Tear Levels of Inflammatory Cytokines in Keratoconus: A Meta-Analysis of Case-Control and Cross-Sectional Studies

Table 2

Study characteristics of all articles included in meta-analysis.

Study year	Country	Mean age, Yrs (SD); KC vs. controls	Male (%); KC vs. controls	No. of eyes; KC vs. controls	Representativeness of the case (%)	Design of studies	Materials	Test methods	Outcome	Contact lens worn (%); KC vs. controls
Lonescu 2018	Romania	23.35 (11.8) vs. 28.66 (3.03)	64.71% vs. 40%	17 vs. 15	Stage I (18%); Stage II (29%); Stage III (24%); Stage IV (29%)	Observational cross-sectional study	Tear fluids	LICA	IL-1β, INF-γ, IL-4, IL-6, IL-10, TNF-α	0
Pásztor 2016	American	44.2 vs. 44.5	NR	55 vs. 24	NR	Cross-sectional	Tear fluids	CBA	IL-6, IL-10, MMP-9, NGF	NR
Sorkhabi 2015	Iran	24.09 (6.50) vs. 24.43 (4.55)	57.14% vs. 43.33%	42 vs. 30	Mild (33.3%); Moderate (33.3%); Severe (33.3%)	Prospective case-controlled study	Tear fluids	ELISA	IL-1β, IL-6, IL-10	0
Balasubramanian 2012	Australia	27.4 (6.0) vs. 29.8 (8.9)	64% vs. 40%	25 vs. 20	NR	Cross-sectional study	Tear fluids	Cytokine antibody array	IL-1β, IL-4, IL-6, IL-10, TNF-α	NR
Lema 2009	Spain	27.1 (8.1) vs. 22.6 (6.6)	70% vs. 47.8%	30 vs. 20	NR	Case-control study	Tear fluids	ELISA	IL-6, TNF-α, MMP-9	56.7 vs. 0
Lema 2008	Spain	22.8 (6.6) vs. 22.6(6.6)	53.6% vs. 25%	28 vs. 20	NR	Case-control study	Tear fluids	ELISA	IL-6, IL-10, TNF-α	0
Lema 2005	Spain	22.4 (6.5) vs. 22.6 (6.6)	47.8% vs. 52.3%	28 vs. 20	Mild (21.4%); Moderate (50%); Severe (28.6%)	Case-control study	Tear fluids	ELISA	IL-4, IL-6, IL-10, TNF-α, MMP-9	0