Open Access Open Access  Restricted Access Subscription or Fee Access

Refractive symmetry analysis of fellow eyes

sankha Jyoti Saha, Dr Kapil Dev, Pratyay Ranjan Dutta


The biological structure of human body frequently exhibit symmetry. The hypothesis of refractive symmetry assumes that the two eyes of an individual should have homogeneous refractive properties. Optometry clinical management mostly rely upon meridional magnification effect, spatial distortion, and binocular spatial perception while prescribing refractive correction. Additionally, bilateral symmetry analysis approach has proven very informative for better diagnosis. This study was multi-centered, cross-sectional, analytical, and retrospective, where we studied refractive errors with conventional clinical notation using the sphere, cylinder, and axis. The collected data were scrutinized using the SPSS, Minitab Statistical Software. In inter-ocular symmetry analysis, if the numerical difference between both axes is zero, Equal Octant or Direct Symmetry is to be considered. While, with Mirror Octants or Mirror Symmetry or Enantiomorphism, the axes difference is not zero, but the portrayal of the figures are reverberatory. 53.23% and 70.15% of the cases rooted in the Equal Octant and Mirror Octant pattern respectively, within 15° of absolute symmetry. Analysis showed that age between 7 to 14 years has the lowest inter-ocular axis difference with both the models. The average difference in inter-ocular axis was significantly reduced in the isorule group compared to the anisorule group, as observed in both direct and mirror symmetry models. Interval plot shows a lower interval proximity for Mirror Octant, in compare to Equal Octant. We tracked down that isorule bilateral astigmatism dominates the study population. Whereas, Mirror Octant is more periodic than Equal Octant.

Full Text:



Johnston, I. G., Dingle, K., Greenbury, S. F., Camargo, C. Q., Doye, J. P. K., Ahnert, S. E., & Louis, A. A. (2022). Symmetry and simplicity spontaneously emerge from the algorithmic nature of evolution. Proceedings of the National Academy of Sciences of the United States of America, 119(11).

Anderson BW, Kortz MW, Black AC, et al. Anatomy, Head and Neck, Skull. [Updated 2023 Apr 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:

Özdemir M, M Das J. Skull Imaging. [Updated 2023 Jan 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:

Luibil N, Lopez MJ, Patel BC. Anatomy, Head and Neck, Orbit. [Updated 2022 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:

Britannica, T. Editors of Encyclopaedia (2020, November 25). enantiomer. Encyclopedia Britannica.

Saad, A., Guilbert, E., & Gatinel, D. (2014). Corneal enantiomorphism in normal and keratoconic eyes. Journal of refractive surgery (Thorofare, N.J. : 1995), 30(8), 542–547.

South, J., Gao, T., Collins, A., Turuwhenua, J., Robertson, K., & Black, J. (2019). Aniseikonia and anisometropia: implications for suppression and amblyopia. Clinical & experimental optometry, 102(6), 556–565.

Hashemi, H., Asharlous, A., Yekta, A., Ostadimoghaddam, H., Mohebi, M., Aghamirsalim, M., & Khabazkhoob, M. (2019). Enantiomorphism and rule similarity in the astigmatism axes of fellow eyes: A population-based study. Journal of optometry, 12(1), 44–54.

Xu, G., Hu, Y., Zhu, S., Guo, Y., Xiong, L., Fang, X., Liu, J., Zhang, Q., Huang, N., Zhou, J., Li, F., Lei, X., Jiang, L., & Wang, Z. (2021). A multicenter study of interocular symmetry of corneal biometrics in Chinese myopic patients. Scientific reports, 11(1), 5536.

Alterson, R., & Plewes, D. B. (2003). Bilateral symmetry analysis of breast MRI. Physics in medicine and biology, 48(20), 3431–3443.

Chan, S., Chen, J. H., Li, S., Chang, R., Yeh, D. C., Chang, R. F., Yeh, L. R., Kwong, J., & Su, M. Y. (2017). Evaluation of the association between quantitative mammographic density and breast cancer occurred in different quadrants. BMC cancer, 17(1), 274.

