LENS GÜCÜNÜN YENİ BİOMETRİ FORMÜLLERİ İLE HESAPLANMASI

Abstract

Amaç: Hastaların fakoemülsifikasyon cerrahisi öncesindeki biometrik ve refraktif verileri kullanılarak, altı biometrik formülün refraktif sonuçlara göre doğruluklarının karşılaştırılması. Gereç ve Yöntem: Retrospektif olarak 2016 Ocak ve 2019 Temmuz tarihleri arasında İstanbul Üniversitesi İstanbul Tıp Fakültesi Göz Hastalıkları kliniğinde fakoemülsifikasyon uygulanan 43 hastanın 65 gözünün verileri retrospektif olarak incelendi. Hastalarda hedeflediğimiz refraksiyon değerine karşılık gelen göz içi lens (GİL) gücü SRK/T formülüne göre hesaplandı. Postoperatif 3. aydan sonra yapılan muayenelerde hastaların sonuç refraksiyon değerleri saptandı. Hastaların optik biometri ölçümleri kullanılarak, aynı kırma gücüne sahip GİL implante edildiğinde, Hoffer Q, T2, Ladas Süper Formülü (Ladas), Barrett Universal II (BU II) ve Hill-RBF formüllerine göre hedef refraksiyon değerleri hesaplandı. Formüllerin saptadığı hedef refraksiyon değerleriyle, hastaların sonuç refraksiyonlarının sferik eşdeğerleri arasındaki fark alındı ve formüller arasındaki refraktif sapma değerleri karşılaştırıldı. Bulgular: Çalışmaya alınan 43 hastanın yaş ortalaması 64,65±8,23 (47-86) yıl idi. Ortalama aksiyel uzunluk 23,5±0,7mm (22,01-24,5) olarak saptandı. SRK/T ile refraktif sapma 0,29±0,29 D, T2 ile 0,27±0,27 D, Hoffer Q ile 0,3±0,24 D, Ladas ile 0,3±0,26 D, BU II ile 0,33±0,28 D, Hill-RBF ile 0,27±0,29 D idi. Formüllerin -1,00 D ile +1,00 D aralığında bulunan refraktif sapma yüzdeleri şu şekildeydi: %98,5 Hoffer Q ve Hill-RBF; %96,9 T2, Ladas, BU II ve SRK/T. Refraktif sapma değerleri açısından formüller arasında istatistiksel olarak anlamlı bir farklılık izlenmedi (p>0,05). Sonuç: Çalışmada yer alan altı biometri formülünün ±1 D içinde refraktif sapma ile hedef refraktif değere ulaşma şansı %96,9 ve üzerindedir. Bu formüllerin her biri normal uzunluktaki gözlerde preoperatif GİL gücünü hesaplamak için güvenli bir şekilde kullanılabilir.

Keywords

• Katarakt cerrahisi
• biometri
• yeni jenerasyon formüller

Thanks

Prof. Dr. Nilüfer Gözüm'e öneri, destek ve katkıları için teşekkür ederim.

CALCULATION OF LENS POWER WITH NEW BIOMETRIC FORMULAS

Abstract

Objective: Comparison of the accuracy of six biometric formulas based on refractive findings using patients' biometric and refractive data before phacoemulsification surgery. Material and Method: A retrospective analysis was conducted of the data of 65 eyes of 43 patients who underwent phacoemulsification at the Ophthalmology Department of Istanbul University Istanbul Faculty of Medicine between January 2016 and July 2019. The intraocular lens (IOL) power corresponding to the target refraction value in patients was calculated using the SRK/T formula. The patients' final refraction values were obtained by examinations conducted after the third postoperative month. After implanting IOLs with the same refractive power, target refraction values were calculated using the optical biometry measurements of the patients and the Hoffer Q, T2, Ladas Super Formula (Ladas), Barrett Universal II (BU II), and Hill-RBF formulas.The refractive refraction deviation values between the formulas were compared, as well as the difference between the target refraction values determined by the formulas and the spherical equivalents of the patients' result refractions. Result: The normal age of the 43 patients in the study was 64.65±8.23 (47-86) years. The mean axial length was 23.5±0.7mm (22.01-24.5). The refractive deviation was 0.29±0.29 D with SRK/T, 0.27±0.27 D with T2, 0.3±0.24 D with Hoffer Q, 0.3±0.26 D with Ladas, and 0.33±0.28 D with BU II, and 0.27±0.29 D with Hill- RBF. The refractive deviation percentages of the formulas in the range of -1.00 D to +1.00 D were as follows: 98.5% Hoffer Q and Hill-RBF; 96.9% T2, Ladas, BU II, and SRK/T. In terms of refractive deviation values, there was no statistically significant difference between the formulas (p>0.05). Conclusion: The probability of obtaining the target refractive value with a refractive deviation within ±1 D of the six biometry formulas included in the study is 96.9% and higher. Any of these formulas can be employed safely to compute preoperative IOL power in the eyes of normal length.

