Glaucoma : its causes, symptoms, pathology, and treatment

Front matter

Section, Shelf. . .

Book, . . . . .

Worcester Dist. Medical Society.

SECTION I— ETIOLOGY. Primary Glaucoma

PAGE

Frequency of occurrence ... ... ... 1

The sexes equally affected ... ... ... 3

A malady of advanced life ... ... ... 4

Usually bilateral ... ... ... ... 5

The chronic more common than the acute ... 5

Acute attacks more common in women ... ... 5

The influence of heredity ... ... ... 6

Commonly associated with hypermetropia ... ... 7

Trigeminal neuralgia — evidence of its association with glaucoma — irritation of fifth nerve in animals — H. Schmidt's investigation as to range of accommodation in cases of toothache —

tonometrical measurements in cases of toothache 8

Other nerve disorders ... ... ... ... 15

The climacteric change... ... ... ... 16

Induction of glaucoma by atropine ... ... 16

Secondary Glaucoma.

Iritis and synechia

Injury and dislocation of lens ...

Vll.

Foreign bodies

Sympathetic inflammation

Intraocular tumours

Myopia

Eetinal haemorrhage

Glaucoma occasionally associated with retinitis pigmentosa, retinitis albuminurica, primary atrophy of optic nerve, detachment of retina, aphakia ...

PAGE

22 22 22 22 23

SECTION II. — ESTIMATION OF TENSION. General principles ... ... ... ... 27

Tonometry — sources of error — variations in elasticity of sclera, size of eye, form of eye, curvature of

sclera at point of impression ... ... 29

Eelative accuracy of different methods — experiments... 33

Action of the tonometer ... .. ... 40

Mode of application ... ... ... ... 42

Comparison of this with other methods ... ... 44

Table of trial measurements ... ... ... 47

Note — further experiments — relation of tonometrical

measurements to internal pressure ... ... 48

SECTION III. — SYMPTOMS. General Descripti

ON.

Primary glaucoma

Chronic glaucoma

Sub-acute glaucoma

Acute glaucoma

Haemorrhagic glaucoma...

Absolute glaucoma

Secondary glaucoma vm.

Analysis op Symptoms.

page

Apparatus for experiment ... ... ... 69

Diminution of accommodation — experiment ... 70

Changes of refraction ... ... . . ... 72

Iridescent vision — experiment ... ... ... 74

Corneal opacity ... .., ... ... 76

Corneal anaesthesia ... ... ... ... 78

Dilatation of pupil ... ... ... ... 80

Dilatation of anterior ciliary arteries and veins ... 82

Pulsation of vessels of optic disc .., ... 82

Contraction of field of vision — experiment ... 87

Cupping of optic disc ... ... .. ... 90

SECTION IV.— PATHOLOGY.— P APT I. Outline of its history up to present time... ... 93

The intraocular pressure ... ... ... 97

Its normal height — experiments ... ... 97

Its relation to hlood pressure ... .,. 100

Influence of fifth nerve ... ... 103

Influence of sympathetic nerve ... ... 105

Not affected by accommodation ... ... 105

Equal in aqueous and vitreous chambersopposite opinion of Weber examined —

experimental evidence ... ... 106

Influence of atropine and eserine .. 110

Aqueous humour secreted by ciliary processes ... 112 Aqueous humour escapes at angle of anterior chamber

— Leber's experiments ... ... ... 113

Angle of anterior chamber closed in glaucomatous

How is this closure produced 1 — theories of Max Knies

and Adolph Weber ... ... ... 118

Experiments — description of apparatus ... ... 123

IX.

Slight excess of pressure in vitreous chamber closes

angle of anterior chamber ... ... 128

Glaucoma is due to some condition which exalts vitreous

pressure above aqueous pressure ... ... 135

Nutrient supply to vitreous humour proceeds from

ciliary processes... ... ... ... 137

And escapes by passing through suspensory ligament

into aqueous chamber — experiments ... 141

Summary of the foregoing ... ... ... 147

SECTION V.— PATHOLOGY.— PAET II. Primary Glaucoma

Glaucoma usually associated with commencing senility 150

Senile changes in lens capable of raising vitreous

pressure — evidence in support of this theory,

viz., hypermetropic structure, action of atropine

and eserine, rapid onset of presbyopia ... 152

Vascular changes — dilatation of anterior ciliary veins —

swelling, of ciliary processes ... ... 156

Theoretical explanation of glaucoma — narrowing of the

" circumlental space" ... ... ... 158

Acute glaucoma — sudden change in lens? — sudden swelling of ciliary processes — arterial hyperemia — neuralgia in relation to acute attacks ... 159

Ultimate stagnation of the intraocular fluid ... 163

Influence of iridectomy ... ... ... 164

In acute glaucoma ... ... ... 167

In chronic glaucoma ... ... ... 168

" Malignant " glaucoma due to excessive diameter of lens — observations of Adolph Weber and H. Pagenstecher ... ... 169

Method of cure practised by Weber ... ... 172

X.

