Cataract Knife Research Articles

CATARACT EYE SPECULUM

This speculum is designed to lay over the nose with the hinge or joint over the nonoperated eye, leaving the temporal region, on the side of the operation, entirely free from parts that might in any way limit the operator's freedom or come into accidental contact with the cataract knife or other sharp instruments. Special attention is directed to the distinctive form of the lower arm of the speculum, which is bent sharply upward, and returns, crossing the straight upper arm in the median line (anatomically speaking). The object of this bend is to have the two arms of the speculum cross the nose at the same level; otherwise the speculum is tilted out at the bottom and dislodged. The speculum is easily inserted and firmly retained, regardless of the size or shape of the nose. The speculum was devised particularly for cataract operations to give the operator perfect freedom

Investigations on the Normal Values for the Haemoglobin and Cell Volume in the Small Child.

Résumé1. On perusing the literature a considerable lack of agreement in the value given for the Hb. in small healthy children is found.2. The divergencies are partly due to technical errors, and party to physiological errors. National characteristics also seem to play a role.3. In the author's own investigations a physiological lability of the small child's capillary system is demonstrated. Incision with a sharp instrument, where the mechanical irritation of the capillaries is at a minumum, gives relatively low Hb. values, while incision with a blunter instrument causing greater irritation gives relatively high values. The explanation of this is that a contraction of the vessels takes place, the degree of which is regulated by the strength of the irritamentum, which affects the number of red corpuscles, and this finds an excellent analogy in Krogh's experiments on frogs.4. From this it follows that, when dealing with small children, a sharp instrument (cataract knife) must be used in all cases where the blood is taken from the ear and that the incision or puncture should preferably to deep, otherwise quite inconsistent results will be obtained.5. It does not seem to be of any importance which drop of blood is used for the Hb. determination after the incision is made.6. The examination of 85 healthy children, from a fortnight to 2 years old, showed a rapid fall in the Hb. curve from birth, reaching a minimum about the 2nd. or 3rd. month, irrespective of sex. The curve then remained level for the first year at about 80 % (100 % Hb. = 18,5 volumes % oxygen) and only rose again during the 2nd. year.7. The cell volume of the blood in healthy small children, except in the first few months of life, is about the same as that of healthy adult women.8. The relation between the Hb. percentage and the cell volume is denoted by the term Hv. This value signifies the relation between the Hb. of the blood corpuscles and their volume, just as the ordinary index (F. I.) signifies the relation between the Hb. and their number. The small child's physiological chlorosis is demonstrated by means of the Hv. value.9. An increase in Hv. above the physiological limit can be explained by a drying up of the blood.

A FEW PARAGRAPHS ON AFFECTIONS OF THE LACHRYMAL APPARATUS.

It will be apparent to any one who is at all familiar with the anatomic conformation of the lachrymal passages, that certain shaped appliances fashioned from a practically unyielding metal, under the name of lachrymal probes, do not meet the requirement for the purpose they were designed. We have evidence at every hand of the great injury following the passage of the probe, and the difficulty of effecting a cure for obstinate cases of epiphora, due to obstruction of the lachrymal canal. The "slitting up" or destruction of the punctæ and canaliculi, for frequent probings, the indiscriminate "plunging" and "twisting" of a bistoury or a sharp double-edged Graefe cataract knife into the tissues of the nasal duct, the application of caustic, tissue-destroying agents, have not only signally failed to effect a cure but, in the majority of cases, have entailed future discomfort and irreparable damage, with little or no permanent

A KNIFE PROTECTOR.

Almost everyone who has had occasion to. employ a Graefe cataract knife or a keratome, has at some time or other had the misfortune to have had the point blunted or the edge dulled by coming in contact with the sides of the dish in which sterilization was being performed, either while the instruments were being sterilized or while the dish containing them was being moved. If one has a rack in which to place all of the delicate cutting eye instruments the above misfortune is not likely to occur. But as a rack is not always to be had when needed, the author has devised an instrument shown in the accompanying diagram, so small as to be easily carried in the instrument case, which will protect the point and edge of the knife while being sterilized or moved about prior to the operation. The device is so well shown