R I S, 



after its protnifion, and coiifeqiiciitly it fufTors a great deal 

 more from the comprcflion and irritation. The patient at 

 firft complains of a pain like that of a thorn in the eye, and 

 )3 alfo afterwards affliflcd with an iineafy fcnfation of tight- 

 i!cis or conllrirtioii of tiie organ. To thofc complaints are 

 foon added an inflaintnation of the conjnndtiva and eye-lids, 

 a difch?.r;j;e of irritating tears, and an inability to hear the 

 light. I'he protruded piece of the iris iinavcidaiily drags 

 towards it the reft of this membrane ; and hence the fliape of 

 tiie pupil is changed from round to oval, and its fituation 

 undergoes an approximation to the wound or ulcer, through 

 which the prolapfus of the iris has taken place. 



When the difeafe has prevailed a confiderable time, the 

 intenfity of tlie pain, inflammation, and other fyinptoms, is 

 fometimes leflened, inllead of incrcafed. Scarpa informs us 

 of fuch an example in a man, fifty years of age, -.vho for 

 ten weeks had liad a prolapfus of the iris twice as large as a 

 millet-feed. Tl;e patient bore the difeafe with the utmoft 

 indifference, being merely troubled with a flight chronic 

 rcdncfs of the cou'iundliva, and a difficulty in moving the 

 eye ball with freedom. The little tumour felt to the finger 

 hard, and almoft callous. 



In the treatment of this difeafe, fomc praftitioners have 

 recommended pulhing the iris back again into its natural 

 fituation, by means of a whalc-bone probe ; and, in cafe of 

 this being found difficult of accomphiliment, they have ad- 

 vifed the wound or ulcer of the cornea to be dilated as far as 

 ncccffary, in the fame manner as the Ihifture of a ftran- 

 gulatcd hernia is divided, for the purpofe of enabling the 

 furgeon to reduce the protruded bowels. Others have 

 fuggefted, irritating the projedting portion of the iris, in 

 order to make it contraft and return into its proper place 

 again ; and, with the fame intentipn, it has been propofcd 

 to expofe the eye fuddenly to a very vivid light. The ex- 

 perienced and judicious Scarpa, however, fets down all ihefe 

 methods as inefTeftual, if not dangerous ; for, fays he, ad- 

 mitting that we could, in any of llicfe ways, replace the 

 iris, without lacerating or hurting it, ilill there would con- 

 tinue in the wound or ulcer of the cornea an opening, 

 through which tlie aqueous humour would efcape^ and carry 

 out with it again a fold of the iris. 



It cannot be denied that a prolapfus of the iris is a mod 

 unpleafant kind of accident ; but yet, as we are utterly un- 

 poflefled of any means whereby we can ftop the efcape of 

 the aqueous humour through certain wounds and ulcers of 

 the cornea, we ought, according to Scarpa, to coniider the 

 prolapfus of the iris a beneficial occurrence, and preventive 

 of the total deflruftion of the eye, inafmucli as tiie pro- 

 truded fold of this membrane, adling like a plug, prevents 

 the entire lofs of the aqueous humour, which foon coUefts 

 again in the anterior chamber, and liinders a further pro- 

 trufion of the iris, by feparating this membrane from the 

 cornea, and re-eftabliiliing the equilibrium between it and 

 the other humours of the eye. Hence Scarpa reprobates 

 the foregoing plans as ufelefs and dangerous. 



The principles laid down by this eminent furgcou tend to 

 eftablilh two chief indications, in cafes of recent prolapfus 

 of the iris : one is to diminiili the extreme fcniibility of the 

 piece of the iris projefting out of the cornea ; the other is to 

 effcft a gradual deftruftion of the protruded portion of the 

 iris, to fuch a depth as will render the wound or ulcer 

 capable of healing, but not fo deeply as to break the adhe- 

 fion which the iris lias contracted to the bottom of the 

 lircach in the cornea. 



