ACTA OPHTHALMOLOGICA 1956

(Southampton Eye Hospital, England)

SURGICAL PROGNOSIS IN GLAUCOMA SIMPLEX

BY

George Bennett")

Though it has long been recognised that glaucoma is not cured by operations which control the intraocular pressure, comparatively few authors have at- tempted to analyse their material in a systematic manner. Reese in 1939 showed that 10 to 40 O/O of his cases made normotensive by surgery lost vision subse- quently, and Burke in 1940 gave a proportion of 50 o/o for corresponding cases watched over a 5 year period. The latter author related prognosis to the severity of the visual defect at operation rather than to the age of the patient.

I t was not until 1943 that Sidney A. Fox proposed certain criteria upon which future surveys should be based so that results could be strictly com- parable with those of other surveys, and readily appreciated. The thesis set out by Kronfeld and McGarry (1948) was one of the first to adopt this system, and as a model investigation will be referred to in later parts of this thesis. These authors found a visual failure rate, in glaucoma simplex eyes made normotensive by surgery, which varied from 12 to 50 O/O according to the degree of failure already present at operation; the course to be taken was usually determined by the end of the first year's follow-up. With narrow-angle cases, however, a constant failure rate of only 10 O/O was obtained irrespective of initial severity. Reese (1939) had obtained similar, if not strictly comparable figures for chronic glaucoma (10-40 O/O failures). Subsequently, we have the papers written by Briantseva (quoted by Samoiloff A. J., 1948), Duke-Elder (1949), Sourdille (1950), and Lloyd (1951 a). Most of the authors illustrate the rather unsatisfactory results of surgery which has succeeded in lowering the tension. Duke-Elder gives an average failure rate of 300/0 (15 to 500/0), griantseva 48 to 89 O/O. The results of Sourdille are rather more favourable, with an average failure rate of 15 O/O. The authors quoted above cannot always be said to have acknowledged or compensated for all types of selectivity in the cases composing their series; nor hqve they applied statistical methods to

*) Received July 28th 1955.

73 Acta Ophthalmol. vol. 34, I1

assess significance in their results. A further apparent weakness is that they do not always state whether or not the eyes have at any time suffered some complication such as intraocular hemorrhage or cataract formation, which may affect vision although not specifically the outcome of the glaucomatous process.

SELECTION OF MATERIAL AND ANALYSES

The material consists of cases operated on over a 12 year period at a Pro- vincial Eye Hospital.

Firstly, all cases which could possibly be considered *secondary* glaucomas were eliminated. Secondly, all cases which at any time suffered congestive episodes and showed narrowing of the chamber angle were removed from the Series. There is evidence (Barkan, 1938, 1954 a, b, c; Grant, 1951; Lloyd, 1951 b; Duke-Elder, 1952; Weekers and Prijot, 1952; Miller, 1953; Rosengren, 1953; Ascher, 1953; de Roetth, 1954) apart from clinical bias to justify this distinction. and congestive cases will therefore be considered separately in a later paper.

This leaves us with what we may call the Initial Series. This consisted of 132 patients, 74 of whom were males, and 58 female, being

the total number of cases of glaucoma simplex, according to our accepted de- finition, subjected to a filtration operation over the 12 year period. The total number of operated eyes was 182. In 5 patients (6 eyes) the diagnosis did not seem sufficiently established for inclusion in this Series. Excepting these we are left with 127 patients (73 male (57 "0) and 54 female) and 176 eyes (102 male (58 O/O) and 74 female). A minimum follow-up period of one year after operation was insisted upon. In all cases surgery had been undertaken because the tension was uncontrolled and the vision was failing, this being the in- dication generally adopted at this hospital. Many cases had been under observation for long pre-operative periods and the diagnosis and the course of the condition was usually well established. Eyes which possessed vision less than 6/60 i. e. cases of absolute and terminal glaucoma with a hopeless progno- sis were also excluded. Miotics were frequently prescribed post-operatively, but no distinction is made between those receiving or not receiving them.

To ensure that all visual loss subsequent to operation could be ascribed to the specific neuro-retinal changes of glaucoma, all cases showing at any time any complication or condition which might affect vision, were then excluded. In addition, certain criteria defining the ~successu of operations were applied, viz: -

( 1 ) . Uneventful recovery from operation with no loss of vision and without complications.

