scholarly journals Unintended changes in ocular biometric parameters during a 6-month follow-up period after FS-LASIK and SMILE

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Junjie Wang ◽  
Bernardo T. Lopes ◽  
Hechen Li ◽  
Riccardo Vinciguerra ◽  
Si Cao ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Corneal Endothelium ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Laser In Situ Keratomileusis ◽  
Biometric Parameters ◽  
Refractive Outcomes ◽  
Post Surgery ◽  
Before And After

AbstractBackgroundCorneal refractive surgery has become reliable for correcting refractive errors, but it can induce unintended ocular changes that alter refractive outcomes. This study is to evaluate the unintended changes in ocular biometric parameters over a 6-month follow-up period after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE).Methods156 consecutive myopic patients scheduled for FS-LASIK and SMILE were included in this study. Central corneal thickness (CCT), mean curvature of the corneal posterior surface (Kpm), internal anterior chamber depth (IACD) and the length from corneal endothelium to retina (ER) were evaluated before and after surgery over a 6-month period.ResultsBoth the FS-LASIK and SMILE groups (closely matched at the pre-surgery stage) experienced flatter Kpm, shallower IACD and decreased ER 1 week post-surgery (P < 0.01), and these changes were larger in FS-LASIK than in SMILE group. During the 1 week to 6 months follow up period, Kpm, IACD and ER remained stable unlike CCT which increased significantly (P < 0.05), more in the FS-LASIK group.ConclusionsDuring the follow up, the posterior corneal surface became flatter and shifted posteriorly, the anterior chamber depth and the length from the corneal endothelium to retina decreased significantly compared with the pre-surgery stage. These unintended changes in ocular biometric parameters were greater in patients undergoing FS-LASIK than SMILE. The changes present clear challenges for IOL power calculations and should be considered to avoid affecting the outcome of cataract surgery.

scholarly journals Biometric changes after vitrectomy with silicone oil tamponade

2021 ◽  
Vol 2 (2) ◽  
pp. 56-62
Author(s):  
Simin Hosseini ◽  
Amir Faramarzi ◽  
Siamak Moradian ◽  
Mehdi Yaseri
Keyword(s):  
Silicone Oil ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Biometric Data ◽  
Cavity Depth ◽  
Time Points ◽  
Biometric Parameters ◽  
Before And After ◽  
Silicone Oil Tamponade

Background: The Lenstar LS 900 (Haag-Streit AG, Koeniz, Switzerland) is an optical biometer, and its measurements are highly repeatable and precise in cataractous eyes. This study investigated changes in biometric parameters, including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), vitreous cavity depth (VD), and central corneal thickness (CCT) before and after three-port 23-Gauge pars plana vitrectomy with silicone oil tamponade. Methods: This was a prospective follow-up study. Patients who were scheduled for surgery underwent a detailed slit-lamp examination and objective cycloplegic refraction preoperatively. In eligible cases, the Lenstar LS 900 was used to measure biometric parameters. At the 1-month postoperative follow-up, we repeated the same assessments for the silicone oil (SO)-filled eyes. Data were analyzed to assess the significance of changes and to test the possible correlation of values between the two time points. Results: Twenty-three patients with a mean ± SD age of 60 ± 12 years completed the study. Postoperatively, we found a significant increase in AL and a decrease in ACD and CCT (all P < 0.05), with no significant changes in LT and VD. A significant correlation was found for ACD, CCT, and cylinder values between the two time points (all P < 0.05). Postoperatively, the spherical and cylindrical components of refraction demonstrated a hyperopic shift, but did not change statistically significantly. Conclusions: The Lenstar LS 900 underestimated the ACD and overestimated the AL in SO-filled eyes when comparing pre- and postoperative values, in phakic as well as pseudophakic eyes. In planning for cataract surgery in this group of patients, it is more reasonable to calculate IOL power based on the biometric data of the fellow eye, although this may not eliminate possible errors. Further studies with a larger sample size, longer follow-up, and robust study design are necessary to confirm our preliminary results.

scholarly journals Refractive Stability and Ocular Biometric Changes After Customized LASEK for Correction of Myopia; 8 Years Follow up

