Fifteen-year Argon Laser and Xenon Photocoagulation Results of Bascom Palmer Eye Institute's Patients Participating in the Diabetic Retinopathy Study GEORGE W. BLANKENSHIP, MD
Abstract: Fifteen years after panretinal photocoagulation in the Diabetic Retinopathy Study, 86 (57%) patients had died, 14 (9%) could not be located, and 51 (34%) of 151 patients were examined to determine the long-term treatment effects. Of the eyes randomized to photocoagulation only 1 (5%) of 19 argontreated and 1 (3%) of 32 xenon-treated eyes had received additional laser treatment, but 8 argon-treated and 7 xenon-treated eyes had had cataract removal. Eleven (58%) of the initially argon-treated and 13 (41 %) of the initially xenon-treated eyes had 20/40 or better acuity, and 18 (95%) of the initially argon-treated and 26 (82%) of the initially xenon-treated eyes had 20/200 or better acuity. Of the control eyes 17 (33%) had 20/40 or better, and 30 (58%) had 20/200 or better acuity. Argon and xenon panretinal photocoagulation for diabetic retinopathy provide good results for at least 15 years. Ophthalmology 1991; 98: 125-128
The Diabetic Retinopathy Study (DRS)'-6 provided important information concerning the understanding and treatment of proliferative diabetic retinopathy. The ranOriginally received: August 22, 1990. Revision accepted: October 9, 1990. From the Departments of Ophthalmology, University of Miami School of Medicine, Miami, and Pennsylvania State College of Medicine, Hershey. Presented at the 126th American Ophthalmological Society Meeting, The Homestead, Hot Springs, Virginia, May 1990, and at the American Academy of Ophthalmology Annual Meeting, Atlanta, Oct/Nov 1990. Supported in part by the patients and contributors of the Bascom Palmer Eye Institute, and the Department of Ophthalmology, Pennsylvania State University, Research to Prevent Blindness, Inc, New York, New York, Pennsylvania Lions Vision and Research Center, Hershey, Pennsylvania, and the Breen Green Diabetic Retinopathy Fund, Miami, Florida. Reprint requests to George W. Blankenship, MD, College of Medicine, University Hospital, The Milton S. Hershey Medical Center, PO Box 850, Hershey, PA 17033.
domized, controlled, clinical trial determined the natural history of the disease without photocoagulation by following randomly selected control eyes, and confirmed the previously suggested beneficial treatment results with xenon arc and argon laser photocoagulation 7- '4 by examining a large number of patients at regular intervals for an extended time period. 4- 6 Four retinopathy risk factors associated with an increased risk of severe visual loss were identified. 3 Fifteen clinical research centers I participated in this large collaborative study, with each center recruiting, randomizing, treating, and following patients using standardized techniques and examinations at regularly scheduled intervals. These DRS follow-up examinations were terminated in June 1979 after the study's major goals had been achieved. 6 Many of the DRS patients being followed at the Bascom Palmer Eye Institute's clinical research center continued to return or were seen by area ophthalmologists for regular 125
OPHTHALMOLOGY
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eye examinations after completion of the DRS. This article describes the IS-year follow-up experience of those patients.
METHODS Between 1972 and 1980 the Bascom Palmer Eye Institute of the University of Miami's School of Medicine participated as a research clinical center in the National Eye Institute's Diabetic Retinopathy Study. This clinical trial had been reviewed and approved by the University of Miami's Human Subjects Committee, and all patients gave informed consent. In 1988 and 1989 the original DRS records of all DRS patients recruited, randomized and enrolled, treated, and followed at the Bascom Palmer Eye Institute between 1972 and 1974 were reviewed. Patients who currently were not being followed at the Bascom Palmer Eye Institute were traced with information obtained from the patients' original DRS records, contacted family members and friends, and last known physicians. Surviving patients who had not been examined during 1988 or 1989 were encouraged to obtain followup examinations. The results of eye examinations performed during 1988 or 1989 were obtained from Bascom Palmer Eye Institute records or the patients' current ophthalmologist, and retrospectively reviewed. Ten-year follow-up information was not available on seven of the argon laser-photocoagulated or six of the xenon-photocoagulated cases.