(2). At no time after operation was a history of haloes or congestive attacks

74

to be given. Tonometry never over 28 m. m. Schiotz post-operatively. Hospitali- zation and four-hourly tonometry was undertaken in a limited number of cases; these showed no rise in tension above 28 m. m. at any time. In other cases measurements were made at different times of the day on the same or on different visits to the Out-Patient dept. Provocative tests were also employed.

As a result of these limitations, 45 eyes (23 male, 22 female) were excluded from the Initial Series. This sometimes meant one eye was accepted and one rejected in the same patient; nevertheless, it resulted in the complete exclusion of 27 patients (11 males, 16 females). These figures include the misdiagnoses mentioned above. The causes of rejection are listed in Table I.

Table 1. Causes of rejection (eyes).

Misdiagnosis Preoperative cause Postoperative cause Inadequate detail Tension uncontrolled

6. 6.

10. 17. 6.

Total 45.

I (a ) - preoperative causes. 4 eyes. 2 eyes.

- Vision less than 6/60 - Cataract present - -

I ( b ) - postoperative causes. (1) Early (< 3 months after operation) = 6 eyes.

Choroidal detachment 1. Cataract 4. Malignant glaucoma 1 .

(2) Late (> 3 months after operation) = 4 eyes. Hemorrhage or thrombosis 2. . Cataract 2. .

These tables are self-explanatory in the light of the notes given above, and

The remaining 137 eyes were subjected to further analyses. The sex distribution was found to be 80 male, (58 O/O) and 57 female eyes.

These involved 63 male (600/0) and 42 female patients. The distribution of the eyes according to sex, type of and age at operation, is given in Table 11.

The first column includes 2 case’s under 31 years of age - both males, one of whom had suffered bilateral iridencleises, the other a single trephine operation.

show nothing out of the ordinary.

75 6*

Table I I Showing sex distribution, age at, and type of operation for all eyes accepted.

Age C50 50-4 55-9 6 0 4 65-9 70-4 75-9 Total

Trephines (97 = 71 O/o)

Male. 4 8 11 11 9 9 7 Female. 3 4 5 1 0 9 6 1

59 (61 OJo)

38 (39 O/o)

Totals. (137) 13 1 7 23 29 25 22 8 I 131

Iridencleises (40 = 29 O/o)

Male. 5 0 3 3 5 5 0 Female. 1 5 4 5 2 2 0

I

21 (52.5%) 19 (47.50/0)

The total number of trephines (97 = 71 O/o) exceeds that of the iridencleises (40) as the former is the more popular operation among the srlrgeons con- cerned. 61 O/O of the trephined eyes and 52.5 */o of the eyes undergoing iriden- cleisis belonged to the male sex, which accounted for 58 O/O of the total number of eyes; but while 74 010 of the male eyes underwent trephination, only 67 O/a

of the female did so. The ,scatter<< is fairly even for both operations in all age groups; the maximum incidence occurs at 60-64 years for both.

This latter is in accordance with previous surveys, the rate for 61-70 year groups varying from 29 to 39.6 O/O of all cases (see Sugar, 1951). The author’s figure for the 60-69 year group is 54 eyes, or 39 O/o of all eyes. This maximal operative rate holds for either sex taken separately.

The preponderance of males in this Series, and in the Initial Series, requires examination. If we take the latter figures, as being less selective, we note 74 male patients (560/0) as opposed to 58 female. Comparing these with the numbers of male and females in the general population aged 50-79 years, we find a definite significance exists (XY = 5.037, n = 1 , P = 0.05 - 0.02). Does this mean that more men than women suffer from chronic glaucoma, or that a man suffering from this disease is more likely to require surgery than a woman? The true incidence of glaucoma simplex in the general population is difficult to assess, but most published series indicate a higher proportion of males than females: e. g. Garvill (1932) gives 54 O/O and Priestley Smith (1891) 53 O/O males. This suggests that the former explanation is the correct one; and we infer that males are no more requiring of surgery than females.

76

The eyes were then divided into 3 grades according to the extent of visual loss found at the time of operation.

Grade A: Visual loss not greater than a Bjerrum scotoma for 2/1000 white isopter.

Grade B: Visual loss varying between Bjerrum scotoma and peripheral nasal loss for 3/330 white isopter up to but not encroaching on the 15' parallel.

