To estimate the frequency of convergence insufficiency (Cl) and its related characteristics among 8- to 12-year-old children randomly selected from 2 optometry clinic populations.
Clinic records of 620 children were randomly selected and reviewed according to a standard protocol, using a systematic sampling method based on the total number of 8- to 12-year-old children seen over a 1-year period at 2 optometry clinics. Records were reviewed for demographic and clinical data. Data on Cl-related symptoms were obtained at one of the sites. Records that met the eligibility criteria of: good visual acuity (20/30 or better in both eyes); minimal refractive error (-0.50 to +1.00 D and < or = 1.00 D of astigmatism in either eye, and < or = 1.00 D of anisometropia); and no strabismus were evaluated for Cl-related characteristics. Eligible children were classified according to the direction of their near heterophoria and the number of the following clinical signs present: (1) exophoria at near > or = 4 delta than at far; (2) insufficient fusional convergence [i.e., failing Sheard's criterion or minimum normative positive fusional vergence (PFV) of 12 delta base-out (BO) blur/15 delta BO break]; and (3) receded nearpoint of convergence (NPC) of > or = 7.5 cm break or > or = 10.5 cm recovery. Children were then classified as: no Cl (nonexophoric at near or < 4 delta difference between far and near); low suspect (exophoric at near and 1 sign); high suspect (exophoric at near and 2 signs); or definite Cl (exophoric at near and 3 signs).
Sixty-seven percent (415/620) of the records met the eligibility criteria and had complete data on phoria, NPC, and PFV. The age (mean +/- SD) of the study population was 10.2 +/- 1.2 years. Ethnicity data were available for 85% of those eligible; the ethnic distribution was 36% African American, 29% Caucasian, 19% Hispanic, and 1% Asian. About one-half of the 415 children were classified as either low suspect (33%); high suspect (12%); or definite Cl (6%). Clinically significant Cl (high suspect and definite categories) was identified in 17.6% of the children. The percentage of children rated as symptomatic increased with the number of Cl-related clinical signs present.
These findings suggest a high frequency of Cl in optometry clinic populations and a potential correlation between patient symptoms and the number of Cl signs present.
This research output has an Altmetric Attention Score of 4. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 13 December 2022.
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#8,230,784
of 27,777,630 outputs
Outputs from Optometry and Vision Science
#517
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Outputs of similar age
#18,030
of 102,183 outputs
Outputs of similar age from Optometry and Vision Science
#3
of 7 outputs
Altmetric has tracked 27,777,630 research outputs across all sources so far. This one has received more attention than most of these and is in the 69th percentile.
So far Altmetric has tracked 2,440 research outputs from this source. They typically receive more attention than average, with a mean Attention Score of 7.6. This one has done well, scoring higher than 77% of its peers.
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