2020 ◽  
Author(s):  
Seyed Javad Hashemian ◽  
Acieh Es'haghi ◽  
Hossein Aghaei ◽  
Leila Ghiasian ◽  
Mohammad Ebrahim Jafari ◽  
...  
Keyword(s):  
Cohort Study ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Spherical Equivalent ◽  
Biometric Data ◽  
Biometric Parameters ◽  
Refractive Outcomes

Abstract BACKGROUND: To assess long-term Visual and refractive stability and ocular biometric changes in low to moderate myopic subjects treated by customized LASEK. METHODS: Seventy eyes of 35 patients were treated by customized LASEK for correction of less than 6 diopter myopia in this cohort study. Uncorrected visual acuities (UCVA) and distance corrected visual acuities (DCVA), keratometry values and ocular biometric data by Lenstar LS900 including anterior chamber depth (ACD), aqueous depth, central corneal thickness(CCT),lens thickness(LT) and axial length(AL) were evaluated pre and 8 years postoperatively. RESULTS: Mean pre-operative spherical equivalent was -3.99 ±1.38 diopter (D) that improved to 0.01 ±0.27 D and -0.10 ±0.31 D, 6 months and 8 years postoperative respectively. Mean pachymetry, flat, steep and mean keratometry values increased significantly from 6 months to 8 years postoperative. Although, these changes had no significant effect on visual outcomes and subjective refraction. ACD decreased and LT increased significantly over 8 years follow-up in comparison with preoperative values. The change in AL was not significant at 8 years follow up.CONCLUSIONS: The long-term visual and refractive outcomes of customized LASEK in correction of low to moderate myopia were stable and predictable, although changes in ocular biometric parameters have occurred.

The effect of mydriasis on moderate-to-high myopic eyes with implantable collamer lenses V4 and V4c

2019 ◽  
Vol 30 (3) ◽  
pp. 462-468 ◽  
Author(s):  
Yi Zhu ◽  
Jing Zhang ◽  
Haobin Zhu ◽  
Jili Chen ◽  
Jibo Zhou
Keyword(s):  
Observational Study ◽  
Anterior Chamber ◽  
Corneal Endothelium ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Central Hole ◽  
Pressure Equilibrium ◽  
Before And After ◽  
Icl V4c

Purpose:To evaluate the vault change and anterior segment movement induced by mydriasis in moderate-to-high myopic eyes with implantable collamer lenses (ICL).Setting:Shanghai, ChinaDesign:A prospective consecutive observational study.Methods:A total of 45 eyes of 24 patients with ICL V4 implantation and 128 eyes of 65 patients with ICL V4c implantation were included and analyzed. Anterior chamber depth, posterior corneal endothelium-to-ICL distance, and vault before and after mydriasis were measured by Pentacam (Oculus, Wetzlar, Germany) at 1, 3, and 6 months after surgery.Results:Significant vault increases and anterior chamber depth increases induced by mydriasis were noted in both ICL V4 and V4c groups at 1, 3, and 6 months postoperatively. The corneal endothelium-ICL distance increased significantly in eyes with implanted ICL V4c after mydriasis at 3 and 6 months. Moreover, mydriasis-induced vault increases were greater in the ICL V4 group than in the ICL V4c group at 3 and 6 months. In eyes with implanted ICL V4c, mydriasis-induced vault increases were significantly greater at 1 month than at 3 and 6 months.Conclusion:Mydriasis results in a general vault increase in eyes with implanted ICLs. The adjustment of the pressure equilibrium via the central hole of the ICL V4c has an important role in vault change. The mydriasis-induced vault increases tend toward stability after 3 months postoperatively. Mydriasis is relatively safe in eyes with ICL implantation.

Evaluation of biometric parameters in phacomorphic glaucoma and mature cataracts

2020 ◽  
pp. 112067212091453
Author(s):  
Ali Keleş ◽  
Emine Şen ◽  
Ufuk Elgin
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Odds Ratio ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Mature Cataract ◽  
Biometric Parameters ◽  
Significant Difference ◽  
The Mean

