 PD in convergence amplitude and ≥ 5 PD in divergence amplitude occurred in 10 and 5 patients, respectively. Four patients had initial NPC> 10 cm which remained unchanged after surgery. Out of 9 (6%) patients with baseline stereopsis> 60 seconds of arc, 2 (1.33%) showed an improvement in stereopsi...
Near Point of Accommodation and Convergence after Photorefractive Keratectomy (PRK) for Myopia
Binocular Vision Strabology Quarterly Simms Romano S, 2013
Purpose: Near point of convergence (NPC) and near point of accommodation (NPA) were evaluated before and after photorefractive keratectomy (PRK) in normal myopic eyes. Methods: In this prospective cross sectional study, NPC and NPA were measured in 120 myopic eyes (60 patients) before and 3 months after PRK. Excluding criteria were manifest tropia, previous eye surgery, amblyopia, and any other ocular pathology. All subjects were younger than35 years old. Results: Fifty-one females (85%) and nine males (15%) participated in the study. The average age of the participants was 25.75 years. Before the operation, the average NPC and NPA were 4.35 cm and 6.9 cm (14.5 D), respectively. NPC and NPA increased significantly 5.63 (p = 0.025) and (p 0.05) to 7.983 cm (12.5 D) (p 0.001), respectively, after 3 months. Conclusion: NPC and NPA may increase significantly after PRK. Convergence and accommodation problems may affect near visual performance. Therefore, for any PRK candidate, accommodation and convergence should be evaluated.
Photorefractive keratectomy. A 6-year follow-up study
Ophthalmology
This study aimed to assess the long-term stability and efficacy of excimer laser photorefractive keratectomy. Patients who participated in the first United Kingdom photorefractive keratectomy clinical trial were asked to attend a 6-year follow-up assessment. Eighty-three patients (68%) of the original cohort of 120 participants were observed for 6 years. A Summit Technology UV200 excimer laser with a 4-mm ablation zone had been used with patients allocated to one of six groups according to their preoperative refraction. Each group received one of the following spherical corrections: -2, -3, -4, -5, -6, or -7 diopters (D). Within each group, all patients received an identical treatment, and thus emmetropia was not the goal in all patients. The induced refractive change, objective corneal haze, glare, and halo measurements, together with possible late-phase complications, were analyzed. All groups achieved a refractive undercorrection, and the magnitude of the undercorrection was rela...
International ophthalmology, 2018
To evaluate refractive, binocular vision and ocular alignment outcomes of photorefractive keratectomy (PRK) for the treatment of hyperopia in esotropic patients. Medical charts of hyperopic patients with full or partial accommodative esotropia (FAE or PAE) or consecutive exotropia (CE) undergone PRK from 2011 to 2014 were reviewed. The primary outcome was to assess the efficacy of PRK in improving ocular alignment. The secondary outcomes were the assessments of uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent (SE) and stereoacuity. Sixty-four eyes of 32 hyperopic patients were included. Three patients were affected by FAE, 24 by PAE and 5 by CE. All FAE patients and 4 PAE patients underwent only PRK; the remaining 25 patients underwent PRK plus strabismus surgery. After PRK, the mean corrected esodeviation decreased significantly in the overall esotropic population [7.15 ± 9.42 prism diopters (PD) vs. 5.04 ± 8.83 PD; p = 0.03] and in partic...
Eight-year follow-up of photorefractive keratectomy for myopia
American Journal of Ophthalmology, 2004
matic (0.9%), sarcoidosis (0.9%), sympathetic ophthalmia (0.5%), Vogt-Kayanagi-Harada syndrome (0.5%), Reiter's syndrome (0.5%), and psoriatic arthritis (0.5%). Anatomically, anterior uveitis was the most common presentation (43.4%), followed by posterior uveitis (31.1%), panuveitis (13.7%), and intermediate uveitis (11.9%). Bilateral involvement was most commonly encountered with juvenile rheumatoid arthritis, pars planitis, and Behcet's disease. One or more significant complications occurred in 173 (51%) eyes. The most common complications were cataract (28.9%), maculopathy (17.4%), band keratopathy (10.9%), and glaucoma (8.3%). One or more surgical procedures were performed on 71 (20.9%) eyes, most of which were attributable to juvenile rheumatoid arthritis, pars planitis, or Behcet's disease. The most common surgical interventions were cataract extraction with or without vitrectomy (15.3%), EDTA chelation (3.5%), peripheral cryotherapy (3.2%), and filtration surgery (1.8%).
Corneal Aberrations Before and After Photorefractive Keratectomy
Journal of Optometry, 2008
PURPOSE: To determine whether -and which -higher-order corneal aberrations, up to the sixth order, are induced by photorefractive keratectomy (PRK). METHODS: 197 eyes of 197 patients have been examined with a corneal aberrometer for a 3.5 and a 6.0 mm pupil simulation, both before and 1, 3 , 6 months after myopic PRK treatment ranging from -15.25 D to -0.5 D (mean -5.31±2.95 D). The statistical evaluation was performed using a paired Student's T-test. RESULTS: After PRK there is a clear-cut increase in almost all the higher-order corneal aberrations for both a 3.5 and a 6.0 mm pupil simulation. These aberrations tend to normalize after 3 and 6 months mainly for a 3.5 mm simulation, whereas such normalization is not present for a 6.0 mm simulation. CONCLUSIONS: PRK induces significant aberrations both for 3.5 and 6 mm pupils, 1 month after PRK, but a trend towards normalization is evident at the 6 month follow-up for the smaller pupil size. (J Optom 2008;1:53-58 ©2008 Spanish Council of Optometry) KEY WORDS: photorefractive keratectomy; higher-order aberrations.
Cornea, 2009
Purpose: To evaluate 8-year results of photorefractive keratectomy (PRK) for myopia in terms of safety, efficacy, stability, and late complications. Methods: From 371 myopic eyes of 203 patients who underwent PRK using NIDEK EC-5000 excimer laser with 5.5-to 6-mm ablation zones in Basir Eye Center, Tehran, Iran, during 1997-1998, data of 179 myopic eyes of 98 patients, who participated in annual examinations, were analyzed. Treated eyes were divided into 3 groups according to preoperative refraction: low myopia [#26.00 diopters (D)], moderate myopia (26.10 to 210.00 D), and high myopia (.210.00 D). The main outcome measures were safety, efficacy, stability, and postoperative complications. Results: Eight years after PRK, 69.64%, 44.44%, and 45.65% of the low, moderate, and high myopic groups were within 60.5 D of emmetropia. Sixteen eyes (4.31% of original cases) underwent retreatment mainly because of regression. Although a small myopic shift occurred up to 8 years after surgery, changes in myopic regression stabilized in all myopic groups within 24 months. Four eyes (2.06%) lost 2 lines of best spectacle-corrected visual acuity (1 eye for corneal haze and other 3 for problems not related to refractive surgery). Corneal haze occurred in 11.34% especially in medium and high myopic groups, but it cleared within 2 years in 68.2% of cases. Conclusions: Based on our study, PRK seems to be a safe, efficient, and stable surgical procedure, and if patients obtain a good result with the initial treatment, then their results are relatively stable over time.