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Cataract Extraction after Brachytherapy for Malignant Melanoma of the Choroid
Cataract Extraction after Brachytherapy for Malignant Melanoma .of the Choroid GARY EDD FISH, MD,I,2 BRADLEY F. JOST, MD,I .2 WILLIAM B. SNYDER, MD,I .2 DWAIN G. FULLER, MD;,2 DAVID G. BIRCH, PhD 2,3
Abstract: Thirteen eyes of 55 consecutive patients treated with brachytherapy for malignant melanoma of the choroid developed postirradiation cataracts. Cataract development was more common in older patients and in patients with larger and more anterior tumors. Eleven eyes had extracapsular cataract extraction and intraocular lens implantation. Initial visual improvement occurred in 91 % of eyes, with an average improvement of 5.5 lines. Visual acuity was maintained at 20/60 or better in 55% of the eyes over an average period of follow-up of 24 months (range, 6 to 40 months). These data suggest that, visually, cataract extraction can be helpful in selected patients who develop a cataract after brachytherapy for malignant melanoma of the choroid. Ophthalmology 1991 ,. 98:619-622
Melanoma of the choroid is treated most often by either enucleation or irradiation of the tumor. Frequently, irradiation is effective in controlling th e tumor within the globe. I - I I To date, studies comparing sur vival between patients treated with enucleation and th ose treated with irradiation ha ve not shown either therapy to be more effective.l -' Th e Collaborative Ocular Melanoma Study is now attempting to pro vide an answer to the important question regarding th e best management of choroidal melanoma. Irradiation can be achieved by external beam (H + or He ++)or brachytherapy using a plaque source (cobalt 60, ruthenium 106, iodine 125). Complications of radiation to the globe include radiation retinopathy, neuropathy, rubeosis, loss oflashes, and radiation-induced cataract. A previous report indicated that cataract extraction in eyes
Originally received : Octob er 31, 1990. Revision accepted : January 15, 1991. 1
2
3
Texas Retina Associates , Dallas. Department of Ophthalmology, University of Texas Southwestern Medical School, Dallas. Retina Found ation of the Southwest, Dallas.
Presented at the American Academy of Ophthalmology Ann ual Meeting, Atlanta, October / Novembe r 1990. Reprint requests to Gary Edd Fish, MD , 7150 Greenville Ave, Suite 400, Dallas, TX 75231.
that had developed a mature radiation cataract after cobalt 60 plaque radiotherapy did not seem to improve visual function .' ? We reviewed the visual function and survival of II patients who had cataract extraction for symptomatic lens opa cities after bra chytherapy for choroidal melanoma. In addition, we compared the eyes that developed cataracts with those th at did not to see if factors could be identified that related to cataract form ation.
MATERIALS AND METHODS We reviewed the records of 55 consecutive phakic patients who presented between January 1981 and April 1987 with brachytherapy for malignant melanoma of th e choroid. Th e age, sex, eye involvement, location of anterior border of tumor, maximal basal diameter of tumor, tumor height , type of plaque used to treat the tumor, and total radiation dose to the tumor apex were analyzed. The surgical technique of brachytherapy for choroidal melanoma has been described previously and consists of localizing the tumor and placing the plaque on the sclera immediately adjacent to the tumor.':' Irradiation was delivered eith er with a cobalt 60 or iodin e 125 plaque. All tumors received approximately 8000 rad to the tumor ape x. The plaque selected was determined by the tumor diameter, height, and date of treatment. Larger tumors were mu ch more likely to ha ve been treated with cobalt 6 19
OPHTHALMOLOGY
•
MAY 1991
Table 1. Patient Profile Average Age, yrs (range)
Lens Status No cataract (n = 42) Cataract (n = 13) Cataract extraction (n
=
11)
59.0 (35-84) 65.6 (54-77) 63.8 (54-73)
Sex
Eye
22F/20M 1700/250S 7F/6M 700/60S 6F/5M 600/50S
00 = right eye; OS = left eye.
60 plaques. Our use of iodine 125 plaques began in December 1984, whereas cobalt 60 plaques were used exclusively before that date. Thirty-five patients were treated with cobalt 60 plaques and 20 patients were treated with iodine 125 plaques. Visually significant cataracts developed in 13 patients after irradiation. These 13 patients were compared with those patients in whom cataracts did not develop. Eleven patients underwent cataract extraction after brachytherapy. The II cataract extractions were performed by II different ophthalmologists. Extracapsular extraction with intraocular lens implantation was used in each case. Ten eyes received a posterior chamber lens and one eye received an anterior chamber lens. Preoperative conditions that were potentially vision limiting were assessed in these patients along with preoperative visual acuity, type of intraocular lens implanted, intraoperative complications, early postoperative visual acuity, postoperative complications, and long-term visual acuity. Snellen acuity values were converted to log minimum angle of resolution (IogMAR) to facilitate quantitative analysis. The 10gMAR scale represents steps of equal discriminability so that, for example , a 0.3 change in 10gMAR value is equivalent to a doubling of the visual angle regardless of the initial visual acuity (20/200 to 20/400 = 20/20 to 20/40).14An improvement of 0.115 in the 10gMAR value was considered to be a significant improvement. IS In addition, a "tumor size factor" was calculated by multiplying the longest tumor diameter by the tumor height. Survival data and evidence of metastatic disease were determined for all 55 patients.