Secondary Glaucoma.

PAGE

Associated with posterior synechia ... ... 175

„ anterior synechia .... ... 177

„ cataract extraction ... ... 178

,, buphthalmos ... 180

„ staphyloma of cornea ... ... 181

„ traumatic cataract ... ... 181

„ dislocation of lens ... ... 183

,, tumours of retina and choroid ... 185

„ intraocular haemorrhage ... ... 187

Objections to the obstruction theory of glaucoma

Closure of angle of anterior chamber does not cause

glaucoma under all circumstances ... ... 191

If secretion of intraocular fluid be suppressed 192

If it find an abnormal outlet ... ... 194

If closure be of limited extent .... ... 195

SECTION VI.— TREATMENT. Iridectomy

Degree of improvement obtainable

Urgency in acute glaucoma

Less beneficial in chronic glaucoma

Mode of performance ...

After treatment, progress, accidents

Malignant course after iridectomy

Outbreak in fellow eye

Sclerotomy

Other substitutes for iridectomy...

Eserine and other myotics

General treatment

Note — theoretical considerations as to treatment

Note — anaesthesia by chloral and ether

XI.

Section VII. — Appendix. Page

Table of tonometrical measurements ... ... 276

PLATES.

xm.

INTRODUCTION.

The nomenclature and the general arrangement adopted in the following pages require a few words of explanation.

The commonly adopted division of glaucomatous diseases into a primary and a secondary group is here retained. Eecent discoveries have tended, in some measure, to show that this division is arbitrary, and, on scientific grounds, untenable ; that primary glaucoma, if the term indicate a condition in which a rise of the intraocular pressure is antecedent to any structural change, does not exist, and that secondary glaucoma includes conditions the etiology of which entitles them to be classed with the primary. Granting that this is true, I believe that, practically, the division is both simple and useful; and, further, I believe that, with a few slight exceptions, it classifies glaucomatous diseases in strict accordance with fundamental differences in their causes.

I include, under the term glaucoma, or glaucomatous, every condition of the eye characterised by an excess of tension. It is said that not every excess of tension is glaucoma, but it appears to me that to apply or

XIV.

to withhold the name in accordance with the presence or absence of certain of the secondary symptoms is only to create confusion as to the nature of the essential change. From a clinical point of view, the importance of an excess of tension is doubtless exactly proportionate to its duration and amount ; but, to the pathologist, it is the causes which are of chief moment, and these must be studied no less when temporary than when persistent.

At the foot of each page are given references to the sources of the information set forth, or to the other parts of the essay where the subject in question is dealt with more fully. I have referred only to those writings to which I myself have had direct access. In many of these, and especially in the article on Glaucoma by Hermann Schmidt in the Handbuch of Graefe and Saemisch, very much fuller references to the original papers may be found.

In recording conditions of refraction and the power of lenses, I have employed the system of inches, as being that on which nearly all my clinical records have been made.

The work is divided into sections, in accordance with the arrangement of the subject prescribed by the College of Surgeons. This involves a discussion of

XV.

the causes of the disease apart from its pathology — a separation which is at first sight unnatural, but which has, in this case, no disadvantage, inasmuch as the general circumstances and conditions under which glaucoma occurs — its etiology — have long been clearly defined, whereas the intimate nature of the process — its pathology — is, so far as I understand it, a matter of recent discovery, and in part still undetermined. I have divided this latter portion of the subject into two sections, in order to separate, to some extent, that which is demonstrable by experiment from that which is theoretical. The pathology of the secondary effects of pressure finds a more suitable place in the section which treats of symptoms.

A distinct section is devoted to " the estimation of tension," as being a subject of primary importance in the study of glaucoma.

The Table of Contents which precedes this introduction is intended to serve at once as an index* and an epitome of the work.

