Mitomycin as Adjunct Chemotherapy with Trabeculectomy STEVEN S. PALMER, MD
Abstract: Preliminary experience is reported in using mitomycin to improve the prognosis in trabeculectomy operations considered otherwise likely not to suc ceed. The medication is applied intraoperatively during an otherwise standard trabeculectomy procedure. Surgery was considered successful if the pressure was lowered to a predetermined target level, the only vision reduction was believed to be on the basis of cataract development, and there was no pro gression of cupping or visual field loss. With a follow-up of 6 to 42 months, the overall success rate is 84%. Ophthalmology 1991; 98:317-321
Chen 1 and Chen et al 2 first reported the use of mito mycin as adjunct chemotherapy during trabeculectomy surgery. Mitomycin is an antibiotic isolated from the broth of Streptomyces caespitosis. It has been found to inhibit DNA synthesis and is usually used by systemic injection for its antitumor activity. It was used in the glaucoma operations because it inhibits fibroblast proliferation. 3 This report describes a 3.5-year experience, with a min imum follow-up of 6 months, using a technique derived from that described by Chen. 1 Surgery was performed on 33 eyes of 29 patients. In formed consent was obtained from all patients. Eyes were chosen in which standard surgery was not likely to suc ceed. All eligible eyes were chosen. Selection was limited to neovascular glaucoma, glaucoma in aphakia, secondary glaucoma, advanced low-tension glaucoma, and previ ously operated eyes. Chen et al 2 reported success rates of 76% using a mitomycin concentration of0.1 mg/ml, 100% using a concentration of 0.2 mg/ml, and 100% using a concentration of 0.4 mg/ml. In this study, only the 0.2 mg/ml concentration was used.
Originally received: September 4, 1990. Revision accepted: November 9, 1990. From the Department of Ophthalmology, Blodgett Memorial Medical Center, Grand Rapids. Reprint requests to StevenS. Palmer, MD, 515 Lakeside Drive, Sf;, Grand Rapids, Ml 49506.
METHODS After a limbal-based conjunctival flap is prepared (without excision of Tenon's layer), a 2 X 3-mm rectan gular scleral flap of 1h to 1h scleral thickness is dissected into clear cornea. A solution of 0.2 mg/ml mitomycin is prepared, on the same day, by mixing the contents of a 5-mg vial of mitomycin into 25 ml of sterile water for injection. A small surgical sponge is soaked with the so lution and held in contact with the exposed scleral surface and the bed of the scleral flap, with the conjunctival/ten ons layer draped over the sponge. After 5 minutes, the sponge is removed and the entire area is lightly irrigated with balanced salt solution. The procedure is then com pleted as a standard trabeculectomy, although there are a few subtle modifications. The scleral flap is made slightly thicker and is sutured more securely than usual. The con junctival and tenons layers are sutured more securely and with slightly more tissue being enclosed in each stitch. Postoperative medication is topical cycloplegic (cyclo pentolate, 1%) and steroid (prednisolone sodium phos phate, 1%).
RESULTS Thirty-three eyes were followed for 6 to 42 months. The average length of follow-up was 15.6 months. Seven eyes were followed for 30 months or longer. Two patients were considered study successes, although they died after 317
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VOLUME 98
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Table 1. Summary of All Patients Age Patient Eye (yrs) Sex No.
