Accuracy of biometric formulae in hypermetropic patients undergoing cataract surgery

2018 ◽  
Vol 29 (5) ◽  
pp. 510-515
Author(s):  
Mohammad Z Mustafa ◽  
Ashraf A Khan ◽  
Harry Bennett ◽  
Andrew J Tatham ◽  
Mark Wright
Keyword(s):  
Cataract Surgery ◽  
Anterior Chamber ◽  
Axial Length ◽  
Mean Absolute Error ◽  
Anterior Chamber Depth ◽  
Absolute Error ◽  
University Hospital ◽  
Prediction Errors ◽  
Refractive Outcomes ◽  
Significant Difference

Purpose: To audit and analyse the accuracy of current biometric formulae on refractive outcomes following cataract surgery in patients with axial length less than 22 mm. Methods: A total of 84 eyes from 84 patients with axial length <22 mm were identified from consecutive patients undergoing cataract surgery retrospectively at a single university hospital. All subjects had biometry using the IOLMaster (Carl Zeiss Meditec, Inc, Dublin, CA, USA) and a Sensar AR40 intraocular lens implant (Abbott Medical Optics, CA, USA). One eye from each patient was randomly selected for inclusion. Prediction errors were calculated by comparing expected refraction from optimized formulas (SRK/T, Hoffer Q, Haigis and Holladay 1) to postoperative refraction. A national survey of ophthalmologists was conducted to ascertain biometric formula preference for small eyes. Results: The mean axial length was 21.00 ± 0.55 mm. Mean error was greatest for Hoffer Q at −0.57 dioptres. There was no significant difference in mean absolute error between formulae. SRK/T achieved the highest percentage of outcomes within 0.5 dioptres (45.2%) and 1 dioptre (76.2%) of target. Shallower anterior chamber depth was associated with higher mean absolute error for SRK/T (p = 0.028), Hoffer Q (p = 0.003) and Haigis (p = 0.016) but not Holladay (p = 0.111). Conclusion: SRK/T had the highest proportion of patients achieving refractive results close to predicted outcomes. However, there was a significant association between a shallower anterior chamber depth and higher mean absolute error for all formulae except Holladay 1. This suggests that anterior chamber depth with axial length should be considered when counselling patients about refractive outcome.

scholarly journals Evaluation of Anterior Chamber Depth in 28,709 Adult Cataract Patients in China using Swept-Source Optical Biometry

2021 ◽  
Author(s):  
Qiong Lei ◽  
Haixia Tu ◽  
Xi Feng ◽  
Yong Wang
Keyword(s):  
Cataract Surgery ◽  
Anterior Chamber ◽  
Axial Length ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Multivariate Regression Analysis ◽  
Swept Source ◽  
Mean Values ◽  
The Mean ◽  
Cataract Patients

Abstract Background: To create an anterior chamber depth (ACD) regression model for adult cataract surgery candidates from China, and to evaluate the distribution of their ocular biometric parameters.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, 44.09 ± 3.25 D; corneal astigmatism (CA), 1.06 ± 0.98 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. The proportion of patients with long axial length (AL >25 mm) decreased with age. ACD, LT, AL, Km, WTW, and age were correlated. 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 = 0.629.Conclusions: The results show that high myopes are inclined to schedule cataract surgery at a younger age. LT and AL were found to be important factors that affect ACD. This study provides reference data for cataract patients from China.

scholarly journals Evaluation of Anterior Segment’s Structures in Tilted Disc Syndrome

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Ercan Ozsoy ◽  
Abuzer Gunduz ◽  
Ersin Ersan Demirel ◽  
Tongabay Cumurcu
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Control Group ◽  
Tilted Disc Syndrome ◽  
Chamber Volume ◽  
Significant Difference ◽  
Tilted Disc