Section I. Etiology Of Glaucoma

Primary glaucoma, though not rare, is one of the less common maladies of the eye. It appears to constitute a little less than one per cent, of all ophthalmic diseases. Secondary glaucoma, if we include under this term all cases of disease of the eye which are complicated by excess of tension, is met with much more frequently. Exact statistics concerning the prevalence either of glaucomatous diseases in general, or of the two classes separately, are hardly to be obtained. My own hospital case books for the last four years show that primary glaucoma occurs once in a little over one hundred cases, but the total numbers are not large enough to justify a general conclusion. The published statistics of our ophthalmic institutions — which alone furnish figures of sufficient magnitude — do not distinguish between the primary and secondary forms, and, moreover, are vitiated, in some cases, by the separate tabulation of diseases of in-patients and out-patients, whereby cases of more than ordinary gravity, like glaucoma, are frequently registered twice over, and more frequently so than cases of a class which seldom demands admission. The great majority of the cases registered as glaucoma are doubtless primary, while secondary glaucoma is necessarily scattered under many headings — e.g., iritis, synechia, traumatic cataract, intraocular tumour, &c, &c.

The following table exhibits the registry of glaucoma in five of the chief ophthalmic hospitals in this country, as contained in their published statistics : —

*r ST agss

Royal London Ophthalmic Hospital ... j ,g£7 I .64 ... 1 in 156 Birmingham and Midland Eye Hospital j ]g^ I .59 ... 1 in 169 Manchester Royal Eye Hospital j }^7 I L08 •'- * in 93

Liverpool Eye and Ear Infirmary (Eye ( 1876 ) .„- , . n^n

cases only)

Kent county Ophthalmic Hospital ... I ^77 \ '50 ... 1 in 200

The average is "63 per cent., or one case of glaucoma in 158 ophthalmic cases of all kinds.

Statistics from abroad show a higher proportion than this. The following figures, quoted from H. Schmidt, show the percentages derived from very large numbers of cases treated in three continental cities. (*)

Berlin 1-27 per cent. ... 1 in 78

Wiesbaden 1-48 „ ... 1 in 68

The percentage derived from the previous table is, very probably, somewhat two low. Especially in the case of simple chronic glaucoma, in an early stage, is a very searching examination, and frequently more than one, necessary to decide with certainty the nature of the malady. Where registration of the cases is made previous to such complete examination, one of the leading symptoms — e.g., presbyopia, hypermetropia — is likely to be entered as the essential disorder ; an oversight which, where entries are very numerous, is not likely to be corrected when subsequent

1 Handbuch der gesammten Augenheilkunde Band, v. 1., 61.

examination defines the presence of glaucoma. On the whole, I think we may assume that the percentage originally stated — viz., nearly one per cent. — is approximately correct.

' The prevalence of the disease differs somewhat, probably, in different localities ; (*) but, for this country at least, we have no statistics which give certain evidence of the fact.

Secondary glaucoma is certainly met with among the working population of large towns in larger proportion than the primary disease. Its frequency among this class is due, in great part, to mechanical injuries, and to neglected iritis. It is, of necessity, so frequently registered under other names, that statistics are hardly to be obtained.

Primary glaucoma exhibits no decided preference for either sex. It has been asserted that women are more liable to the disorder than men, but there is no satisfactory proof of the statement. The following list, from which I exclude the figures of Laqueur, which refer to both forms of the disease, is given by Schmidt, with full reference to the sources whence it is derived : — (2)

Males.

Females

H. Schmidt ...

Eydel

...

Vienna Hospital, v. Wecker

Arlt

. . .

Donders

. . .

Forster...

...

Totals

Having regard to the not very large number of cases tabulated, and to the preponderance of females in the adult population, it cannot be allowed that these figures establish any marked difference in the liability of the sexes.

Secondary glaucoma, on the other hand, is, in my experience, more commonly met with in men than in women, which is doubtless attributable to the greater exposure of the former to injuries. Laqueur gives the proportion for both forms together as three males to two females. Contrasting this with the figures already given, it is probable that the preponderance of males is here due to the inclusion of secondary glaucoma.