Preoperative Target Postoperative Preoperative No. of Pressure Pressure Pressure Visual Postoperative Postoperative Follow-up (mmHg) (mmHg) (mmHg) Acuity Visual Acuity Medications (mos)
1 2 3
OD OD OS
65 70 9
M M M
30 26 26
16 16 12
14 10 8
20/50 20/60 FC
20/50 20/60 FC
2 0 0
6* 11* 8
4
OS
82
F
20
10
8
FC
FC
0
6
5
OS
75
F
36
16
13
HM
HM
0
8
6
OD
39
M
17
10
6
20/20
20/20
0
7
7
OD
63
F
20
10
8
20/70
20/200
0
31
8
OS
40
F
18
10
7
20/20
20/20
0
4
9
OD
69
M
23
10
8
20/50
20/100
0
13
10
OS
56
F
56
18
17
20/400
20/400
OD
56
F
50
18
16
FC
20/300
0
6
11
OD
55
F
19
10
6
20/50
20/50
0
6
12
OS
75
F
35
16
6
20/200
20/200
0
12
13
OD
67
M
26
16
15
20/30
20/30
0
30
14
OD
69
F
25
16
13
20/60
20/30
OS
69
F
20
16
11
20/200
20/200
OD
36
M
44
16
33
HM
HM
OS
36
M
33
16
10
HM
HM
0
15
16
OD
72
F
30
16
20
20/100
20/400
2
13
17
OD
81
F
20
10
5
20/40
20/60
0
11
18
OS
74
M
31
18
17
HM
HM
2
13
15
318
8
41 0
39 21
Preoperative Characteristics POAG, 1 previous filter POAG, 1 previous filter Infantile glaucoma, 3 previous filters LTG, Field loss into fixation POAG, black, temporal island of vision remaining POAG, black, field loss within 5° of fixation POAG, 1 previous filter, field loss splits fixation LTG and chronic angle closure, field loss within 5° of fixation POAG, 1 previous filter, field loss within 5° of fixation Diabetic neovascular glaucoma, cyclocryotherapy Diabetic neovascular glaucoma, ECCE with PC IOL, cyclocryotherapy Traumatic angle recession, black, 1 previous filter Scarred cornea and extensive synechiae from herpes simplex now inactive ECCE with PC IOL, 1 retinal reattachment surgery, 2 previous filters POAG, 1 previous filter, field loss within 5° of fixation POAG, field loss within 5° of fixation Diabetic neovascular glaucoma, previous vitrectomy Diabetic neovascular glaucoma, previous vitrectomy ICCE with AC IOL, 2 previous filters, field loss splits fixation ECCE with PC IOL, 1 previous filter, field loss splits fixation ECCE with AC IOL, corneal decompensation with IOL exchange to PC IOL
PALMER
•
MITOMYCIN WITH TRABECULECTOM Y
Table 1 (continued) Age Patient Eye (yrs) Sex No.
No. of Preoperative Target Postoperative Preoperative Postoperative Postoperative Follow-up Visual Pressure Pressure Pressure (mos) Visual Acuity Medications Acuity (mmHg) (mmHg) (mmHg)
19
OS
68
M
28
16
10
20/300
20/300
0
13
20
OS
75
M
16
10
21
20/300
20/300
2
8
21
00
55
M
44
16
8
20/200
FC
0
7
22
OS
27
M
32
16
12
20/200
20/100
0
35
23
OS
41
F
25
12
16
20/200
20/200
3
18
24
00
69
M
22
12
12
20/30
20/30
0
12
OS
69
M
29
12
9
20/25
20/25
0
8
25
OS
84
F
45
16
10
20/70
20/70
0
8
26
00
86
F
25
12
7
20/40
20/40
0
6
27 28
00 00
85 74
M M
20 28
12 12
7 11
20/40 20/70
20/40 20/70
0 0
42
29
OS
5
F
24
12
8
20/25
20/70
0
6
6
Preoperative Characteristics Traumatic angle recession, Black, 1 previous filter, field loss into fixation POAG, ICCE and vitrectomy for primary amyloidosis, field loss splits fixation Traumatic hyphema, 1 anterior chamber washiout, cyclocryotherapy, 1 filtration operation, ECCE with PC IOL Infantile glaucoma, 2 previous filters Chronic active uveitis despite maximum tolerable immunosuppression POAG, field loss within 5° of fixation POAG, 1 previous filter, field loss within 5° of fixation Chronic angle closure, ECCE with PC IOL, field loss within 5° of fixation POAG, ICCE with iris supported IOL, central island of vision remained POAG, ECCE with PC IOL POAG, 1 previous filter and unsuccessful filter revision Infantile glaucoma, 2 previous filters
00 = right eye; POAG = primary open-angle glaucoma; OS = left eye; FC = finger counting; LTG = low-tension glaucoma; HM = hand motion; ECCE = extracapsular cataract extraction; PC IOL = posterior chamber intraocular lens; ICCE = intracapsular cataract extraction; AC IOL = anterior chamber intraocular lens. * Patient died.
