Anesthetic Eye Drops Research Articles

Tear Studies in Ocular Rosacea

To determine whether tear pH in ocular rosacea was alkaline or acidic compared to normal, I studied tear pH measured by pH electrode or paper in 12 patients with rosacea without ocular manifestations, 23 patients with mild ocular manifestations, and nine patients with severe ocular manifestations. There was no diagnostically useful difference in tear pH between any of these groups and normal controls. Possible pitfalls include the effect of anesthetic eyedrops on tear pH, the effect of basal tear secretion, and discrepancies between electrode and paper measurements. Measurements by pH paper cannot be adjusted by an error constant to yield an equivalent electrode value. Treatment of active ocular rosacea with tetracycline for one month had no effect on tear pH in six patients.

Bacterial flora of the normal conjunctiva. I. Topographical distribution.

The bacterial flora of 100 normal conjunctivas was studied. Staphylococcus albus and corynebacteria were the most common microorganisms recovered, followed by Staphylococcus aureus, gram‐negative bacilli and streptococci. The topographical distribution of S. albus and corynebacteria on 12 different anatomical regions of the conjunctiva was examined, and showed that both bacteria occurred less frequently on the bulbar regions. No differences between the upper and lower parts, nor between the outer and inner regions could be found. A culture obtained from the lower fornical and tarsal conjunctiva revealed about 93% of S. albus and corynebacteria actually harbouring on the conjunctiva.The instillation of anaesthetic eye drops (0.2% benoxinate hydrochloride) immediately before obtaining cultures was seen to alter the preexisting bacterial distribution on the conjunctiva to preponderance in its lower parts, presumably by a “washing out” effect.