COMPARISON O F IN VITRO CORTICOSTEROID RESPONSE IN PIGMENTARY GLAUCOMA AND PRIMARY OPEN-ANGLE GLAUCOMA H A R R Y A. Z I N K , M.D., H. S A U L SUGAR, M.D.,
P A U L F. P A L M B E R G , M.D.,
A L A N SUGAR,
M.D.,
H E R B E R T L. C A N T R I L L , M.D., B E R N A R D B E C K E R , AND J O H N F. B I G G E R , M.D.
M.D.,
St. Louis, Missouri 1
In 1949, Sugar and Barbour first de scribed pigmentary glaucoma as a sepa rate entity. It was distinguished clinically from primary open-angle glaucoma by the presence of marked pigment dispersion in the anterior segment of the eye, 1 and associated concentric atrophy of the midperipheral portion of the iris pigment epithelium, often demonstrable on iris transillumination. 2 Pigment released from the atrophic posterior iris and car ried forward by the flow of aqueous humor was found on the zonules and circumference of the lens, the corneal endothelium (Krukenberg's spindle), an terior iris surface, and the filtering portion of the trabecular area. Controversy has existed as to whether or not pigmentary glaucoma is etiologically separate from primary open-angle glaucoma. Those supporting a separate cause for pigmentary glaucoma have felt that the development of this glaucoma is secondary to mechanical obstruction of the outflow channels by pigment alone, 3 - 6 or in combination with abnormalities of the angle structures. 7 " 9 In support of this concept, the severity of the glaucoma has been correlated with the degree of pigmentation. 6 In addition, pigmentary glaucoma generally occurs in younger pa tients than does primary open-angle glau coma, and shows a marked predilection From the Department of Ophthalmology, Wash ington University School of Medicine, St. Louis, Missouri. This study was supported in part by grants EY-0036 and EY-01167 from the National Eye Institute, and a grant from the Seeing Eye, Inc., Morristown, New Jersey. Reprint requests to Paul Palmberg, M.D., Depart ment of Ophthalmology, Washington University School of Medicine, 660 S. Euclid, St. Louis, MO 63110.
for men while primary open-angle glau coma shows no sex predilection. 3 On the other hand, those supporting a common etiology for the outflow obstruc tion in these glaucomas have implied that trabecular pigment deposition is a conse quence rather than a cause of aqueous obstruction, and that the occurrence of pigment releasing iris atrophy merely makes the pigment accumulation more dramatic. In support of this view, occa sional pigment deposition occurs in the absence of iris atrophy in one half 1 to two thirds 1 0 of primary open-angle glaucoma patients, and also in patients with secon dary glaucoma due to uveitis or trau ma. 11,12 Further, the adequacy of pigment alone to obstruct aqueous outflow is ques tionable since 90% of persons with pig ment dispersion, manifested by Kruken berg's spindles, did not have glaucoma. 3,8 Becker and Podos 1 2 reported the occur rence of pigmentary glaucoma and pri mary open-angle glaucoma in the same families, suggesting a common genetic basis. They also examined topical corticosteroid response in 15 persons with Kru kenberg's spindles without glaucoma, and found more corticosteroid responders than in the general population. The corti costeroid responses of the patients with Krukenberg's spindles approximated those of the offspring and siblings of primary open-angle glaucoma patients, suggesting a link of pigment disperson to corticosteroid responsiveness and pri mary open-angle glaucoma. We evaluated the possible relationship of pigmentary glaucoma to primary open-angle glaucoma by comparing in vitro cellular sensitivity to corticosteroid in the two groups, as assayed by inhibi-
478
VOL. 80, NO. 3, PART I
CORTICOSTEROID RESPONSE
tion of lymphocyte transformation. Previ ous results of this assay correlated well with those of ocular corticosteroid test ing, and demonstrated a markedly in creased sensitivity to corticosteroids at the cellular level in primary open-angle glaucoma.13,14 Use of a nonocular assay allowed study of corticosteroid sensitivity in persons whose spontaneous intraocular pressures would have been too elevated to permit meaningful topical testing. It avoided the potential problem that in topical testing the presence of pigment in the trabecular region may augment the apparent response to corticosteroid. SUBJECTS AND METHODS
Twenty patients with pigmentary glau coma had elevated intraocular pressures before treatment, gonioscopically open angles, and evidence of pigment disper sion including Krukenberg's spindles and heavy trabecular pigmentation. Ten had iris transillumination defects. All had vis ual field loss characteristic of glaucoma, and most had appreciable cupping of the optic nerve head. All but one (newly diagnosed) were receiving medical thera py for their glaucoma at the time of test ing. Only one was receiving acetazolamide. There were 16 men and four wo men. The men averaged 49 ± 14 (CT) years of age at testing, and 41 ± 15 years at diagnosis. The women averaged 40 ± 15 years of age at testing and 38 ± 15 years at diagnosis. Eighteen of the patients were myopic, although only five had myopia greater than 5 diopters. Four patients had a contributory family history of glauco ma, with two known to be primary openangle glaucoma (Table 1). The technique for preparation of lym phocyte cultures, corticosteroid preincubation, phytohemagglutinin stim ulation, cell harvesting, scintillation counting, and data analysis have been described.13,14 We determined the con centration of prednisolone-21-phosphate required to inhibit tritiated thymidine up