follow-up of 7 and ll months, respectively. One patient was considered a study failure, after failing to return for follow-up after 7 months (Table 1). Sixteen patients had at least one previous filtering pro cedure that had failed. Two patients had juvenile glau coma. Four patients had neovascular glaucoma. Ten pa tients were aphakic. In eight patients, it was the first non laser operation on the eye. Mitomycin was used in these patients because they had advanced cupping with visual field loss endangering fixation and it was believed that unusually low pressures were needed. With a follow-up of 6 to 42 months, the overall success rate was 84%. Four
operations were considered successful despite a final visual acuity reduction. Two eyes (patients 7 and 9) had vision return to preoperative levels with later reduction con comitant with cataract progression. One pseudophakic eye (patient 17) had posterior capsule opacification progress. In all three, there has been no disc change or field loss progression and potential acuity measurements are at least equal to preoperative visual acuity levels. Posterior sub capsular lens opacities developed in the fourth patient (patient 29; age, 5 years), which explained her vision re duction. In all operations deemed successful, the final pressure was 17 mmHg or less, with a range of 5 to 17 319
OPHTHALMOLOGY
•
MARCH 1991
Fig I. Typical filtering bleb appearance (patient 7).
Table 2. Surgical Aphakia Success
Failure
5 1 1
1 0 2
ECCE With intact aqueous/vitreous barrier Without intact barrier ICCE
ECCE = extracapsular cataract extraction; ICCE = intracapsular cataract extraction. Table 3. Success Correlations Success No previous surgery Previous filtration surgery 1 operation 2 operations 3 operations Previous nonlaser surgery of any type* 1 operation 2 operations 3 operations 4 operations
Failure
88%
8 8 2 1 12 7
1 1
Percentage Successful
1 1 0
88% 66% 100%
1
92% 100% 50% 50%
0 1 1
•
VOLUME 98
•
NUMBER 3
There was a characteristic bleb formation present in the successful eyes, typically appearing as a large, elevated, avascular bleb (Fig 1). The bleb was absent in one failure where the postoperative pressure was higher than the pre operative pressure. The bleb was noticeably smaller and more localized when the filter was performed in previously operated conjunctiva, with correspondingly less impres sive pressure fall. It is not yet known how well these blebs will survive subsequent cataract surgery. For those in whom this was the first nonlaser operation, seven of eight were successful. One failure (patient 23) also had active uveitis despite maximum tolerated im munosuppression (including azathioprine) and was con sidered a failure because the target pressure was not reached. Her target pressure was 12 because she experi enced severe disc damage with pressures in the mid-twen ties. The two patients with juvenile glaucoma were both considered successful, despite two previously unsuccessful operations in one eye and three in the other. Of the four neovascular glaucomas, three were successful. There were 3 failures in the 10 aphakic eyes (Table 2). One failure (patient 16) had a pressure fall from 30 mm to 20 mm, but the patient's visual acuity was reduced from 20/100 to 20/400. Previously she had an intracap sular cataract extraction with anterior chamber lens im plantation followed by two unsuccessful filtration oper ations. The second failure was in a patient (patient 21) with a severely traumatized eye with four previous op erations where the mitomycin trabeculectomy lowered the pressure from 44 to 8; but his visual acuity fell from 20/ 200 to finger counting. The third failure (patient 20) was in a patient who had had two prior operations: a diag nostic/therapeutic vitrectomy for primary amyloidosis and an intracapsular cataract extraction. In the 28 eyes considered successful, 3 needed post operative glaucoma medications. One patient is using one medication, two others are using two. In those cases con sidered successful, the fall in pressure averaged 63%. In the five failures, one had a pressure rise of 31%. The other four failures had pressure falls of 25%, 33%, 36%, and 82%, respectively. There were no instances of epithelial toxicity, flat an terior chamber, wound leak, hyphema, choroidal effusion, or hemorrhage. Table 3 summarizes the results. Note that several of the eyes listed under Previous Filtration Surgery also had other surgical procedures. The No Previous Surgery and Previous Nonlaser Surgery ofAny Type groups correctly sum to the total 33 eyes reported. The number of eyes is too small to give clear statistical support, but the definite clinical impression is that the surgery is less successful in eyes with more previous surgery.
* Including filtration surgery, vitrectomy, cataract removal, cyclocryo therapy.
DISCUSSION
mmHg and an average of9.7 mmHg. There were 28 suc cessful surgeries and 5 failed surgeries, for an overall suc cess rate of 84%.
