Convergence Insufficiency, Accommodative Insufficiency, Visual Symptoms, and Astigmatism in Tohono O’odham Students

Table 1

Rate of convergence insufficiency (“common” (2 clinical signs) or “classic”/clinical (3 clinical signs)) and accommodative insufficiency (AI) in school-based study samples.

Study	Age in years: range; Mean (SD)			CI	CI only,; no AI^†	AI^†	AI^† only,; no CI	CI and AI^†
Letourneau and Ducic [6]	6 to 13; —		1954	2.3%	—	—	—	—
Rouse et al. [7]	9 to 13; 11.3 (0.6)		453	13.0%	4.9%	—	—	—
Borsting et al. [8]	8 to 15; 10.46 (1.41)		392	17.3%	10.5%	17.3%	10.5%	6.9%
Marran et al. [1]	—; 11.5 (0.63)		299	18.1%	14.7%	8.0%	4.7%	3.3%
Wajuihian and Hansraj [9]	13 to 19; 16.27 (1.79)		1201	12.2%	10.3%	4.5%	2.6%	1.9%
Present study	8 to 15; 11.67 (1.81)	All students	484	31.4%	16.7%	32.4%	17.8%	14.7%
		No/low astigmatism	212	26.9%	11.8%	33.0%	17.9%	15.1%
		Moderate astigmatism	126	34.1%	22.2%	31.0%	19.0%	11.9%
		High astigmatism	146	35.6%	19.2%	32.9%	16.4%	16.4%

Convergence insufficiency (CI): presence of 2 or 3 clinical signs (exophoria at near greater than at far in addition to insufficient PFV and/or receded NPC) for all studies except Letourneau and Ducic [6] (defined only by near point of convergence >10 cm and exophoria greater at near than at distance).
Accommodative insufficiency (AI): accommodative amplitude (AA) 2D from Hofstetter’s minimum age expected AA, except for Wajuihian and Hansraj who defined AI by reduced accommodative amplitude combined with high values on monocular estimation retinoscopy and/or poor accommodative facility.