479
take in mitogen-transformed cells by 50% (half inhibition concentration, or Iso) for each patient. Patient data were accepted for the study if they met the following three criteria. First, the coefficient of vari ation of the phytohemagglutinin-P stimu lated controls was 20% or less. Second, the uptake of tritiated thymidine was 10% or less of the total amount present. Third, the correlation coefficient, r, for the re gression analysis of the dose-response curve was .75 or greater. RESULTS
We obtained the distribution of I50 val ues for each of the patients with pigmen tary glaucoma, and for 100 other pa tients 14 (Figure). The previously reported patients included 36 patients with pri mary open-angle glaucoma. We classified the rest by topical ocular dexamethasone testing (application of 0.1% dexamethasone-21-phosphate eyedrops to one eye, four times daily, for six weeks). Based on Becker's criteria, these included: 22 NN individuals: low responders, whose final intraocular pressure „ remained < 20 mm Hg. 15 NG individuals: intermediate re sponders, whose final intraocular pressure was between 20 and 31 mm Hg. 27 GG individuals: high respond ers, whose final intraocular pres sure was > 31 mm Hg. We studied these 100 patients during the present study. In the lymphocyte assay, tjhe lower the Iso value obtained, the mor,e sensitive is the individual to corticosteroids. Means for each group in the Figure are noted by a horizontal bar. The primary open-angle glaucoma and GG groups had nearly equal mean sensitivities, and greater mean sensitivity than NG patients, who in turn had greater mean sensitivity than NN patients. Pigmentary glaucoma pa tients exhibited a wide range of I5o values,
— +
— — — -
43
61
28
69
23
35
43
30
29
33
33
56
40
56
22
21
M
M
F
F
M
M
M
M
M
M
M
F
M
M
M
M
M
M
W
w w w w w w w w
B
w w w w w w w w
60
47
62
28
69
24
43
55
48
65
29
34
55
58
49
50
62
22
3
4
5
6
7
8
9
10
11
12
13*
14
15
16
17
18
19
20
63
45
-
—
—
+
-
+
—
—
—
44
M
W
44
2
-
31
F
W
39
1
Age at Onset, Family History yrs
Sex
Race
Age, yrs
Case No.
TABLE 1I
RE: - 3 . 7 5 L E : - 1 . 2 5 + 0.25 x 180° RE: piano L E : - 9 . 5 0 + 2.00 x 180° RE: - 2 . 0 0 LE: -2.50 RE: - 1 . 2 5 + 0.25 x 110° LE: -1.75 RE: - 0 . 7 5 + 0.75 x 45" L E : - 0 . 7 5 + 0.75 x 140° RE: - 3 . 2 5 + 1.25 x 180° L E : - 2 . 7 5 + 0.75 x 180° RE: +0.75 L E : +0.75 RE: - 7 . 0 0 + 1.00 x 5° L E : - 6 . 0 0 + 1.00 x 160° RE: - 7 . 7 5 + 1.25 x 90° LE: -7.50 RE: - 2 . 7 5 + 0.75 x 180° L E : - 2 . 7 5 + 0.75 x 170° RE: - 0 . 5 0 + 0.25 x 180° L E : piano RE: +0.50 L E : + 1.00 RE: - 4 . 0 0 LE: -4.00 RE: - 3 . 7 5 + 0.50 x 125° L E : - 4 . 2 5 + 1.25 x 180° RE: - 2 . 2 5 L E : - 2 . 0 0 + 0.25 x 5° RE: - 0 . 7 5 + 1.50 x 180° L E : - 1 . 2 5 + 1.75 x 180° RE: - 6 . 0 0 LE: -7.00 RE: - 1 2 . 5 0 + 1.25 x 100° L E : - 1 1 . 0 0 + 0.50 x 180° RE: - 2 . 7 5 + 0.25 x 65° LE: -4.00 RE: - 4 . 0 0 + 0.75 x 160° L E : - 4 . 0 0 + 0.50 x 40°
Refraction
Visual Fields
Krukenberg's Spindles
+ 20/70 Central island 20/20 Normal 20/30 Normal + 20/80 Inferior Bjerrum HM + Temporal island 20/20 Superior Bjerrum + 20/30 Superior Bjerrum 20/20 Normal + 20/25 Normal 20/20 Inferior Bjerrum + 20/15 Nasal step 20/15 Normal + 20/200 Superior Bjerrum 20/70 Superior Bjerrum 20/20 Superior Bjerrum, nasal step + 20/20 Nasal step 20/20 Normal + 20/25 Blind spot elongation + 20/20 Normal 20/20 Superior nasal step + 20/20 Bjerrum 20/20 Normal + 20/20 Inferior nasal loss 20/20 Inferior nasal loss 20/20 Inferior arcuate + 20/20 Inferior arcuate + 20/20 Nasal step 20/30 Superior and inferior BjerrurrI + 20/25 Superior Bjerrum 20/20 Normal + 20/20 Superior Bjerrum 20/20 Inferior Bjerrum 20/25 Superior and inferior Bjerrum + 20/20 Inferior Bjerrum, nas al step 20/100 Superior and inferior Bjerrum + 20/30 Superior Bjerrum 20/25 Normal + 20/400 Central island only 20/20 Paracentral scotoma + 20/20 Normal
Visual Acuity
C L I N I C A L DATA
68
—
+
+
+
+
+
+
+
+
+
39
60
23
+
72
81
— +
15
60 +
+
87
101
— +
+
74
— +
+
62
+
51
-
57
61
61
60
72
53
96
w
+
—
+
+
+
-
+
+
+
+
+
+
+
+
+
Iris Heavy T ransillumTrabecular ination Pigmentation Defects
VOL. 80, NO. 3, PART II
CORTICOSTEROID RESPONSE
481
150 (ng/ml ) tO 0
0
^ 0
1
0» 0
1
00 0
1
O 0
1
1
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•
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Figure (Zink and associates). Distribution of I50 values by categories of topical dexamethasone low responder (NN), intermediate responder (NG), high responder (GG), primary open-angle glaucoma (OAG), and pigmentary glaucoma (PG).