There is a need for a reliable method to lower intra ocular pressure in uncontrolled glaucomatous eyes known to have a poor prognosis with standard filtering proce dures. The current study is most encouraging, with an
320
PALMER
•
MITOMYCIN WITH TRABECULECTOMY
overall success rate of 84%. The potential for both short and long-term complications must be carefully considered. Using mitomycin as adjunct chemotherapy in ptery gium surgery has demonstrated some possible local ocular toxicity: scleral and corneal ulceration, scleromalacia, symblepharon, and scleral calcification. Fortunately, this 4 appears to be dose-related and Hayasaka et al reported on an 8-year follow-up of what seems to be a safe and effective dose. There has been no sign Of these compli 1 cations in either my series or that of Chen. 1 In Chen's original series of 20 eyes, he described a deterioration of vision with ocular hypotony in 3 patients. The actual levels of visual acuity were not stated. In his subsequent report, where 47 eyes were followed for at least I year, 8 eyes were found to have long-lasting hy potony, which implies vision reduction. However, he also reported that 43 of the 47 eyes had successful pressure control with no visual deterioration.2 In the current study, the only marked fall in vision occurred in a severely trau matized eye and was present with a pressure of 8 mmHg. A subsequent patient, now 5 months postsurgery and so not included in the study, has a pressure of 2 mmHg and a reduction in visual acuity from 20/50 to finger counting.
Preoperatively, she had low-tension glaucoma with a pressure of 16, total cupping, and field loss progression into the central 5° offixation. Ocular hypotony with vision loss continues to be of concern, but preliminary results indicate that the procedure is a reasonable surgical risk to take in this glaucoma population. The preliminary results using mitomycin as adjunct chemotherapy are encouraging, and it is believed the technique should continue to be evaluated in carefully selected eyes.
REFERENCES 1. Chen C-W. Enhanced intraocular pressure controlling effectiveness of trabeculectomy by local application of mitomycin-C. Trans Asia Pacific Acad Ophthalmol 1983; 9:172-7. 2. Chen C-W, Huang H-T, Shen M-M. Enhancement of lOP control effect of trabeculectomy by local application of anticancer drug. In: ACTA XXV Concilium Ophthalmologicum (Rome), 1986. Vol. 2:1487-91 . 3. Tahery MM, Lee DA. Review: pharmacologic control of wound healing in glaucoma filtering surgery. J Ocul Pharmacol1989; 5:155-79. 4. Hayasaka S, Noda S, Yamamoto Y, Setogawa T. Postoperative in stillation of low-dose mitomycin C in the treatment of primary pterygium. Am J Ophthalmol1988; 106:715-8.
321
Abstract: Preliminary experience is reported in using mitomycin to improve the prognosis in trabeculectomy operations considered otherwise likely not to suc ceed. The medication is applied intraoperatively during an otherwise standard trabeculectomy procedure. Surgery was considered successful if the pressure was lowered to a predetermined target level, the only vision reduction was believed to be on the basis of cataract development, and there was no pro gression of cupping or visual field loss. With a follow-up of 6 to 42 months, the overall success rate is 84%. Ophthalmology 1991; 98:317-321
Chen 1 and Chen et al 2 first reported the use of mito mycin as adjunct chemotherapy during trabeculectomy surgery. Mitomycin is an antibiotic isolated from the broth of Streptomyces caespitosis. It has been found to inhibit DNA synthesis and is usually used by systemic injection for its antitumor activity. It was used in the glaucoma operations because it inhibits fibroblast proliferation. 3 This report describes a 3.5-year experience, with a min imum follow-up of 6 months, using a technique derived from that described by Chen. 1 Surgery was performed on 33 eyes of 29 patients. In formed consent was obtained from all patients. Eyes were chosen in which standard surgery was not likely to suc ceed. All eligible eyes were chosen. Selection was limited to neovascular glaucoma, glaucoma in aphakia, secondary glaucoma, advanced low-tension glaucoma, and previ ously operated eyes. Chen et al 2 reported success rates of 76% using a mitomycin concentration of0.1 mg/ml, 100% using a concentration of 0.2 mg/ml, and 100% using a concentration of 0.4 mg/ml. In this study, only the 0.2 mg/ml concentration was used.
Originally received: September 4, 1990. Revision accepted: November 9, 1990. From the Department of Ophthalmology, Blodgett Memorial Medical Center, Grand Rapids. Reprint requests to StevenS. Palmer, MD, 515 Lakeside Drive, Sf;, Grand Rapids, Ml 49506.
