Comparing refractive outcomes of a standard industry toric IOL calculator using anterior corneal astigmatism and total corneal refractive power

2019 ◽  
Vol 258 (2) ◽  
pp. 345-350
Author(s):  
C. Kern ◽  
L. El Kaissi ◽  
K. Kortuem ◽  
M. Shajari ◽  
E. Vounotrypidis ◽  
...  
Keyword(s):  
Corneal Astigmatism ◽  
Toric Iol ◽  
Refractive Power ◽  
Refractive Outcomes ◽  
Corneal Refractive Power ◽  
Anterior Corneal Astigmatism

Combined implantation of toric and spherical intraocular lenses for low corneal astigmatism correction

2021 ◽  
Vol 1 (3) ◽  
pp. 118-123
Author(s):  
Valeria Albano ◽  
Alessandra Sborgia ◽  
Carmela Palmisano ◽  
Giovanni Alessio
Keyword(s):  
Low Power ◽  
Corneal Astigmatism ◽  
Intraocular Lenses ◽  
Toric Iol ◽  
Refractive Outcomes ◽  
Astigmatism Correction ◽  
Uncorrected Distance Visual Acuity ◽  
Toric Iols ◽  
Standard Deviation Range ◽  
Spherical Iol

Background: This study compared outcomes of combined toric versus spherical intraocular lens (IOL) implantation in patients with low corneal astigmatism. Methods: In this retrospective contralateral study, patients with corneal astigmatism who received combined toric (FIL 611 T, Soleko, Rome, Italy) and spherical IOL (FIL 611 T, Soleko, Rome, Italy) implants were recruited. Eyes were examined preoperatively and then again 3 months postoperatively. Postoperatively, uncorrected distance visual acuity (UCDVA), residual astigmatism, and spherical equivalent (SE) were compared between the toric IOL-implanted eyes and the spherical IOL-implanted fellow eyes. Results: Among the 46 included cases (age 69 ± 12.7 years [mean± standard deviation]; range: 60‒78 years), 86.9% of eyes (n = 40) in the toric IOL group had a postoperative refractive cylinder of ≤ 0.25 diopters (D), compared with 4.3% (n = 2) of eyes in the spherical IOL group. Both groups showed a statistically significant reduction in refractive cylinder and improvement in UCDVA after cataract surgery (both P = 0.01). Similarly, toric IOLs were superior (69.6%) to spherical lenses (2.2%) in obtaining a SE of ≤ 0.25 D. Conclusions: To our knowledge, no previous study had sought to compare low-power toric and spherical IOLs in low corneal astigmatism in the same patient's eyes. Our findings suggest that low-power toric IOLs may result in good refractive outcomes as compared with spherical IOLs implanted in the fellow eye of the same patient, although both result in significant UCDVA improvement. Well‐designed clinical research studies with a longer follow-up and more participants are necessary to confirm these findings.

Total corneal refractive power and shape in Down syndrome

2019 ◽  
pp. 112067211988359 ◽  
Author(s):  
Soheila Asgari ◽  
Shiva Mehravaran ◽  
Akbar Fotouhi ◽  
Ali Makateb ◽  
Hassan Hashemi
Keyword(s):  
Down Syndrome ◽  
Normal Subjects ◽  
Normal Group ◽  
Corneal Astigmatism ◽  
Q Value ◽  
Refractive Power ◽  
Coefficients Of Variation ◽  
The Mean ◽  
And Gender ◽  
Corneal Refractive Power

Purpose: To determine the total corneal refractive power in 1–8 mm corneal zones and the 8 mm Q-value in non-keratoconic patients with Down syndrome and normal subjects aged 10–30 years. Methods: Right eye data from 203 Down syndrome patients (mean ± standard deviation age: 17.0 ± 4.7 years) and 189 age- and gender-matched normal subjects (17.1 ± 4.5 years) were compared. Main extracted Pentacam indices were total corneal refractive power in steep and flat axes, and mean and difference (corneal astigmatism) total corneal refractive power in 1–8 mm zones. Results: Mean total corneal refractive power in 1–8 mm zones was 45.17–45.74 D and 42.91–43.52 D in Down and normal group, respectively (all p < 0.001). The coefficients of variation of total corneal refractive power from the center to the periphery were similar in the two groups (p = 0.855). None of the mean total corneal refractive powers significantly correlated with age, and all of them were significantly higher in females (p < 0.001). Mean total corneal refractive power–based corneal astigmatism in these zones changed from 1.46 to 1.66 D in Down syndrome patients and 1.64 to 1.99 D in normal group. All corneal astigmatism indices were similar between two groups (all p > 0.05). The prevalence of against the rule and oblique astigmatism in all zones were higher in the Down syndrome group (all p < 0.05). Conclusion: Adolescent and young non-keratoconic patients with Down syndrome have a more prolate cornea and a homogeneous keratometry distribution. In this population, females have a steeper cornea.

scholarly journals Effect of 1.8-mm steep-axis clear corneal incision on the posterior corneal astigmatism in candidates for toric IOL implantation