and a mean I 50 that was between the NN and NG means. Table 2 summarizes the data numerically, and notes the signifi cant difference in sensitivity (P < .001) between the pigmentary glaucoma and primary open-angle groups. There were significant differences in sensitivity be tween the pigmentary glaucoma group and both the NN (P < .01), and GG (P < .01) groups, but no significant differ ence between the pigmentary glaucoma group and the NG group. We found no significant correlation among the patients with pigmentary glau coma between I 50 and a positive family
TABLE 2 PREDNISOLONE-21-PHOSPHATE INHIBITION OF LYMPHOCYTE TRANSFORMATION BY OCULAR CLASSIFICATION
Classification*
No.
Mean Iso
Standard Deviation
NN NG GG POAG PG
22 15 27 36 20
78.41 59.00 39.44 37.25 62.65
12.55 11.10 12.45 12.50 21.19
*POAG, primary open-angle glaucoma; PG, pig mentary glaucoma.
482
AMERICAN JOURNAL OF OPHTHALMOLOGY
history of primary open-angle glaucoma, myopia greater than five diopters, a diag nosis of glaucoma made at > 40 years of age, the presence of iris transillumination defects, or the city (Detroit or St. Louis) where the patient was treated (Table 3). DISCUSSION
The etiologies of pigmentary glaucoma and primary open-angle glaucoma are un known. In the case of primary open-angle glaucoma, however, there is circumstan tial evidence that increased sensitivity to corticosteroids may play a role in the pathogenesis of the disease. Corticoster oids applied to the eyes of susceptible persons lead to marked elevation of intra ocular pressure, decreased outflow facili ty, optic nerve head cupping, and charac teristic glaucomatous visual field loss, thus mimicking primary open-angle glau coma. 15 While marked pressure elevations (to > 31 mm Hg) may be elicited by topical corticosteroids in 82% of patients with primary open-angle glaucoma, only 6% of the general population responds in this manner. 16,17 The association of primary open-angle glaucoma and increased sensitivity to cor ticosteroids also holds on the cellular level. In vitro determination of sensitivity TABLE 3 PIGMENTARY GLAUCOMA SUBGROUPS
No.
Mean I50
Isoof others*
Family history of glaucoma
4
65 ± 32
62 ± 19
Myopia > 5 diopters
5
53 ± 18
66 ± 22
64 ± 10
61 ± 28
Subgroup
Age at diagnosis > 40 years Iris transillumination defects
10
58 ± 2 0
68 ± 22
From St. Louis
12
59 + 16
68 ± 28
*Patients from Detroit.
SEPTEMBER, 1975
to corticosteroid by assay of inhibition of lymphocyte transformation yielded re sults that correlated well with topical testing results (correlation coefficient, r = .81), 14 and showed significantly increased sensitivity to corticosteroids in patients with primary open-angle glaucoma. 13,14 If pigmentary glaucoma were merely a variant of primary open-angle glaucoma, we would expect to find a similar degree of increased sensitivity to corticosteroid. Contrarily, as a group, these 20 pigmen tary glaucoma patients did not manifest markedly increased sensitivity to cortico steroids. The mean I 50 for the pigmentary glaucoma patients was 63 ± 21 ng/ml, vs. 37 ± 12 for the primary open-angle glau coma patients (Table 2). The difference is significant (P < .001 by two-tailed f test). While the pigmentary glaucoma pa tients were not as sensitive as primary open-angle glaucoma patients, the ques tion arises whether or not they are more sensitive than the general population. A direct answer is not available. We are studying 100 randomly selected subjects to characterize the response of the general population, but sufficient data have not been collected. We may, however, esti mate the average response of the general population based on the results for the NN, NG, and GG patients already tested (Table 4). 18 That average I 50 is 69 ng/ml, slightly higher than the value of 63 ng/ml for the pigmentary glaucoma patients. We can assess the corticosteroid sensi tivity of either the primary open-angle glaucoma or pigmentary glaucoma pa tients by classifying the in vitro responses into three arbitrary categories corre sponding to the three topical response categories. The boundaries for these in vitro categories are obtained from the regression line for I50 vs. final pressure achieved. 14 The dividing points of ocular testing, at 20 and 31 mm Hg, correspond to in vitro Iso values of 71 and 51 ng/ml, respectively. The distribution of low, in-
VOL. 80, NO. 3, PART I
CORTICOSTEROID RESPONSE
483
TABLE 4
TABLE 5
ESTIMATION OF THE MEAN I50 FOR THE
DISTRIBUTIONS OF CORTICOSTEROID RESPONDERS
GENERAL POPULATION
Category
I50
NN 78.41 x NG 59.00 x GG 39.44 x General population
% of General Population
Contribution, ng/ml
58 36 6
45.48 21.24 2.37
100
69.09
termediate, and high responders, for both ocular 16 and in vitro testing of primary open-angle glaucoma patients, is given in Table 5. The correspondence of the re sults is good. The distributions for in vitro testing of pigmentary glaucoma pa tients, and ocular testing of a general population, 1 7 are listed for comparison. The difference between the distributions for primary open-angle and pigmentary glaucoma patients on in vitro testing is significant (P < .001 by chi-square analy sis contingency). Assuming the validity of cross-test comparison, it appears there is some enrichment of in vitro corticosteroid responders (intermediate and high) in the pigmentary glaucoma group relative to the general population, but clearly that enrichment is small compared to that seen for the primary open-angle glaucoma group. A similar enrichment of corticosteroid responders was noted on topical testing of the normal fellow eye of patients with angle recession glaucoma. 19 Presumably, the compromising additive effects of trau ma and a latent tendency to primary open-angle glaucoma are sufficient to cause disease, while neither trauma alone (in a similarly injured corticosteroid nonresponder) nor the latent tendency alone (in the similarly responsive but uninjured fellow eye) is sufficient. An analogous postulate may be offered to account for the small enrichment of in vitro respond ers among the pigmentary glaucoma
Group
NN, %
NG, % GG, %
Pigmentary open-angle glaucoma Ocular testing In vitro testing
1 (1) 0 (0)
17 (17) 19 (7)
82 (82) 81 (29)
Pigmentary glaucoma In vitro
35(7)
50(10)
15(3)
General population Ocular testing
58(174) 36(108)
6(18)
•Numbers in parentheses indicate subjects.
