Visual and Refractive Outcomes of Topography-guided Laser-assisted In Situ Keratomileusis in Virgin Eyes

Hashmani, Sharif; Hashmani, Nauman; Haroon, Husna; Hashmi, Yusra

doi:10.7759/cureus.2131

Cited by 6 publications

(3 citation statements)

References 26 publications

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“…Although some recent studies have achieved results similar to those obtained in the FDA trial, 30,31 some of the authors of this report (MCL, TPL), as well as several other investigators, [32][33][34] have been unable to obtain the excellent postoperative visual acuities obtained during the FDA trial when the same treatment protocol was applied to eyes encountered in routine clinical practice. Various alternative strategies have been proposed, therefore, to determine the appropriate laser entry for the Treatment sphero-cylindrical refraction.…”

Section: Discussionmentioning

confidence: 54%

<p>Topography-Guided Refractive Astigmatism Outcomes: Predictions Comparing Three Different Programming Methods</p>

Stulting

Durrie

Potvin³

et al. 2020

OPTH

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Purpose: To identify the laser programming strategy that will achieve optimal refractive outcomes of LASIK with a topography-guided laser for eyes with a disparity between cylinder measured by manifest refraction and cylinder measured by topography. Setting: Six surgeons at 5 clinical sites in the USA. Design: Retrospective data review. Methods: Preoperative, treatment, and postoperative data on 52 eyes that underwent topographyguided LASIK with the WaveLight EX500 Contoura ® Vision excimer laser ablation profile in which the vectors representing the preoperative refractive cylinder and the cylinder measured by the WaveLight ® Topolyzer™ VARIO Diagnostic Device (Vario cylinder) differed by >/= 0.50D and/or >/= 10 degrees of orientation were analyzed retrospectively. Data were contributed by six surgeons using the laser at 5 different clinical sites. Vector analysis of postoperative cylindrical refractive error and the actual laser programming strategy was used to calculate the cylindrical correction that would, theoretically, have completely eliminated postoperative refractive cylinder. This was compared to expected results using the preoperative manifest cylinder, the topographic cylinder, and the Phorcides Analytic Engine (Phorcides LLC, North Oaks MN; Phorcides). For analysis, subjects were stratified on the basis of the vector difference between Manifest and Topo cylinder (High, >0.75 D; and Low, ≤0.75 D). Results: The poorest calculated theoretical outcomes were obtained with the manifest refraction (centroid: −0.43, 0.22; mean calculated error vector: 0.56 ± 0.42 D; p=ns). Better outcomes were obtained with the topographically measured refraction (centroid: 0.37, 0.02; mean calculated error vector: 0.47 ± 0.33 D; p=ns). The best outcomes were obtained with Phorcides (centroid: −0.15, 0.06; mean calculated error vector: 0.39 ± 0.28 D; p=ns). The mean error vector magnitude in the Phorcides Low group was significantly lower than for the Manifest and Topo Low groups (0.26 D vs 0.48 D and 0.33 D; p<0.01). The mean error magnitude in the Phorcides High group was nearly 0.25 D lower than for the Manifest High group (0.48 D vs 0.70 D; p<0.01), but was the same as for the Topo High group (0.48 D vs 0.48 D). Conclusion: Our study suggests that using the topographically measured cylinder or the cylinder selected by Phorcides will produce more desirable refractive outcomes than entry of the preoperative refractive cylinder as the basis for correction of myopia and myopic astigmatism with the WaveLight Contoura Vision excimer laser.

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Section: Discussionmentioning

confidence: 54%

<p>Topography-Guided Refractive Astigmatism Outcomes: Predictions Comparing Three Different Programming Methods</p>

Stulting

Durrie

Potvin³

et al. 2020

OPTH

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“…Many studies have shown excellent outcomes when planning treatment based solely on subjective manifest refractive astigmatism [9,[17][18][19][20][21][22][23]. However, only one study [9] reported differences between manifest astigmatism and topographic astigmatism.…”

Section: Discussionmentioning

confidence: 99%

Mutual comparative analysis: a new topography-guided custom ablation protocol referencing subjective refraction to modify corneal topographic data