Primary glaucoma is pre-eminently a disease of advanced life. About seventy per cent, of the cases met with are in persons over fifty years of age. (x) Below the age of forty, primary glaucoma is a rare disease. The youngest person in whom I have seen it was a woman aged thirty-one, and in that case the symptoms were only premonitory until the use of atropine induced an acute attack. (2) Statements of its occurrence in early life can only be received on high authority, and with the express exclusion of any confusion between primary and secondary glaucoma. Critchett records one such case in a man aged twenty-five. (3) The media and corneas were perfectly clear. The discs were deeply cupped. Complete blindness was reached in six months from the commencement of the symptoms. There had been no pain in the eyes themselves. Both were very hard, but not congested. Cases of the disease at the ages of nine and twelve are on record. (4)

Secondary glaucoma, on the other hand, is not confined to any period of life. Most of the maladies which induce it are less common in advanced than in middle life, and since buphthalmos is essentially a secondary glaucoma, modified only by extensibility of the slcera, childhood is not by any means exempt.

1 Handbuch d. g. A., v. 1., 63 (deduced from table of percentages).

In the large majority of cases primary glaucoma is a bilateral affection. The disease may progress equally in the two eyes from first to last, but more commonly one is persistently in advance of the other. The interval which may elapse between the first manifestation of the disease in the two eyes respectively is various, but we very rarely see a case in which one eye is in an advanced state of chronic glaucoma, as evidenced by deep excavation of the disc and contraction of the visual field, while the other is entirely free from signs of the commencement of the malady.

The more purely chronic and non-irritative, the more likely is glaucoma to be bilateral. In the section on pathology I shall attempt to prove that the cause of glaucoma in its simplest form is a physiological change which presumably affects both eyes alike, while the exciting causes of acute attacks are various, and are capable of influencing either eye alone, and may operate in eyes which previously are not glaucomatous, provided the changes which predispose to glaucoma are already present. Hence the bilateral character of chronic glaucoma, and the unilateral acute attacks.

The chronic is more common than the acute, probably in the proportion of three to one, at least. The absence of exact demarcation between the types, the conversion of one into the other, and the coexistence of the two in the same individuals, render a precise numerical statement of this point unattainable.

Though the two sexes show an equal liability to glaucoma, yet women suffer the larger proportion of acute attacks. (]) This is due, most probably, in part to the vascular congestions so common at the climacteric period of life, in part to the greater sensitiveness and excitability of

the nervous system, and possibly to the habitual constipation from which many women suffer. An acute attack in a woman aged sixty-eight, under my own care, was associated with a five days' accumulation of hardened fasces in the large intestine. All causes which produce congestion of the vessels of the head may, under predisposing conditions, induce an acute attack.

It has been asserted, by more than one writer, that primary glaucoma occurs, in the majority of cases, in persons with dark eyes. Granting this to be true, the fact has no significance unless accompanied by statistics as to the relative frequency of dark and light eyes in the particular population which furnished the cases. Should such statistics be found to actually prove that dark eyes are more liable than others to glaucoma, the fact may possibly depend upon the apparent especial liability of Jews as a race.

The influence of heredity has been distinctly traced in a considerable number of instances : thus, by Arlt in a mother and two daughters, and in a father and three sons ; by Pagenstecher in a mother and three sons, and in a father and son ; and by v. Graefe in one family through three, if not four, generations. (x) The opportunities for fairly studying the question of heredity are necessarily infrequent, for the patients who form the starting point of enquiry are generally elderly people, and can give no very accurate account of any maladies of sight from which their parents may have suffered. I have asked the question many times, but have obtained nothing but doubtful or negative replies.

Within a stone's throw of the Hospital have lived for some years past an elderly couple, both totally blind from absolute primary glaucoma. They have three children living, aged from twenty-five to forty-four; amongst these no imperfection of sight has yet manifested itself. (2)

1 Handbuch d. g. A.} v. 1, 65. 2 Cases 22, 23, Section VII.

The theory of glaucoma which I advance in the section on pathology points to peculiarities in the structural conditions of the eye as the cause of glaucoma, especially as regards the size of the lens and the shape of the ciliary muscle. It is certain that such peculiarities, at least as regards the hypermetropic structure, are frequently hereditary.

The foregoing paragraphs treat only of the general circumstances and conditions under which glaucoma occurs. Certain conditions, which appear to be more or less concerned in the causation of the disease, must now be noticed. Here it is important to separate, as clearly as possible, the primary from the secondary form. The special associations of secondary glaucoma will, therefore, be noticed later by themselves.

Hypermetropia is present in the majority of cases of primary glaucoma — viz., from fifty to seventy-five per cent, according to different observers. (x) It is important to ascertain whether it is a result of the excessive pressure, or whether the hypermetropic structure predisposes to glaucoma.

