Observations on two Distinct Varieties of Ophthalmia, prevalent ́British army, a disease unparalleled in the medical records of our country, cannot fail to be an object of much importance to the medical inquirer. The disease still proves a source of great uneasiness to the feelings of army surgeons; and while we are glad to find that much has been done towards establishing the cure of this disease, much yet remains; and in spite of all our efforts, a foundation is often laid to diseases, which though slow in their progress, do assuredly injure, and too often destroy vi- In the 2d battalion of the 71st regiment, stationed, during these two years, in barracks at Glasgow, ophthalmia made its The opportunity I had of observing the symptoms of this malady, soon convinced me that it attacked under two very distinct forms. These I at first regarded as different diseases; an opinion which the strongest evidence has since compelled me to alter, and to consider them as the same, modified by circumstances; to scrutinize which would form a difficult, though highly interesting inquiry. Any attempt to distinguish these varieties, by the general names of acute and chronic, would, from the received definition of them among surgeons, only tend to mislead. The form which has claimed the greatest share of attention, begins with an itchy sensation of the eyelids: on a little rubbing by the finger of the patient, the whole ball of the eye may be observed to have an appearance of fulness; but it requires minute examination to discover a slight vascularity affecting the tunica conjunctiva, in a concentric line, at a small distance from the circumference of the cornea, exactly opposite to which, on the surface of that membrane, as it is reflected to cover the eyelids, a corresponding redness is observable. These vessels are of small size, but in the progress of the complaint become more prominent; and it is worthy of remark, that as the redness extends along the conjunctiva covering the eye, so it does on the surface of that covering the eyelids; till, at the place of its reflection, a white line may be perceived for a few hours, which at last is involved in the complaint. This fact, it may be remarked, has entered into the description generally given of the symptoms of this disease. I have been induced to notice this, only from its having been stated with an accurary, that might have led us to rank it as a characteristic feature of the disease, a place to which I believe it is by no means entitled. It is an appearance which bears a very strong analogy with the phenomena of inflammation in membranes of a different class, and can convey but little information concerning the disease under consideration. In the place where the redness is originally discovered, the disease first gains its height; and the vessels of the tunica conjunctiva, by their minuteness and number, give to the eye something of the appearance called chemosis, though that state has not yet taken place; for, at this time, on pressing the eyeball with the finger, the eyelid being interposed, and removing it quickly, the whole surface becomes white, and, for the first time, the vessels of the sclerotic coat are seen increased in size, carrying red blood, and running in straight lines towards the cornea. On removing the pressure, these are first filled, and present a purple rather than red tint, immediately afterwards; those of the conjunctiva, more tortuous and. large, are longer of filling, and become of a deep red. Soon after the first appearance of the symptoms now detailed, purulen cy commences, constituting, according to those who have described this disease, its second stage, at which time the eye puts on an appearance which I have not seen described, nor have I ever remarked it in the more violent forms of inflammation to which the organ is liable from external injury. In different points, under the conjunctiva, covering the eyeball, small patches of a scarlet hue appear of different sizes and irregular figures, which no pressure can remove, and which, I apprehend, are formed by extravasated blood: these, by a very gradual increase, unite; and thus chemosis is formed. This state of the eye gives to the countenance of one affected with it a very striking appearance; but I am far from wishing it to be understood, that this account of the early appearance of chemosis, is drawn out with the desire of its forming a pathognomonic feature; certainly, the most prominent symptom is the very early and copious effusion of a purulent-like fluid, though this can with difficulty be admitted as characteristic of the complaint, since it is by no means uncommon in the more severe attacks of inflammation of the eye, from great violence done to that organ, as in the operations of couching and extracting. A slight feeling of stiffness, and afterwards of a painful sensation of a mote in the eye, announces to the patient, at the very earliest period of attack, that inflammation has taken place, the recurrence of which at regular periods has, though I know not with what decision, been remarked. In general, the observations which have been made by army surgeons, tend to confirm the remark, that exposure of the eye to light, in this variety of ophthalmia, is not productive of much uneasiness; a fact, in my opinion, of high importance, as on it I believe a diagnosis may be grounded with much propriety. The texture of the cornea does not appear apt to become affected with opacity, or increase of vascularity; for, a few hours before it gives way, and the contents of the eye discharge themselves, it may be seen sunk in the hollow of a great chemosis, transparent and natural; and when it bursts, such is the rapidity of the change from the healthy state, that one would be inclined to lay aside the action of the absorbents entirely. The different appearances which the eye puts on, from the time at which the disease baffles the surgeon, would form a very interesting inquiry to a writer on morbid anatomy; but farther than the