Purpose. To evaluate anterior segment’s structures by Pentacam in patients with tilted disc syndrome (TDS).Methods. Group 1 included forty-six eyes of forty-six patients who have the TDS. Group 2 including forty-six eyes of forty-six cases was the control group which was equal to the study group in age, gender, and refraction. A complete ophthalmic examination was performed in both groups. All cases were evaluated by Pentacam. The axial length (AL) of eyes was measured by ultrasound. Quantitative data obtained from these measurements were compared between two groups.Results. There was no statistically significant difference for age, gender, axial length, and spherical equivalent measurements between two groups (p=0.625,p=0.830,p=0.234, andp=0.850). There was a statistically significant difference for central corneal thickness (CCT), corneal volume (CV), anterior chamber angle (ACA), and pupil size measurements between two groups (p=0.001,p=0.0001,p=0.003, andp=0.001). Also, there was no statistically significant difference for anterior chamber depth (ACD), anterior chamber volume (ACV), and lens thickness (LT) measurements between two groups (p=0.130,p=0.910, andp=0.057).Conclusion. We determined that CCT was thinner, CV was less, and ACA was narrower in patients with TDS. There are some changes in the anterior segment of the eyes with tilted disc.

scholarly journals Influence of anterior chamber depth on postoperative refractive outcome in Chinese eyes

2018 ◽  
Vol 16 (2) ◽  
pp. 79-85
Author(s):  
Rachel SH Wong ◽  
Keith Ong
Keyword(s):  
Cataract Surgery ◽  
Anterior Chamber ◽  
Anterior Chamber Depth ◽  
Demographic Variables ◽  
Refractive Outcomes ◽  
Positive Linear Correlation ◽  
The Mean ◽  
The Difference ◽  
Linear Correlations ◽  
Refractive Surprise

Aim or Purpose: This study aims to evaluate the refractive surprise (RS) after cataract surgery with various intraocular lens (IOL) formulas in eyes with very shallow or deep anterior chamber depth (ACD). Design: This is a prospective cohort study of patients from a private ophthalmology practice in Sydney. Methods: Thirty-one patients who had their cataract surgery in 2014 were included. The cohort consists of 20 eyes with ACD < 2.8 mm and 25 eyes with ACD > 3.2 mm. Patients’ demographic variables and their predicted refractive outcomes using the SRK-T, Haigis, Holladay 1, and Holladay 2 IOL formulas were collected. Actual refractive outcomes were obtained from consultations at least one-month postoperatively. RS was calculated from the difference between predicted refraction outcome of IOL formulas and the actual postoperative refraction achieved. Results: The linear correlations between ACD and RS were not significant (p > 0.05). In the group with ACD < 2.8 mm, the mean refractive surprise using SRK-T, Haigis, Holladay 1, and Holladay 2 formulas were -0.191 ± 0.541, -0.189 ± 0.444, -0.201 ± 0.449, and -0.154 ± 0.489 D, respectively. In the group with ACD > 3.2 mm, the mean refractive surprise using the IOL formulas were -1.364 ± 0.541, -1.420 ± 0.541, 0.027 ± 0.394, and -0.045 ± 0.343 D, respectively.  Conclusion: The positive linear correlation between ACD and RS was weak. In eyes with ACD < 2.8 mm, the least RS was found with the Holladay 2 formula, while in eyes with ACD > 3.2 mm, this was found with Holladay 1.

scholarly journals Progress in Modern Cataract Surgery – New Steps and Algorithms for Precise Measuring and Intraocular-lens Calculations

2017 ◽  
Vol 11 (02) ◽  
pp. 95
Author(s):  
Fritz H Hengerer ◽  
Gerd U Auffarth ◽  
Ina Conrad-Hengerer ◽  
◽  
◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Anterior Chamber ◽  
Intraocular Lens ◽  
Axial Length ◽  
Refractive Surgery ◽  
Anterior Chamber Depth ◽  
Corneal Surface ◽  
Intraocular Lens Calculations ◽  
Target Refraction ◽  
Intraocular Lens Calculation

In standard cataract surgery, one of the major goals is to reach target refraction. Based on keratometry measurements, axial length and anterior chamber depth, most of the intraocular lens calculation formulae are suitable to achieve this aim. Further evaluation of corneal refractive parameters like anterior and posterior corneal surface by Scheimpflug devices led to a significant enhancement of precision in astigmatic and post-refractive surgery cases.