Grade C: Visual loss greater than B, but visual acuity equal to or greater than 6/60.

Similar gradings were employed by Kronfeld and McGarry (1948) in their

The distribution of grades according to age at operation is shown in study.

Table 111.

Age

Table I I I . Grade distribution according to age at operation (all eyes).

49 and under 50-4 55-9 60-4 65-9 70 4-

Grade A 3 3 3 7 4 3 23O/o 18O/0 13O/o 24O/o 16O/o 1 oo/o

Grade B 5 7 10 11 9 I 38.5O/o 41 O/o 43.5O/o 38O/o 36O/o 23O/o

Grade C 5 7 10 11 12 20 38.5% 41 O/o 43.5O/o 38% 48O/o 67O/o

Totals

17 010

36 O/o

41 O/o

~~ ~

Totals 13 11 23 29 25 30 I 137

We see that the proportion of Grade A cases decreases with advancing years, that of Grade B peaks at the 55-59 group, while that of Grade C increases with age. This demonstrates the greater severity of the condition in the older age-groups.

The distribution of grades according to sex is shown in Table IV (a). I t appears that Grade A has a preponderance of female, and B and C of

male, eyes. If we correct these proportions for the unequal totals of male and female eyes, we derive Table IV (b).

This indicates that whereas Grade B and C eyes are distributed almost equally between the sexes, only 31 O/O of Grade A are male. This figure, how- ever, is not significant (P > 0.05) considering the relatively small number of

77

TabEe IV (a). Distribution of grades uccording to sex (eyes).

I Male

Grade

Grade A I 1 010 9 39 010

GradeB 390io 31 63 O/o

GradeC 5 O O l o 40 62 OIo

Totals 100010 80 58 010

Female Totals

Female

010 in Grade

25 OIo 14 61 O/o

31 O/o 18 37 010

44 010 25 38 010

100 010 57 42 O/o

Totals

~

23 (1 7 Vo) 49 (3S0/0) 65 (47O/o)

137

Grade A 1 1 (31 O/o)

Grade B 39 (56 O/o)

Grade C 50 (53 Ole)

25 31 44

36 70 94

I I I

Totals 100 (50 O/o) 200

cases involved, so we need not conclude there is truly a female excess of mild cases of chronic glaucoma.

Table V gives account of the maximal follow-up periods obtaining for each technique. No special comment is necessary at this stage.

The prognosis of all the eyes over the full period reviewed (1-14 years) is shown in Table VI (a).

It is apparent from the Table that only a relatively small percentage of cases showed improvement (average 11 o / o ) , and only an average of 26 O/o remained unchanged over the full period of their reviewal. If we examine each grade of the disease in turn we see that 65010, 63010 and 62010 of Grades A, B and C respectively deteriorated; there is no significant difference statistically (P > 0.05) between these figures. Thus at whatever stage surgery is under- taken, vision tends to fail inexorably in over half the eyes over the full period considered in this Series. I t is also seen that about half the eyes had reached the advanced grade (C) before operation.

Table V. Maximal follow-up times (eyes).

Period 1 2 3 5 8 10 over

15 15yrs

Trephines 19 8 21 30 11 7 - 1

Improved No change

- 11 7 13 8 1 - - lridencleises { 37O/o 47O/o 38O/o 2lQ/o 8O/o @'/o - -

Worse Totals

Totals 30 15 34 38 12 7 - 1

Grade A 1 7 15 (65 O/o)

Grade B 5 13 31 (63 O h ) Grade C 9 16 40 (62 O/o)

Totals

23 (17 O/o)

49 (36 O/o)

65 (47 O/o)

97

40

137

Totals 15 (11 O/o) 36 (26 O/o) 86 (63 O/o)

Table VI (a). Grnded prognosis - all eyes, maximal period.

137

Improved or same Worse Totals

46 40

If Grades A and B are combined in Table VI (b), we see that 62 O / o of the most advanced, and 64 O/O of the milder cases fail; there is again no statistical difference between these two figures. (P > 0.05).

72 (53 O h ) 65 (47 Ole)

Table Vl (b). Overall prognosis - abbreviated.

Grade A & B 26 (36 O h ) Grade C 25 (38 OJo)

Totals 51 (37 O/o) ' 86 I 137

79

We can conclude from this that the ultimate prognosis does not depend on the stage at which operation was performed; from the other viewpoint we can say that operation is as justifiable in the severe as in the more moderate cases of glaucoma.

