Journal of Paramedical Sciences & Rehabilitation

Journal of Paramedical Sciences & Rehabilitation

Evaluation of Visual Acuity and Refractive Errors after IOL Placement in Cataract ‎Patients with Regular Astigmatism

Document Type : Original Article

Authors
A Azimi Khorasani 1
Sh Movassagh Nekounam 1
E Jafarzadehpur 2
H Hashemian 3
J Heravian Shandiz 1
1 Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.
2 Department of Optometry, School of Paramedical Sciences, Iran University of Medical Sciences, Tehran, Iran.
3 Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
10.22038/jpsr.2022.62066.2336
Abstract
Purpose:
Astigmatism is a common refractive error and is common in patients requiring cataract surgery. Cataract surgery is usually accompanied by an intraocular lens (IOL) implantation. However, global sanctions in Iran and the high cost of toric IOLs sometimes lead to the application of spherical IOLs and hence residual astigmatism. Given the average age of the middle-aged Iranian population, the need to address the issue of astigmatism and cataracts is clear. To evaluate the visual acuity and refractive errors in cataract patients with regular astigmatism after spherical IOL placement and to evaluate the results of the calculation formulas for determining IOL power.
Methods:
This cross-sectional study was performed on 100 eyes of 72 patients aged 50 to 75 years with regular astigmatism who underwent phacoemulsification surgery and simultaneous spherical IOL implantation at Farabi Eye Hospital in Tehran. Patients' visual acuity was performed by LogMAR chart and refractive examination using Topcon autokeratorefractor preoperatively and one month after surgery. The results of preoperative and postoperative examinations, according to the formula used and target refraction, were statistically analyzed using analysis of variance, paired t-test, and Pearson correlation in SPSS software.
Results:
The selection of “Plano” target refraction, improved patients' vision and refraction. The mean of Uncorrected Distance Visual Acuity before and after surgery showed a significant difference (p<0.001). The mean of Corrected Distance Visual Acuity and spherical refractive error before and after surgery did not show a statistically significant difference (p>0.05). The mean of refractive and corneal astigmatism, before and after surgery showed a significant difference (p<0.001).
Conclusion:
The age of cataract patients with astigmatism can be an indicator for choosing the appropriate IOL formula. Cataracts cause astigmatism by altering the Crystalline lens, which can be reduced with surgery. With accurate refraction, the quality of patients' vision can be increased with spectacles before cataract surgery. The SRK / T formula, which has the highest frequency among the three formulas, has better visual and refraction results.
Keywords
Astigmatism
Cataract
Intraocular lens
Visual Acuity
Refraction
  1. Borish IM. Borish's Clinical Refraction. Second Edition ed 2006.
  2. Afsaneh K. Astigmatism Types - Regular and Irregular 28 January 2021.
  3. Hardten DR, Hardten AG. Handling regular and irregular astigmatism during cataract surgery. Curr Opin Ophthalmol 2021; 32(1): 13-18.
  4. Shahdadi H, Aminifard MN, Balouchi A, Rafiemanesh H, et al. Frequency of Cataract in Iran: A Meta-Analysis and Systematic Review. Middle East Afr J Ophthalmol. 2018; 25(1): 40-46. [Persian]
  5. Nizami AA, Gulani AC. Cataract.  StatPearls. Treasure Island (FL): StatPearls Publishing Copyright © 2020, StatPearls Publishing LLC.; 2020.
  6. Toh T, Morton J, Coxon J, Elder MJ. Medical treatment of cataracts. Clin Exp Ophthalmol 2007; 35(7): 664-671.