Purpose: The aims of this study were to compare the biometric parameters and axial lengths of eyes with phacomorphic glaucoma and mature cataract and to identify differences that might predispose to development of phacomorphic glaucoma. Methods: Three hundred forty-two patients were enrolled in this retrospective study. The eyes were divided into four groups—Group (G)1: phacomorphic glaucoma ( n = 29), G2: mature cataract ( n = 313), G3: contralateral phacomorphic glaucoma ( n = 29), and G4: contralateral mature cataract ( n = 313). Central corneal thickness and anterior chamber depth were assessed by optical low-coherence reflectometry (Lenstar LS 900®; Haag-Streit AG, Switzerland), while axial length was determined by A-scan ultrasound biometry. Results: The mean central corneal thickness of G1 was significantly higher than in other groups ( p < 0.001) and the mean anterior chamber depth of G1 was the lowest among the groups ( p < 0.001). Also, G2 had lower mean anterior chamber depth than G4 ( p < 0.001) and G3 had lower mean anterior chamber depth than G4 ( p = 0.007). Anterior chamber depth less than 3.27 mm had the higher odds ratio for distinguishing G3 versus G4 (odds ratio = 10.79, p < 0.001). Furthermore, patients aged ⩾68.9 years had the higher odds ratio for distinguishing G1 versus G2 (odds ratio = 2.82, p = 0.019). There was no significant difference in the presence of pseudoexfoliation material between G1 and G2 ( p = 0.057). There were no significant differences in axial length values among the four groups ( p = 0.097). Conclusion: Advanced age and shallow anterior chamber depth were found to be risk factors for developing phacomorphic glaucoma, but the presence of pseudoexfoliation material was not found to play a role as a risk factor in phacomorphic glaucoma development.

scholarly journals Distribution of ocular biometric parameters and optimal model of anterior chamber depth regression in 28,709 adult cataract patients in China using swept‐source optical biometry

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qiong Lei ◽  
Haixia Tu ◽  
Xi Feng ◽  
Julio Ortega-Usobiaga ◽  
Danmin Cao ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Anterior Chamber ◽  
Multivariate Regression ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Multivariate Regression Analysis ◽  
Swept Source ◽  
Biometric Parameters ◽  
The Mean ◽  
Cataract Patients

Abstract Background The purpose of this study was to evaluate the ocular biometric parameters in adult cataract patients from China and create an anterior chamber depth (ACD) regression model. Methods The ocular biometric records of 28,709 right eyes of cataract surgery candidates who were treated at Aier Eye Hospitals in nine cities from 2018 to 2019 were retrospectively analyzed. All measurements were taken with IOLMaster 700. We included patients who were at least 40 years old and were diagnosed with cataract. Results The mean age of the patients was 68.6 ± 11.0 years. The mean values recorded were as follows: axial length (AL), 24.17 ± 2.47 mm; mean keratometry (Km) value, 44.26 ± 1.70 D; corneal astigmatism (CA), 1.06 ± 0.96 D; ACD, 3.02 ± 0.45 mm; lens thickness (LT), 4.52 ± 0.45 mm; central corneal thickness (CCT), 0.534 ± 0.04 mm; and white to white (WTW) corneal diameter, 11.64 ± 0.46 mm. ACD correlated positively with AL (Spearman coefficient, 0.544) and WTW (0.300), but negatively with LT (-0.660) and age (-0.285) (all P < 0.01). In the multivariate regression analysis of ACD, which included LT, AL, WTW, sex, Km, CCT, and age, there was a reasonable prediction with adjusted R2 = 0.641. Conclusions Cataract patients with longer AL and wider WTW have deeper ACD. With increasing age and lens thickening ACD becomes shallower. Based on the standardized coefficients of ACD multivariate regression analysis from the study, LT is the main factor that affects ACD, and is followed by AL.

scholarly journals The Effects of Ramadan Fasting on Anterior Segment Parameters, Visual Acuity and Intraocular Pressures of the Eye

2017 ◽  
Vol 11 (1) ◽  
pp. 152-155 ◽  
Author(s):  
Ozlem Barut Selver ◽  
Melis Palamar ◽  
Kevser Gerceker ◽  
Sait Egrilmez ◽  
Ayse Yagci
Keyword(s):  
Visual Acuity ◽  
Anterior Chamber ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Ophthalmological Examination ◽  
Significant Difference ◽  
Before And After ◽  
Group 2 ◽  
Group 1