Further sub-division considering trephines and iridencleises separately is made in Tables VII and VIII.

Improved Unchanged Worse

Grade A 1 4 12 (71 O/o)

Grade B 1 6 23 (77 O/o)

Grade C 7 12 31 (62 O/o)

Totals

1 7 (17 O/o)

30 (31 O/o)

50 (52"/0) ~ ~~

Totals 9 22 66 (66 O/o) I 97

Improved Unchanged Worse

Table VIII. Overall graded prognosis for iridencleises.

Totals

Grade A 0 3 3 (50 O/o)

Grade C 2 4 9 (60 Ole) Grade B 4 7 8 (42 O/o)

6 (15 O/o)

15 (37.5 O/o)

19 (47.5 V O )

Totals 6 14 20 (50 O/o) I 40

The number of iridencleises (40) is less than half that of trephines (97) as the latter is the more favoured operation a t this hospital. The overall pro-' portions of cases which deteriorated for each of these operations (50 O/O and 660/0) was much the same as that obtained for the combined series (630/0), and there is no statistically significant difference between the results obtained by these two techniques (X2 = 3.21, n = 1, P = 0.10 - 0.05). This indicates a similar prognosis for either operation. As the effect of both operations, if satisfactorily executed, is the same, i. e. to produce a 'safety exit' for the aqueous, we should anticipate this result. Lloyd (1951 a) also concluded that there was nothing to choose between the two operations.

Table IX compares the results of trephinations and inclusions for advanced cases only.

80

Table I X . Overall Prognosis of trephines and inclusions. Grade cases.

Totals 9 63 25 (26 O/o)

Trephines 19 31 (62 O/o) 50 Iridencleises 6 9 (60 O/o) I l 5

97

I Totals 25 40

We see that 62 010 of the trephines and 60 010 of the inclusions continue to fail after operation; these proportions show no significant difference (P =

0.9-0.8) so it cannot be said that one or the other is the better operation for late cases.

If we compare Grade A eyes only, there is again no preference for either operation (P = 0.7 - 0.5). But with Grade B eyes, those of moderate severity, there is a significant bias in favour of iridencleisis (P = 0.05-0.02).

Prognosis at the end of the first, second and fifth year after operation was then considered separately for trephines and iridencleises. The results are demonstrated in Tables X and XI, (a), (b), and (c).

It will be seen that about a quarter of the trephined and a fifth of the ,included<< eyes showed deterioration one year after operation. The difference between these proportions is not significant (X2 = 0.25, n = 1, P = 0.7-0.5). I t is also to be noted that the inclusions comprised a greater proportion of milder cases than the trephines. The grade distribution of cases remained very consistent in the tables for each technique.

At the end of the second year the percentage of failures is slightly less for both operations, and the difference is again without significance (Xz = 0.524,

Table X (a). Progress of trephines at end of first year.

Improved Worse Totals

Grade A 4 (24 O/o) 1 7 (17 O/o)

Grade B 9 (30 O/o) 30 (31 O/o)

Grade C 31 12 (24 O/o) 50 (52 O/o)

81

Improved Same

Table X (c). Progress of trephines at end of 5 years.

Worse Totals

1 Improved I s;e I Worse 1 Totals

Grade A 3 (37.50/0) 8 (17 O/o)

Grade C 13 (57 O/o) 23 (48 O/o)

Grade B 8 (47 V O ) 1 7 (35 O/O)

Grade A 1 1 1 3 (20 O/O)

Grade B 1 19 5 (20 “0)

Grade C 6 23 9 (24 O/o)

Totals 8 53 17 (22 O/O)

I ‘t8 Totals 5 19 24 (50 O/o)

15 (19O/o) 25 (32 Yo) 38 (49 O/o)

78

Table X I (a). Progress of iridencleises end of 1st . year.

Grade A - 5 1 (17 O/o)

Grade C 2 10 3 (20 V O )

Grade B 3 12 4 (21 %)

Improved I Same I Worse Totals I 6 (15 O/o)

15 (37.5 Ole) 19 (47.”)