Keywords

• Cataract surgery
• biometrics
• new generation formulas

References

1. Haigis W. Challenges and approaches in modern biometry and IOL calculation. Saudi J Ophthalmol 2012;26(1):7-12. google scholar
2. Olson RJ. Cataract surgery from 1918 to the present and future— just imagine! Am J Ophthalmol 2018;185:10-3. google scholar
3. Khandelwal SS, Jun JJ, Mak S, Booth MS, Shekelle PG. Effectiveness of multifocal and monofocal intraocular lenses for cataract surgery and lens replacement: a systematic review and meta-analysis. Graefes Arch Clin Exp Ophthalmol 2019;257(5):863-75. google scholar
4. Aristodemou P, Sparrow JM, Kaye S. Evaluating refractive outcomes after cataract surgery. Ophthalmology 2019;126(1):13-8. google scholar
5. Melles RB, Kane JX, Olsen T, Chang WJ. Update on intraocular lens calculation formulas. Ophthalmology 2019;126(9):1334-5. google scholar
6. Khoramnia R, Auffarth G, Łabuz G, Pettit G, Suryakumar R. Refractive outcomes after cataract surgery. Diagnostics 2022;12(2):243. google scholar
7. Retzlaff JA, Sanders DR, Kraff MC Development of the SRK/T intraocular lens implant power calculation formula. J Cataract Refract Surg 1990;21(3):313-319. google scholar
8. Sheard RM, Smith GT, Cooke DL Improving the prediction accuracy of the SRK/T formula: the T2 formula. J Cataract Refract Surg 2010;36(11):1829-34. google scholar

9. Ladas JG, Siddiqui AA, Devgan U, Jun AS A 3-D “Super Surface” combining modern intraocular lens formulas to generate a “Super Formula” and maximize accuracy. JAMA Ophtalmol 2015;133(12):1431-6. google scholar
10. Aristodemou P, Knox Cartwright NE, Sparrow JM, Johnston RL Formula choice: Hoffer Q, Holladay 1, or SRK/T and refractive outcomes in 8108 eyes after cataract surgery with biometry by partial coherence interferometry. J Cataract Refract Surg 2011;37(1):63-71. google scholar
11. Barrett GD An improved universal theoretical formula for intraocular lens power prediction. J Cataract Refract Surg 1993;19(6):713-20. google scholar
12. Roberts T V., Hodge C, Sutton G, Lawless M. Comparison of Hill-radial basis function, Barrett Universal and current third generation formulas for the calculation of intraocular lens power during cataract surgery. Clin Exp Ophtalmol 2018;46(3):240-6. google scholar
13. Chylack LT, Jr., Wolfe JK, Singer DM, Leske MC, Bullimore MA, Bailey IL, et al. The Lens Opacities Classification System III. The Longitudinal Study of Cataract Study Group. Arch Ophthalmol 1993;111(6):831-6. google scholar
14. User Group for Laser Interference Biometry. Optimized IOL constants for the Zeiss IOLMaster calculated from patient data on file (last revision Oct 31, 2016). Available at: www. ocusoft.de/ulib/c1.html. Accessed on May, 2023. google scholar
15. Eğrilmez S, Dalkılıç G, Yağcı A. A vectorial analysis software for the analysis of astigmatism. T Oft Gaz 2003;33(3):404-16. google scholar
16. Doğan M, Polat O, Yavaş GF, Küsbeci T, İnan S, İnan Ü. The reliability of biometric measurements obtained by ALScan optic biometer in intraocular lens power calculation. Turkiye Klin J Ophthalmol 2015;24(4):246-50. google scholar
17. Sánchez-Liñan N, Pérez-Rueda A, Parrón-Carreño T, Nievas-Soriano B-J, Castro-Luna G. Evaluation of biometric formulas in the calculation of intraocular lens according to axial length and type of the lens. Scientific Reports 2023;13(1):4678. google scholar
18. Cooke DL, Cooke TL. Prediction accuracy of preinstalled formulas on 2 optical biometers. J Cataract Refract Surg 2016;42(3):358-62. google scholar
19. Cooke DL, Cooke TL. Comparison of 9 intraocular lens power calculation formulas. J Cataract Refract Surg 2016;42(8):1157-64. google scholar
20. Kane JX, Van Heerden A, Atik A, Petsoglou C. Intraocular lens power formula accuracy: comparison of 7 formulas. J Cataract Refract Surg 2016;42(10):1490-500. google scholar
21. Nemeth G, Modis Jr L. Accuracy of the Hill–radial basis function method and the Barrett Universal II formula. Eur. J. Ophthalmol 2021;31(2):566-71. google scholar
22. Aristodemou P, Cartwright NEK, Sparrow JM, Johnston RL. Formula choice: Hoffer Q, Holladay 1, or SRK/T and refractive outcomes in 8108 eyes after cataract surgery with biometry by partial coherence interferometry. J Cataract Refract Surg 2011;37(1):63-71. google scholar
23. Sheard RM, Smith GT, Cooke DL. Improving the prediction accuracy of the SRK/T formula: the T2 formula. J Cataract Refract Surg 2010;36(11):1829-34. google scholar
24. Altinkurt E, Gözüm N, Cebeci Z, Taş Ay, Gücükoğlu A. Comparison of corneal pachymetry changes and surgically induced astigmatism of microcoaxial phacoemulsification surgery and coaxial phacoemulsification surgery. J Ist Faculty Med 2018;81(3):77-83. google scholar