METHODS After a limbal-based conjunctival flap is prepared (without excision of Tenon's layer), a 2 X 3-mm rectan gular scleral flap of 1h to 1h scleral thickness is dissected into clear cornea. A solution of 0.2 mg/ml mitomycin is prepared, on the same day, by mixing the contents of a 5-mg vial of mitomycin into 25 ml of sterile water for injection. A small surgical sponge is soaked with the so lution and held in contact with the exposed scleral surface and the bed of the scleral flap, with the conjunctival/ten ons layer draped over the sponge. After 5 minutes, the sponge is removed and the entire area is lightly irrigated with balanced salt solution. The procedure is then com pleted as a standard trabeculectomy, although there are a few subtle modifications. The scleral flap is made slightly thicker and is sutured more securely than usual. The con junctival and tenons layers are sutured more securely and with slightly more tissue being enclosed in each stitch. Postoperative medication is topical cycloplegic (cyclo pentolate, 1%) and steroid (prednisolone sodium phos phate, 1%).
RESULTS Thirty-three eyes were followed for 6 to 42 months. The average length of follow-up was 15.6 months. Seven eyes were followed for 30 months or longer. Two patients were considered study successes, although they died after 317
•
OPHTHALMOLOGY
MARCH 1991
•
VOLUME 98
•
NUMBER 3
Table 1. Summary of All Patients Age Patient Eye (yrs) Sex No.
Preoperative Target Postoperative Preoperative No. of Pressure Pressure Pressure Visual Postoperative Postoperative Follow-up (mmHg) (mmHg) (mmHg) Acuity Visual Acuity Medications (mos)
1 2 3
OD OD OS
65 70 9
M M M
30 26 26
16 16 12
14 10 8
20/50 20/60 FC
20/50 20/60 FC
2 0 0
6* 11* 8
4
OS
82
F
20
10
8
FC
FC
0
6
5
OS
75
F
36
16
13
HM
HM
0
8
6
OD
39
M
17
10
6
20/20
20/20
0
7
7
OD
63
F
20
10
8
20/70
20/200
0
31
8
OS
40
F
18
10
7
20/20
20/20
0
4
9
OD
69
M
23
10
8
20/50
20/100
0
13
10
OS
56
F
56
18
17
20/400
20/400
OD
56
F
50
18
16
FC
20/300
0
6
11
OD
55
F
19
10
6
20/50
20/50
0
6
12
OS
75
F
35
16
6
20/200
20/200
0
12
13
OD
67
M
26
16
15
20/30
20/30
0
30
14
OD
69
F
25
16
13
20/60
20/30
OS
69
F
20
16
11
20/200
20/200
OD
36
M
44
16
33
HM
HM
OS
36
M
33
16
10
HM
HM
0
15
16
OD
72
F
30
16
20
20/100
20/400
2
13
17
OD
81
F
20
10
5
20/40
20/60
0
11
18
OS
74
M
31
18
17
HM
HM
2
13
15
318
8
41 0
39 21
Preoperative Characteristics POAG, 1 previous filter POAG, 1 previous filter Infantile glaucoma, 3 previous filters LTG, Field loss into fixation POAG, black, temporal island of vision remaining POAG, black, field loss within 5° of fixation POAG, 1 previous filter, field loss splits fixation LTG and chronic angle closure, field loss within 5° of fixation POAG, 1 previous filter, field loss within 5° of fixation Diabetic neovascular glaucoma, cyclocryotherapy Diabetic neovascular glaucoma, ECCE with PC IOL, cyclocryotherapy Traumatic angle recession, black, 1 previous filter Scarred cornea and extensive synechiae from herpes simplex now inactive ECCE with PC IOL, 1 retinal reattachment surgery, 2 previous filters POAG, 1 previous filter, field loss within 5° of fixation POAG, field loss within 5° of fixation Diabetic neovascular glaucoma, previous vitrectomy Diabetic neovascular glaucoma, previous vitrectomy ICCE with AC IOL, 2 previous filters, field loss splits fixation ECCE with PC IOL, 1 previous filter, field loss splits fixation ECCE with AC IOL, corneal decompensation with IOL exchange to PC IOL
PALMER
•
MITOMYCIN WITH TRABECULECTOM Y
Table 1 (continued) Age Patient Eye (yrs) Sex No.
