Spherical Equivalent Refraction, Amplitude of Accommodation, and Relative Accommodation in a Young Nigerian Population

Eghosasere Iyamu; Godsgift Obi; clinton okechukwu

doi:10.65636/cjo.v88i3.6404

Authors

Eghosasere Iyamu https://orcid.org/0000-0002-1833-3175
Godsgift Obi https://orcid.org/0009-0006-1017-097X
clinton okechukwu University of Benin, Benin-City, Edo

DOI:

https://doi.org/10.65636/cjo.v88i3.6404

Abstract

Abstract
Introduction
We investigated the relationship between spherical equivalent refraction (SER), amplitude of accommodation (AA), and relative accommodation (RA) in young adults in Nigeria to improve understanding of accommodative function across refractive groups.
Methods
We conducted a prospective observational study at the optometry clinic at the University of Benin with 70 patients (35 males and 35 females) who came in, aged 17-35 years. Measurements included SER, AA (using push-up to blur, minus-lens to blur, and modified push-up to blur methods), RA (negative relative accommodation [NRA], and positive relative accommodation [PRA]) without wearing corrective lenses. Maximum plus and minus lenses were used to assess accommodation. We analyzed data using analysis of variance (ANOVA), Duncan’s multiple range test for pairwise comparisons, linear regression, and t-test.
Results
AA varied significantly across refractive groups, with patients with myopia showing higher AA (10.93 ± 1.10 D) than patients with hyperopia (far sightedness) (9.00 ± 0.59 D). Mean NRA and PRA were +2.25 ± 0.29 D and ‒2.43 ± 0.37 D, respectively. NRA was significantly higher in patients with hyperopia (+2.51 ± 0.19 D), while PRA was higher in patients with myopia (‒2.72 ± 0.20 D). AA decreased with age (r = –0.66, P < .001), while NRA increased with age (r = 0.45, P = .001).
Discussion
Patients with myopia exhibited greater PRA, while patients with hyperopia had higher NRA, aligning with their respective accommodative needs. The decline in AA with age highlights the need for early assessment of accommodation function. The correlations between age, NRA, and PRA suggest that accommodation changes dynamically over time.
Conclusion
The findings highlight the significant influence of refractive error on accommodation, with patients with myopia having greater accommodative reserves, potentially allowing for sustained near-vision tasks with comfort. In contrast, patients with hyperopia experiencing higher accommodative needs, which may lead to visual fatigue or discomfort over time. In other words, these findings underscore the clinical importance of accommodation assessments in refractive error management, particularly in prescribing lenses that optimize visual comfort and performance.

References

1. Hoffman DM, Girshick AR, Akeley K, Banks MS. Vergence–accommodation conflicts hinder visual performance and cause visual fatigue. J Vis. 2008;8(3):1-30. https://doi.org/10.1167/8.3.33 DOI: https://doi.org/10.1167/8.3.33

2. Rucci M, Victor JD. Perspective: Can eye movements contribute to emmetropization? J Vis. 2018;18(7):10. https://doi.org/10.1167/18.7.10 DOI: https://doi.org/10.1167/18.7.10

3. Hofstetter HW, Griffin JR, Berman MS, Everson RW. Dictionary of vision science and related clinical terms. Boston: Butterworth-Heinemann; 2000.

4. Croft MA, Glasser A, Kaufman PL. Accommodation and presbyopia. Int ophthalmol Clin. 2001;41(2):33-46. https://doi.org/10.1097/00004397-200104000-00005 DOI: https://doi.org/10.1097/00004397-200104000-00005

5. Doshi S, Harvey W. Investigative Techniques and Ocular Examination. Elsevier Health Sciences; 2003. https://doi.org/10.1016/B978-0-7506-5404-3.X5001-6 DOI: https://doi.org/10.1016/B978-0-7506-5404-3.X5001-6

6. Glickstein M, Millodot M. Retinoscopy and eye size. Science. 1970;168(3931):605-606. https://doi.org/10.1126/science.168.3931.605 DOI: https://doi.org/10.1126/science.168.3931.605

7. Rosenfield M, Logan N (eds.). Optometry: Science, Techniques and Clinical Management. Elsevier Health Sciences; 2016.

8. Duke-Elder, S., Abrams, D. Practice of Refraction (9th ed.). Churchill Livingstone; 1993.

9. Morgan IG, Rose KA, Ellwein LB, Refractive error study in children survey group. Is emmetropia the natural endpoint for human refractive development? An analysis of population‐based data from the refractive error study in children (RESC). Acta ophthalmol. 2010;88(8):877-884. https://doi.org/10.1111/j.1755-3768.2009.01800.x DOI: https://doi.org/10.1111/j.1755-3768.2009.01800.x

