Effective Ocular Biometry and Intraocular Lens Power Calculation

Turczynowska, Magdalena; Koźlik-Nowakowska, Katarzyna; Gaca-Wysocka, Magdalena; Grzybowski, Andrzej

doi:10.17925/eor.2016.10.02.94

Cited by 16 publications

(25 citation statements)

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“…Nejnovější technologií pro měření optické biometrie je tzv. swept source OCT (ss-OCT), kterou využívá IOLMaster 700 (Carl Zeiss Meditec, Jena, Německo) a ARGOS (Movu, Santa Clara, Kalifornie, USA) [5]. Přístroje pro optickou biometrii obsahují software, který dosadí změřené hodnoty do vzorců pro výpočet dioptrické hodnoty PC IOL.…”

Section: úVodunclassified

The Effect of Pharmacological Pupil Dilation on Intraocular Lens Power Calculation in Patients Indicated for Cataract Surgery

Autrata¹,

Chrapek²,

Drahorád³

2021

CSO

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Purpose: To evaluate the influence of pupil dilation on ocular parameters measured by optical biometry and the influence of pupil dilation on intraocular lens (PC IOL) power calculation by using the third-generation (SRK/T) and the fourth-generation (Haigis) formula. Methods: 40 eyes of patients indicated for cataract surgery were included in this study. Each patient was examined by optical biometer firstly without artificial mydriasis (AM) and then after AM, which was achieved using local application of short-term acting mydriatics. Biometric data were measured by Lenstar LS 900 optical biometer, we recorded axial length of the eye (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and corneal astigmatism and optical power of cornea. These data we measured were used for calculation of the PC IOL optical power using both the SRK/T and the Haigis formula. The target postoperative refraction was set to emmetropia. Statistical analysis was performed for evaluation of influence of AM on each ocular parameter and influence of AM on the recommended PC IOL power calculated by the SRK/T and the Haigis formula. Results: No statistically significant effect of AM on AL, LT and keratometry was demonstrated. On the contrary we demonstrated significant effect on CCT and ACD. No effect of AM on the PC IOL power calculation using the SRK/T formula was proved – the PC IOL optical power before AM and after AM did not differ in any case. When using the Haigis formula for the PC IOL power calculation, the recommended optical power of the PC IOL changed by +0.5 Dpt in 9 eyes, i.e., 22.5 % of the whole group, but statistical analysis did not show this change as statistically significant. Conclusion: Pharmacological dilation of the pupil significantly affects some intraocular parameters measured by optical biometer and in the case of using the Haigis formula it can influence recommended power of the PC IOL. Conversely, when using the SRK/T formula, pharmacological dilation of pupil does not affect the recommended PC IOL power.

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Section: úVodunclassified

The Effect of Pharmacological Pupil Dilation on Intraocular Lens Power Calculation in Patients Indicated for Cataract Surgery

Autrata¹,

Chrapek²,

Drahorád³

2021

CSO

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“…These results are also in agreement with other studies comparing both methods of IOL power calculation. [17][18][19] The process of ocular biometry has become simplified with IOL master. Since IOL master is noncontact technique, so topical anesthesia is not required.…”

Section: Discussionmentioning

confidence: 99%

“…The study was started after taking approval from hospital ethics committee (201/ERC/AFIO dated 29- [11][12][13][14][15][16][17][18][19]. In this cross-sectional comparative study, a total of 70 patients visiting cataract clinic of Armed Forces Institute of Ophthalmology for cataract surgery were included, from June to December 2018.…”

Section: Methodsmentioning

confidence: 99%

Comparison of Optical Biometry and a Scan for Calculation of Intraocular Lens Power in Age Related Nuclear Cataract at Tertiary Care Eye Hospital

Rafique

Zafar

Khan

2021

PAFMJ

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Objective: To compare optical biometry and A-scan for calculating intraocular lens power in patients with nuclear cataract at tertiary care eye hospital. Study Design: Cross sectional comparative study. Place and Duration of Study: Armed Forces Institute of Ophthalmology, Pak Emirates Military Hospital, Rawalpindi, from Jul to Dec 2018. Methodology: In this study 70 eyes of 70 patients planned for cataract surgery by phacoemulsification underwent both optical biometry with intraocular lens master and ultrasound biometry applanation by A scan after informed consent. Intraocular lens power calculated by these two methods of biometry was compared. Phacoemulsification surgery was performed through a 2.3 mm superior temporal clear corneal incision. All patients underwent in the bag implantation of the same intraocular lens type. Results: The mean age of the patients was 62.89 ± 6.69 years. A significant (p-value<0.001) difference in intraocular lens power calculation was noted (20.96 ± 1.76 vs. 22.03 ± 1.61) with optical biometry and A-scan respectively. Association on the basis of age groups showed a significant (p-value<0.001) difference in both strata that was among patients having age ≤65 years and patients having age >65 years. Conclusion: Optical biometry was found efficient and safe method for calculation of intraocular lens power. Optical biometry is noncontact method having very less chance of infection and suitable for most of the eye types.

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“…Optimal refractive outcomes can be achieved by employing good surgical technique, aiming for a low rate of posterior capsular rupture, having a capsulorhexis size smaller than the optical diameter, and having an in-the-bag IOL placement [ 2 ]. Continuous curvilinear capsulorhexis ensures positional stability and enhances refractive predictability [ 2 , 25 ], while small incisions without sutures and the use of foldable IOLs reduce the incidence of complications and surgically induced astigmatism (SIA) [ 51 ], and complete ophthalmic viscosurgical device removal reduces the likelihood of IOL misalignment [ 52 ]. Non-intentional SIA can be prevented by pre-operative assessment of corneal hysteresis and biomechanical properties of the cornea, followed by microincision surgery using corneal topography data and standard IOL power formulae [ 3 ].…”

Section: Pre- Intra- and Post-operative Factors That Affect Refractiv...mentioning

confidence: 99%

Refractive Outcomes after Cataract Surgery

et al. 2022

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A post-operative manifest refractive error as close as possible to target is key when performing cataract surgery with intraocular lens (IOL) implantation, given that residual astigmatism and refractive errors negatively impact patients’ vision and satisfaction. This review explores refractive outcomes prior to modern biometry; advances in biometry and its impact on patients’ vision and refractive outcomes after cataract surgery; key factors that affect prediction accuracy; and residual refractive errors and the impact on visual outcomes. There are numerous pre-, intra-, and post-operative factors that can influence refractive outcomes after cataract surgery, leaving surgeons with a small “error budget” (i.e., the source and sum of all influencing factors). To mitigate these factors, precise measurement and correct application of ocular biometric data are required. With advances in optical biometry, prediction of patient post-operative refractory status has become more accurate, leading to an increased proportion of patients achieving their target refraction. Alongside improvements in biometry, advancements in microsurgical techniques, new IOL technologies, and enhancements to IOL power calculations have also positively impacted patients’ refractory status after cataract surgery.

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Effective Ocular Biometry and Intraocular Lens Power Calculation

Cited by 16 publications

References 0 publications

The Effect of Pharmacological Pupil Dilation on Intraocular Lens Power Calculation in Patients Indicated for Cataract Surgery

The Effect of Pharmacological Pupil Dilation on Intraocular Lens Power Calculation in Patients Indicated for Cataract Surgery

Comparison of Optical Biometry and a Scan for Calculation of Intraocular Lens Power in Age Related Nuclear Cataract at Tertiary Care Eye Hospital

Refractive Outcomes after Cataract Surgery

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