Totals 5 (12.5 O/o) 27 (67.5 O/o) 8 (20 O/a) I 40

n = 1, P = 0.5-0.3). Five years after operation results for iridencleises appear much worse than for trephines, 890/0 of the former and 500/0 of the latter failing. These proportions do not show a significant difference however (X* = 3.21, n = I , P = 0.1-0.05) and the iridencleises largely belong to Grade C. We conclude therefore on these figures, there is generally no advantage in either technique as shown by the progress at any time post-operatively of all

82

Improved

Table XI (c). Progress of iridencleises at end of 5th. year.

Same Worse Totals

Grade A - 4 - ( 0 010)

Grade B 3 11 - ( 0 010)

Grade C 1 7 4 (33 010)

Totals 4 (13 Olo) 22 (74 %) 4 (13 O/o)

1 2 5

Grade A - - Grade 3 1 Grade C - -

-

4 (13 O l o ) 14 (47 Ole) 12 (40 O/o)

30

1 (11 010)

3 (330lO) 5 (56 O l o )

Improved Same Worse

Totals 1 0 8 (89 O h ) I 9

Totals

cases taken together. If again, we take each grade separately we find that there is no significant difference between the results for trephines and iriden- cleises (P > 0.05) 1, 2 or 5 years after operation. This is interesting insofar as it has been commonly maintained that iridencleisis is the better operation for advanced cases.

These Tables and Table XJII below can be, combined in abbreviated form as in Table XII.

Table XI11 gives the progress found at the end of 8 years for all eyes followed for this length of time.

In Table XI1 we observe the proportions increase as we produced down- wards and to the right. The increases occurring between the 2nd. and 5th. years are statistically significant (P > 0.05).

These results can be compared with those obtained by Kronfeld and McGarry (1948). These authors graded their patients in a manner rather similar to that adopted here; in their Grade 1, 88 O/O of surgical cases and 81 'O/O of cases under miotics had no further visual loss, in' their Grade 2, 38 O/o of surgical cases suf- fered further loss, and in their Grade 3 50 O/O failed, considered overall.

83

We may now compare the results obtained in males, with those in females. Table XIV shows that 670/0 of the female and 600/0 of the male eyes

deteriorated, all operations and all grades being considered together. The above proportions are not statistically significant (P > 0.05), so it is apparent that prognosis does not vary with sex, all operations being considered.

If we take trephines and iridencleises separately, we see again there is no statistical difference between the results for the two sexes (P > 0.05).

Tables XV (a) and (b) set out the prognosis according to age and sex for all operations.

There is a tendency, albeit irregular, for prognosis to deteriorate with in- creasing age, in both these tables.

It is seen that only in the very young (under 50) and very old (over 70) groups is there any significant difference in prognosis between the sexes, males faring better in both instances (P > 0.05).

End of: 1st. yr. 2nd. 8th. Overall 5th.

All eyes 33 21 32 10 86 (24 V o ) (1 9 010) (56 O h ) (62.5 Ole) (63 O/o)

Improved or same Worse

Table XIII. Progress at end of eight years. - all cases.

Totals

1 (33 ' l o ) 4 (57 010)

5 (83 "10)

Grade A Grade B Grade C

3 (19 010)

7 (44 010)

6 (37 O/o)

2 3 1

I 1 6 ' Totals 6 (37.5 O/o) 10 (62.5 O/o)

84

Table XIV. Overall Prognosis according to sex and operation (eyes).

Improved or same Worse Totals

Male I

49 & less 50-4

3 8(64 "/a) 10 (48.6 O/o) } 48 I i; } 8o

(60 O/o) (26 O/o irids.)

Trephines Iridencleises

(40 "/o)

55-9 60-4 65-9 70 4- Totals

Female I

Improved 8 3 6 5 5 5 or same Worse 1 5 8 9 9 16

(1l0/o) (62.5"/0) (57O/o) (64"/0) (64O/o) (76O/o)

10 (52 " l o ) '; } 19 Trephines Iridencleises

(33 "/a) (33 % irids.)

32 (40 O/o)

48 (60 O/o)

Totals 51 (37 O/o) 86 (63 "lo) I137

49 ' 50-4 less

Table X V (a}. Prognosis according to age at operation - in male eyes.