It must be remembered that the tendency of the emmetropic eye at the age of fifty or thereabout is towards hypermetropia ; (2) any comparison, therefore, of the relative frequency of hypermetropia in glaucomatous persons and in the general population is fallacious, unless only such degrees are included as cannot be due to senile changes in the lens ; otherwise the frequency of hypermetropia in the general population must be estimated by the examination of those persons only who have passed middle life. Seeing however that the effect of glaucomatous pressure upon the refraction of the eye is perhaps as often in the direction of myopia as in that of hypermetropia, and seeing also that high degrees of hypermetropia are often associated with glaucoma, and that

1 Handbuch d. g. A., v. 1, 4. 2 Donders. Accommodation and Kefraction (N. Sydenham S.), p. 208.

their pre-existence may be established by the fact that spectacles have been worn at an unusually early age, we may, I think, conclude a 'priori, that the hypermetropic eye is somewhat more liable to the malady than the emmetropic or myopic.

The theory by which I have sought to explain the primary nature of the malady points to the peculiar shape of the hypermetropic ciliary muscle as a predisposing cause. Ad. Weber lays stress upon this same point, but accounts for its effects in a somewhat different way. The reason of the susceptibility of the hypermetropic eye has been supposed to lie in the greater thickness of its sclera, by reason of which it yields with difficulty to an excess of pressure. I will not deny this connection entirely, but I believe that differences of elasticity in the sclera have very little to do with causing glaucoma, for we witness the malady in its secondary form in the highly elastic eyes of children. Their effect is seen rather in the results of the malady. The youthful elastic eye enlarges to an excessive size under a pressure which cannot extend the more rigid sclera of the adult ; the pressure is equal in both, however, and produces results equally disastrous as regards the function of the retina. Another particular in which the hypermetropic eye probably offers a predisposition to glaucoma is the shallowness of the anterior chamber. " A more anterior position of the iris and crystalline lens is part of the peculiarity of the hypermetropic structure." (*) On this point, however, I lay less stress, than upon the excessive thickness and prominence of the ciliary muscle. (2)

Trigeminal neuralgia is a precursor of glaucoma in some cases, occasionally over periods of many years. The question of a causal relationship between the two is of much importance as a point of evidence in the nerve-theory of

1 Donders, Op. Cit., p. 246. 2 See Section Y., p. 152.

glaucoma. I believe that trigeminal neuralgia excites glaucoma where the predisposing conditions (to be described later) have already brought the eye to a point of danger, but I do not accept this connection as evidence that glaucoma is the expression of a persistent hypersecretion due to perverted nerve influence. The pathology of this question is dealt with in another place. Here I shall deal only with the observations which tend to show that some connection exists. They are of several kinds.

First, we have a series of cases in which the outbreak of glaucoma has been preceded by a neuralgic affectation. Hutchinson records a case in which severe pain in the left cheek, left malar bone, and left forehead occurred very frequently for seven years, and at the end of that time an attack similar in all respects to the previous ones ushered in the outbreak of glaucoma. (*) With regard to this particular case, and others like it, there can be little doubt that the nerve disorder was distinctly antecedent to the glaucoma ; but caution is necessary in this class of cases, lest the effect be mistaken for the cause. A slight excess of pressure suffices, in some persons, to produce considerable pain, and, provided the excess be transient, the eye may remain long free from permanent symptoms of glaucoma. Again, if we assume that the glaucoma is caused by the neuralgia, how is it that the neuralgia entirely subsides, as it sometimes does {e.g. Hutchinson's case), directly after the cure of the glaucoma by iridectomy ?

Secondly, we know that artificial irritation of the fifth nerve in animals may induce excessive increase of the intraocular pressure, although, be it observed, a persistent glaucoma has never been thus induced. (2)

Thirdly, we have, clinically, in dental caries a condition of severe peripheral irritation of the fifth nerve, which has been proved to produce morbid changes in the eye. I have several times detected symptoms of asthenopia in connection with the pain of diseased teeth. Quite recently I have had under my care a young man, the near point of whose left eye was at eight inches, that of the right at five inches. The difference arose during an attack of pain in the teeth, with swelling of the cheek of the left side, brought on by cold, and disappeared completely five days after the subsidence of the pain.