patients, with additive components of ob struction due to pigment (or angle anoma lies) and latent primary open-angle glau coma. As a group, pigmentary glaucoma pa tients do not have the markedly increased sensitivity to corticosteroids seen in pa tients with primary open-angle glaucoma. If increased sensitivity to corticosteroids plays an essential role in the pathogenesis of primary open-angle glaucoma, then pigmentary glaucoma appears to be etiologically, as well as clinically, a separate entity. SUMMARY
We used an in vitro assay utilizing corticosteroids to inhibit transformation of peripheral blood lymphocytes to evalu ate a group of 20 patients with pigmen tary glaucoma. The pigmentary glaucoma patient group did not manifest the mark edly increased cellular sensitivity to corti costeroids associated with primary openangle glaucoma. If increased sensitivity to corticosteroids plays an essential role in the pathogenesis of primary openangle glaucoma, then pigmentary glauco ma appears to be etiologically, as well as clinically, a separate entity. ACKNOWLEDGMENTS
Steven Podos, M.D., Theodore Krupin, M.D., Jack Kayes, M.D., Robert Drews, M.D., and Jacob Wilen-
484
AMERICAN JOURNAL OF OPHTHALMOLOGY
sky, M.D., referred patients. Merck, Sharp and Dohme provided prednisolone-21-phosphate. REFERENCES 1. Sugar, H. S., and Barbour, F. A.: Pigmentary glaucoma. A rare clinical entity. Am. J. Ophthalmol. 32.90, 1949. 2. Bick, M. W.: Pigmentary glaucoma in females. Arch. Ophthalmol. 58:483, 1957. 3. : Sex differences in pigmentary glauco ma. Am. J. Ophthalmol. 54:831, 1962. 4. Scheie, H. G., and Fleischhauer, H. W.: Idiopathic atrophy of the epithelial layers of the iris and ciliary body. Arch. Ophthalmol. 59:216, 1958. 5. Sugar, H. S.: Pigmentary glaucoma. A 25-year review. Am. J. Ophthalmol. 62:499, 1966. 6. Peterson, H. P.: Pigmentary glaucoma. Acta Ophthalmol. 39:688, 1961. 7. Malbran, J.: Pigmentary glaucoma. Its relation with congenital glaucoma. Mod. Probl. Ophthalmol. 1:132, 1957. 8. Evans, W. H., Odum, R. E., and Wenaas, E. J.: Krukenberg's spindle. A study of 202 collected cases. Arch. Ophthalmol. 26:1023, 1941. 9. Perkins, E. S.: Glaucoma in the younger age groups. Arch. Ophthalmol. 64:882, 1960. 10. Barkan, O.: Pigment changes in the anterior segment in primary glaucoma. Trans. Am. Ophthal mol. Soc. 55:395, 1957.
OPHTHALMIC
SEPTEMBER, 1975
11. Levinsohn, G.: Beitrag zur pathologischen anatomie und pathogenese des glaucoms. Arch. Augenheilkd. 62:131, 1909. 12. Becker, B., and Podos, S. M.: Krukenberg's spindles and primary open-angle glaucoma. Arch. Ophthalmol. 76:635, 1966. 13. Bigger, J. F., Palmberg, P. F., and Becker, B.: Increased cellular sensitivity to glucocorticoids in primary open-angle glaucoma. Invest. Ophthalmol. 11:832, 1972. 14. Bigger, J. F., Palmberg, P. F., and Zink, H. A.: In vitro corticosteroid response. Correlation with primary open-angle glaucoma and ocular cortico steroid sensitivity. Am. J. Ophthalmol. 79:92, 1975. 15. Goldmann, H.: Cortisone glaucoma. Int. Ophthalmol. Clin. 6: p. 991, 1966. 16. Kolker, A. E., and Hetherington, J.: BeckerShaffer's Diagnosis and Therapy of the Glaucomas. St. Louis, C. V. Mosby Co., 1970, p. 244. 17. Becker, B.: Diabetes mellitus and primary open-angle glaucoma. Am. J. Ophthalmol. 71(pt. 1):1, 1971. 18. Bickel, P. J., Hammel, E. A., and O'Connell, J. W.: Sex bias in graduate admissions. Science 187:398, 1975. 19. Armaly, M. F.: Steroids and glaucoma. In Symposium on Glaucoma. Transactions of the New Orleans Academy of Ophthalmoloy. St. Louis, C. V. Mosby Co., 1967, p. 115.