Totals 55-9 60-4 65-9 70 4-

- Improved 1 4 6 4 4 or same Worse 3 5 3 11 7 9

(75O/o) (.%.~O/O) (33O/o) (73O/a) (64%) (100"/0)

19

38 (67 "/a)

(33 O/O)

Totals 9 8 14 14 14 21 1 80

Table X V (b). Prognosis according to age at operation - in female eyes.

Totals 4 9 9 15 11 9 I 57

85

In the former group, 44 O l o Grade C. In the latter group, cannot ascribe these different males.

We may combine these two

Under 60

of males, yet only 250/0 of females belong to the same percentages are 71 and 55. Thus we prognoses to an excess of milder cases in the

tables to obtain Table X V (c).

Table X V Icl.

Over 60

. . Prognosis according to age at operation, all cases.

Worse No. 4 10 11 20 16 25 % 31 59 48 69 64 83

This indicates a general deterioration of prognosis as age advances. If we summate the first and last three groups we obtain a failure rate of 47 O/o and 73 O/O respectively. This difference is very significant (P < 0.05).

Table XVI shows that a higher proportion of good prognoses was obtained with iridencleisis in the younger (under 60) and in the older (over 60) age groups. The proportional difference (43 and 72 O/o) is significant (P < 0.05) for the former; the proportional difference (26 and 32 O/O) is not significant (P > 0.05). for the latter.

To enquire further into the differential analysis we have split up the tre- phines and inclusions into two age groups as in Table XVII.

This makes us suspect that the superiority of iridencleisis in Grade B (as indicated earlier) is due to the relative excess of this combination in the under 60’s. To check this, we may compare the prognosis of Grade B for iridencleiscs and trephines. This is done in Table XVIII (a).

86

Table XVII. Distribution of eyes according to age, grade, and operation.

Under 60

I I Under 60 60 and over

60 and over

Trephines Grade A 7 B 12 c 16

Grade A 10 B 18 c 34

Inclusions Grade A 2 B 10 C 6

Grade A 4 B 9 c 9

Trephines Iridencleises

9 (75 V O ) 1 (100/0)

14 (78Oio) not significant

(P < 0.05) 7 (78 O/o) significant

This shows the superiority is genuine in the younger groups only, the dif-

Tables XVIII (b) and (c) give comparisons for Grades A and C respectively. ference here being very significant (P < 0.05).

Table XVIIl (b). Failures in Grade A according to age and operation.

I I 60 and over i Under 60 . I

I I

Trephines Iridencleises

4 (57 O/O)

1 (50 O/o) 2 (50 O/o) w H

8 (800/0) not significant

(P > 0.05)

None of these proportions show any significant difference vertically in either table. Horizontal significances are indicated.

Next we have Table XIX which contrasts the prognosis in the eyes which were not operated on, but in wliich the tension was controlled by miotics, the fellow eye having suffered surgery.

87

Table XVIII (c). Failures in Grade C according to age and operation.

Improved

I Under 60 60 and over I I

Same Worse Totals

Trephines

Iridencieises

Operated Unoperated

7 (44 010)

2 (33 %)

24 (71 "/o) significant (P < 0.05)

7 (78O/o) not significant (P > 0.05)

Operated All operated rejects eyes

Grade A - 10 7 Grade B 5 9 6 Grade C 1 2 5

1 7 (38 Ole) 20 (44 V O )

8 (18 %) i Totals 6 21 18 (40 "/o) I 45

12 unoperatetl eyes had vision less than 6/60 (= Grade D); all showed persistently

Grade C and D = 20 eyes (35% of all eyes). elevated tension.

Table X X . Comparison of gradings of operated and unoperated eyes.

Totals 45 137 1 7 154

Grade D 12 0 4 4

Unknown 17

88

The criteria applied for these eyes is the same as that in the surgical group, The two groups are compared in Table XX. W e include here the designation of the eyes operated upon but rejected, wherever it is certainly known (viz. in 21 eyes out of 39 rejected).

W e see that 38 010 of the unoperated and 17 O/o of the operated eyes belong to Grade A, These figures show a very significant difference (P < 0.01).

Table XXI compares the prognosis in operated and unoperated eyes. The unoperated Grade D eyes all had persistently elevated tension and are not included.

