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. 2023 Jan;43(1):105-115.
doi: 10.1111/opo.13062. Epub 2022 Oct 22.

Vergence/accommodative therapy for symptomatic convergence insufficiency in children: Time course of improvements in convergence function

Erin C Jenewein  1 , Susan Cotter  2 , Tawna Roberts  3 , Marjean Kulp  4 , G Lynn Mitchell  4 , Lisa A Jones-Jordan  4 , Angela M Chen  2 , Kristine Hopkins  5 , Kristine Huang  2 , Deborah Amster  6   7 , Gregory Fecho  6 , Julie Tyler  2   6 , Shivakhaami Meiyeppen  1 , Mitchell Scheiman  1 ; Convergence Insufficiency Treatment Trial - Attention and Reading Trial (CITT-ART) Investigator Group
Collaborators, Affiliations

Vergence/accommodative therapy for symptomatic convergence insufficiency in children: Time course of improvements in convergence function

Erin C Jenewein et al. Ophthalmic Physiol Opt. 2023 Jan.

Abstract

Purpose: To evaluate the time course of improvements in clinical convergence measures for children with symptomatic convergence insufficiency treated with office-based vergence/accommodative therapy.

Methods: We evaluated convergence measures from 205, 9- to 14-year-old children with symptomatic convergence insufficiency randomised to office-based vergence/accommodative therapy in the Convergence Insufficiency Treatment Trial - Attention and Reading Trial (CITT-ART). Near-point of convergence (NPC) and near-positive fusional vergence (PFV) were measured at baseline and after 4, 8, 12 and 16 weeks of therapy; mean change in NPC and PFV between these time points were compared using repeated measures analysis of variance. Rates of change in NPC and PFV from: (1) baseline to 4 weeks and (2) 4-16 weeks were calculated. For each time point, the proportion of participants to first meet the normal criterion for NPC (<6 cm), PFV blur (break if no blur; >15Δ and >2 times the exodeviation) and convergence composite (NPC and PFV both normal) were calculated.

Results: The greatest change in NPC and PFV (7.6 cm and 12.7 Δ) and the fastest rate of improvement in NPC and PFV (1.9 cm/week and 3.2 Δ/week, respectively) were both found during the first 4 weeks of therapy, with both slowing over the subsequent 12 weeks. After 12 weeks of therapy, the NPC, PFV and convergence composite were normal in 93.2%, 91.7% and 87.8% of participants, respectively, and normalised with another 4 weeks of therapy in 4.4%, 2.0% and 4.4% of participants, respectively.

Conclusion: Although the greatest improvements in NPC and PFV occurred in the first 4 weeks of therapy, most participants had weekly improvements over the subsequent 12 weeks of treatment. While most children with convergence insufficiency obtained normal convergence following 12 weeks of therapy, an additional 4 weeks of vergence/accommodative therapy may be beneficial for some participants.

Keywords: convergence insufficiency; near-point of convergence; positive fusional vergence; treatment kinetics; vergence/accommodative therapy.

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Figures

Figure 1:
Figure 1:
Mean near point of convergence (NPC) break (cm) using baseline NPC of 8cm (25th percentile), 13.8 cm (mean) and 18cm (75th percentile).
Figure 2:
Figure 2:
Positive fusional vergence (PFV) blur (if no blur, break) using baseline PFV of 9Δ (25th percentile), 12Δ (mean) and 14Δ (75th percentile)
Figure 3:
Figure 3:
Percentages of participants who had normal values for near point of convergence (NPC < 6cm), positive fusional vergence (PFV >15Δ blur and passing Sheard’s Criteria), and normal convergence composite (normal NPC and PFV) at each time point during the study.
Figure 4:
Figure 4:
Comparison of the mean near point of convergence (NPC) in cm in the Convergence Insufficiency Treatment Trial (CITT) and the Convergence Insufficiency Treatment Trial - Attention and Reading Trial (CITT-ART) trial.
Figure 5:
Figure 5:
Comparison of the mean positive fusional vergence (PFV) in Δ (pd) in the Convergence Insufficiency Treatment Trial (CITT) and the Convergence Insufficiency Treatment Trial - Attention and Reading Trial (CITT-ART) trial.
See this image and copyright information in PMC

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