A comparison of different methods to calculate the axial length measured by optical biometry.

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Giacomo Savini ◽  
Kenneth J Hoffer ◽  
Laura Carballo ◽  
Leonardo Taroni ◽  
Domenico Schiano-Lomoriello
Keyword(s):  
Axial Length ◽  
Optical Biometry

scholarly journals OPTICAL BIOMETRY OF THE EYE: THE PRINCIPLE AND THE DIAGNOSTIC POTENTIAL OF THE METHOD

2017 ◽  
Vol 12 (1) ◽  
pp. 35-42
Author(s):  
T. N Kiseleva ◽  
O. G Oganesyan ◽  
L. I Romanova ◽  
S. V Milash ◽  
A. V Penkina
Keyword(s):  
Comparative Analysis ◽  
Anterior Chamber ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
Laser Interferometry ◽  
Basic Principles ◽  
Optical Biometry ◽  
Advantages And Disadvantages ◽  
Diagnostic Potential ◽  
Corneal Diameter

Optical biometry is based on the laser interferometry technique for the measurement of the biometric characteristics of the eyes, such as the antero-posterior axial length, anterior chamber depth, lens and retina thickness, corneal diameter and parameters of keratometry. The present article was designed to overview the basic principles of this method, its advantages and disadvantages, indications and contraindications for its application. The comparative analysis of the characteristics of the following optical biometric devices was undertaken: IOL-Master 500, Lenstar LS 900, Aladdin, OA-1000, OA-2000, Al-3000, Al-Scan, Galilei G6, IOL-Master 700.

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

Optical Biometry Derived Axial Length Measurements Following Intravitreal Anti-Vascular Endothelial Growth Factor Treatment for Macular Edema

2017 ◽  
Vol 33 (4) ◽  
pp. 488-491 ◽  
Author(s):  
George D. Kymionis ◽  
Athanassios Giarmoukakis ◽  
Ioanna K. Apostolidi ◽  
Styliani V. Blazaki ◽  
Konstantinos I. Tsoulnaras ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Macular Edema ◽  
Axial Length ◽  
Vascular Endothelial ◽  
Optical Biometry ◽  
Length Measurements ◽  
Endothelial Growth Factor ◽  
Growth Factor Treatment

scholarly journals Comparison of biometric methods in young children with congenital cataracts in their eyes

2021 ◽  
Vol 16 (3) ◽  
pp. 11-18
Author(s):  
T. B Kruglova ◽  
Tatyana N. Kiseleva ◽  
L. A. Katargina ◽  
N. S. Egiyan ◽  
A. S. Mamykina ◽  
...  
Keyword(s):  
Young Children ◽  
General Anesthesia ◽  
Axial Length ◽  
Power Calculation ◽  
Congenital Cataracts ◽  
Optical Biometry ◽  
Iol Power Calculation ◽  
Length Difference ◽  
Iol Power

BACKGROUND: Relevant keratometric and biometric indicators are necessary for intraocular lens (IOL) power calculation, which is difficult to verify in young children. AIM: Evaluation of the accuracy of various ultrasound methods and optical biometry for axial length measurement in young children with congenital cataracts. MATERIAL AND METHODS: Forty-six children (74 eyes) with congenital cataracts (43 eyes) and pseudophakia (31 eyes) at the age of 6 months to 4 years were examined. Various methods measured the axial length: ultrasound A-scan under general anesthesia by US-4000, ultrasound B-scan without general anesthesia by Voluson E8, and optical biometry by AL-Scan in cases of transparent optics. RESULTS: The greater axial length difference was observed between A-scan and optical biometry (less by 0,78 mm) than between B-scan and optical biometry (more by 0,27 mm). The median axial length difference between A-scan and B-scan was equal for infants and young children with congenital cataracts (0,525 mm and 0,535 mm, respectively). CONCLUSION: Axial length should be measured by different methods in young children with their further comparison to obtaining more accurate biometric indicators for IOL power calculation. The decrease of 12 mm in axial length, which occurs during the A-scan, can lead to errors in the IOL calculation of 36 diopters and unplanned refraction in the long-term period.

scholarly journals Optical Biometry and Influence of Media Opacity Due to Cataract on Development of Axial Length in Pediatric Eyes