MINIATURE
His labour is not yet at an end: he must know many languages and many sciences; and, that his stile may be worthy of his thoughts, must by incessant practice, familiarize to himself every delicacy of speech and grace of harmony. Samuel Johnson, The History ofRasselas, Prince of Abissinia Harvard University Press, 1951
P A U L F. P A L M B E R G , M.D.,
A L A N SUGAR,
M.D.,
H E R B E R T L. C A N T R I L L , M.D., B E R N A R D B E C K E R , AND J O H N F. B I G G E R , M.D.
M.D.,
St. Louis, Missouri 1
In 1949, Sugar and Barbour first de scribed pigmentary glaucoma as a sepa rate entity. It was distinguished clinically from primary open-angle glaucoma by the presence of marked pigment dispersion in the anterior segment of the eye, 1 and associated concentric atrophy of the midperipheral portion of the iris pigment epithelium, often demonstrable on iris transillumination. 2 Pigment released from the atrophic posterior iris and car ried forward by the flow of aqueous humor was found on the zonules and circumference of the lens, the corneal endothelium (Krukenberg's spindle), an terior iris surface, and the filtering portion of the trabecular area. Controversy has existed as to whether or not pigmentary glaucoma is etiologically separate from primary open-angle glaucoma. Those supporting a separate cause for pigmentary glaucoma have felt that the development of this glaucoma is secondary to mechanical obstruction of the outflow channels by pigment alone, 3 - 6 or in combination with abnormalities of the angle structures. 7 " 9 In support of this concept, the severity of the glaucoma has been correlated with the degree of pigmentation. 6 In addition, pigmentary glaucoma generally occurs in younger pa tients than does primary open-angle glau coma, and shows a marked predilection From the Department of Ophthalmology, Wash ington University School of Medicine, St. Louis, Missouri. This study was supported in part by grants EY-0036 and EY-01167 from the National Eye Institute, and a grant from the Seeing Eye, Inc., Morristown, New Jersey. Reprint requests to Paul Palmberg, M.D., Depart ment of Ophthalmology, Washington University School of Medicine, 660 S. Euclid, St. Louis, MO 63110.
for men while primary open-angle glau coma shows no sex predilection. 3 On the other hand, those supporting a common etiology for the outflow obstruc tion in these glaucomas have implied that trabecular pigment deposition is a conse quence rather than a cause of aqueous obstruction, and that the occurrence of pigment releasing iris atrophy merely makes the pigment accumulation more dramatic. In support of this view, occa sional pigment deposition occurs in the absence of iris atrophy in one half 1 to two thirds 1 0 of primary open-angle glaucoma patients, and also in patients with secon dary glaucoma due to uveitis or trau ma. 11,12 Further, the adequacy of pigment alone to obstruct aqueous outflow is ques tionable since 90% of persons with pig ment dispersion, manifested by Kruken berg's spindles, did not have glaucoma. 3,8 Becker and Podos 1 2 reported the occur rence of pigmentary glaucoma and pri mary open-angle glaucoma in the same families, suggesting a common genetic basis. They also examined topical corticosteroid response in 15 persons with Kru kenberg's spindles without glaucoma, and found more corticosteroid responders than in the general population. The corti costeroid responses of the patients with Krukenberg's spindles approximated those of the offspring and siblings of primary open-angle glaucoma patients, suggesting a link of pigment disperson to corticosteroid responsiveness and pri mary open-angle glaucoma. We evaluated the possible relationship of pigmentary glaucoma to primary open-angle glaucoma by comparing in vitro cellular sensitivity to corticosteroid in the two groups, as assayed by inhibi-
478
VOL. 80, NO. 3, PART I
CORTICOSTEROID RESPONSE
tion of lymphocyte transformation. Previ ous results of this assay correlated well with those of ocular corticosteroid test ing, and demonstrated a markedly in creased sensitivity to corticosteroids at the cellular level in primary open-angle glaucoma.13,14 Use of a nonocular assay allowed study of corticosteroid sensitivity in persons whose spontaneous intraocular pressures would have been too elevated to permit meaningful topical testing. It avoided the potential problem that in topical testing the presence of pigment in the trabecular region may augment the apparent response to corticosteroid. SUBJECTS AND METHODS
Twenty patients with pigmentary glau coma had elevated intraocular pressures before treatment, gonioscopically open angles, and evidence of pigment disper sion including Krukenberg's spindles and heavy trabecular pigmentation. Ten had iris transillumination defects. All had vis ual field loss characteristic of glaucoma, and most had appreciable cupping of the optic nerve head. All but one (newly diagnosed) were receiving medical thera py for their glaucoma at the time of test ing. Only one was receiving acetazolamide. There were 16 men and four wo men. The men averaged 49 ± 14 (CT) years of age at testing, and 41 ± 15 years at diagnosis. The women averaged 40 ± 15 years of age at testing and 38 ± 15 years at diagnosis. Eighteen of the patients were myopic, although only five had myopia greater than 5 diopters. Four patients had a contributory family history of glauco ma, with two known to be primary openangle glaucoma (Table 1). The technique for preparation of lym phocyte cultures, corticosteroid preincubation, phytohemagglutinin stim ulation, cell harvesting, scintillation counting, and data analysis have been described.13,14 We determined the con centration of prednisolone-21-phosphate required to inhibit tritiated thymidine up
