The Action of Drugs Upon the Eye

The Action of Drugs Upon the Eye
We have now completed our survey of the principal drugs which act upon the eye; and it remains that we consider them together, for purposes of grouping, of comparison, and of discrimination. We shall best do this, I think, by studying them in relation to the several tissues of the organ, and to the morbid state to which these are liable. The catalogue raisonnee you will see on the board behind me gives the classification I would suggest. The medicines below the line in each group are such as I have not discussed in my lectures, but which should be mentioned in connection with the therapeutics of each region.
The following is the list to which reference is made:
Conjunctiva
Argentum nitricum, Arseicum, Belladonna, Chloral, Digitalis, Euphrasia, Hepar, Kali bichromicum, Mercurious, Pulsatilla, Rhus, Sulphur, Graphites,Guaraea, Ruta hia., Silicia, Staphisagria, Zincum.
Cornea
Apis, Arsenicum, Aurum, Calcarea, Cannabis, Euphrasia, Hepar, Kali bichromicum, Mercurius corrosives, Sulphur.
Sclera
Aconite, Kali bichromicum, Spigelia, Sulphur, Thuja
Iris
Belladonna, Clematis, Euphrasia, Kali bichromicum, Mercurius, Physostigma, Terebinthina, Sulphur, Bryonia, Thuja.
Choroid
Aurum, Digitalis, Gelsemium,  Ipecacuanha, Phosphorus, Santonine, Kali iodatum
Retina and Optic Nerve
Acidum picricum, Belladonna, Mercurius, Phosphorus, Plumbum, Santonine, Strychina, Kali iodatum, Lithium, Tabacum.
Lens
Santonine, Sulphur, Causticum, Calcarea, Magnesia Carbonica, Phosphorus, Sepia, Silicia.
Muscles
Actaea, Physostigma, Rhus, Ruta, Jaborandi, Natrum muriaticum, Senega.
Nerves
Aconite, Agaricus, Argentum, Belladonna, Conium, Gelsemium, Lilium, Spigelia, Causticum, Colocynth, Prunus spinous, Senega.
1. Conjunctiva.-As acting upon the mucous membrane of the ball and lids, with its glandular involutions, we have a list of twelve principal and six secondary
medicines. Of these, eight correspond to catarrhal conjunctivitis of the bail-Arsenicum, Belladonna, Chloral, Euphr asia, Kali, hlchrornicum, Mercurius,
Sulphur, and Guarcea, When acute, Euphrasia, Belladonna, Sulphur, Chloral, and Guarcea are suitable, Euphrasia, when much lachrymation is present (especially if it is acrid) ; Belladonna when the membranes is rather dry and burning; Sulphur when, with a slighter degree of the Belladonna symptoms, there is also itching, and when the subject is unhealthy; Guarcea , in the presence of chemosis. The distinctive place of Chloral is hardly yet ascertained; it must be borne in mind as a possible alternative to any of these. Araenicum, Kali bichrornicum and Mercurius belong rather to chronic conjunctivitis. The discharges of the first are characteristically thin; but practically it is the remedy for almost every case of chronic inflarnmation of the ocular conjunctiva, Kali bichromicum and Mercurial preparations taking its place when that of the lids is more affected. The former is suitable when there is granulation of the membrane leading to pannus: the latter when the Meibomian glands are more affected, thickening the eyelids, and causing profuse muco-purulent discharge. Under these last circumstances Hepar sulphuris also comes into action, its discharges being somewhat thicker; and Digitalis may find place. Hepar is also effective in, inflammation of the palpebral margins (blepharitis ciliaris), where it finds an ally in Graphites when the symptoms are of a more passive character, Pulsatilla corresponds to the previously mentioned sphere of Hepar-its discharges
being thick and bland; but is of especial use when the Meibomian inflammation is concentrated in a single gland, constituting hordeolum, or “stye”. Staphisagria. reinforces it here when this affection tends to recurrent.
When the prolongation of the conjunctiva into the lachrymal ducts, cure has been wrought by Graphttes, by Sulphur, and by Mercurius corrosives.
In true purulent ophthalmia, while some benefit is got from Hepar sulphuris, from Mercirius, and from Pulsatilla, the most effective remedy is Argentum
nitricum. In strumous opthalmia any of the conjunctival remedies hitherto mentioned may find place, according to their respective indications but when the phlyctenular
character of this affection is very marked, they all yield to Rhus.
