. 2011 Feb;178(2):817–827. doi: 10.1016/j.ajpath.2010.10.037

Table 1.

Premalignant Ocular Disease Reported in Association with Pterygium and Pinguecula

References	Study population	Tissues	Sample size	Associated ocular disease	%
Sevel and Sealy³¹	Cape Town, South Africa	pterygia	n = 100	squamous cell carcinoma	12
Sevel and Sealy³¹	Cape Town, South Africa	pterygia	n = 100	carcinoma in situ	17
Clear et al¹⁷	Malawi	pinguecula and pterygia	n = 167	hyperplasia or mild dysplasia	75.4
				moderate dysplasia	11.4
				carcinoma in situ	12.6
Erie et al³⁴	Mayo Clinic, Minnesota	pterygia	n = 92	carcinoma in situ	9.8
Perra et al³³	Ecuador	pterygia	n = 80	PAM without atypia	6.3
				PAM with atypia	2.5
				nevi	2.5
Hirst et al³²	Queensland, Australia	pterygia	n = 533	OSSN	9.8

PAM, primary acquired melanosis; OSSN, ocular surface squamous neoplasia.