2020 ◽  
Author(s):  
Xi Li ◽  
Xiang Chen ◽  
Suhong He ◽  
Wen Xu
Keyword(s):  
T Test ◽  
Corneal Astigmatism ◽  
Corneal Incision ◽  
Toric Iol ◽  
Iol Implantation ◽  
Clear Corneal Incision ◽  
Significant Difference ◽  
Paired T Test ◽  
Anterior Corneal Astigmatism ◽  
Posterior Corneal Astigmatism

Abstract PURPOSE In the present study, we aimed to analyze the effects of cataract surgery using a 1.8-mm steep-axis clear corneal incision (CCI) on the posterior corneal surfaces based on the keratometry from the rotating Scheimpflug imaging device (Pentacam HR) in candidates for toric intraocular lens (IOL) implantation. METHODS Preoperative and at least 1-month postoperative data measured by Pentacam HR were collected in patients for toric IOL implantation. Surgically induced astigmatism on the posterior cornea (P-SIA) was calculated based on the preoperative and postoperative keratometric data, and the related factors of P-SIA were analyzed. RESULTS A total of 60 eyes from 56 patients were enrolled. The preoperative anterior and posterior corneal astigmatism was 1.58±0.61 D and 0.28±0.22 D, respectively. The postoperative anterior and posterior corneal astigmatism was 1.26±0.68 D and 0.41±0.26 D, respectively. The astigmatism was significantly decreased on anterior surface (P<0.001, paired t-test) and increased on posterior surface (P<0.001, paired t-test). The mean of P-SIA calculated by Holladay–Cravy–Koch method was 0.34±0.20 D, with 0.5 D or greater accounting for 26.7%. P-SIA showed no significant difference among with-the-rule (WTR) astigmatism, against-the-rule (ATR) astigmatism and oblique astigmatism (F=1.85, P=0.167). A statistically significant correlation was observed between the P-SIA and preoperative anterior corneal astigmatism (r = 0.29, P=0.024), as well as preoperative posterior corneal astigmatism (r=0.27, P=0.038). CONCLUSIONS In candidates for toric IOL implantation with a 1.8-mm steep-axis CCI, the incision caused a significant reduction of the anterior corneal astigmatism but an increase of the corneal posterior astigmatism. P-SIA could not be ignored, and it played a significant role in SIA, especially in cases with higher preoperative anterior or posterior corneal astigmatism.

scholarly journals Effect of 1.8-mm steep-axis clear corneal incision on the posterior corneal astigmatism in candidates for toric IOL implantation

2020 ◽  
Author(s):  
Xi Li ◽  
Xiang Chen ◽  
Suhong He ◽  
Wen Xu
Keyword(s):  
Corneal Astigmatism ◽  
Corneal Incision ◽  
Toric Iol ◽  
Iol Implantation ◽  
Clear Corneal Incision ◽  
Paired T Test ◽  
Anterior Posterior ◽  
Anterior Corneal Astigmatism ◽  
Posterior Corneal Astigmatism ◽  
Total Corneal Astigmatism

Abstract Background: In the present study, we aimed to analyze the effects of cataract surgery using a 1.8-mm steep-axis clear corneal incision (CCI) on the posterior corneal surfaces based on the keratometry from the rotating Scheimpflug imaging device (Pentacam HR) in candidates for toric intraocular lens (IOL) implantation. Methods: Preoperative and at least 1-month postoperative data measured by Pentacam HR were collected in patients for toric IOL implantation. Surgically induced astigmatism on the posterior cornea (P-SIA) was calculated based on the preoperative and postoperative keratometric data, and the related factors of P-SIA were analyzed. Results: A total of 60 eyes from 56 patients were enrolled. The preoperative anterior, posterior and total corneal astigmatism was 1.58±0.61 D ,0.28±0.22 D and 1.70 ± 0.52 D respectively. The postoperative anterior, posterior and total corneal astigmatism was 1.26±0.68 D, 0.41±0.26 D and 1.30 ± 0.51 D respectively. The astigmatism was significantly decreased on anterior surface (P＜0.001, paired t-test) and increased on posterior surface (P＜0.001, paired t-test). The mean of P-SIA calculated by Holladay–Cravy–Koch method was 0.34±0.20 D, with 0.5 D or greater accounting for 26.7%. A statistically significant correlation was observed between the P-SIA and preoperative anterior corneal astigmatism (r = 0.29, P=0.024), as well as preoperative posterior corneal astigmatism (r=0.27, P=0.038). Multivariate regression analysis showed the preoperative anterior and posterior corneal astigmatism had a significant effect on P-SIA (F=7.344, P=0.001). Conclusions: In candidates for toric IOL implantation with a 1.8-mm steep-axis CCI, the incision caused a significant reduction of the anterior corneal astigmatism but an increase of the posterior corneal astigmatism. P-SIA could not be ignored, and it played a significant role in SIA, especially in cases with higher preoperative anterior or posterior corneal astigmatism.

scholarly journals Does pterygium morphology affect corneal astigmatism?

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.

Corneal refractive power after myopic LASIK

Ophthalmology ◽  
2003 ◽  
Vol 110 (9) ◽  
pp. 1857 ◽  
Author(s):  
Louis E Probst ◽  
Jack T Holladay
Keyword(s):  
Refractive Power ◽  
Corneal Refractive Power
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