Ratanhia and Zincum correspond to that curious affection of the conjunctiva known as pterygium.
2.  Cornea.-The drugs that’ act on the cornea are fewer in number, but their sphere is well-defined. Apis corresponds to its simple inflammation. Mercurius
corrosivus and Arsenicum are suitable when the mischief is ulcerative, the choice between the two being determined by the. lesser degree of inflamrnatory action which
characterises the later; and Hepar sulphur where suppuration occurs. Euphrasia and Kali bichromioum are in place when the morbid process begins in the conjunctiva, and invades the cornea only secondarily. Aurum and Calcarea suitable to a more chronic and interstitial keratitis, the former in both the syphilitic and the strumous forms of the complaint, the latter in the strumous only, where also Sulphur may do something. Several of these medicines, but chiefly Calcarea are of  avail to remove opacities of the .membrane ; and here we have also the aid of Cannabis.
3.  Sclera – For the affections of the sclerotic coat of the eye our dependence must be placed on the four medicines from our list which you see before you, and perhaps on Thuja, which is considered by Drs. Allen and
Norton as exerting upon this membrane a more marked action than any other drug. Aconite is suitable in primary sclerities from exposure to cold, when the pain is diffused, and Spigelia, under like circumstances, when
it is darting and shooting like neuralgia. Kali biochromicum is of great service when the conjunctiva is involved. and the cornea threatened. Sulphur (in the lower triturations) suits cases of a more passive and lingering character.
4.             Iris – It is of the iris as a part susceptible of inflammation that we have now to speak: as a contractile curtain it must be considered among the muscles of the eye. The only drug which has proved its power of inflaming it is Physostigma as we have seen reason to put Mercury out of court in this respect; but the other members of my group have attained unquestioned creditin the cure of iritis. Belladonna seems effective in its simple form. such as may come on frorn traumatism. In rheumatic iritis, if the effusion be serous only, Mercuriusmay suffice, though Euphrasia and Terebinthina must not be forgotten, and Physostigma may prove the best remedy
of all. In the syphilitic form, our chief reliance must be placed on Clematis and Kali bichromicum though Thuja may be useful (as stated by Dr. Norton) in removing the deposits of lymph. Bryonia and Sulphur find place. if anywhere in the rheumatic form, the first in the painful
stage, the second to wind up the case satisfactorily.
5.      Choroid.-For simple choroidal congestions Digitalis, Ipecacuanba, Phosphorus and Santonine claim consideration. Their differential indications are hardlv
known, but the choice of the third would be determined by the constitutional condition. For serous choroiditis, Gelsemium seems facile princeps, and for the plastic ( disseminate ) form, Aurum and Kali iodatum. Rhus is reported very effective when choroiditis becomes suppurative, and constitutes the affection known as panophthamitis.
6.      Retina and optic nerve – For simple retinal congestion, as form over-use of the eyes, we need not go farther than Santonine. In retinitis simplex, and Optic neuritis before exudation has taken place, Belladonna is the great remedy; later Mercurius and Picric acid are indicated. In albuminuric retinitis, our reliance should be placed on Mercurius ( best in the form of the corrosive sublimate ) and Plumbum; in syphilitic, on Kali iodatum. Strychnia corresponds to retinal hyperaesthesia, Lithia and Tabacum to the opposite condition.
7.      Lens – The choice of remedies for cataract must depend rather upon the general condition and the anamenesis than on any differences in the opacity itself. The indications thereby afforded for Calcarea, Sepia, Silica and Sulphur are obvious enough; and in their absence, the other remedies mentioned may be tried in order.
8.      Muscles – Of the medicines classed as acting on the muscles of the eye, Physostigma and Jaborandi would correspond to their irritable condition, Actea to their involvement in rheumatism, Rhus and Senega to their paralysis. Ruta and Natrum muriaticum are most effective in asthenopia.
9.      Nerves – The sensory nerves of the eyes are affected Aconite, Colocynth, Prunus and Spigelia in the direction of neuralgia, by Belladonna and Conium in that of hyperaesthesia. Its motor nerves are excited to spasm by Agaricus and Lilium, depressed to paralysis by Argentum, Conium, Gelsemium, Causticum and Senega.