Evaluation of horizontal fusional vergence in young children with intermittent exotropia using the synoptophore and prism bar.

Rajesh Kumar; Malhar Tushar Vyas; Neebha Passi

doi:10.33700/jhrs.4.2.159

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Open Access

Authors

Rajesh Kumar Department of Optometry, Nims College of Allied & Health care Sciences , NIMS University Rajasthan, Jaipur, Rajasthan, 303121 India https://orcid.org/0000-0002-6032-2437
Malhar Tushar Vyas Associate Professor, Department of Ophthalmology, Nims University Rajasthan, Jaipur, Rajasthan, 303121 India; https://orcid.org/0009-0004-2123-6634
Neebha Passi Regional Institute of Ophthalmology, Pt. B. D. Sharma Post Graduate Institute of Medical Sciences, Rohtak, Haryana 124001 India https://orcid.org/0000-0003-4387-3357

https://doi.org/10.33700/jhrs.4.2.159

Keywords:

Intermittent exotropia, Horizontal Fusional vergence, synoptophore, prism bar, office control score, step vergence method

Abstract

Purpose: The aim of the study was to compare the synoptophore and prism bar for assessing horizontal fusional vergence (HFV) in young children with intermittent exotropia (IXT).

Methods: The research involved ninety-eight subjects with IXT, aged between six and sixteen years. The examination included vision assessment, a cover test, identification of the dominant eye, and measurement of the angle of deviation using a prism bar. The subjects' HFV (positive and negative fusional vergence) was assessed using a horizontal prism bar and synoptophore at both near and far distances. We assessed IXT's control utilizing the Newcastle score for both near and far distances.

Results: The positive fusional vergence (PFV) break points of the synoptophore above those of the prism bar at both near and distance ranges (P < 0.01). There was a statistically significant difference in PFV recovery points for both near (P < 0.01) and distance (P < 0.01). There were no statistically significant changes in the near-negative fusional vergence (NFV) blur and break points as determined by the prism bar and synoptophore. The distance, NFV blur, and break points were larger on the synoptophore compared to the prism bar (P < 0.01).The difference in NFV recovery points was statistically significant at both near (P = 0.05) and distance (P = 0.03).

Conclusion: It is essential to exercise caution when assessing the PFV and NFV in young children with IXT, as the synoptophore and prism bar are not comparable in these kinds of situations.

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