Contrast sensitivity curves of 211 randomly selected patients were drawn using the VCTS chart. Depending on the type of curve obtained, patients were grouped in different diagnostic categories following the instructions supplied with the chart. Clinical examination revealed that the VCTS chart curves indicated a false diagnosis of cataract in 65.5% patients and in 54.2% patients a false diagnosis of glaucoma. In a number of additional patients, VCTS chart testing had failed to indicate the presence of cataract or glaucoma. Contrary to the claims of the manufacturer our results demonstrate that the VCTS chart has no value as a screening device in a clinical practice.

A section paper selected by the JOURNAL, authored by Lilia McMillan (Active Member, AWWA), sr. electron microscopist, and Roy Stout, microscopist, Wtr. Purific. Lab., City of Chicago, III._____________________________________(Chicago, III.) Iron bacteria have been found in untreated Lake Michigan water for the past ten years. Sphaerotilus, the filamentous bacteria, are the most prevalent. The nonfilamentous bacteria, Caulobacter and Gallionella, found sporadically in the lake, are most common in iron-bearing waters. These organisms are only a minor problem in the Chicago distribution system and are usually found only in dead-end mains; however, they create difficulties in some systems. Various methods for the growth and isolation of iron bacteria are also discussed.

No abstract