fact of rupture of the cornea I cannot enter, as unconnected with the object of these pages. I believe, in every case of the variety of ophthalmia which I have mentioned, the sclerotic coat to be affected with increased vascularity; a fact which in my opinion has been overlooked, from the account of the symptoms having been drawn out at an advan The opportunity I had of observing the symptoms of this malady, soon convinced me that it attacked under two very distinct forms. These I at first regarded as different diseases; an opinion which the strongest evidence has since compelled me to alter, and to consider them as the same, modified by circumstances; to scrutinize which would form a difficult, though highly interesting inquiry. Any attempt to distinguish these varieties, by the general names of acute and chronic, would, from the received definition of them among surgeons, only tend to mislead. The form which has claimed the greatest share of attention, begins with an itchy sensation of the eyelids: on a little rubbing by the finger of the patient, the whole ball of the eye may be observed to have an appearance of fulness; but it requires minute examination to discover a slight vascularity affecting the tunica conjunctiva, in a concentric line, at a small distance from the circumference of the cornea, exactly opposite to which, on the surface of that membrane, as it is reflected to cover the eyelids, a corresponding redness is observable. These vessels are of small size, but in the progress of the complaint become more prominent; and it is worthy of remark, that as the redness extends along the conjunctiva covering the eye, so it does on the surface of that covering. the eyelids; till, at the place of its reflection, a white line may be perceived for a few hours, which at last is involved in the complaint. This fact, it may be remarked, has entered into the description generally given of the symptoms of this disease. I have been induced to notice this, only from its having been stated with an accurary, that might have led us to rank it as a characteristic feature of the disease, a place to which I believe it is by no means entitled. It is an appearance which bears a very strong analogy with the phenomena of inflammation in membranes of a different class, and can convey but little information concerning the disease under consideration. In the place where the redness is originally discovered, the disease first gains its height; and the vessels of the tunica conjunctiva, by their minuteness and number, give to the eye something of the appearance called chemosis, though that state has not yet taken place; for, at this time, on pressing the eyeball with the finger, the eyelid being interposed, and removing it quickly, the whole surface becomes white, and, for the first time, the vessels of the sclerotic coat are seen increased in size, carrying red blood, and running in straight lines towards the cornea. On removing the pressure, these are first filled, and present a purple rather than red tint, immediately afterwards; those of the conjunctiva, more tortuous and. large, are longer of filling, and become of a deep red. Soon after the first appearance of the symptoms now detailed, purulen cy commences, constituting, according to those who have described this disease, its second stage, at which time the eye puts on an appearance which I have not seen described, nor have I ever remarked it in the more violent forms of inflammation to which the organ is liable from external injury. In different points, under the conjunctiva, covering the eyeball, small patches of a scarlet hue appear of different sizes and irregular figures, which no pressure can remove, and which, I apprehend, are formed by extravasated blood: these, by a very gradual increase, unite; and thus chemosis is formed. This state of the eye gives to the countenance of one affected with it a very striking appearance; but I am far from wishing it to be understood, that this account of the early appearance of chemosis, is drawn out with the desire of its forming a pathognomonic feature; certainly, the most prominent symptom is the very early and copious effusion of a purulent-like fluid, though this can with difficulty be admitted as characteristic of the complaint, since it is by no means uncommon in the more severe attacks of inflammation of the eye, from great violence done to that organ, as in the operations of couching and extracting. A slight feeling of stiffness, and afterwards of a painful sensation of a mote in the eye, announces to the patient, at the very earliest period of attack, that inflammation has taken place, the recurrence of which at regular periods has, though I know not with what decision, been remarked. In general, the observations which have been made by army surgeons, tend to confirm the remark, that exposure of the eye to light, in this variety of ophthalmia, is not productive of much uneasiness; a fact, in my opinion, of high importance, as on it I believe a diagnosis may be grounded with much propriety. The texture of the cornea does not appear apt to become affected with opacity, or increase of vascularity; for, a few hours before it gives way, and the contents of the eye discharge themselves, it may be seen sunk in the hollow of a great chemosis, transparent and natural; and when it bursts, such is the rapidity of the change from the healthy state, that one would be inclined to lay aside the action of the absorbents entirely. The different appearances which the eye puts on, from the time at which the disease baffles the surgeon, would form a very interesting inquiry to a writer on morbid anatomy; but farther than the fact of rupture of the cornea I cannot enter, as unconnected with the object of these pages. I believe, in every case of the variety of ophthalmia which I have mentioned, the sclerotic coat to be affected with increased vascularity; a fact which in my opinion has been overlooked, from the account of the symptoms having been drawn out at an advan |