The etiology of chronic catarrhal conjunctivitis is not clearly defined. With no single causative factor in evidence, a variety of agents and conditions have been regarded as inciting or contributing causes. Among the more important of these are the following: (1) bacteria, principally Haemophilus lacunatus (the diplobacillus of Morax and Axenfeld) ; (2) viruses, such as those causing molluscum contagiosum and the common wart; (3) acne rosacea; (4) allergy; (5) streptotrichal concretions of the canaliculi; (6) trichiasis; (7) minute foreign bodies; (8) irritants, such as smoke; (9) refractive errors; (10) excessive secretion of the meibomian glands; (11) vitamin deficiency; (12) deficient lacrimal secretion, and (13) chronic nasal sinusitis.
It is proposed in this series of studies to consider the bacterial factors in chronic catarrhal conjunctivitis and to endeavor to determine the relationship of each bacterium to the disease. The term chronic catarrhal conjunctivitis will be used to include all forms