Cao¹,

Liu²,

Zhang³

et al. 2020

Eye and Vis

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Background: Several planning algorithms have been developed for topography-guided custom ablation treatment (T-CAT), but each has its own deficiencies. The purpose of this study is to demonstrate the potential of a novel mutual comparative analysis (MCA) informed by manifest refraction and corneal topographic data and the patient's subjective perception in correcting ametropia. Methods: This retrospective review included patients with significant preoperative differences in the power or axis of astigmatism according to the manifest refraction and corneal topographic data (power > 0.75 D and/or axis > 10°). T-CAT planning was designed using MCA. Follow-ups were conducted for at least 6 months. Results: Seventy-nine patients (121 eyes) were included. The mean preoperative deviation in the astigmatic power and axis were 0.72 ± 0.43 D and 20.18 ± 23.68°, respectively. The average oculus residual astigmatism (ORA) was 0.81 ± 0.32 D (range: 0.08-1.66 D). Six months postoperatively, the mean spherical equivalent refraction was 0.04 ± 0.42 D, and the mean cylinder was − 0.27 ± 0.24 D. The mean efficacy and safety indices were 1.10 and 1.15, respectively. The uncorrected distance visual acuity in 92% of the eyes was the same or better than the corrected distance visual acuity. The angle of error was ±5°in 61% of eyes and ± 15°in 84% of eyes. Residual astigmatism was ≤0.5 D in 91% of eyes. Optical quality and photopic contrast sensitivity did not change significantly (p > 0.05), and the scotopic contrast sensitivity decreased at 3, 6, and 12 cpd (p < 0.05). The vertical coma and horizontal coma of the anterior corneal surface significantly decreased postoperatively but increased during follow-up. Conclusions: The MCA demonstrated safety, efficacy, accuracy, predictability, and stability and can be used as a complementary and feasible method for T-CAT.

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“…Refractive surgery for hyperopia has been a challenge for surgeons in last few decades (1, 2). Hyperopia contributes to around 1/3 of all of refractive anomalies (3), but still the focus of corneal refractive surgery has centered primarily on myopia. Many studies have reported high level of safety and efficacy of Laser in situ Keratomileusis (LASIK) in correction of low hyperopia(up to 4 D) (1-2, 4-5).…”

Section: Introductionmentioning

confidence: 99%

Lasik as a Solution for High Hypermetropia

Biščević¹,

Pidro²,

Pjano³

et al. 2019

Med Arch

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Aim: To evaluate safety and efficacy of Laser in situ Keratomileusis (LASIK) procedure for the correction of high hypermetropia. Methods: Retrospective study of 160 patients (266 eyes) who underwent LASIK procedure for the correction of hypermetropia between +3.00 and +7.00 diopters(D) and cylinder up to 2.00D from January 2013 and August 2015. All ablations were performed with Wavelight Allegretto Eye-Q400Hzexcimer laser (Alcon, Forth Worth, TX, USA) with aberration free module and were centered on a corneal vertex. All flaps were made with Moria M2 (Moria, Antony, France) mechanical microkeratome (90μm head). Preoperative and postoperative uncorrected and corrected distant visual acuity (UDVA, CDVA), spherical equivalent (SE) and a berrometry for 5mm pupil were measured. Measurements were taken at 1 week, 1,3,6 and 12 months after the surgery. Wilcoxon Signed Ranks Test was used for statistical analysis. Results: Postoperative UDVA was lower than preoperative CDVA at 1 week( p =0.001), at 1 month there was no difference ( p =0.099), and at 3,6 and 12 months UDVA was better ( p <0.0001). Preoperative SE was 4.69±1.20D (+3.75 to +7.50D). At 1 week SE was 0.03±0.67D (-0.50 to +0.63D), while at 1 year regressed to 0.58±0.56D (+0.25 to +0.88D). Sphere shifted from negative values targeted in treatment planning to compensate for regression to positive values. There was significant difference in SE at every time point ( p <0.0005). There was a significant increase in coma ( p <0.0001), trefoil ( p <0.0001, p =0.0006) and spherical aberration ( p =0.022, p =0.0052) at 1 week and 1 month postoperatively, without change throughout the rest of follow up. Conclusion: LASIK for high hypermetropia showed satisfactory results in postoperative refraction with reasonable regression without significant loss of lines of visual acuity. However, more test are necessary to asses optical quality.

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Visual and Refractive Outcomes of Topography-guided Laser-assisted In Situ Keratomileusis in Virgin Eyes

Cited by 6 publications

References 26 publications

<p>Topography-Guided Refractive Astigmatism Outcomes: Predictions Comparing Three Different Programming Methods</p>

<p>Topography-Guided Refractive Astigmatism Outcomes: Predictions Comparing Three Different Programming Methods</p>

Mutual comparative analysis: a new topography-guided custom ablation protocol referencing subjective refraction to modify corneal topographic data

Lasik as a Solution for High Hypermetropia

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