No. of Preoperative Target Postoperative Preoperative Postoperative Postoperative Follow-up Visual Pressure Pressure Pressure (mos) Visual Acuity Medications Acuity (mmHg) (mmHg) (mmHg)
19
OS
68
M
28
16
10
20/300
20/300
0
13
20
OS
75
M
16
10
21
20/300
20/300
2
8
21
00
55
M
44
16
8
20/200
FC
0
7
22
OS
27
M
32
16
12
20/200
20/100
0
35
23
OS
41
F
25
12
16
20/200
20/200
3
18
24
00
69
M
22
12
12
20/30
20/30
0
12
OS
69
M
29
12
9
20/25
20/25
0
8
25
OS
84
F
45
16
10
20/70
20/70
0
8
26
00
86
F
25
12
7
20/40
20/40
0
6
27 28
00 00
85 74
M M
20 28
12 12
7 11
20/40 20/70
20/40 20/70
0 0
42
29
OS
5
F
24
12
8
20/25
20/70
0
6
6
Preoperative Characteristics Traumatic angle recession, Black, 1 previous filter, field loss into fixation POAG, ICCE and vitrectomy for primary amyloidosis, field loss splits fixation Traumatic hyphema, 1 anterior chamber washiout, cyclocryotherapy, 1 filtration operation, ECCE with PC IOL Infantile glaucoma, 2 previous filters Chronic active uveitis despite maximum tolerable immunosuppression POAG, field loss within 5° of fixation POAG, 1 previous filter, field loss within 5° of fixation Chronic angle closure, ECCE with PC IOL, field loss within 5° of fixation POAG, ICCE with iris supported IOL, central island of vision remained POAG, ECCE with PC IOL POAG, 1 previous filter and unsuccessful filter revision Infantile glaucoma, 2 previous filters
00 = right eye; POAG = primary open-angle glaucoma; OS = left eye; FC = finger counting; LTG = low-tension glaucoma; HM = hand motion; ECCE = extracapsular cataract extraction; PC IOL = posterior chamber intraocular lens; ICCE = intracapsular cataract extraction; AC IOL = anterior chamber intraocular lens. * Patient died.
follow-up of 7 and ll months, respectively. One patient was considered a study failure, after failing to return for follow-up after 7 months (Table 1). Sixteen patients had at least one previous filtering pro cedure that had failed. Two patients had juvenile glau coma. Four patients had neovascular glaucoma. Ten pa tients were aphakic. In eight patients, it was the first non laser operation on the eye. Mitomycin was used in these patients because they had advanced cupping with visual field loss endangering fixation and it was believed that unusually low pressures were needed. With a follow-up of 6 to 42 months, the overall success rate was 84%. Four
operations were considered successful despite a final visual acuity reduction. Two eyes (patients 7 and 9) had vision return to preoperative levels with later reduction con comitant with cataract progression. One pseudophakic eye (patient 17) had posterior capsule opacification progress. In all three, there has been no disc change or field loss progression and potential acuity measurements are at least equal to preoperative visual acuity levels. Posterior sub capsular lens opacities developed in the fourth patient (patient 29; age, 5 years), which explained her vision re duction. In all operations deemed successful, the final pressure was 17 mmHg or less, with a range of 5 to 17 319
OPHTHALMOLOGY
•
MARCH 1991
Fig I. Typical filtering bleb appearance (patient 7).
Table 2. Surgical Aphakia Success
Failure
5 1 1
1 0 2
ECCE With intact aqueous/vitreous barrier Without intact barrier ICCE
ECCE = extracapsular cataract extraction; ICCE = intracapsular cataract extraction. Table 3. Success Correlations Success No previous surgery Previous filtration surgery 1 operation 2 operations 3 operations Previous nonlaser surgery of any type* 1 operation 2 operations 3 operations 4 operations
Failure
88%
8 8 2 1 12 7
1 1
Percentage Successful
1 1 0
88% 66% 100%
1
92% 100% 50% 50%
0 1 1
•
VOLUME 98
•
NUMBER 3
There was a characteristic bleb formation present in the successful eyes, typically appearing as a large, elevated, avascular bleb (Fig 1). The bleb was absent in one failure where the postoperative pressure was higher than the pre operative pressure. The bleb was noticeably smaller and more localized when the filter was performed in previously operated conjunctiva, with correspondingly less impres sive pressure fall. It is not yet known how well these blebs will survive subsequent cataract surgery. For those in whom this was the first nonlaser operation, seven of eight were successful. One failure (patient 23) also had active uveitis despite maximum tolerated im munosuppression (including azathioprine) and was con sidered a failure because the target pressure was not reached. Her target pressure was 12 because she experi enced severe disc damage with pressures in the mid-twen ties. The two patients with juvenile glaucoma were both considered successful, despite two previously unsuccessful operations in one eye and three in the other. Of the four neovascular glaucomas, three