10. Yekta A, Hashemi H, Khabazkhoob M, Ostadimoghaddam H, Ghasemi-Moghaddam S, Jafarzadehpur E, Shokrollahzadeh F. The distribution of negative and positive relative accommodation and their relationship with binocular and refractive indices in a young population. J Curr Ophthalmol. 2017;29(3):204-209. https://doi.org/10.1016/j.joco.2017.01.001 DOI: https://doi.org/10.1016/j.joco.2017.01.001

11. Abu EK, Ocansey S, Yennu J, Asirifi I, Marfo R. Comparing different methods of measuring accommodative amplitude with Hofstetter’s normative values in a Ghanaian population. Curr Eye Res. 2018;43(9):1145-1150. https://doi.org/10.1080/02713683.2018.1480044 DOI: https://doi.org/10.1080/02713683.2018.1480044

12. Iyamu E, Iyamu JE, Oghovwerha L. Anthropometry, amplitude of accommodation, and spherical equivalent refractive error in a Nigerian population. International Scholarly Research Notices. 2012; 2012:295613. https://doi.org/10.5402/2012/295613 DOI: https://doi.org/10.5402/2012/295613

13. Mathebula SD, Ntsoane MD, Makgaba NT, Landela KL. Comparison of the amplitude of accommodation determined subjectively and objectively in South African university students. Afr Vis Eye Health. 2018;77(1). https://doi.org/10.4102/aveh.v77i1.437 DOI: https://doi.org/10.4102/aveh.v77i1.437

14. Momeni-Moghaddam H, Kundart J, Askarizadeh F. Comparing measurement techniques of accommodative amplitudes. Indian J Ophthalmol. 2014;62(6):683-687. https://doi.org/10.4103/0301-4738.126990 DOI: https://doi.org/10.4103/0301-4738.126990

15. Cooper JS, Burns CR, Cotter SA, Daum KM, Griffin JR, Scheiman MM. Care of the Patient with Accommodative and Vergence Dysfunction. American Optometric Association, 2011. https://www.aoa.org/AOA/Documents/Practice%20Management/Clinical%20Guidelines/Consensus-based%20guidelines/Care%20of%20Patient%20with%20Accommodative%20and%20Vergence%20Dysfunction.pdf

16. Scheiman M, Wick B. Clinical management of binocular vision: Heterophoric, accommodative, and eye movement disorders. Lippincott Williams & Wilkins; 2008.

17. Morgan MW Jr. The clinical aspects of accommodation and convergence. Am J Optom Arch Am Acad Optom. 1944;21(8):301-313. https://doi.org/10.1002/j.2330-9474.1944.tb00044.x DOI: https://doi.org/10.1002/j.2330-9474.1944.tb00044.x

18. Chen AH, Abidin AHZ. Vergence and accommodation system in Malay primary school children. Malays J Med Sci. 2002;9(1):9-15.

19. Borsting E, Rouse M, Shin S, Dold E, McClallen A. Repeatability of the visagraph II in the analysis of childrens eye movements during reading. Optom Vis Dev. 2007;38(2):67-73.

20. Jorge J, de Almeida JB, Parafita MA. Binocular vision changes in university students: A 3-year longitudinal study. Optom Vis Sci. 2008;85(10):E999-E1006. https://doi.org/10.1097/OPX.0b013e3181890d35 DOI: https://doi.org/10.1097/OPX.0b013e3181890d35

21. Padavettan C, Nishanth S, Vidhyalakshmi S, Madhivanan N, Madhivanan N. Changes in vergence and accommodation parameters after smartphone use in healthy adults. Indian J Ophthalmol. 2021;69(6):1487-1490. https://doi.org/10.4103/ijo.IJO_2956_20 DOI: https://doi.org/10.4103/ijo.IJO_2956_20

22. Masihuzzaman M, Dhakal P, Gautam K. Relationship of negative, positive relative accommodation and negative, positive fusional vergence in ametropes and emmetropes in young population of Nepal. Acta Sci Ophthalmol. 2021;4(1): 3-8. https://actascientific.com/ASOP/ASOP-04-0191.php