Air in the eye.

THE introduction of air, or saline, into the eye is a fairly recent innovation. The practice has its advocates and its critics, so that a short review of its uses by one of the former may be of interest. The author's experience, chiefly with air, forms the basis of this paper. Recently, however, it has become apparent to him that there are occasions when saline is preferable. In the conclusion, therefore, the relative merits of air and saline are briefly discussed. In the anterior chamber, the most common use of air is probably after cataract extraction. It has even been stated that the injection of air is the most important part of the operation! In most instances it is unnecessary because, with the use of sutures-which again is a controversial matter-the anterior chamber reforms rapidly. There are, however, occasions when the iris is lacking in tone and when at the end of the operation it seems wise to push it away from the section with a bubble of air. This applies to both extraand intra-capsular extractions. The only likely serious complication is the passage of the air through the pupil, behind the iris, where of course it does the opposite of what is desired. The writer was first made aware of this possibility in a patient in whom a large bubble of air entered in the " wash-out" and filled the anterior chamber. All looked so satisfactory that it was decided to leave it there and the patient went back to bed in Fowler's position. Next day the iris was found to be hard up against the section with no sign of any air. It seemed advisable to abscise the threatened prolapse and the patient came back to the theatre for this to be done. As she lay flat on the table a bubble of air emerged through her pupil into the anterior chamber. Even then what had really happened was not understood and the abscission was completed. It was only later, when a rather similar event occurred in another patient, that the problem was solved. This danger is sufficient to antagonize some surgeons against the use of air after a cataract operation, but it is quite easily avoided by ensuring that the patient is kept reasonably flat-with not more than three pillows instead of a bed-rest for the first day or two after operation. Air is probably contraindicated where there has been a complete