Table 1 Characteristics and findings of randomised clinical trials included in the systematic review of 27 studies.

Study	Drugs	Treatment (drops/day; duration)	Efficacy in reducing signs and symptoms (significant difference)
Akpek et al31	Mitomycin‐C 0,01% (G1) vs placebo (G2)	3; 14 days	G1>G2: photophobia, tarsal papillae, corneal involvement, limbal disease, hyperaemia
Gunduz et al26	Lodoxamide 0,1% (G1) vs NAAGA (G2)	4; 60 days	G1>G2: itching, tearing, photophobia, tarsal papillae, corneal involvement
Caldwell et al20	Lodoxamide 0,1% (G1) vs cromolyn sodium 4% (G2)	4; 28 days	G1>G2: itching, tearing, tarsal papillae, limbal disease, hyperaemia
Bonini et al19	Nedocromil sodium 2% (G1) vs placebo (G2)	4; 42 days	G1>G2: itching, tearing, hyperaemia
Leonardi et al27	Lodoxamide 0,1% (G1) vs sodium cromoglycate 4%	4; 10 days	G1>G2: total signs and symptoms
Foster and Duncan12	Cromolyn sodium 4% (G1) vs placebo (G2)	4; 42 days	G1>G2: itching, corneal involvement, hyperaemia
Pucci et al34	Ciclosporin 2% (G1) vs placebo (G2)	4; 14 days	G1>G2: total signs and symptoms
Foster16	Cromolyn sodium 4% (G1) vs placebo (G2)	4; 42 days	G1>G2: itching, tearing, tarsal papillae, corneal involvement, limbal disease, hyperaemia
Dahan and Appel15	Sodium cromoglycate (G1) vs dexamethasone 0,1% (G2) vs placebo (G3)	4; 28 days	G1>G3; G2 vs G3; G1+G2 vs G3: total signs
El Hennawi22	Sodium cromoglycate 2% (G1) vs nedocromil sodium 2% (G2) vs placebo (G3)	4; 28 days	G1>G3; G2 > G3: total signs and symptoms, limbal disease
Verin et al33	Lodoxamide 0,1% (G1) vs Levocabastine 0,05% (G2)	4; 90 days	G1>G2: total signs and symptoms, itching, tearing, photophobia, tarsal papillae, hyperaemia
Santos et al23	Lodoxamide 0,1% (G1) vs placebo (G2)	4; 90 days	G1>G2: total signs and symptoms, tarsal papillae, corneal involvement, limbal disease
Tabbara and Arafat11	Cromolyn sodium 2% (G1) vs placebo (G2)	4; 365 days	G1>G2: total symptoms, corneal involvement, limbal disease
Bleik and Tabbara18	Ciclosporin 2% (G1) vs placebo (G2)	4; 42 days	G1>G2: itching, photophobia, corneal involvement, limbal disease, hyperaemia
Fahy et al21	Lodoxamide 0,1% (G1) vs cromoglycate 2% (G2)	4; 28 days	G1>G2: total signs and symptoms
Secchi et al17	Ciclosporin 2% (G1) vs placebo (G2)	4; 15 days	G1>G2: total signs and symptoms
Tabbara and Al‐Kharashi29	Nedocromil sodium 2% (G1) vs fluorometholone 0,1% (G2)	4; 14 days	G2>G1: limbal disease, ocular surface temperature
Verin et al30	Nedocromil sodium 2% (G1) vs sodium cromoglicate 2% (G2)	4; 154 days	G1>G2: photophobia, tarsal papillae, corneal involvement, hyperaemia
Centofanti et al25	Mipragoside 0,5% (G1) vs placebo (G2)	4; 14 days	G1>G2: total signs and symptoms, itching, hyperaemia
Gupta et al32	Ciclosporin 2% (G1) vs placebo (G2)	4; 120 days	G1>G2: total signs
Easty et al10	Disodium cromoglycate 1% (G1) vs placebo (G2)	4; 42 days	G1>G2: total signs and symptoms
El Hennawi14	Disodium cromoglycate 2% (G1) vs 4% (G2)	4; 42 days	No statistically significant differences reported
Kosrirukvongs et al35	Ciclosporin 0,5% (G1) vs lodoxamide (G2)	4; 30 days	No statistically significant differences reported
Sud et al24	Flurbiprofen 0,03% (G1) vs bethametasone 0,1% (G2) vs placebo (G3)	4; 42 days	G1+G2>G3: total signs and symptoms
Sharma et al28	Ketorolac 0,5% (G1) vs placebo (G2)	4; 14 days	G1>G2: itching
Baryishak et al13	Sodium cromoglycate 2% (G1) vs placebo (G2)	4; 14 days	G1>G2: total signs
Avunduk9	Lodoxamide 0,1% (G1) vs cromolyn sodium 4% (G2)	8; 10 days	G1>G2: total signs and symptoms