were successful. There were 3 failures in the 10 aphakic eyes (Table 2). One failure (patient 16) had a pressure fall from 30 mm to 20 mm, but the patient's visual acuity was reduced from 20/100 to 20/400. Previously she had an intracap sular cataract extraction with anterior chamber lens im plantation followed by two unsuccessful filtration oper ations. The second failure was in a patient (patient 21) with a severely traumatized eye with four previous op erations where the mitomycin trabeculectomy lowered the pressure from 44 to 8; but his visual acuity fell from 20/ 200 to finger counting. The third failure (patient 20) was in a patient who had had two prior operations: a diag nostic/therapeutic vitrectomy for primary amyloidosis and an intracapsular cataract extraction. In the 28 eyes considered successful, 3 needed post operative glaucoma medications. One patient is using one medication, two others are using two. In those cases con sidered successful, the fall in pressure averaged 63%. In the five failures, one had a pressure rise of 31%. The other four failures had pressure falls of 25%, 33%, 36%, and 82%, respectively. There were no instances of epithelial toxicity, flat an terior chamber, wound leak, hyphema, choroidal effusion, or hemorrhage. Table 3 summarizes the results. Note that several of the eyes listed under Previous Filtration Surgery also had other surgical procedures. The No Previous Surgery and Previous Nonlaser Surgery ofAny Type groups correctly sum to the total 33 eyes reported. The number of eyes is too small to give clear statistical support, but the definite clinical impression is that the surgery is less successful in eyes with more previous surgery.
* Including filtration surgery, vitrectomy, cataract removal, cyclocryo therapy.
DISCUSSION
mmHg and an average of9.7 mmHg. There were 28 suc cessful surgeries and 5 failed surgeries, for an overall suc cess rate of 84%.
There is a need for a reliable method to lower intra ocular pressure in uncontrolled glaucomatous eyes known to have a poor prognosis with standard filtering proce dures. The current study is most encouraging, with an
320
PALMER
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MITOMYCIN WITH TRABECULECTOMY
overall success rate of 84%. The potential for both short and long-term complications must be carefully considered. Using mitomycin as adjunct chemotherapy in ptery gium surgery has demonstrated some possible local ocular toxicity: scleral and corneal ulceration, scleromalacia, symblepharon, and scleral calcification. Fortunately, this 4 appears to be dose-related and Hayasaka et al reported on an 8-year follow-up of what seems to be a safe and effective dose. There has been no sign Of these compli 1 cations in either my series or that of Chen. 1 In Chen's original series of 20 eyes, he described a deterioration of vision with ocular hypotony in 3 patients. The actual levels of visual acuity were not stated. In his subsequent report, where 47 eyes were followed for at least I year, 8 eyes were found to have long-lasting hy potony, which implies vision reduction. However, he also reported that 43 of the 47 eyes had successful pressure control with no visual deterioration.2 In the current study, the only marked fall in vision occurred in a severely trau matized eye and was present with a pressure of 8 mmHg. A subsequent patient, now 5 months postsurgery and so not included in the study, has a pressure of 2 mmHg and a reduction in visual acuity from 20/50 to finger counting.
Preoperatively, she had low-tension glaucoma with a pressure of 16, total cupping, and field loss progression into the central 5° offixation. Ocular hypotony with vision loss continues to be of concern, but preliminary results indicate that the procedure is a reasonable surgical risk to take in this glaucoma population. The preliminary results using mitomycin as adjunct chemotherapy are encouraging, and it is believed the technique should continue to be evaluated in carefully selected eyes.
REFERENCES 1. Chen C-W. Enhanced intraocular pressure controlling effectiveness of trabeculectomy by local application of mitomycin-C. Trans Asia Pacific Acad Ophthalmol 1983; 9:172-7. 2. Chen C-W, Huang H-T, Shen M-M. Enhancement of lOP control effect of trabeculectomy by local application of anticancer drug. In: ACTA XXV Concilium Ophthalmologicum (Rome), 1986. Vol. 2:1487-91 . 3. Tahery MM, Lee DA. Review: pharmacologic control of wound healing in glaucoma filtering surgery. J Ocul Pharmacol1989; 5:155-79. 4. Hayasaka S, Noda S, Yamamoto Y, Setogawa T. Postoperative in stillation of low-dose mitomycin C in the treatment of primary pterygium. Am J Ophthalmol1988; 106:715-8.
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