Comparison of Axial Length and Anterior Chamber Depth Measurement among Optical, Applanation and Immersion Biometry

2019 ◽  
Vol 11 (1) ◽  
pp. 59-64
Author(s):  
Harun Ur Rashid ◽  
AQM Omar Sharif ◽  
Zinat Rehana Shipu ◽  
Debashish Ghosh ◽  
Sofia Akhter ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Anterior Chamber ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
Power Calculation ◽  
Strong Positive Correlation ◽  
Care Hospital ◽  
Optical Biometry ◽  
Depth Measurement ◽  
The Mean

Background: Precise biometry is one of the major key factors for obtaining desired refractive outcome after cataract surgery. Visual outcome strongly depends on accuracy of ocular parameters especially axial length (AL) and anterior chamber depth (ACD). It is very important to evaluate different biometry methods to have accurate measurements for IOL power calculation. Objective: The aim of the study is to compare and analyze the difference between the measurement of axial length (AL) and anterior chamber depth (ACD) using ultrasound applanation, immersion and optical biometry. Methodology: A prospective study conducted on 168 patients enrolled for cataract surgery from January 2018 to December 2018 in Dhaka Eye Care Hospital, Dhaka. 280 eyes have been tested by a single observer. Axial length (AL) and anterior chamber depth (ACD) was measured consecutively by optical, applanation and immersion biometry. The results have been statistically evaluated to establish efficacy and correlation among the three methods of biometry. Results: Statistical analysis showed the mean of axial length (AL) obtained from optical biometry is 23.36 ± 1.99 mm, which is 0.10mm (p=0.00) less by applanation biometry and 0.04 mm (p=0.00) less by immersion biometry. For anterior chamber depth (ACD), the mean value from optical biometry is 3.13 ± 0.47mm. This value is highest in compare to both applanation (0.002 mm less with p = 0.824) and immersion (0.04 mm less with p = 0.00) biometry. Further analysis reveals strong correlation of optical biometry with applanation biometry (r = 0.994 for AL and 0.945 for ACD) and immersion biometry (r = 0.995 for AL and 0.947 for ACD). Conclusion: The study reveals that among optical, applanation and immersion method the optical biometry method appeared to be the most precise way of measuring axial length (AL) and anterior chamber depth (ACD) of eye. The study also shows an excellent agreement and strong positive correlation of optical biometry with applanation and immersion biometry. J Shaheed Suhrawardy Med Coll, June 2019, Vol.11(1); 59-64

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 Assessment of anterior chamber angle changes after phacoemulsification with swept-source OCT

2021 ◽  
Vol 14 (10) ◽  
pp. 1527-1532
Author(s):  
Qian Zheng ◽  
◽  
Zhang-Liang Li ◽  
Ping-Jun Chang ◽  
Yun-E Zhao ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Cataract Surgery ◽  
Anterior Chamber ◽  
Anterior Chamber Depth ◽  
Anterior Chamber Angle ◽  
Swept Source ◽  
Narrow Angle ◽  
Significant Difference ◽  
Shallow Anterior Chamber ◽  
Chamber Angle

AIM: To assess the changes of anterior chamber angle in patients with shallow anterior chamber after phacoemulsification combined with intraocular lens (IOL) implantation, based on anterior segment swept-source optical coherence tomography (AS-SS-OCT) measurements. METHODS: This was a prospective case control study; sixty eyes of sixty case were scheduled for cataract surgery with normal intraocular pressure (IOP). Based on anterior chamber depth (ACD) and gonioscopy findings, the eyes were divided into two groups: group of shallow anterior chamber and narrow angle (SAC group, 30 eyes); and group of normal anterior chamber group with wide angle (NAC group, 30 eyes). Measurements of ACD, anterior chamber volume (ACV), iris volume (IV), lens vault (LV), angle opening distance (AOD), angle recess area (ARA), trabecular iris space area (TISA), and trabecular iris angle (TIA) were conducted in each group before and 3mo after surgery. RESULTS: There was no significant difference in age, axial length (AL), corneal curvature, corneal diameter, intraocular pressure, and IV between two groups before surgery, except for the LV (P=0.000). ACD and ACV were prominently larger in the NAC group than the SAC group 3mo after operation (3.69±0.38 vs 3.85±0.39 mm, P=0.025; 161.37±19.47 vs 178.26±20.30 mm3, P=0.002). AOD750, ARA750 in nasal and inferior quadrants, TISA750 in all quadrants except temporal, and TIA750 in all quadrants in SAC group were significantly smaller than those in NAC group after operation (all P<0.05). CONCLUSION: Cataract surgery can deepen anterior chamber and increase the width of anterior chamber angle in Chinese subjects, but the angle related parameters including AOD750, ARA750, TISA750, TIA, TISA750, and ACV in patients with shallow anterior chamber and narrow angle do not reach the normal level.

