Korean J Ophthalmol.  2012 Feb;26(1):39-44. 10.3341/kjo.2012.26.1.39.

The Analysis of AC/A Ratio in Nonrefractive Accommodative Esotropia Treated with Bifocal Glasses

Affiliations
  • 1B&VIIT Eye Center, Seoul, Korea.
  • 2The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea. 491209@yuhs.ac
  • 3Department of Ophthalmology, Aju University College of Medicine, Suwon, Korea.

Abstract

PURPOSE
To report the long term results of bifocal treatment in nonrefractive accommodative esotropia and to analyze the changes of accommodative convergence to accommodation (AC/A) ratio.
METHODS
Sixteen patients treated with bifocal glasses for at least 5 years were evaluated retrospectively. Angle of deviation at near and distance, refractive error, and AC/A ratio by the lens gradient method were analyzed. The changes of AC/A ratios were also compared after dividing the patients according to continuation or cessation of bifocal therapy.
RESULTS
Six patients (38%; bifocal stop group, BSG) were able to stop using bifocal glasses at an average age of 10.8 years (range, 6.5 to 15.4 years) during their follow-up. However, the other ten patients (62%; bifocal continue group, BCG) had to continue using bifocal glasses until the final visit, which was 13.8 years on average (range, 11.3 to 18.5 years). The AC/A ratio decreased from time of bifocal prescription to the last visit in both groups, from 4.4 to 2.7 in the BSG and from 5.9 to 4.5 in the BCG. AC/A ratios were significantly higher (p = 0.03) in the BCG than that of the BSG from the beginning of bifocal treatment and this difference was persistent until the final visit (p = 0.03).
CONCLUSIONS
The AC/A ratio decreased with age in both groups but was significantly higher throughout the entire follow-up period in the BCG. AC/A ratio at bifocal prescription could be an important factor in predicting response to bifocal treatment.

Keyword

Accommodation; Convergence; Esotropia

MeSH Terms

Accommodation, Ocular/*physiology
Adolescent
Child
Cyclopentolate/administration & dosage
Esotropia/*physiopathology/*therapy
*Eyeglasses
Female
Humans
Male
Phenylephrine/administration & dosage
Retrospective Studies
Statistics, Nonparametric
Tropicamide/administration & dosage

Figure

  • Fig. 1 Regression graph of the change in accommodative convergence to accommodation (AC/A) ratio according to age in the bifocal stop group compared with the bifocal continue group. Graphs depicting change in AC/A ratio over time for two groups show a decrease in AC/A ratio with age, -0.01 × (age) + 4.84 in the bifocal stop group and -0.01 × (age) + 6.28 in the bifocal continue group.


Cited by  1 articles

The Ratio of Accommodative-Convergence to Accommodation in Patients with Nonrefractive Accommodative Esotropia
Rebecca Kim, Se Youp Lee
J Korean Ophthalmol Soc. 2014;55(2):267-270.    doi: 10.3341/jkos.2014.55.2.267.


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