479
take in mitogen-transformed cells by 50% (half inhibition concentration, or Iso) for each patient. Patient data were accepted for the study if they met the following three criteria. First, the coefficient of vari ation of the phytohemagglutinin-P stimu lated controls was 20% or less. Second, the uptake of tritiated thymidine was 10% or less of the total amount present. Third, the correlation coefficient, r, for the re gression analysis of the dose-response curve was .75 or greater. RESULTS
We obtained the distribution of I50 val ues for each of the patients with pigmen tary glaucoma, and for 100 other pa tients 14 (Figure). The previously reported patients included 36 patients with pri mary open-angle glaucoma. We classified the rest by topical ocular dexamethasone testing (application of 0.1% dexamethasone-21-phosphate eyedrops to one eye, four times daily, for six weeks). Based on Becker's criteria, these included: 22 NN individuals: low responders, whose final intraocular pressure „ remained < 20 mm Hg. 15 NG individuals: intermediate re sponders, whose final intraocular pressure was between 20 and 31 mm Hg. 27 GG individuals: high respond ers, whose final intraocular pres sure was > 31 mm Hg. We studied these 100 patients during the present study. In the lymphocyte assay, tjhe lower the Iso value obtained, the mor,e sensitive is the individual to corticosteroids. Means for each group in the Figure are noted by a horizontal bar. The primary open-angle glaucoma and GG groups had nearly equal mean sensitivities, and greater mean sensitivity than NG patients, who in turn had greater mean sensitivity than NN patients. Pigmentary glaucoma pa tients exhibited a wide range of I5o values,
— +
— — — -
43
61
28
69
23
35
43
30
29
33
33
56
40
56
22
21
M
M
F
F
M
M
M
M
M
M
M
F
M
M
M
M
M
M
W
w w w w w w w w
B
w w w w w w w w
60
47
62
28
69
24
43
55
48
65
29
34
55
58
49
50
62
22
3
4
5
6
7
8
9
10
11
12
13*
14
15
16
17
18
19
20
63
45
-
—
—
+
-
+
—
—
—
44
M
W
44
2
-
31
F
W
39
1
Age at Onset, Family History yrs
Sex
Race
Age, yrs
Case No.
TABLE 1I
RE: - 3 . 7 5 L E : - 1 . 2 5 + 0.25 x 180° RE: piano L E : - 9 . 5 0 + 2.00 x 180° RE: - 2 . 0 0 LE: -2.50 RE: - 1 . 2 5 + 0.25 x 110° LE: -1.75 RE: - 0 . 7 5 + 0.75 x 45" L E : - 0 . 7 5 + 0.75 x 140° RE: - 3 . 2 5 + 1.25 x 180° L E : - 2 . 7 5 + 0.75 x 180° RE: +0.75 L E : +0.75 RE: - 7 . 0 0 + 1.00 x 5° L E : - 6 . 0 0 + 1.00 x 160° RE: - 7 . 7 5 + 1.25 x 90° LE: -7.50 RE: - 2 . 7 5 + 0.75 x 180° L E : - 2 . 7 5 + 0.75 x 170° RE: - 0 . 5 0 + 0.25 x 180° L E : piano RE: +0.50 L E : + 1.00 RE: - 4 . 0 0 LE: -4.00 RE: - 3 . 7 5 + 0.50 x 125° L E : - 4 . 2 5 + 1.25 x 180° RE: - 2 . 2 5 L E : - 2 . 0 0 + 0.25 x 5° RE: - 0 . 7 5 + 1.50 x 180° L E : - 1 . 2 5 + 1.75 x 180° RE: - 6 . 0 0 LE: -7.00 RE: - 1 2 . 5 0 + 1.25 x 100° L E : - 1 1 . 0 0 + 0.50 x 180° RE: - 2 . 7 5 + 0.25 x 65° LE: -4.00 RE: - 4 . 0 0 + 0.75 x 160° L E : - 4 . 0 0 + 0.50 x 40°
Refraction
Visual Fields
Krukenberg's Spindles
+ 20/70 Central island 20/20 Normal 20/30 Normal + 20/80 Inferior Bjerrum HM + Temporal island 20/20 Superior Bjerrum + 20/30 Superior Bjerrum 20/20 Normal + 20/25 Normal 20/20 Inferior Bjerrum + 20/15 Nasal step 20/15 Normal + 20/200 Superior Bjerrum 20/70 Superior Bjerrum 20/20 Superior Bjerrum, nasal step + 20/20 Nasal step 20/20 Normal + 20/25 Blind spot elongation + 20/20 Normal 20/20 Superior nasal step + 20/20 Bjerrum 20/20 Normal + 20/20 Inferior nasal loss 20/20 Inferior nasal loss 20/20 Inferior arcuate + 20/20 Inferior arcuate + 20/20 Nasal step 20/30 Superior and inferior BjerrurrI + 20/25 Superior Bjerrum 20/20 Normal + 20/20 Superior Bjerrum 20/20 Inferior Bjerrum 20/25 Superior and inferior Bjerrum + 20/20 Inferior Bjerrum, nas al step 20/100 Superior and inferior Bjerrum + 20/30 Superior Bjerrum 20/25 Normal + 20/400 Central island only 20/20 Paracentral scotoma + 20/20 Normal
Visual Acuity
C L I N I C A L DATA
68
—
+
+
+
+
+
+
+
+
+
39
60
23
+
72
81
— +
15
60 +
+
87
101
— +
+
74
— +
+
62
+
51
-
57
61
61
60
72
53
96
w
+
—
+
+
+
-
+
+
+
+
+
+
+
+
+
Iris Heavy T ransillumTrabecular ination Pigmentation Defects
VOL. 80, NO. 3, PART II
CORTICOSTEROID RESPONSE
481
150 (ng/ml ) tO 0
0
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00 0
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Figure (Zink and associates). Distribution of I50 values by categories of topical dexamethasone low responder (NN), intermediate responder (NG), high responder (GG), primary open-angle glaucoma (OAG), and pigmentary glaucoma (PG).
and a mean I 50 that was between the NN and NG means. Table 2 summarizes the data numerically, and notes the signifi cant difference in sensitivity (P < .001) between the pigmentary glaucoma and primary open-angle groups. There were significant differences in sensitivity be tween the pigmentary glaucoma group and both the NN (P < .01), and GG (P < .01) groups, but no significant differ ence between the pigmentary glaucoma group and the NG group. We found no significant correlation among the patients with pigmentary glau coma between I 50 and a positive family
TABLE 2 PREDNISOLONE-21-PHOSPHATE INHIBITION OF LYMPHOCYTE TRANSFORMATION BY OCULAR CLASSIFICATION
Classification*
No.
