232 Arch. f. Augenheilkunde und Ohrenheilkunde, vii. 2, p. 508.
233 Deutsches Zeitschrift f. prakt. Med., No. 2, 1878.
Affections of the Fifth Pair.
HERPES FACIALIS.—Herpes facialis frequently appears on the lips and angles of the mouth, and occasionally in the eye and its appendages. When upon the conjunctiva or cornea, it commences as clear watery vesicles, usually in groups, which soon burst and leave open ulcers looking very much like abrasions or scratches of this membrane. They usually occur in successive crops after fevers, especially pneumonia, although at times they may appear without any assignable cause. They are also slow to heal, but are not dangerous to the eyesight, except where they give rise to purulent infiltration leading to hypopyon.
HERPES ZOSTER OPHTHALMICUS.—Herpes zoster ophthalmicus is a far more formidable affection. The eruption, as is well known, follows the distribution of the divisions of the ophthalmic branch of the trigeminus, and when the eyeball is affected the sight is always threatened. Clear watery blisters form on the cornea, which soon burst, the exposed tissue taking on purulent infiltration, while pus is not infrequently deposited in the anterior chamber. These ulcers are slow to heal under the most careful treatment, which, as a rule, consists in washing with disinfecting solutions and applying a bandage, etc. There is almost always iritis, as evidenced by the sluggish pupil and at times by marked synechiæ.
The burning and pricking pain at the seat of eruption is marked, and there is severe neuralgia in the temple, forehead, and side of the nose. The intensity of the iritis varies considerably in different cases, and, although some terminate favorably, having had but few and slight symptoms, yet the one case reported by Noyes, where it led to cyclitis, followed by shrinking of the eyeball, which ultimately gave rise to sympathetic irritation of the fellow-eye, shows how serious its consequences may be. Permanent opacities of the cornea are not infrequent. The disease is, fortunately, a rare one. It usually comes on either in middle or declining life, although Wadsworth has reported a case in a child four years old. The cornea becomes anæsthetic, both in the ulcers and over the rest of its surface, a long time often elapsing before any of its sensibility is regained. Horner234 was the first to demonstrate that the corneal ulcers originated in vesicles, and the very great diminution of intraocular pressure in the affected eyeball, and also to show the marked difference in the temperature of the skin of the two sides. The temperature on the affected side is usually one and a half to two degrees higher than on the other side, while the cutaneous sensibility is markedly diminished; as, for instance, the æsthesiometer might give twelve lines on the healthy forehead as against twenty-two lines on the diseased side, and the superciliary ridges and the upper eyelid on the normal side might give respectively nine and five lines as against seventeen and seven lines on the affected side. In the cases which the writer has had an opportunity of studying he has found similar variations in intraocular tension, temperature, and sensibility. Hutchinson235 thinks that the affection of the nasal branch is always accompanied by inflammation of the eyeball, and says: "Thus far, I have never seen inflammation of the whole side of the nose without witnessing inflammation of the eye;" while Bowman236 says that he has "not found affections of the eyeball to occur, especially in those cases of ophthalmic zoster in which the eruption followed the course of the nasal branch." Wadsworth237 gives a case where the entire side of the nose was involved, the eyeball and conjunctivæ not being affected. He suggests that possibly the explanation in these cases is an anomaly of distribution described by Turner, where the side of the nose is supplied by a long, slender infratrochlear branch. Bowman,238 although realizing that peripheral excitement of sensory nerves may originate in a central or reflected source, and induce tenderness and redness in the parts supplied by them, yet nevertheless holds that ophthalmic zoster is a peripheral disease, having its primary seat in the branches of common sensation, the nerves probably becoming inflamed in the more superficial portions of their trunks, as the eruption succeeding as an extension of vascular excitement to the cutaneous tissue: he thus explains the tenderness of the skin before it reddens and the often lasting alteration of sensibility. In reference to whether the neuritis causing the eruption is an ascending or descending one, the only two careful autopsies that give answer with which the writer is familiar are those of Wyss and of Weidner, where both show extensive changes in the nerve-centres. The latter, made five years after the attack, showed cicatricial shrinking of the ganglion of Gasser and of the root of the nerve between it and the medulla; while that of Wyss, made within two weeks of the outbreak of the affection, showed that the entire ophthalmic branch of the trigeminus was thickened, reddened, softened, and surrounded by extravasation of blood from the entrance of the orbit up to the ganglion of Gasser; while the other branches of the trigeminus were normal in size and appearance. The Gasserian ganglion itself was enlarged and bright red, while that of the other side of the head was yellowish-white. As is well known, zoster in other parts of the body not infrequently affects the two sides simultaneously; and there are recorded cases where it has twice attacked the same locality, but the writer is not familiar with any such facts as regards ophthalmic zoster.
234 Klinische Monatsblätter f. Augenheilkunde, 1871, p. 321.
235 R. L. O. H. Rep., 1866, pp. 191-215.
236 Ibid., 1867.
237 Trans. of Amer. Oph. Soc., 1874.