Unoperated Operated

Improved or unchanged 27 (60 O/o) 51 (37 O/o)

Worse 18 (40 O/o) 86 (63 O/o)

Totals 45 137

Totals

78 104

182

We again see that prognosis is much more favourable in the unoperated eyes, 60 O/o retaining their visions as opposed to 37 O/o of those subjected to surgery. These differences are again very significant (P < 0.02). It appears that when an eye ceases to respond to miotics it becomes a far worse 'risk'. Miotically controlled eyes are reasonably healthy organs and may remain so for a long time; only 40 O/O suffer any further visual loss, and only a quarter of the failures have a severe degree of visual defect.

CONCLUSIONS - PROGNOSIS I N CHRONIC G L A U C O M A

The investigation reveals the following: - (1) Of certain selected cases of chronic glaucoma simplex successfully

operated on by a filtration technique, over 60 O/O showed further visual failure over reviewal periods ranging from one to sixteen years.

(2) The Series contained a significant excess of males over females, and nearly half of the eyes had attained a severe degree of visual loss. ,Peak* incidence occurred in the 60-69 yeai-group in both sexes.

(3) Severity of the affliction did not vary with sex, but increased with age.

89 Acta Ophthalmol. vol. 54, I1 1

(4) A higher proportion of eyes showed deterioration the remoter the operation became in time.

( 5 ) In general, the outcome does not depend on the stage at which operation was performed, the type of filtration operation, or the sex of the patient.

(6) The exception to (5 ) is that iridencleisis is more favourable in patients under 60 with glaucoma of moderate severity. Neither operation is more advantageous for mild or severe cases at any age, nor for any cases aged over 60. If we assess the eyes at the end of each post-operative year, even this difference disappears.

( 7 ) Proqnosis is better for males than for females in the very young and very old age-groups. Generally, prognosis deteriorates increasingly with age in both sexes.

(8) The unoperated miotically controlled fellow-eyes showed a higher pro- portion in Grade A, and had ; better prognosis, than operated eyes.

(9) Eyes which generally had a good prognosis showed this also in the fellow-eye if controlled by miotics alone.

ACKNOWLEDGEMENTS

An earlier version of this paper was prepared in competition for, and was awarded, a prize offered by the South-Western Metropolitan Regional Hospital Board for research by Registrars in 1953.

I should like to express my gratitude to the Surgeons of the Southampton Eye Hospital, for their encouragement in the making of this study and per- mission to examine their cases and use the case-histories.

BIBLIOGRAPHY

Ascher, K W. (1953). Arch. Ophth., Chicago, 49, 438. Barhan, 0. (1938). Am. J. Ophth., 21, 1099. Barhan, 0. (1951 a). ibid., 37, 332. Barhan, 0. (1954 b). ibid., 37, 504. Barkan, 0. (1954 c). ibid., 37, 724. Briantsevc!, quoted by Samoiloff, A. J. (1948). *Modern Trends in Ophthalmology*,

Burke, /. W . (1940). Am. J. Ophth., 25, 657. Carvill, hl. (1932). Tr. Am. Ophth. SOC., 30, 71 . Duke-EZdm, S. (1949). Arch. Ophth., Chicago, 42, 538. Duke-Eldr,r, S. (1952). Am. J. Ophth., 35, 1. Fox, S. A . (1943). cited by Kronfeld, P. C. and McGarry, H. I. (1948). Grant, W . M. (1951). Arch. Ophth., Chicago, 46, 113. Kronfeld, P. C. and McGarry, H . I . (1948). J . A . M . A . , 136, 957. Lloyd, /. P. F . (1951 a). Am. J. Ophth., 34, Pt. 1 , 705.

Series I[, ed. A. Sorsby, pg. 310, Butterworth & Co., London.

90

Lloyd, /. P. F. (1951 b). Tr. Ophth. SOC. U.K., 71 , 459. Miller, S. /. H . (1953). Brit. J. Ophth., 37, 1, 70. Reese, A . B. (1939). Tr. Sect. Ophth., Amer. Med. Assoc., 58. de Roettk, A . (1954). Arch. Ophth., Chicago, 51, 740. Rosengren, B . (1953). Am. J. Ophth., 3ti, 488. Smith, Priestley. (1891). *The Pathology and Treatment of Glaucoma*. London, J. &

SourdiZle, G. P . (1950). Brit. J. Ophth., 34, 435. Sugar, H . S. (1951). *The Glaucomas<. pg. 218 et seq., pg. 131 et seq., Hy. Kimpton.

A. Churchill.

London.

91