RESULTS Between 1972 and 1974, 151 diabetic patients were recruited, randomized and enrolled, treated, and followed in the DRS at the Bascom Palmer Eye Institute. Within 5 years of enrollment, 35 (23%) of these patients had died. Within 10 years, a total of 71 (47%) had died, and, after 15 years, 86 (57%) of the 151 patients had died. An additional 14 (9%) patients could not be located 15 years after entering the DRS and were classified as lost to followup. Fifteen-year follow-up information was obtained on the remaining 51 (34%) of the original 151 patients. In the DRS, the eye to receive treatment and the treatment modality to be used were randomly selected, and the fellow eye was followed as a control. Of the 51 patients examined 15 years after enrollment and treatment, 19 eyes had been randomly assigned argon laser and 32 eyes xenon photocoagulation. Fifteen years after initial treatment in the DRS, the argon-treated group consisted of 11 right and 8 left eyes assigned for treatment. There were ten male and nine female patients whose ages ranged from 35 to 81 years, with a mean of 56 years. Sixteen (84%) of the 19 patients were being maintained on insulin, and the remaining 3 (16%) patients were maintained on oral medications. The 19 patients had known of their diabetes from 15 to 50 years, with a mean of 33 years. 126
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The xenon-treated group 15 years after initial treatment consisted of 17 right and 15 left eyes. There were 14 male and 18 female patients whose ages ranged from 36 to 77 years, with a mean of 52 years. Twenty-nine (91 %) of the 32 patients were being maintained on insulin, and the remaining 3 (9%) patients were maintained on oral medication. The 32 patients had known of their diabetes from 15 to 48 years, with a mean of 30 years. During the IS-year follow-up period, most of the eyes originally randomized for photocoagulation did not receive any additional photocoagulation or ocular surgery. Only one argon laser- and one xenon-photocoagulated eye received additional laser treatment following completion of the DRS. Traction macular detachments developed in four xenon-treated eyes after DRS photocoagulation and required pars plana vitrectomies. One argon-treated eye required a vitrectomy for a nonclearing vitreous hemorrhage that developed approximately 7 years after initial DRS treatment. Eight argon-treated and seven xenontreated eyes subsequently had cataract surgery, and one additional argon eye required a trabeculectomy for chronic open-angle glaucoma. Three patients whose original DRS treatment was argon laser and one xenon-photocoagulated patient were requiring renal dialysis 15 years after DRS enrollment, but an additional one argon and two xenon patients had received kidney transplants. The best corrected visual acuities obtained just before randomization and treatment, at the last official DRS follow-up examination 3 to 5 years after treatment, and at regular follow-up examinations 10 years and 15 years after treatment for eyes randomized to receive photocoagulation, are shown in Table 1. Visual acuities of 20/40 or better were obtained from 11 (58%) of the 19 argon and 13 (41%) of the 32 xenon eyes, but 1 (5%) of the argon and 6 (19%) of the xenon eyes had worse than 20/200, 15 years after randomization and initial photocoagulation. When the acuities for the eyes of both groups initially randomized to photocoagulation were combined, 20/40 or better were obtained from 24 (47%) of the 51 eyes, but 7 (14%) had worse than 20/200. The fellow eyes randomized to function as controls and initially not eligible for photocoagulation had poorer visual acuities at the IS-year examinations. Visual acuities of 20/40 or better were obtained from 17 (33%) of the combined 52 control eyes, but 22 (42%) had worse than 20/200. The presence of disc neovascularization and extent compared to DRS standard photo lOA 1 is shown in Table 2. Corneal and anterior segment opacification prevented follow-up fundus examination of one xenon eye at both the 3- to 5-year and IS-year follow-up periods.