Objective: It is aimed to determine whether fasting during Ramadan has any significant effect on anterior chamber parameters, visual acuity and intraocular pressures. Methods: 31 fasting (Group 1) and 30 non-fasting healthy volunteers (Group 2) were enrolled. All cases underwent an ophthalmological examination and anterior segment parameter evaluation (central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), pupil size) with Pentacam before and after the breaking of the Ramadan fast in Group 1, before and after dinner in Group 2. Results: The mean age was 43.35 ± 13.20 in Group 1, 43.17 ± 12.90 in Group 2 (p= 0.955). No significant difference was detected in any of the parameters in both groups. Conclusion: There is a need for more detailed and associated studies to understand better about the influence of Ramadan fast on various ocular parameters.

scholarly journals The Effect of Pharmacological Dilation on Calculation of Targeted and Ideal IOL Power Using Multivariable Formulas

2019 ◽  
Author(s):  
Noah C Simon ◽  
Asim V. Farooq ◽  
Michael H. Zhang ◽  
Kamran M. Riaz
Keyword(s):  
Pupil Diameter ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Calculation Methods ◽  
Biometric Parameters ◽  
Higher Power ◽  
Before And After ◽  
Dioptric Power ◽  
Iol Power ◽  
Phakic Eyes

Abstract Background/Aims To examine the effect of pharmacologic dilation on biometric parameters measured by the Lenstar LS 900, and whether these changes affect the power of the calculated intraocular lens (IOL) using multivariable formulas in an undilated versus pharmacologically dilated state. Methods Prospective study of 98 phakic eyes from 53 patients. Axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), and keratometry (K) readings were measured. The first set of measurements was taken prior to dilation. After dilation (pupil diameter ≥6.0mm), a second set of measurements was taken. The Barrett, Olsen, Hill-RBF, Haigis, SRK/T, and Holladay I formulas were used to calculate IOL power before and after dilation. Two calculation methods were used: Method A used a commonly available IOL targeted to achieve the lowest myopic spheroequivalent residual refraction (LMP); Method B calculated ideal IOL power for emmetropia (IPE). Results Statistically significant increases were seen in CCT (p<0.01), ACD (p<0.01), and AL (p<0.01) whereas a statistically significant decrease was seen in LT (p<0.01) post dilation. Using Method A, the percentage of eyes which would have received an IOL with 0.5 D or 1.0 D of higher power, if post-dilation measurements were used, were 25.5%, 30.6%, 20.4% and 23.5% for Barrett, Olsen, Hill-RBF and Haigis, respectively. Using Method B, only Haigis and Olsen had a statistically significant increase in ideal IOL power. Conclusions Pharmacologic dilation can be associated with an increase in non-custom IOL dioptric power when using multivariable formulas, which may lead to a myopic surprise.

scholarly journals Four-year observation of the changes in corneal endothelium cell density and the correlated factors after Implantable Collamer Lens V4c implantation

2020 ◽  
pp. bjophthalmol-2020-316144
Author(s):  
Wen Yang ◽  
Jing Zhao ◽  
Ling Sun ◽  
Jiao Zhao ◽  
Lingling Niu ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Anterior Chamber ◽  
Cell Density ◽  
Corneal Endothelium ◽  
Anterior Chamber Depth ◽  
Implantable Collamer Lens ◽  
Distance Visual Acuity ◽  
Icl V4c ◽  
Correlated Factors

BackgroundTo evaluate the changes in corneal endothelium cell density (ECD) and the correlated factors after Implantable Collamer Lens (ICL) V4c implantation.MethodsIn this retrospective, consecutive study, 48 eyes of 25 patients with myopia who underwent ICL V4c implantation were enrolled. Patients were followed up for at least 4 years, during which manifest refraction, uncorrected distance visual acuity, corrected distance visual acuity (CDVA), intraocular pressure, ECD, anterior chamber depth, anterior chamber volume (ACV), anterior chamber angle (ACA), vault and distance from the corneal endothelium to the central ICL (C-ICL) were measured. Spearman’s correlation analysis was used to identify variables correlated with changes in ECD, and generalised estimating equation model adjusting within-patient intereye correlations was used to predict changes in ECD.ResultsAll surgeries were performed safely with no complications during follow-up (average 52±2.9 months). Safety and efficacy indices were 1.23±0.22 and 1.04±0.16, respectively. No eyes had decreased CDVA, and 67% gained one or more lines. Further, 79% were within ±0.50 D, and 100% were within ±1.0 D of the attempted refraction. Additionally, a 4.03%±2.2% reduction in ECD compared with the preoperative value was observed at the last follow-up visit. Changes in ECD were significantly correlated with vault, C-ICL, change in ACA and change in ACV. Vault was the most significant factor for changes in ECD.ConclusionsICL V4c implantation is safe and effective for myopia correction. Anterior segment biometric parameters including the vault, ACA and C-ICL may influence changes in ECD; specifically, the vault plays a major role.

