19 research outputs found

    Original Article IOLMaster versus Manual Keratometry after

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    Purpose: To compare keratometric measurements using a Javal type manual keratometer with IOLMaster in eyes undergoing photorefractive keratectomy (PRK) for myopia. Methods: In this comparative case series, we studied patients aged 21 to 27 years scheduled for myopic PRK. Keratometry was performed preoperatively and three months after the procedure using a Javal type manual keratometer and the IOLMaster. We compared postoperative measurements obtained by both instruments with the clinical history method (CHM). Results: Seventy eyes of 35 patients with mean age of 23.45±1.55 years were studied. Mean preoperative spherical equivalent was-4.53±1.3 D. Average preoperative IOLMaster and manual keratometric readings were 45.95±1.23 D and 46.32±1.18 D, respectively. Postoperatively, mean IOLMaster measurements was 38.03±0.68 D and that of manual keratometry was 43.15±1.1 D. Compared to CHM measurements, the 95 % limits of agreement were ‑5.95 to-0.85 for the IOLMaster and-1.44 to 4.04 for manual keratometry. Conclusion: Keratometric measurements with the IOLMaster and a Javal type manual device are comparable after PRK; both are largely deviant from the CHM and can yield misleading results

    Relative Mydriasis after . . .

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    PURPOSE: To report the incidence of anisocoria after unilateral excimer laser photorefractive keratectomy (PRK) for myopia and subsequent corticosteroid therapy in a retrospective and prospective study and to explore possible etiologies. METHODS: The horizontal pupil diameter was determined in 6 patients (6 eyes) at 21.8 12.6 months after unilateral wide-field excimer laser PRK (retrospective group) as well as in 8 consecutive patients (8 eyes) before and 3.4 2.9 months after unilateral PRK (prospective group). The Schwind-Keratom wide-field excimer laser was used. Measurements were done in an examination room using Rosenbaum card comparison pupillometry and with a Goldmann perimeter at 31.5 asb. In the prospective group, the effect of fitting a hard contact lens of zero diopter power and the application of 0.1% pilocarpine were evaluated. RESULTS: Relative mydriasis was present in all treated eyes and the difference in pupil diameter between the two eyes measured 0.25 to 1.75 mm (..

    Feasibility of Intraoperative Corneal Topography Monitoring During

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    PURPOSE: We propose a feasibility study of new corneal topography technology with the aim of monitoring intraoperative corneal topography during excimer laser photorefractive keratectomy. The PAR system measures corneal topography with single grid projection and triangulation but requires fluorescent fluid to be deposited on the corneal surface for shape extraction. We propose and demonstrate a novel corneal topography system based on structured incoherent visible light projection and triangulation that does not require addition of fluorescent fluid. METHODS: We used a binary liquid crystal spatial light modulator to display multiple fringe patterns onto the cornea. The depth accuracy of the corneal topography system was measured using a white reflected test sphere mounted on a micrometer translation stage. The performance of the corneal topography system was tested on 5 deepithelialized swine eyes in vitro ablated with a VISX excimer laser. RESULTS: Depth accuracy on the test sphere..

    The Effect of Topical Corticosteroids on Refractive Outcome and Corneal

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    BACKGROUND: The effect of topical corticosteroids after excimer laser photorefractive keratectomy (PRK) remains a matter of some controversy. Refractive effects may be different according to the amount of myopia and timing of instillation

    Influence of Patient Age on

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    BACKGROUND: To determine whether the out- comes of photorefractive keratectomy (PRK) for myopia are age-dependent

    Open Access Effectiveness of Scraping and Mitomycin C to Treat Haze After Myopic

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    Abstract: To report the possibility of post myopic photorefractive keratectomy (PRK) haze treatment in a patient with expressed reluctance for any additional laser therapy. Seven months after bilateral PRK with subsequent development of corneal haze and refractive regression in both eyes, a 37-old-year male patient presented a best-spectacle corrected visual acuity (BSCVA) of 20/30 in the right eye and of 20/22 in the left eye. Both eyes were sequentially treated by scraping the stromal surface and application of mitomycin C (MMC) for 2 minutes. Both eyes had significant improvement in corneal transparency. Eighteen months after this treatment BSCVA had improved to 20/20 in each eye. No toxic effects were observed during either re-epithelialization or follow-up periods. In conclusion scraping and application of MMC could be considered a good tool in the treatment of selected cases of haze after myopic PRK, especially with patients that are reluctant to undergo a secondary laser procedure. Keywords: Mitomycin C, Haze, PRK, Scraping

