Articles Vol. 67 No. 6 25/06/2026

RESEARCH ON BINOCULAR VISION CHARACTERISTICS IN PATIENTS WITH STRABISMUS

Ha Nguyen Ngan1,2,3,4, Trang Nguyen Thu2,4, Hue Truong Thu1,3, Dang Tran Hai1,3, Thuy Nguyen Thi Phuong1,3, Thu Dao Thi Minh1,3, Tuyet Tran Thi Anh1,3, Trinh Pham Viet1,3, Thao Dang Thi1,3, Vinh Do Ngoc1,3
1 Hanoi Medical University
2 National Eye Hospital
3 Trường Đại học Y Hà Nội
4 Bệnh viện Mắt Trung ương
DOI: 10.52163/yhc.v67i6.5503
125 Views
47 Downloads
Abstract

Objective: To evaluate binocular visual function characteristics in patients with strabismus.

Subjects and methods: A cross-sectional descriptive study was conducted on 38 patients aged ≥ 5 years with strabismus at the National Eye Hospital and Hanoi Medical University Hospital from September 2025 to April 2026. Patients underwent examinations including visual acuity using the Snellen chart, ocular motility assessment, Hirschberg test, cover-uncover test, prism measurement of deviation, accommodative convergence/accommodation ratio, near point of convergence, positive and negative fusional vergence, amplitude of accommodation, negative and positive relative accommodation, and Worth 4-dot test. Data were analyzed using SPSS 20.0 software.

Results: Exotropia accounted for 73.7% of cases, followed by esotropia, with no cases of vertical deviation. Positive fusional vergence was increased, while negative fusional vergence was markedly reduced. Amplitude of accommodation was below age-expected norms in 77% of eyes. Negative relative accommodation was increased in 90.5% of patients, whereas positive relative accommodation showed variability. Near point of convergence indicated reduced convergence function.

Conclusion: Patients with strabismus exhibit accommodative-vergence imbalance, characterized by convergence predominance and reduced divergence. A comprehensive treatment approach is required.

Keywords
Strabismus, binocular vision, accommodation, convergence.
References
[1]
Cooper J, Jamal N. Convergence insufficiency-a major review. Optometry, 2012, 83 (4): 137-158. Google Scholar
[2]
Rouse M, Borsting E et al. Validity of the convergence insufficiency symptom survey: a confirmatory study. Optometry and Vision Science, 2009, 86 (4): 357-363. doi: 10.1097/OPX.0b013e3181989252 Google Scholar
[3]
Hussaindeen J.R, Rakshit A et al. Prevalence of non‐strabismic anomalies of binocular vision in Tamil Nadu: report 2 of BAND study. Clinical and Experimental Optometry, 2017, 100 (6): 642-648. doi: 10.1111/cxo.12496. Google Scholar
[4]
Scheiman M, Mitchell G.L et al. A randomized clinical trial of vision therapy/orthoptics versus pencil pushups for the treatment of convergence insufficiency in young adults. Optometry and Vision Science, 2005, 82 (7): E583-E595. doi: 10.1097/01.opx.0000171331.36871.2f Google Scholar
[5]
Convergence Insufficiency Treatment Trial Study Group. Randomized clinical trial of treatments for symptomatic convergence insufficiency in children. Archives of Ophthalmology, 2008, 126 (10): 1336-1349. doi: 10.1001/archopht.126.10.1336 Google Scholar
[6]
Mestre C, Neupane S et al. Vergence and accommodation responses in the control of intermittent exotropia. Ophthalmic and Physiological Optics, 2023, 43 (4): 598-614. Google Scholar
[7]
Wajuihian S.O, Hansraj R. Vergence anomalies in a sample of high school students in South Africa. Journal of Optometry, 2016, 9 (4): 246-257. doi: 10.1016/j.optom.2015.10.006 Google Scholar
[8]
Chen A.M, Roberts T.L et al. Effectiveness of vergence/accommodative therapy for accommodative dysfunction in children with convergence insufficiency. Ophthalmic and Physiological Optics, 2021, 41 (1): 21-32. doi: 10.1111/opo.12747 Google Scholar