Arlt's line is seen in-
Arlt's line is seen in trachoma due to conjuctival scrarring,which may be irregular,star shaped or linear. this linear scar present in the sulcus subtarsalis is called Al's line Ref ; A K KHURANA Comorehensive Ophtalmology edition 4,page-69 ref img
Vernal keratoconjunctivitis
Pterygium
Ocular pemphigoid
Trachoma
Conjunctiva