Mean Iso
Standard Deviation
NN NG GG POAG PG
22 15 27 36 20
78.41 59.00 39.44 37.25 62.65
12.55 11.10 12.45 12.50 21.19
*POAG, primary open-angle glaucoma; PG, pig mentary glaucoma.
482
AMERICAN JOURNAL OF OPHTHALMOLOGY
history of primary open-angle glaucoma, myopia greater than five diopters, a diag nosis of glaucoma made at > 40 years of age, the presence of iris transillumination defects, or the city (Detroit or St. Louis) where the patient was treated (Table 3). DISCUSSION
The etiologies of pigmentary glaucoma and primary open-angle glaucoma are un known. In the case of primary open-angle glaucoma, however, there is circumstan tial evidence that increased sensitivity to corticosteroids may play a role in the pathogenesis of the disease. Corticoster oids applied to the eyes of susceptible persons lead to marked elevation of intra ocular pressure, decreased outflow facili ty, optic nerve head cupping, and charac teristic glaucomatous visual field loss, thus mimicking primary open-angle glau coma. 15 While marked pressure elevations (to > 31 mm Hg) may be elicited by topical corticosteroids in 82% of patients with primary open-angle glaucoma, only 6% of the general population responds in this manner. 16,17 The association of primary open-angle glaucoma and increased sensitivity to cor ticosteroids also holds on the cellular level. In vitro determination of sensitivity TABLE 3 PIGMENTARY GLAUCOMA SUBGROUPS
No.
Mean I50
Isoof others*
Family history of glaucoma
4
65 ± 32
62 ± 19
Myopia > 5 diopters
5
53 ± 18
66 ± 22
64 ± 10
61 ± 28
Subgroup
Age at diagnosis > 40 years Iris transillumination defects
10
58 ± 2 0
68 ± 22
From St. Louis
12
59 + 16
68 ± 28
*Patients from Detroit.
SEPTEMBER, 1975
to corticosteroid by assay of inhibition of lymphocyte transformation yielded re sults that correlated well with topical testing results (correlation coefficient, r = .81), 14 and showed significantly increased sensitivity to corticosteroids in patients with primary open-angle glaucoma. 13,14 If pigmentary glaucoma were merely a variant of primary open-angle glaucoma, we would expect to find a similar degree of increased sensitivity to corticosteroid. Contrarily, as a group, these 20 pigmen tary glaucoma patients did not manifest markedly increased sensitivity to cortico steroids. The mean I 50 for the pigmentary glaucoma patients was 63 ± 21 ng/ml, vs. 37 ± 12 for the primary open-angle glau coma patients (Table 2). The difference is significant (P < .001 by two-tailed f test). While the pigmentary glaucoma pa tients were not as sensitive as primary open-angle glaucoma patients, the ques tion arises whether or not they are more sensitive than the general population. A direct answer is not available. We are studying 100 randomly selected subjects to characterize the response of the general population, but sufficient data have not been collected. We may, however, esti mate the average response of the general population based on the results for the NN, NG, and GG patients already tested (Table 4). 18 That average I 50 is 69 ng/ml, slightly higher than the value of 63 ng/ml for the pigmentary glaucoma patients. We can assess the corticosteroid sensi tivity of either the primary open-angle glaucoma or pigmentary glaucoma pa tients by classifying the in vitro responses into three arbitrary categories corre sponding to the three topical response categories. The boundaries for these in vitro categories are obtained from the regression line for I50 vs. final pressure achieved. 14 The dividing points of ocular testing, at 20 and 31 mm Hg, correspond to in vitro Iso values of 71 and 51 ng/ml, respectively. The distribution of low, in-
VOL. 80, NO. 3, PART I
CORTICOSTEROID RESPONSE
483
TABLE 4
TABLE 5
ESTIMATION OF THE MEAN I50 FOR THE
DISTRIBUTIONS OF CORTICOSTEROID RESPONDERS
GENERAL POPULATION
Category
I50
NN 78.41 x NG 59.00 x GG 39.44 x General population
% of General Population
Contribution, ng/ml
58 36 6
45.48 21.24 2.37
100
69.09
termediate, and high responders, for both ocular 16 and in vitro testing of primary open-angle glaucoma patients, is given in Table 5. The correspondence of the re sults is good. The distributions for in vitro testing of pigmentary glaucoma pa tients, and ocular testing of a general population, 1 7 are listed for comparison. The difference between the distributions for primary open-angle and pigmentary glaucoma patients on in vitro testing is significant (P < .001 by chi-square analy sis contingency). Assuming the validity of cross-test comparison, it appears there is some enrichment of in vitro corticosteroid responders (intermediate and high) in the pigmentary glaucoma group relative to the general population, but clearly that enrichment is small compared to that seen for the primary open-angle glaucoma group. A similar enrichment of corticosteroid responders was noted on topical testing of the normal fellow eye of patients with angle recession glaucoma. 19 Presumably, the compromising additive effects of trau ma and a latent tendency to primary open-angle glaucoma are sufficient to cause disease, while neither trauma alone (in a similarly injured corticosteroid nonresponder) nor the latent tendency alone (in the similarly responsive but uninjured fellow eye) is sufficient. An analogous postulate may be offered to account for the small enrichment of in vitro respond ers among the pigmentary glaucoma
Group
NN, %
NG, % GG, %
Pigmentary open-angle glaucoma Ocular testing In vitro testing
1 (1) 0 (0)
17 (17) 19 (7)
82 (82) 81 (29)
Pigmentary glaucoma In vitro
35(7)
50(10)
15(3)
General population Ocular testing
58(174) 36(108)
6(18)
•Numbers in parentheses indicate subjects.
