Differences between Regressive Eyes and Non-Regressive Eyes after LASIK for Myopia in the Time Course of Corneal Changes Assessed with the Orbscan

Pan, Qing; Gu, Yang Shun; Wang, Jing; Du, Chi; Huang, Zhangcheng; Xin, Shuang Hua

doi:10.1159/000076143

Cited by 22 publications

(22 citation statements)

References 24 publications

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“…[106][107][108][109][110][111][112][113][114][115] A notable exception is a study comparing Orbscan topography to the EyeSys system, which suggests that Orbscan curvature topography may be as accurate and precise as the Placido-based EyeSys system. 106 Comparison of Orbscan pachymetry with US techniques continues to provide data that reveal similar or slightly thinner measurements when derived from normal corneas yet significantly underestimates when measuring post-LASIK corneal thickness (0.92 acoustic factor adjustment included).…”

Section: Post Scriptmentioning

confidence: 99%

“…106 Comparison of Orbscan pachymetry with US techniques continues to provide data that reveal similar or slightly thinner measurements when derived from normal corneas yet significantly underestimates when measuring post-LASIK corneal thickness (0.92 acoustic factor adjustment included). [107][108][109][110] Further evidence of Orbscan-defined ectasia following laser refractive surgery has been reported, 111 in sharp contrast to a novel study suggesting that alterations in the magnification of the posterior surface before and after laser refractive surgery may produce artifactual ectasia. 112 Studies of Orbscan assessment of total corneal optical power in normal and surgically altered corneas show close agreements and improved repeatability in manifest refraction.…”

Section: Post Scriptmentioning

confidence: 99%

See 1 more Smart Citation

Orbscan computerized topography: Attributes, applications, and limitations

Cairns

McGhee

2005

Journal of Cataract and Refractive Surgery

216

134

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An extensive electronic search was undertaken in January 2004 to identify all relevant peer-reviewed publications on Orbscan slit-scanning/Placido computerized topography. Ninety-one publications were identified. These address elevation topography and best-fit sphere, accuracy and repeatability of anterior and posterior corneal elevation and keratometric maps, comparison of Orbscan-acquired data and Placido-based computerized videokeratography instruments, pachymetry measurement and correlation with ultrasound, screening eye-bank corneas, detection of keratoconus, identifying corneal ectasia after refractive surgery, and miscellaneous applications. Studies were analyzed and critically compared in relation to attributes, applications, and limitations of Orbscan corneal topography. The review highlights advantages of this technique in assessing the cornea in health and disease and after surgery and identifies specific aspects that require further investigation and clarification.

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Section: Post Scriptmentioning

confidence: 99%

Section: Post Scriptmentioning

confidence: 99%

Orbscan computerized topography: Attributes, applications, and limitations

Cairns

McGhee

2005

Journal of Cataract and Refractive Surgery

216

134

View full text Add to dashboard Cite

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“…However, most previous studies agree that myopic regression after LASIK is attributable to epithelial hyperplasia and stromal remodeling. [10,11] Pan et al [12] compared regressive eyes with nonregressive eyes after LASIK and indicated that refractive regression after LASIK might be mainly induced by corneal protrusion rather than by CCT. Our study also demonstrated that there were no significant changes in CCT in each of the 2 groups (Table 2 and Fig.…”

Section: Discussionmentioning

confidence: 99%

The effect of Timolol 0.5% on the correction of myopic regression after LASIK

Gao

et al. 2017

Medicine

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Backgroud:Postlaser in situ keratomileusis (post-LASIK) refractive regression is defined as the gradual, partial, or total loss of initial correction that limits the predictability, efficiency, and long-term stability of LASIK. Our study assesses the effect of Timolol 0.5% on the correction of myopic regression after LASIK.Methods:This prospective, randomized, controlled study included 62 eyes of 62 patients with myopic regression of −1.18 ± 0.86 diopters (D) after myopic LASIK. They were randomly assigned into either Group 1 who received Timolol 0.5% eye drops for 3 months or Group 2 who received artificial tears as control (during treatment). Patients were followed an additional 2 months after cessation of eye drops treatment (posttreatment).Results:During treatment in Group 1, as the mean true intraocular pressure (IOPT) lowered significantly, regression stopped. As the mean IOPT increased significantly posttreatment and returned to its pretreatment level, regression recurred. The effective rate of Timolol therapy dropped from 62.5% during treatment to 40.6% posttreatment. On the contrary in Group 2, although the mean IOPT did not change significantly, regression continually happened as time passed. During treatment, the mean IOPT, uncorrected visual acuity, spherical equivalent (SE), and corneal refractive power showed significant difference between the 2 groups. In Group 1, the differences of effective rate of Timolol therapy between each of the 2 subgroups of age, gender, preoperative SE (PSE), or pretreatment time (how long we start treatment with Timolol post-LASIK) were not statistically significant.Conclusion:IOP-lowering eye drop Timolol was effective for the correction of myopic regression when a 0.5-D or greater myopic shift is detected after LASIK in patients regardless of age, gender, PSE, or anytime we started the treatment only if regression happened. However, the myopic regression recurred after cessation of Timolol treatment.

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“…But Magallanes et al [11] reported a significant myopic shift with only a slight increase in CCT, but a slight myopic shift with a significant increase in CCT after LASIK. Pan et al [12] compared regressive eyes with nonregressive eyes after LASIK and indicated that refractive regression after LASIK might be mainly induced by corneal protrusion rather than by central corneal thickening. Till now, the mechanism of refractive regression after LASIK is not fully elucidated.…”

Section: Discussionmentioning

confidence: 99%

Regression-Related Factors before and after Laser in situ Keratomileusis

Qi¹,

Hao²,

Xia³

et al. 2006

Ophthalmologica

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The aim of this study was to evaluate the refractive regression-related factors before and after laser in situ keratomileusis (LASIK) for myopia and give a reasonable way to prevent it. The consecutive patients who underwent LASIK from January to June 2004 were reviewed retrospectively. Thirteen eyes from 8 patients with myopic regression and 60 eyes from 42 patients with no myopic regression within 12 months of follow-up were enrolled. We compared the pre- and postoperative data which were associated with regression in the two groups. The mean preoperative intraocular pressure (IOP) was significantly higher in the regression group than in the nonregression group (p = 0.03). During the period of 12 months, the two groups differed in corneal bowing. In the regression group, both posterior and anterior corneal surfaces were significantly bowing (all p < 0.05). In contrast, in the nonregression group, both posterior and anterior surfaces were relatively stable (all p > 0.05). The higher preoperative IOP and the progressive postoperative biomechanical bowing in the posterior and anterior surfaces of the cornea are two factors related to myopic regression in this study. Lowering the IOP preoperatively and postoperatively may be an effective way to prevent the myopic regression after LASIK.

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Differences between Regressive Eyes and Non-Regressive Eyes after LASIK for Myopia in the Time Course of Corneal Changes Assessed with the Orbscan

Cited by 22 publications

References 24 publications

Orbscan computerized topography: Attributes, applications, and limitations

Orbscan computerized topography: Attributes, applications, and limitations

The effect of Timolol 0.5% on the correction of myopic regression after LASIK

Regression-Related Factors before and after Laser in situ Keratomileusis

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