  7. Haigis W. Challenges and approaches in modern biometry and IOL calculation. Saudi J Ophthalmol 2012; 26(1): 7-12.
  8. Ryu SJ, Kim DR, Song IS, Shin YU, et al. The influence of low signal-to-noise ratio of axial length measurement on prediction of target refraction, achieved using IOLMaster. PLoS One 2019; 14(6): e0217584.
  9. Koch DD, Hill W, Abulafia A, Wang L. Pursuing perfection in intraocular lens calculations: I. A logical approach for classifying IOL calculation formulas. J Cataract Refract Surg 2017; 43(6): 717-8.
  10. Anderson DF, Dhariwal M, Bouchet C, Keith MS. Global prevalence and economic and humanistic burden of astigmatism in cataract patients: a systematic literature review. Clin Ophthalmol 2018; 12: 439-452.
  11. Modorati G, Pierro L, Brancato R. Preoperative astigmatic influence on the predictability of intraocular lens power calculation. J Cataract Refract Surg 1990; 16(5): 591-593
  12. Momeni H, Ansari H, Yekta A, Ghiasi F, et al. The comparison of visual acuity and induced astigmatism after phacoemulsification and extracapsular cataract extraction. Quarterly of Horizon of Medical Sciences. 2007; 13(3): 58-62. [Persian]
  13. Kawahara A, Takayanagi Y. Comparison of refractive and keratometric astigmatism after microincision cataract surgery. J Cataract Refract Surg 2017; 43(8): 1050-1053.
  14. Keshav V, Henderson BA. Astigmatism Management with Intraocular Lens Surgery. Ophthalmology 2020.
  15. El-Shehawy A, El-Massry A, El-Shorbagy MS, Atef M, et al. Correction of pre-existing astigmatism with phacoemulsification using toric intraocular lens versus spherical intraocular lens and wavefront-guided surface ablation. BMC Ophthalmol 2022; 22(1): 114.
  16. Kern C, Kortüm K, Müller M, Kampik A, et al. Comparison of Two Toric IOL Calculation Methods. J Ophthalmol 2018; 2018: 2840246.
  17. Richards SC, Olson RJ, Richards WL. Factors associated with poor predictability by intraocular lens calculation formulas. Arch Ophthalmol 1985; 103(4): 515-518.
  18. Ferrer-Blasco T, Montés-Micó R, Peixoto-de-Matos SC, González-Méijome JM, et al. Prevalence of corneal astigmatism before cataract surgery. J Cataract Refract Surg. 2009;35(1):70-75.
  19. Zetterberg M, Celojevic D. Gender and cataract--the role of estrogen. Curr Eye Res 2015; 40(2): 176-190.
  20. Ercegović A, Brajković J, Surać IK, Haluzan MB. Prevalence, distribution, and types of corneal astigmatism in cataract surgery patients in Sibenik County. Acta Clin Croat 2012; 51(2): 275-278.
  21. Amin Najafi HO, Telma Zahirian Moghadam, Afshan Sharghi. Prevalence of Types of Corneal Astigmatism before Cataract Surgery. International Journal of Pharmaceutical Research 2020; 12: 303-311. [Persian]
  22. Yang Y, Lv H, Wang Y, Jiang X, et al. Clinical outcomes following trifocal diffractive intraocular lens implantation for age-related cataract in China. Clin Ophthalmol 2018; 12: 1317-1324.
  23. Olsen T, Bargum R. Outcome monitoring in cataract surgery. Acta Ophthalmol Scand 1995; 73(5): 433-437.
  24. Reading VM. Astigmatism following cataract surgery. Br J Ophthalmol 1984; 68(2): 97-104.
  25. Prasher P, Sandhu JS. Prevalence of corneal astigmatism before cataract surgery in Indian population. Int Ophthalmol 2017; 37(3): 683-689.
  26. Mohammadi M, Naderan M, Pahlevani R, Jahanrad A. Prevalence of corneal astigmatism before cataract surgery. Int Ophthalmol 2016; 36(6): 807-817. [Persian]
  27. Sharma A, Phulke S, Agrawal A, Kapoor I, et al. Prevalence of Astigmatism in Patients Undergoing Cataract Surgery at a Tertiary Care Center in North India. Clin Ophthalmol 2021; 15: 617-622.
Journal of Paramedical Sciences & Rehabilitation
Volume 11, Issue 1
Spring 2022
Pages 57-67