Navalho, M., Resende, C., Rodrigues, A. M., Ramos, F., Gaspar, A., Pereira da Silva, J. A., Fonseca, J. E., Campos, J., & Canhão, H. (2012). Bilateral MR imaging of the hand and wrist in early and very early inflammatory arthritis: tenosynovitis is associated with progression to rheumatoid arthritis. Radiology, 264(3), 823–833.

Mehravaran, S., Dehzangi, I., & Rahman, M. M. (2021). Interocular Symmetry Analysis of Corneal Elevation Using the Fellow Eye as the Reference Surface and Machine Learning. Healthcare (Basel, Switzerland), 9(12), 1738.

Li, Y., & Bao, F. J. (2014). Interocular symmetry analysis of bilateral eyes. Journal of medical engineering & technology, 38(4), 179–187.

Asharlous, A., Khabazkhoob, M., Yekta, A., & Hashemi, H. (2017). Comprehensive profile of bilateral astigmatism: rule similarity and symmetry patterns of the axes in the fellow eyes. Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists), 37(1), 33–41.

Mahmood, F., Sharif, H., & Ali, M. (2022). Rule Similarity and Axis Symmetry Patterns in Young Patients with Bilateral Astigmatism. JPMA. The Journal of the Pakistan Medical Association, 72(1), 42–46.

Skuta, G. L, Cantor, L. B, Weiss, J. S, (2012). 2012-2013 Basic and clinical science course. Section 03, Clinical optics. 110-111. American Academy Of Ophthalmology

Pinazo-Durán, M. D., Zanón-Moreno, V., García-Medina, J. J., Arévalo, J. F., Gallego-Pinazo, R., & Nucci, C. (2016). Eclectic Ocular Comorbidities and Systemic Diseases with Eye Involvement: A Review. BioMed research international, 2016, 6215745.

Patasova, K., Khawaja, A. P., Tamraz, B., Williams, K. M., Mahroo, O. A., Freidin, M., Solebo, A. L., Vehof, J., Falchi, M., Rahi, J. S., Hammond, C. J., & Hysi, P. G. (2021). Association Between Medication-Taking and Refractive Error in a Large General Population-Based Cohort. Investigative ophthalmology & visual science, 62(2), 15.

Green, M. B., & Duker, J. S. (2023). Adverse Ocular Effects of Systemic Medications. Life (Basel, Switzerland), 13(3), 660.

Rezvan, Farhad & Yekta, AbbasAli & Hashemi, Hassan & Mehravaran, Shiva & Ostadi moghaddam, Hadi & Heravian Shandiz, Javad & Yekta, Reihaneh & jafarzadehpur, Ebrahim & Shahnazi, Ashkan & Asgari, Soheila & Khabazkhoob, Mehdi. (2011). The Association between Astigmatism and Spherical Refractive Error in A Clinical Population. Iranian Journal of Ophthalmology. 23. 37-42.

Duckman, R. H. (2006). Visual Development, Diagnosis, and Treatment of the Pediatric Patients. 73-74. Lippincott Williams & Wilkins

Rauniyar, D., & Das, A. V. (2022). Consanguinity and ocular disorders in India: Electronic medical records driven big data analytics. Indian journal of ophthalmology, 70(7), 2401–2407. )

Çavdarlı, C., & Topçu-Yılmaz, P. (2018). Does Long-term Soft Contact Lens Wear Affect Corneal and Anterior Chamber Parameters?. Turkish journal of ophthalmology, 48(4), 166–170.

Wang, X., McCulley, J. P., Bowman, R. W., & Cavanagh, H. D. (2002). Time to resolution of contact lens-induced corneal warpage prior to refractive surgery. The CLAO journal : official publication of the Contact Lens Association of Ophthalmologists, Inc, 28(4), 169–171.

Sheeladevi, Sethu; Seelam, Bharani1,2; Nukella, Phanindra B3; Borah, Rishi R4; Ali, Rahul4; Keay, Lisa1,2. Prevalence of refractive errors, uncorrected refractive error, and presbyopia in adults in India: A systematic review. Indian Journal of Ophthalmology 67(5):p 583-592, May 2019. | DOI: 10.4103/ijo.IJO_1235_18



  • There are currently no refbacks.

Copyright (c) 2023 Research & Reviews: A Journal of Health Professions

This Journal archive has been shifted to: