Excimer laser programming of refractive astigmatism vs. anterior corneal astigmatism in the case of ocular residual astigmatism (ORA)

Abstract Background: To assess the influence of ocular residual astigmatism to anterior corneal astigmatism in children with low and moderate myopia.Methods: Refractive astigmatism was obtained by subjective manifest refraction. Anterior corneal astigmatism was obtained by IOL Master. Using Thibos vector analysis to calculate ocular residual astigmatism. Correlation analysis was used to assess the relationship between the magnitude of ocular residual astigmatism and anterior corneal astigmatism. The influence of ocular residual astigmatism to anterior corneal astigmatism was evaluated by Physical method.Results: The study analyzed 241 right eyes of 241 children aged 8 to 18 years old. In this study, the median magnitude of ocular residual astigmatism was 1.02 D, with interquartile range was 0.58 D. Against-the-rule ocular residual astigmatism was seen in 232 eyes (96.3%). There was a significant and moderate correlation between ocular residual astigmatism and anterior corneal astigmatism (r = 0.50, P < 0.001). The ocular residual astigmatism in 240 eyes (99.6%) had a compensatory effects on anterior corneal astigmatism. The mean compensation value was 1.00 ± 0.41 D (rang 0.02 D to 2.34 D). Based on this effect, 37 eyes had different axial classification of anterior corneal astigmatism and refractive astigmatism. By contrast, one eye (0.4%) had oblique ocular residual astigmatism and superimposed with-the-rule anterior corneal astigmatism.Conclusions: The magnitude of ocular residual astigmatism was relatively huge in myopia children and predominantly compensated anterior corneal astigmatism. The ocular residual astigmatism should be assessed first before fitting orthokeratology.

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The contribution of ocular residual astigmatism to anterior corneal astigmatism in refractive astigmatism eyes

Scientific Reports ◽

10.1038/s41598-020-80106-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jian Lin

Keyword(s):

Correlation Analysis ◽

Interquartile Range ◽

Corneal Astigmatism ◽

Vector Analysis ◽

Spearman Correlation ◽

Inclusion Criteria ◽

Ocular Residual Astigmatism ◽

Anterior Corneal Astigmatism ◽

Superimposed Effect

AbstractTo determine the distribution of ocular residual astigmatism (ORA) in astigmatic eyes and the influence on the anterior corneal (ACA) and refractive astigmatism (RA). A total of 165 children met the inclusion criteria. Right eyes’ data were analyzed. Using Thibos vector analysis to calculate ORA. Spearman correlation analysis was used to obtain the correlation between the magnitude of ORA, ACA and RA. The median magnitude of ORA in astigmatic eyes was 0.57 D, with interquartile range was 0.42 D. And they were main against-the-rule (57.6–75.8%) and oblique astigmatism (13.9–34.5%) ORA. The ORA in 140 eyes (84.8%) acted as an offset to ACA, meanwhile, 25 eyes (15.2%) superimposed it. About 98% (97.9–98.4%) against-the-rule and 75% (73.9–82.5%) oblique ORA counteracted ACA, nevertheless, all with-the-rule ORA had a superimposed effect on ACA. For with-the-rule ACA, about 86% (85.4–85.9%) ORA worked to offset it. There was statistically correlations between ORA and ACA (r = 0.17, P = 0.03), ORA and RA (r = − 0.27, P = 0.001). The magnitude of ocular residual astigmatism was relatively small in children’s astigmatic eyes. Both against-the-rule and oblique ORA can counteract with-the-rule ACA.

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Author Correction: The contribution of ocular residual astigmatism to anterior corneal astigmatism in refractive astigmatism eyes

Scientific Reports ◽

10.1038/s41598-021-93185-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jian Lin

Keyword(s):

Corneal Astigmatism ◽

Ocular Residual Astigmatism ◽

Anterior Corneal Astigmatism

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Contribution of Ocular Residual Astigmatism to Anterior Corneal Astigmatism in Children with Low and Moderate Myopia

10.21203/rs.3.rs-199217/v1 ◽

2021 ◽

Author(s):

Jian Lin ◽

Dexiang An ◽

Yun Lu ◽

Dongmei Yan ◽

Leilei Wang

Keyword(s):

Correlation Analysis ◽

Physical Method ◽

Corneal Astigmatism ◽

Moderate Correlation ◽

Ocular Residual Astigmatism ◽

Manifest Refraction ◽

The Mean ◽

The Relationship ◽

Anterior Corneal Astigmatism

Abstract To assess the contribution of ocular residual astigmatism (ORA) to anterior corneal astigmatism (ACA) in children with low and moderate myopia. Refractive astigmatism (RA) were received by subjective manifest refraction. ACA were obtained by IOL Master. Using Thibos vector analysis to calculate ORA. Correlation analysis was used to assess the relationship between the magnitude of ORA and ACA. The contribution of ORA to ACA was evaluated by Physical method. The study analyzed 241 right eyes of 241 children aged 8 to 18 years old. In this study, the median magnitude of ORA was 1.02 D, with interquartile range was 0.58 D. Against-the-rule ORA was seen in 232 eyes (96.3%). There was a significant and moderate correlation between ORA and ACA (r = 0.50, P < 0.001). The ORA in 240 eyes (99.6%) had a compensatory effects on ACA. The mean compensation value was 1.00 ± 0.41 D. Based on this effect, 37 eyes had different axial classification of ACA and RA. By contrast, one eye (0.4%) had oblique ORA and superimposed with-the-rule ACA. The magnitude of ORA was relatively huge in myopia children and predominantly compensated ACA. The ORA should be assessed first before fitting orthokeratology.

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Faculty Opinions recommendation of Efficacy of laser in situ keratomileusis in correcting anterior and non-anterior corneal astigmatism: comparative study.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.9584956.10246054 ◽

2011 ◽

Author(s):

Miguel Teus ◽

Juan Gros-Otero ◽

Montserrat Garcia-Gonzalez

Keyword(s):

Comparative Study ◽

Corneal Astigmatism ◽

Laser In Situ Keratomileusis ◽

Anterior Corneal Astigmatism

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Does pterygium morphology affect corneal astigmatism?

Therapeutic Advances in Ophthalmology ◽

10.1177/25158414211030423 ◽

2021 ◽

Vol 13 ◽

pp. 251584142110304

Author(s):

Emine Doğan ◽

Burçin Çakır ◽

Nilgün Aksoy ◽

Elif Köse ◽

Gürsoy Alagöz

Keyword(s):

Anterior Segment ◽

Clinical Information ◽

Corneal Astigmatism ◽

Continuous Group ◽

Optic Coherence Tomography ◽

Morphological Pattern ◽

Horizontal Length ◽

The Mean ◽

Anterior Corneal Astigmatism ◽

Posterior Corneal Astigmatism

Purpose: The purpose of this study was to evaluate the correlation between corneal astigmatism and the morphology of pterygium with anterior segment optic coherence tomography (AS-OCT). Material and Methods: The size of pterygium (horizontal length, vertical width) was measured manually; pterygium area and percentage extension of the pterygium onto the cornea were calculated. Anterior and posterior corneal astigmatism, Sim K, K1, K2 were measured using a dual Scheimpflug analyzer. Morphological patterns of the pterygium analyzed with AS-OCT were determined according to the extension of the pterygium apex below the corneal epithelium. Two tomographic patterns were identified: continuous and nodular. Correlation between anterior corneal astigmatism and pterygium size, percentage extension of the pterygium, and morphological pattern of the pterygium was analyzed. Results: The mean ages of the 47 patients were 49.4 ± 16.6 (22–80) years. Mean horizontal pterygium length, vertical width, pterygium area, and percentage extension of the pterygium were 2.8 ± 1.2 mm, 4.8 ± 1.6 mm, 7.42 ± 5.6 mm2 and 24.5 ± 10.4%, respectively. Mean anterior corneal astigmatism was 2.3 ± 2.3 D and simulated keratometry was 43.4 ± 2.02 D. In terms of the morphological pattern of the pterygium, 24 eyes had continuous, 23 eyes had a nodular pattern and the median (interquartile range) anterior corneal astigmatism was 1.87 (1.01–3.80) and 1.22 D (0.58–2.35), respectively ( p = 0.102). Other topographic and pterygium size parameters were similar between groups. Analyzing the correlations in groups separately, a positive moderate statistically significant correlation was present between vertical width, percentage extension, pterygium area, and anterior corneal astigmatism in both continuous and nodular groups. Conclusions: Although not statistically significant, anterior corneal astigmatism was higher in continuous group. Using AS-OCT to standardize the morphology of pterygium could provide additional clinical information.

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