Table 6.
Summary of studies on vergence anomalies.
| Authors/year of study | Country of study | Age (year) | Sample size | Prevalence |
||
|---|---|---|---|---|---|---|
| Convergence insufficiency (%) | Convergence excess (%) | Fusional vergence dysfunction | ||||
| Present study | South Africa | 13–19 | 1211 | CI: Low suspect, 11.8 High suspect 6 Definite 4.3 Pseudoconvergence insufficiency 1.9 |
5.6 | 3.3 |
| Rouse et al. (1995)18 | USA | 9–13 | 35 | Low suspect CI = 33.3 High suspect = 4.2 Definite CI = 4.2 |
||
| Rouse et al. (1998)23 | USA | 8–12 | 415 | Low suspect CI = 33 High suspect CI = 12 Definite CI = 6 |
||
| Rouse et al. (1999)16 | USA | 9–13 | 453 | Low suspect CI = 8.4 High suspect CI = 8.8 Definite CI = 4.2 |
||
| Borsting et al. (2003)17 | USA | 8–15 | 392 | High suspect + definite CI = 17.3 | 0.8 | |
| Marran et al. (2006)19 | USA | 11.5 | 299 | High suspect + definite = 4.7 | 5 | |
| Junghans et al. (2002)14 | Australia | 3–12 | 2697 | Low suspect = 5.9 Definite = 2.1 |
||
| Shin et al. (2009)21 | S/Korea | 9–13 | 114 | 28 | 2.4 | |
| Scheiman et al. (1996)22 | USA | 6–18 | 1650 | 5.3 | 8.2 | 0.4 |
| Dwyer (1992)9 | Australia | 7–18 | 144 | 33 | 15 | |
| Letourneau and Ducic (1988)15 | Canada | 5–13 | 2084 | 2.2 | ||
| Wajuihian and Hansraj (2014)7 | S/Africa | 13–19 | 65 | Low 16 High 1.6 Definite 0 |
3.2 | |
| Dusek et al. (2010)10 | Austria | 6–14 | 328 | 5.2 | 8.2 | |