DISCUSSION The relatively high mortality rate was not surprising, even though patients with severe coexistent diabetic complications or other diseases that might prevent follow-up examinations were excluded. 1 During the early 1970s hemodialysis and kidney transplantation rarely were per-
BLANKENSHIP
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FIFTEEN-YEAR DRS RESULTS
Table 1. Visual Acuities of Bascom Palmer Eye Institute DRS Patients (No. of Eyes) Postphotocoagulation 3-5 Yrs
Prephotocoagulation
15 Yrs
Argon
Xenon
Argon
Xenon
Argon
Xenon
Argon
Xenon
16 2 1
23 7 2'
11 4 1 2 1
10 10 5 2 3 2
2 5 1 3 1
2 11
1 10 1 6
7
6
2 11 6 7 2 3 1
20/15-20 20/30-40 20/50-70 20/100-200 15/200-5/200
Abstract: Fifteen years after panretinal photocoagulation in the Diabetic Retinopathy Study, 86 (57%) patients had died, 14 (9%) could not be located, and 51 (34%) of 151 patients were examined to determine the long-term treatment effects. Of the eyes randomized to photocoagulation only 1 (5%) of 19 argontreated and 1 (3%) of 32 xenon-treated eyes had received additional laser treatment, but 8 argon-treated and 7 xenon-treated eyes had had cataract removal. Eleven (58%) of the initially argon-treated and 13 (41 %) of the initially xenon-treated eyes had 20/40 or better acuity, and 18 (95%) of the initially argon-treated and 26 (82%) of the initially xenon-treated eyes had 20/200 or better acuity. Of the control eyes 17 (33%) had 20/40 or better, and 30 (58%) had 20/200 or better acuity. Argon and xenon panretinal photocoagulation for diabetic retinopathy provide good results for at least 15 years. Ophthalmology 1991; 98: 125-128
The Diabetic Retinopathy Study (DRS)'-6 provided important information concerning the understanding and treatment of proliferative diabetic retinopathy. The ranOriginally received: August 22, 1990. Revision accepted: October 9, 1990. From the Departments of Ophthalmology, University of Miami School of Medicine, Miami, and Pennsylvania State College of Medicine, Hershey. Presented at the 126th American Ophthalmological Society Meeting, The Homestead, Hot Springs, Virginia, May 1990, and at the American Academy of Ophthalmology Annual Meeting, Atlanta, Oct/Nov 1990. Supported in part by the patients and contributors of the Bascom Palmer Eye Institute, and the Department of Ophthalmology, Pennsylvania State University, Research to Prevent Blindness, Inc, New York, New York, Pennsylvania Lions Vision and Research Center, Hershey, Pennsylvania, and the Breen Green Diabetic Retinopathy Fund, Miami, Florida. Reprint requests to George W. Blankenship, MD, College of Medicine, University Hospital, The Milton S. Hershey Medical Center, PO Box 850, Hershey, PA 17033.
domized, controlled, clinical trial determined the natural history of the disease without photocoagulation by following randomly selected control eyes, and confirmed the previously suggested beneficial treatment results with xenon arc and argon laser photocoagulation 7- '4 by examining a large number of patients at regular intervals for an extended time period. 4- 6 Four retinopathy risk factors associated with an increased risk of severe visual loss were identified. 3 Fifteen clinical research centers I participated in this large collaborative study, with each center recruiting, randomizing, treating, and following patients using standardized techniques and examinations at regularly scheduled intervals. These DRS follow-up examinations were terminated in June 1979 after the study's major goals had been achieved. 6 Many of the DRS patients being followed at the Bascom Palmer Eye Institute's clinical research center continued to return or were seen by area ophthalmologists for regular 125
OPHTHALMOLOGY
• FEBRUARY 1991
eye examinations after completion of the DRS. This article describes the IS-year follow-up experience of those patients.
METHODS Between 1972 and 1980 the Bascom Palmer Eye Institute of the University of Miami's School of Medicine participated as a research clinical center in the National Eye Institute's Diabetic Retinopathy Study. This clinical trial had been reviewed and approved by the University of Miami's Human Subjects Committee, and all patients gave informed consent. In 1988 and 1989 the original DRS records of all DRS patients recruited, randomized and enrolled, treated, and followed at the Bascom Palmer Eye Institute between 1972 and 1974 were reviewed. Patients who currently were not being followed at the Bascom Palmer Eye Institute were traced with information obtained from the patients' original DRS records, contacted family members and friends, and last known physicians. Surviving patients who had not been examined during 1988 or 1989 were encouraged to obtain followup examinations. The results of eye examinations performed during 1988 or 1989 were obtained from Bascom Palmer Eye Institute records or the patients' current ophthalmologist, and retrospectively reviewed. Ten-year follow-up information was not available on seven of the argon laser-photocoagulated or six of the xenon-photocoagulated cases.