scholarly journals Presbyopia and its anatomical and physiological variants

1970 ◽  
Vol 3 (2) ◽  
pp. 155-158
Author(s):  
M Gupta ◽  
RR Sukul ◽  
Y Gupta ◽  
M Dey ◽  
A Phougat ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Physiological Parameters ◽  
Corneal Curvature ◽  
Lens Thickness ◽  
Significant Difference ◽  
The Mean

Aim: To study the various ocular anatomical and physiological parameters in presbyopia. Materials and methods: We studied the various ocular anatomical and physiological parameters like corneal curvature (keratometry readings: K1 and K2), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and axial length (AL) in 100 presbyopic patients between 35 - 55 years of age. The patients were divided into two age groups: I (35 – 44 years) and II (45-55 yrs). ACD, AL and LT were measured using an Ascan. CCT was measured with ultrasonic pachymetry. Results: The CCT decreased (BE), LT increased and ACD decreased (RE) significantly with increasing age (p < 0.05). There was no significant difference in males and females. Nearly 3/4th of the total increase in lens thickness was responsible for the decrease in the anterior chamber depth and the rest, 1/4th , goes posteriorly. Corneal curvature and AL showed no significant change with age. Conclusions: The mean of CCT decreased significantly with advancing age. As age increased, the mean value of lens thickness increased and anterior chamber depth decreased. Nearly 3/ 4th of total increase in LT was anteriorly, decreasing the ACD. Corneal curvature and AL has no relation with age. Key words: Presbyopia, central corneal thickness, anterior chamber depth, lens thickness, axial length DOI: http://dx.doi.org/10.3126/nepjoph.v3i2.5269 Nepal J Ophthalmol 2011; 3(2): 155-158

scholarly journals Accuracy of Intraocular Lens Power Calculation Using Anterior Chamber Depth from Two Devices with Barrett Universal II Formula

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Hannah Muniz Castro ◽  
Audrey X. Tai ◽  
Samuel J. Sampson ◽  
Matthew Wade ◽  
Marjan Farid ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Anterior Chamber Depth ◽  
Absolute Error ◽  
Power Calculation ◽  
Intraocular Lens Power Calculation ◽  
Iol Power Calculation ◽  
Significant Difference ◽  
Iol Power ◽  
Retrospective Comparative Study ◽  
Lens Power

Purpose. To compare the preoperative measurements of the anterior chamber depth (ACD) by the IOLMaster and Catalys; additionally, to compare the accuracy of the IOL power calculated by the Barrett Universal II formula using the two different measurements. Setting. University of California, Irvine, Gavin Herbert Eye Institute in Irvine, California. Design. Retrospective comparative study. Methods. This study included 144 eyes of 90 patients with a mean age of 72.0 years (range 40.8 to 92.1 years) that underwent femtosecond laser-assisted cataract surgery using Catalys. Preoperative measurements of ACD were taken by the IOLMaster and Catalys. Manifest refraction and refractive spherical equivalent were measured 1 month postoperatively. Expected refractive results were compared with actual postoperative refractive results. Results. The correlation between the ACD values from the two devices was good (r = 0.80). The Catalys ACD measurements yielded a larger ACD compared to the IOLMaster, with a mean difference of 0.22 mm (P<0.0001). The correlation between the postoperative and predicted RSE of the implanted IOL power was excellent (r = 0.96). There was no statistically significant difference between the mean absolute error derived from the IOLMaster, 0.37 diopter (D) ± 0.34 (SD), and the Catalys, 0.37 ± 0.35 D (P=0.50). Conclusions. The Catalys biometry yielded a significantly larger ACD value than the IOLMaster. This difference in ACD value, however, did not reflect in a statistically significant difference in IOL power calculation and refractive prediction error using the Barrett Universal II Formula.

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