Both thofc indication! may be fulfilled by touching the 

 projcfting part of the iris with tho anlimonium iruriatuin, 

 or, witb what si ftill preferable, the argcntum lutcatum. 



An affiftant, Handing behind the patient's Lead, is to keep \ 

 the upper eye-lid raifed with Peilier's elevator ; and the pa- J 

 tient is to hold his eye as ileady as poffible, by fixing it on i 

 one objeCl. While the affillant raifes the upper eye-lid, Jthe j 

 furgeon is to deprefs the lower one with the index and middle 

 fingers of liis left hand, and with his right touch the pro- 

 truded piece of the ii-is with the argentum nitratum, cut in 

 the ihape of a crayon. The cauftic fliould be preficd upon 

 the centre of the little tumour, fo as to form an cfchar of 

 tlie proper depth. The pain fufFered at this inilant is ex- 

 ceedingly fevere ; but it quickly fubfides, as foon as the eye | 

 has been bathed with warm milk. Tlie cauftic expeditioufly | 

 deftroys the fenfibility of the protruded part of the iris, 

 and the efchar prevents the effects of the friflion of tlie eye- 

 lids, and hinders tie air and tears from caufing any irrita- 

 tion of the projecting portion of that membrane. Hence 

 the pricking and painful tenfion, previoufly felt in the eye, . ■ 

 are diminiftied ; as likewife are the ophthalmy and fecretion' i 

 of fcalding tears. 



The benefit thus produced lafts only as long as the efcliar 

 continues adherent to the tumour formed by the iris. Im- 

 mediately the flough is detached, all the annoying complaints 

 again come on, though in a fomewhat mitigated degree, in 

 confequence of the projecling part of the iris not being quite 

 fo prominent as it was before the cauftic was applied. The 

 efchar frequently feparatcs on the fecond or third day : but 

 whenever it happens, the painful fymptoms recur ; and the 

 fuigeon"s duty is to ufe the argentum nitratum again with- 

 out delay. The application is in this way to be repeated, 

 until the protruded part of the iris is deftroyed fo deeply, 

 that it can no longer hinder the wound or ulcer of the cornea 

 from healing. 



The employment of the argentum nitratum mull not be 

 continued, after the prolapfus of the iris Las been fuf&ciently 

 depreffed ; as we learn from Scarpa, that fuch a plan would 

 bring on all the pain and inflammation again in an aggravated 

 form. When the little tumour has been levelled as much as 

 the indication requires, the caullic is not to be applied 

 again ; and the furgeon is fimply to introduce between the 

 eye and eye-Lds a collyrium, containing fulphate of zinc 

 and mucilage of quincc-fecds, and afterwards infimiate a 

 fmall quantity of the following ointment under the eye-liJs> 

 every morning and evening ; 

 I^ Adipis fuilhe 56. 

 Tutis ptt. 



Bol. Armen. fubtilidimc pulv. a a 3i> 

 Calcis hydrarg. alb. Jj. Mifce. 



This ointment mufl be at fii'fl weakened witli twice or 

 thrice its quantity of lard. 



When the foregoing applications are not too ftimulating, 

 the ulcer is gradually diminiftied, and generally quite healed 

 in about a fortnight. 



As the union, which takes place in the courfe of the treat- 

 ment, between the protruded piece of the iris and the internal 

 edges of the wound, or ulcer, of the cornea, always con- 

 tinues after the cure is cotripleteJ, the pupil muft for ever re- 

 main of an oval fliapc, and a little inclined towards the ci- 

 catrix ir. the cornea. This muil happen even when the 

 treatment L;u been as fuccefsful as poffible. It is pleafing, 

 Lowevcr, to learn from the experienced Scarpa, tLat fuch 

 alteration in the fituation and pofitionof the pupil caufes little 

 or no diminution of the power of feeing the mcift minute 

 objeds, and occafions much lefs impairment of the fight 

 than might be fuppofed, unlefs it unfortunately happen 

 that the fear in the cornea is in the middle of it. 15e- 

 fidts, we are alfo allured by the faiuc dillinguifbed furgeon, 



that 