2021 ◽  
Author(s):  
Harsha Bhattacharjee ◽  
Suklengmung Buragohain ◽  
Henal Javeri ◽  
Saurabh Deshmukh
Keyword(s):  
Axial Length ◽  
Systemic Disease ◽  
Bilateral Cataract ◽  
Optical Biometry ◽  
Paediatric Outpatient ◽  
Group A ◽  
The Difference ◽  
Group B ◽  
Unilateral Cataract ◽  
Fellow Eyes

Abstract Aim: To study the influence of media opacity due to cataract on the development of axial length in paediatric eyes with the help of optical biometry.Method: In this prospective, observational study, all patients attending the paediatric outpatient department (OPD) of the institute underwent a comprehensive ocular and systemic evaluation. Patients suffering from any other ocular disease and systemic disease were excluded. Optical biometry was performed to measure the axial length in all the eyes. In each eye, five biometric measurements were acquired and average of these five readings were considered for the study. Patients were divided into three groups after proper age matching – 1. Group A (Bilateral cataract) 2. Group B (Unilateral cataract) 3. Group C (Bilateral normal). The axial length of the various groups were then compared. Results: A total of 540 eyes of 270 patients were involved in the study. 120 cases (n = 240 eyes) in Group A (bilateral cataract), 30 cases (n = 60 eyes) in Group B (unilateral cataract) and 120 (n = 240 eyes) in Group C (no cataracts). The mean age of the patients in all the groups was 9.38 ± 3.67 years (range: 1-17 years). In Group B, the difference in the AL between the cataractous eyes (22.44±1.48 mm; n = 30) and the fellow eyes (22.09±0.93 mm; n = 30) was not statistically significant (P = 0.277). The difference in the AL between the cataractous right eyes of Group A (22.9±3.51 mm, n = 120) and the non-cataractous right eye of Group C fellow eyes (22.57±0.71 mm, n = 120) was not statistically significant (P = 0.316). The difference in the AL between the cataractous left eyes of Group A (23.06±2.33 mm, n = 120) and the non-cataractous left eyes of Group C fellow eyes (22.56±0.78, n = 120) was statistically significant (P = 0.028). Conclusion: The results of our study and reported literature to date, seem to indicate a more significant role of genetic factors in comparison to media opacity, in the proportionate development of the AL.

scholarly journals Optical biometry features in silicon oil filled eyes

2018 ◽  
Vol 11 (3) ◽  
pp. 15-20
Author(s):  
Alexey N. Kulikov ◽  
Ekaterina V. Kokareva ◽  
Alexander R. Kuznetsov
Keyword(s):  
Surgical Treatment ◽  
Measurement Error ◽  
Axial Length ◽  
Silicone Oil ◽  
Iol Implantation ◽  
Optical Biometry ◽  
The Real ◽  
Anteroposterior Axis ◽  
Silicon Oil ◽  
Silicone Oil Tamponade

Background. The article presents results of axial length (AL) measurement in eyes filled with silicone oil and in those without silicone oil with IOLMaster and Lenstar LS 900 optical biometry methods. Materials and methods. The anteroposterior axis was measured in 27 eyes of 27 patients with silicone oil tamponade after surgical treatment of several vitreoretinal conditions. Using IOLMaster, the AL of eyes without silicone oil tamponade varied from 21.99 mm to 29.38 mm, Lenstar LS 900 biometry gave results from 21.96 mm to 29.41 mm. Results. According to data obtained and to their distribution, all cases were divided into 2 groups: I group — eyes with AL less than 23.63 mm, and II group — eyes with AL more than 23.63 mm. In the group II, the disparity of consecutive measurements was reliable and amounted to 0.28 ± 0.46 mm (р = 0.024) for IOLMaster and 0.23 ± 0.44 mm (р = 0.029) for Lenstar LS 900. Conclusion. So AL values at IOLMaster and Lenstar LS 900 biometry of silicone oil filled eyes may significantly overestimate the real ones when exceeding 23.63 mm. In case of simultaneous phacoemulsification with IOL implantation, this could lead to hypermetropic shift of postoperative refraction. Lenstar LS 900 measurement error in silicon oil filled eyes is less than that of IOLMaster, thus making the first biometry method preferable. In eyes with AL shorter than 23.63 mm, the measurement difference was not reliable, thus the biometry accuracy in silicone oil filled “short” eyes becomes higher.

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