RESULTS Between 1972 and 1974, 151 diabetic patients were recruited, randomized and enrolled, treated, and followed in the DRS at the Bascom Palmer Eye Institute. Within 5 years of enrollment, 35 (23%) of these patients had died. Within 10 years, a total of 71 (47%) had died, and, after 15 years, 86 (57%) of the 151 patients had died. An additional 14 (9%) patients could not be located 15 years after entering the DRS and were classified as lost to followup. Fifteen-year follow-up information was obtained on the remaining 51 (34%) of the original 151 patients. In the DRS, the eye to receive treatment and the treatment modality to be used were randomly selected, and the fellow eye was followed as a control. Of the 51 patients examined 15 years after enrollment and treatment, 19 eyes had been randomly assigned argon laser and 32 eyes xenon photocoagulation. Fifteen years after initial treatment in the DRS, the argon-treated group consisted of 11 right and 8 left eyes assigned for treatment. There were ten male and nine female patients whose ages ranged from 35 to 81 years, with a mean of 56 years. Sixteen (84%) of the 19 patients were being maintained on insulin, and the remaining 3 (16%) patients were maintained on oral medications. The 19 patients had known of their diabetes from 15 to 50 years, with a mean of 33 years. 126
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The xenon-treated group 15 years after initial treatment consisted of 17 right and 15 left eyes. There were 14 male and 18 female patients whose ages ranged from 36 to 77 years, with a mean of 52 years. Twenty-nine (91 %) of the 32 patients were being maintained on insulin, and the remaining 3 (9%) patients were maintained on oral medication. The 32 patients had known of their diabetes from 15 to 48 years, with a mean of 30 years. During the IS-year follow-up period, most of the eyes originally randomized for photocoagulation did not receive any additional photocoagulation or ocular surgery. Only one argon laser- and one xenon-photocoagulated eye received additional laser treatment following completion of the DRS. Traction macular detachments developed in four xenon-treated eyes after DRS photocoagulation and required pars plana vitrectomies. One argon-treated eye required a vitrectomy for a nonclearing vitreous hemorrhage that developed approximately 7 years after initial DRS treatment. Eight argon-treated and seven xenontreated eyes subsequently had cataract surgery, and one additional argon eye required a trabeculectomy for chronic open-angle glaucoma. Three patients whose original DRS treatment was argon laser and one xenon-photocoagulated patient were requiring renal dialysis 15 years after DRS enrollment, but an additional one argon and two xenon patients had received kidney transplants. The best corrected visual acuities obtained just before randomization and treatment, at the last official DRS follow-up examination 3 to 5 years after treatment, and at regular follow-up examinations 10 years and 15 years after treatment for eyes randomized to receive photocoagulation, are shown in Table 1. Visual acuities of 20/40 or better were obtained from 11 (58%) of the 19 argon and 13 (41%) of the 32 xenon eyes, but 1 (5%) of the argon and 6 (19%) of the xenon eyes had worse than 20/200, 15 years after randomization and initial photocoagulation. When the acuities for the eyes of both groups initially randomized to photocoagulation were combined, 20/40 or better were obtained from 24 (47%) of the 51 eyes, but 7 (14%) had worse than 20/200. The fellow eyes randomized to function as controls and initially not eligible for photocoagulation had poorer visual acuities at the IS-year examinations. Visual acuities of 20/40 or better were obtained from 17 (33%) of the combined 52 control eyes, but 22 (42%) had worse than 20/200. The presence of disc neovascularization and extent compared to DRS standard photo lOA 1 is shown in Table 2. Corneal and anterior segment opacification prevented follow-up fundus examination of one xenon eye at both the 3- to 5-year and IS-year follow-up periods.
DISCUSSION The relatively high mortality rate was not surprising, even though patients with severe coexistent diabetic complications or other diseases that might prevent follow-up examinations were excluded. 1 During the early 1970s hemodialysis and kidney transplantation rarely were per-
BLANKENSHIP
•
FIFTEEN-YEAR DRS RESULTS
Table 1. Visual Acuities of Bascom Palmer Eye Institute DRS Patients (No. of Eyes) Postphotocoagulation 3-5 Yrs
Prephotocoagulation
15 Yrs
Argon
Xenon
Argon
Xenon
Argon
Xenon
Argon
Xenon
16 2 1
23 7 2'
11 4 1 2 1
10 10 5 2 3 2
2 5 1 3 1
2 11
1 10 1 6
7
6
2 11 6 7 2 3 1
20/15-20 20/30-40 20/50-70 20/100-200 15/200-5/200