Hermann Schmidt has investigated the point very fully. He accurately measured the range of accommodation, in each eye separately, in ninety- two cases of toothache. (*) In seventy-three of these cases he found the range too small, in some, much too small in one eye or in both, in proportion to the age of the patient; and in many cases he was able to observe an increase in the range a few days after the cessation of the pain. He states his conclusions as follows : —

1. " Pathological irritation of the dental branches of

the trigeminus causes limitation of greater or lesser degree in the range of accommodation."

2. "These limitations may be either unilateral or

bilateral; in the former case they occur invariably on the side affected by pain."

3. " These accommodative changes are most common

in youth ; in advanced life they are rarely, if ever, observed."

4. "They are due to increase of the intraocular

pressure."

The fourth conclusion is not proved by the investigation, and must be treated as an assumption. In its favour, however, is the fact that similar limitations of accommoda-

1 Arch. f. Ophth., XIV., 1, 107.

tion constantly accompany the onset of glaucoma ; and the additional fact, proved experimentally by myself, that they occur when the tension of the healthy eye is artificially raised. (*) On the other hand, the theory of glaucoma which I have to advance, is intimately dependent upon alterations in the lens in advanced life. Now, the asthenopic symptoms produced by neuralgia may not improbably depend upon nerve-paresis. In fact, we witness total paralysis of accommodation apparently depending upon peripheral irritation of nerves in exceptional cases. From this it appears possible that the limitations of accommodation observed by Schmidt may be quite unconnected with changes of tension, and yet that they may occasionally bear a causal relationship to glaucomatous attacks.

I have endeavoured further to elucidate this matter by tonometrical measurements in a series of cases of toothache at the Dental Hospital. The results obtained give no very decided evidence either way, but, at least, they show that in young persons toothache rarely, if ever, causes a decided rise of tension. I estimated the tension— in each case from a series of measurements — in sixteen persons suffering at the moment or recently from severe pain in the teeth. The position of the near point was ascertained by noting the distance from the eye at which a group of fine lines on white paper lost their definition. It would have been more satisfactory to have examined the eyes, in every case, during the continuance of severe pain ; but, apart from the apparent cruelty of what appears to the patient a needless examination at such a time, it would, I think, be extremely difficult to accomplish, for, over and over again, I was told by patients that the toothache, previously so violent, had vanished on approaching the dentist's chair — a result, I presume, of nervous apprehension.

1 Section III., p. 70.

The following table exhibits the results obtained: —

Name.

to

o ™

Duration and Character of Pain.

Time since

Cessation of

Pain.

OS

•2 3

h- 1 W

yrs.

in.

in.

Mm.

Mm.

1. — Ada A n

4£

Severe ; three weeks . .

•89

2.— Jessie K n ..

4%

Six months ; severe last night.

•92

■84

3.— Kate D — n ..

Three weeks

•71

•72

4.— Elizabeth F d

Several months;intense yesterday.

15 hours

1-08

•89

5.— Geo. Y s

6. — John J s

7.— Fred. T n ..

8.— The same, four days later

Five weeks ; "eye often feels full, as though pushed forward."

Twelve months ; constant last two days and nights.

Severe four weeks ; intense last two days and nights.

Severe again yesterday.

1£ hour

2 hours

10 minutes.

Tooth cleaned

for stopping 1 hour. Tooth

removed.

•79 •84 ■73 •69

■85

•74

•so

•72

9.— Eliza J r

Fourteen days ; severe all last night.

1 hour

•83

•83

1-0. — Ellen M s ..

j

Fourteen days

12 hours

■88

11.— William L d..

Nearly constant last seven days.

15 minutes ..

•81

•94

12. — Richard L e..

One month ; severe to-day.

Still continues.

•74

■77

13.— Ann C n

14. — Simeon W s . .

29 18

Six months, with frequent swelling of face.

Severe ; four days

Still continues.

Continues . .

■66 •98

•70 ■84

Twelve months ; severe three days.

-

■70

•71

16. —Stephen H n . .

Ten days ; severe to-day.

Continues , ,

•83

•95

17. — The same, two days later

—

—

—

Slight pain still..

Continues . .

■84

•95

18- Charles S m ..

j

One month ; swelling of face ; no sleep three nights.

Totals ..

Averages . .

■86

•82

14.72

14 96

*

.82

•83

Eemembering the investigations of H. Schmidt, I was surprised to find no anomaly of accommodation in fifteen out of the sixteen cases. It should, however, be observed that I did not ascertain the state of refraction present, so that it is possible that the presence of myopia may have masked a retrocession of the near point in some cases.