patients, with additive components of ob struction due to pigment (or angle anoma lies) and latent primary open-angle glau coma. As a group, pigmentary glaucoma pa tients do not have the markedly increased sensitivity to corticosteroids seen in pa tients with primary open-angle glaucoma. If increased sensitivity to corticosteroids plays an essential role in the pathogenesis of primary open-angle glaucoma, then pigmentary glaucoma appears to be etiologically, as well as clinically, a separate entity. SUMMARY
We used an in vitro assay utilizing corticosteroids to inhibit transformation of peripheral blood lymphocytes to evalu ate a group of 20 patients with pigmen tary glaucoma. The pigmentary glaucoma patient group did not manifest the mark edly increased cellular sensitivity to corti costeroids associated with primary openangle glaucoma. If increased sensitivity to corticosteroids plays an essential role in the pathogenesis of primary openangle glaucoma, then pigmentary glauco ma appears to be etiologically, as well as clinically, a separate entity. ACKNOWLEDGMENTS
Steven Podos, M.D., Theodore Krupin, M.D., Jack Kayes, M.D., Robert Drews, M.D., and Jacob Wilen-
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AMERICAN JOURNAL OF OPHTHALMOLOGY
sky, M.D., referred patients. Merck, Sharp and Dohme provided prednisolone-21-phosphate. REFERENCES 1. Sugar, H. S., and Barbour, F. A.: Pigmentary glaucoma. A rare clinical entity. Am. J. Ophthalmol. 32.90, 1949. 2. Bick, M. W.: Pigmentary glaucoma in females. Arch. Ophthalmol. 58:483, 1957. 3. : Sex differences in pigmentary glauco ma. Am. J. Ophthalmol. 54:831, 1962. 4. Scheie, H. G., and Fleischhauer, H. W.: Idiopathic atrophy of the epithelial layers of the iris and ciliary body. Arch. Ophthalmol. 59:216, 1958. 5. Sugar, H. S.: Pigmentary glaucoma. A 25-year review. Am. J. Ophthalmol. 62:499, 1966. 6. Peterson, H. P.: Pigmentary glaucoma. Acta Ophthalmol. 39:688, 1961. 7. Malbran, J.: Pigmentary glaucoma. Its relation with congenital glaucoma. Mod. Probl. Ophthalmol. 1:132, 1957. 8. Evans, W. H., Odum, R. E., and Wenaas, E. J.: Krukenberg's spindle. A study of 202 collected cases. Arch. Ophthalmol. 26:1023, 1941. 9. Perkins, E. S.: Glaucoma in the younger age groups. Arch. Ophthalmol. 64:882, 1960. 10. Barkan, O.: Pigment changes in the anterior segment in primary glaucoma. Trans. Am. Ophthal mol. Soc. 55:395, 1957.
OPHTHALMIC
SEPTEMBER, 1975
11. Levinsohn, G.: Beitrag zur pathologischen anatomie und pathogenese des glaucoms. Arch. Augenheilkd. 62:131, 1909. 12. Becker, B., and Podos, S. M.: Krukenberg's spindles and primary open-angle glaucoma. Arch. Ophthalmol. 76:635, 1966. 13. Bigger, J. F., Palmberg, P. F., and Becker, B.: Increased cellular sensitivity to glucocorticoids in primary open-angle glaucoma. Invest. Ophthalmol. 11:832, 1972. 14. Bigger, J. F., Palmberg, P. F., and Zink, H. A.: In vitro corticosteroid response. Correlation with primary open-angle glaucoma and ocular cortico steroid sensitivity. Am. J. Ophthalmol. 79:92, 1975. 15. Goldmann, H.: Cortisone glaucoma. Int. Ophthalmol. Clin. 6: p. 991, 1966. 16. Kolker, A. E., and Hetherington, J.: BeckerShaffer's Diagnosis and Therapy of the Glaucomas. St. Louis, C. V. Mosby Co., 1970, p. 244. 17. Becker, B.: Diabetes mellitus and primary open-angle glaucoma. Am. J. Ophthalmol. 71(pt. 1):1, 1971. 18. Bickel, P. J., Hammel, E. A., and O'Connell, J. W.: Sex bias in graduate admissions. Science 187:398, 1975. 19. Armaly, M. F.: Steroids and glaucoma. In Symposium on Glaucoma. Transactions of the New Orleans Academy of Ophthalmoloy. St. Louis, C. V. Mosby Co., 1967, p. 115.
MINIATURE
His labour is not yet at an end: he must know many languages and many sciences; and, that his stile may be worthy of his thoughts, must by incessant practice, familiarize to himself every delicacy of speech and grace of harmony. Samuel Johnson, The History ofRasselas, Prince of Abissinia Harvard University Press, 1951