    Removal of Corneal Epithelium with Phototherapeutic Technique during

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    BACKGROUND: The therapeutic mode of the VISX 20/20 excimer laser was used to remove the corneal epithelium prior to performing photorefractive keratectomy (PRK) with a multizone, multipass technique. METHODS: A retrospective analysis was performed of 120 eyes of 90 patients that were treated for preoperative spherical refractive errors from -1.00 to-7.00 diopters (D) (mean-3.90 D, SD 1.54) by one surgeon (DGJ) over 7 months. RESULTS: Six-month follow-up was obtained in 76 eyes (63%). Sixty-nine eyes (91%) achieved a spherical equivalent refraction within 1.00 D of emmetropia. Regression of effect averaged-0.35 D (SD 0.53 D) from 1 to 6 months after surgery. Mean postoperative uncorrected visual acuity at 6 months was 20/25 (range 20/15 to 20/200). Seventythree eyes (96%) achieved uncorrected visual acuity of 20/40 or better, 67 (88%) achieved uncorrected visual acuity of 20/25 or better, and 76 (71%) achieved 20/20 or better. Three eyes (4%) lost one line of spectacle-corrected visual ..

    Topical Tetracaine With Bandage Soft Contact Lens Pain Control After

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    PURPOSE: A major disadvantage of photorefractive keratectomy (PRK) is pain and discomfort in the first three postoperative days. We tried to assess the efficacy and safety to the cornea of a limited amount of topical tetracaine given to patients for use when needed to manage severe pain. METHODS: Sixty-nine eyes of 49 patients who underwent PRK between June 21, 1996 and June 15, 1998 by a single surgeon were prospectively included. Approximately 10 drops of commercial, non-preserved 0.5% tetracaine were given to patients to use when needed to control severe pain. A bandage soft contact lens was applied. Patients were examined at 1 and 3 days after surgery, at which time corneal re-epithelization was assessed and the number of tetracaine drops used was noted. No systemic analgesic or topical non-steroidal antiinflammatory was prescribed. RESULTS: All eyes healed within 3 days. The mean number of drops of tetracaine used was 2.3 drops over 3 days, although in 33 eyes (48%) the patient ..

    Muscular Asthenopia and Eccentric Ablation After Photorefractive Keratectomy

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    PURPOSE: To investigate the relationship between muscular asthenopia and eccentric ablation after photorefractive keratectomy (PRK). METHODS: Sixteen eyes of eight myopic patients whose muscular asthenopia was corrected by subjectively accepted spectacle prism after PRK, with visual acuity better than 0.8, were followed for 6 to 14 months. On the basis of preoperative and postoperative data and corneal topography, we calculated the total corrected corneal power using the Holladay formula and then measured the ablation eccentricity (h, millimeters) and its direction. According to the formula # Dh, the prism effective value (#) caused by the eccentric ablation was computed and compared with the objectively accepted spectacle prism. RESULTS: The subjectively accepted spectacle prisms were similar to calculated values from the formula. Mean difference was 0.10 0.25 # . The direction of the subjectively accepted prism was in the direction of the ablation deviation. CONCLUSIONS: Eccen..

    Original Article Early Postoperative Pain and Visual Outcomes Following Epipolis-Laser In Situ Keratomileusis and

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    Purpose: To compare early postoperative pain and visual outcomes after epipolis-laser in situ keratomileusis (epi-LASIK) and photorefractive keratectomy (PRK) in the treatment of myopia. Methods: A retrospective chart review was designed and included 49 eyes in 30 patients who underwent epi-LASIK and 54 eyes in 29 patients who underwent PRK. During the early postoperative period (days 1 to 5), pain, uncorrected visual acuity (UCVA), and time to epithelial healing were recorded. Visual outcomes were followed for up to six months. Results: Mean preoperative spherical equivalent refraction for the epi-LASIK group was-3.99±1.39 diopters (D) and that of the PRK group was-3.54±1.27 D. The pain scores on the fourth postoperative day were significantly higher in the epi-LASIK group than in the PRK group (p=0.017). Duration of pain in the epi-LASIK group was longer than in the PRK group (p=0.010). Mean healing time was significantly longer in the epi-LASIK group than in the PRK group (p<0.000). In addition, UCVA in the epi-LASIK group at postoperative days 1 and 3 were significantly lower than those in the PRK group (p=0.021 and p<0.000, respectively). Uncorrected visual acuity at one week and one month after epi-LASIK were lower than those after PRK (p=0.023 and p=0.004, respectively). Conclusions: In the epi-LASIK patients, pain relief, corneal healing, and visual recovery seemed to be slower during the early postoperative period compared to those of the PRK patients. With longer duration of follow-up, however
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