Linear extraction is employed for fluid or soft cataracts in subjects under 25 or 3o years of age, and is suitable after the failure of discission. It is performed by making a short incision within the margin of the cornea by a triangular keratome, after which the capsule of the lens is incised by the cystotome; and, gentle pressure being applied, the softened lens is evacuated through the corneal wound. The iris is left untouched unless prolapse occurs, when an iridectomy may be necessary if this cannot be satisfactorily reduced.
Congenital cataract should be operated upon early—i.e., before the end of the first year—especially when the opacity is complete, though often other serious ocular defects are also present. Needling is usually satisfactory when the cataract is fluid; in hard opacity the linear opera tion will be required, and the capsule may require removal by forceps.
The lamellar cataracts occurring in young subjects may be treated by an iridectomy when the periphery of the lens is clear and the opacity is limited, otherwise needling must he resorted to, the iris being left intact; in either case often a considerable defect of vision may be usually antici pated.
In traumatic cataract as little operative interference as possible should be undertaken; atropine may be safely instilled only so long as the tension in the injured eye is low. After the lapse of several months needling or linear extraction may be resorted to, but binocular vision must not be expected. When a foreign body in the lens complicates the condition the lens with the contained substance demands immediate extraction.
In all cataract operations for senile or other types only one eye should be operated upon at a time, and extraction should not be undertaken in the presence of conjunctivitis and of lachrymal tumour or mucocele, and when the projection of light is indicative •Elf deep-seated disease in the fundus, but the presence of glycosuria need not prohibit operative measures, and sometimes albuminuric cases make a satisfactory though slow recovery.
CATARRH—see also Bronchitis.
This affection is but the first stage of a laryngeal or bronchial attack, the inflammatory process extending downwards as in ordinary catarrhs or " colds." When confined to the nasal membrane it is known as Catarrhal Rhinitis.
Preventive treatment consists in the use of Anticatarrhal vaccines pre pared from the Friedlander bacillus or of the Wimpole Institute " Com bined vaccine for colds," immunity being securable for some months after the injection of a tube containing 125 to 50o million organisms.
Any cause of the susceptibility should be sought out and removed; thus adenoids, hypertrophied turbinates, polypi, deviation of the septum, or pharyngeal tonsils, &c., may be the chief factors, and their treatment may entirely remove the tendency towards recurrence of acute attacks of catarrh.
The wearing of too heavy clothing and living in heated rooms owing to the dread of draughts is a fertile source of attacks, and can only be remedied by an education in the principles of open-air living and general hygiene. When an attack has already occurred undoubtedly the only reli able method of causing its speedy abortion is the injection of a full dose of the combined vaccine previously mentioned. This vaccine has been also
given by the mouth with success. A hot bath followed by a full dose of Morphia at bedtime is a favourite remedy with some, and Benzoate of Soda in one dose of 45 grs. is often efficacious. A popular method of treatment is to give teaspoonful doses of the Ammoniated Tincture of Quinine, and the equivalent of this dose can be procured in the capsular or tabular form combined with Camphor and Atropine with a little Morphia. A local spray of Carbolic Acid is sometimes efficacious at this early stage.
When free secretion has already appeared the latter-mentioned abortive remedies should not be employed, the best treatment at this stage being that indicated at the beginning of an attack of acute bronchitis. After a hot bath the patient should go to his bed, and perspiration should be encouraged by a smart diaphoretic like Sweet Spirit of Nitre in dr. doses with double this amount of Mindererus Spirit and not more than 3 mins. of Liquor Morphia administered every three hours. By these means the catarrh may often be prevented from extending downwards to the larynx and bronchi.
Local applications for the relief of sneezing and other symptoms of irritation may be demanded. The most efficacious of these is an inhala tion of the vapour of very hot water to which a little Carbolic Acid, Hem lock Juice, or Tr. Benzoin. Co. has been added. Ordinary inhalers are of little use; a large basin of almost boiling water should be placed under the patient's head, and a sheet thrown loosely over him; the air becomes rapidly saturated by the vapour. Dry heated air is always irritating, and the sick-room atmosphere should be kept saturated with moisture.
For mild attacks Ferrier's Snuff, consisting of Morphine Hydrochloride gr., Powdered Gum Acacia i dr., and Oxynitrate of Bismuth 3 drs., may be insufflated frequently. Cocaine usually gives speedy but dearly purchased relief, as the irritation returns in an aggravated form. The best local anaesthetic is Menthol; this may be added with advantage to Ferrier's Snuff (5-1 o grs. per oz.). A spray for use in the atomiser con sisting of i per cent. Menthol in pure liquid Paraffin to which a little Cam phor is added makes a valuable local soothing application. Plugs of cotton-wool saturated with a 5 per cent. ointment of Menthol in lanolin may be inserted up each nostril, or the ointment can be smeared over the nasal membrane by the finger tip. Relief is often afforded by frequently sniffing the vapour of Eucalyptus Oil from a small phial warmed by the heat of the hand.
Chronic nasal catarrh is best treated by the Ammonium Chloride Inhaler; the posterior nares may be washed out frequently by a r per cent. solution of Ammonium Chloride, which is sniffed up from the palm of the hand. Half a teaspoonful of the following powder dissolved in a tumbler ful of warm water may be used in a similar manner several times a day: Sodii Bibor., Sodii Bicarb., Sodii Chloridi, ana 5ss. Where the discharge continues, though no obvious local cause can be detected, a cautious cauterisation of the posterior wall often arrests the inflammatory process.
CHANCRE—For Hard Chancre see under Syphilis.