Evaluation of ocular biometric parameters in keratoconic eyes relative to healthy myopic eyes

2021 ◽  
pp. 112067212110644
Author(s):  
Ayşe Yağmur Kanra ◽  
Haşim Uslu
Keyword(s):  
Anterior Chamber ◽  
Statistical Method ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Posterior Segment ◽  
Biometric Parameters ◽  
Lens Thickness ◽  
Biometric Features

Objective To assess the biometric features of keratoconic eyes using the Lenstar LS900 and Pentacam systems relative to healthy myopic eyes. Materials and Methods Seventy-three eyes of keratoconic subjects and 83 eyes of control subjects were enrolled. To evaluate the reproducibility of the Lenstar and Pentacam devices’ measurements, keratometric readings [in flattest meridian (Kf), in steepest meridian (Ks), and mean (Km)], central corneal thickness (CCT), and anterior chamber depth (ACD) were obtained using both systems. Axial length and lens thickness (LT) were measured by the Lenstar. The compatibility between the two devices was investigated using the Bland-Altman statistical method. Results Axial length was longer in the myopic group than in eyes with keratoconus (24.94  ±  0.7 and 23.88  ±  0.96 mm, respectively, p  <  0.001). LT and vitreous depth were also higher in the myopic group, although ACD values were similar. Compared to the Lenstar, the Pentacam measured the ACD and CCT values higher in the myopia group [with a difference of 0.07  ±  0.12 mm ( p <0.001) and 4.47  ±  11.33 µm ( p   =   0.001), respectively] and measured the CCT values higher in the keratoconus group. Pentacam found all keratometry values significantly lower than Lenstar in the keratoconus group. Conclusions Axial length was longer in the myopic eyes due to the differences starting from the lens and extending to the posterior segment. Lenstar and Pentacam can be used interchangeably for Km, Kf, and ACD in the myopic group and only for ACD in the keratoconus group.

scholarly journals Predictive factors of the accelerated transepithelial corneal cross-linking outcomes in keratoconus

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Mi Tian ◽  
Weijun Jian ◽  
Xiaoyu Zhang ◽  
Ling Sun ◽  
Yang Shen ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Cross Linking ◽  
Radius Of Curvature ◽  
Chamber Volume ◽  
Anterior Chamber Volume ◽  
Time Point

Abstract Background This study aimed to evaluate the clinical outcomes and assess preoperative characteristics that may predict outcomes in keratoconus 1 year after accelerated transepithelial corneal cross-linking (ATE-CXL). Methods This prospective study included 93 eyes of 84 consecutive keratoconus patients with 1-year follow-up after ATE-CXL. Preoperative characteristics included corneal astigmatism, anterior chamber depth, anterior chamber volume, radius of curvature, posterior elevation, central corneal thickness (CCT), thinnest corneal thickness, steepest meridian keratometry, flattest meridian keratometry, and the maximum keratometry (Kmax). Data were obtained preoperatively and at 1, 3, 6, and 12 months postoperatively. The patient eyes were grouped into 3 subgroups according to CCT and Kmax values to observe the changes of keratoconus progression. Results All patients were successfully operated without complications at any follow-up time point. Mean changes of Kmax from baseline at 6 and 12 months were − 0.60 ± 2.21 D (P = 0.011) and − 0.36 ± 1.58 D (P = 0.030), respectively. Eyes with a thinner CCT and higher Kmax values exhibited a tendency for topographic flattening of ≥1.0 D (P = 0.003; P = 0.003). In the subgroup comparison, the Kmax values decreased significantly at 6 and 12 months after ATE-CXL in the group with CCT ≤ 450 μm (P = 0.018 and P = 0.045); the Kmax values of the group with Kmax > 65.0 D decreased significantly at 6 months postoperatively (P = 0.025). Conclusion ATE-CXL is a safe and effective treatment for keratoconus patients. Patients with thinner CCT and higher Kmax values are more likely to benefit from ATE-CXL.

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