“…Since its introduction (Egbert et al , 1977), IC has been found to be useful in assessing the ocular surface in various ocular disorders such as dry eye/keratoconjunctivitis sicca (KCS; Wittpenn et al, 1986; Brignole et al, 2001), cicatricial ocular pemphigoid (Rivas et al, 2004), and vitamin A deficiency (McKelvie, 2003; Natadisastra et al, 1988) and has been used in clinical trials to evaluate HLA-DR expression in ocular surface diseases (Barabino et al, 2010; Mrugacz et al, 2007; Rolando et al, 2005; Baudouin et al, 2002; Brignole et al, 2000; Pisella et al, 2000; Tsubota et al, 1999; Baudouin et al, 1997; Baudouin et al, 1992). However, the reliability, reproducibility and storage limitations for the use of relative HLA-DR expression on IC-collected cells as a biomarker of inflammation for clinical trials has not yet been clearly established although there are several articles highlighting the uses of IC (Barabino et al, 2010; Baudouin et al, 1992; Baudouin et al, 1997; Baudouin et al, 2000; Brignole et al, 1998; Brignole et al, 2000; Brignole et al, 2001; Brignole-Baudouin et al, 2004a; Brignole-Baudouin et al, 2004b; Calonge et al, 2004; Lopin et al, 2009; Fernandez et al, 2001; McKelvie, 2003; Natadisastra et al, 1987; Natadisastra et al, 1988; Nelson et al, 1983; Puangsricharern and Tseng, 1995; Rolando et al, 2005; Roy et al, 2011; Singh et al, 2005; Stern et al, 2002; Stevenson et al, 2000; Thiel et al, 1997; Tole et al, 2001; Tseng, 1985. Tsubota et al, 1999; Wittpenn et al, 1986).…”