RESULTS The characteristics of the patients with cataracts and those without cataracts were similar except for age (Table I). The average age of patients in whom cataracts developed was 65.6 years, and the average age of those without cataracts was 59 years. Eyes that developed cataracts were more likely to have tumors with a larger diameter (average, 14.54 mm versus 11.45 mm), greater height (average, 7.35 mm versus 5.89 mm) and more anterior location (Table 2). Eyes that developed cataracts were significantly more likely to have tumors with a maximal basal diameter of 12 mm or greater (chi-square = 4.123, P::; 0.05). Although eyes with cataracts tended to have tumors with greater height and more anterior location, these differences did 620
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not attain statistical significance. Eyes that developed cataracts also were more likely to have been treated with larger cobalt plaques (92% versus 52%). The average time between irradiation for the melanoma and development ofa significant cataract was 40 months (12 to 73 months). In contrast, patients who are cataract free have an average follow-up from the time of irradiation of only 26 months (range, 2 to 70 months). Five of 13 patients who developed cataracts have died (two with metastases) compared with 6 of 42 (three with metastases) in the noncataract group. Of those patients having cataract extraction, 3 of II have died (two with metastases). The visual results after cataract extraction in II patients are shown in Table 3. Eight of II patients had visual acuity of finger counting or worse before cataract extraction. None of the eyes experienced worsened visual acuity after surgery. Seven eyes had an initial improvement to 20/50 or better, and six of these eyes have maintained visual acuity of 20/60 or better at the most recent followup or until the time of death (average follow-up, 24 months) . One patient was lost to follow-up after 5 months, and two patients, who initially improved, worsened significantly over time . Of the four patients who were either not helped visually by cataract extraction or did not maintain an initial improvement, two had radiation retinopathy and two had notable vitreous opacities believed to be vitreous hemorrhage. The average 10gMAR value before surgery was 1.3 (20/400), 0.59 (20/80) shortly after surgery, and 0.67 (20/90) after an average of 24 months. Average initial improvement was 0.71 10gMAR(approximately 5.5 Snellen lines). The average maintained improvement (24 months) was 0.63 10gMAR(approximately 4.5 Snellen lines). Eyes that maintained visual improvement had an average tumor size factor (longest diameter X height) of 65, while those that were either not improved or had deteriorated over time had an average tumor size factor of 182. The critical'tumor size factor in this small series was between 102 (largest tumor that maintained visual improvement) and 145 (the smallest tumor that did not experience improvement). Several patients were known to have diagnoses that were potentially vision-limiting before cataract surgery (Table 4). All patients had extracapsular cataract extraction, and intraoperative complications were not seen in any of the patients. A wide range of postoperative complications were seen, although none of them were severe (Table 5).
DISCUSSION Brachytherapy, the placement of the radioactive source near a tumor, relies on proximity for tumor kill. Irradiation influences normal tissue close to the tumor site as well as the tumor tissue itself. Larger and more anteriorly located tumors in this study were more prone to develop cataracts after irradiation. These tumors required larger plaques placed nearer to the lens, necessitating a significant
FISH et al
•
CATARACT EXTRACTION AFTER BRACHYTHERAPY
Table 2. Tumor Profile Lens Status
Anterior Border of Tumor
Average Longest Basal Diameter (range)
Average Height (range)
Plaque
No cataract (n = 42) Cataract (n = 13) Cataract extraction (n = 11)
15P/18E/90ra 1P/5E/70ra 1P/3E/70ra
11.45 mm (4.5-24) 14.54 mm (9-20) 14.27 mm (9-20)
5.89 mm (1.6-12.4) 7.35 mm (3-13) 7.11 mm (3-13)
191/22C2/1 C1 11/12C2 11/10C2
P = posterior to equator; E = equator to ora; I.= iodine 125; C1 = 7.5 mm cobalt 60; C2 = 10 to 15 mm cobalt 60.
Table 3. Cataract Surgery Patient No.
Preoperative Visual Acuity
Early Postoperative Visual Acuity
1 2 3 4 5 6 7 8 9 10 11
20/60 20/100 FC 20/200 FC FC FC FC HM FC FC
20/50 20/25 20/400 20/20 20/80 20/30 20/50 20/70 FC 20/40 20/40
FC
=
finger counting; HM
=
Long-term Visual Acuity
Follow-up (mos)
20/40 20/60 20/200 20/25 20/300 20/50 20/200
25 18 36 25 15 18 39 5 9 19 36
HM 20/40 20/40
Comments Deceased Cystoid macular edema Radiation retinopathy Deceased Posterior capsule opacity, potential acuity 20/25 Radiation retinopathy Lost to foliow-u P Moderate vitreous hemorrhage Deceased
hand motions.
dose to the lens to permit an adequate dose to be delivered to the tumor apex. Accordingly, these plaques were farther from the fovea and optic nerve, and thus led to relative sparing of these structures. Tumor size was the parameter most important in determining whether an eye would have improved visual acuity after cataract surgery and maintain this improvement over time. Large tumors required larger plaques and higher doses of radiation. Therefore, the likelihood of radiation to other parts of the eye was increased. In a previous report, Augsburger and Shields" suggested that cataract extraction after brachytherapy for malignant melanoma ofthe choroid is unrewarding because of macular or optic nerve damage, cystoid macular edema, or choroidal hemorrhage precluding long-term improvement of reasonable visual function. They reported on seven eyes with mature radiation-induced cataracts, all with visual acuity of 20/400 or worse, that had cataract extraction. Direct comparison between their study group and the present study group is impossible. All of their patients had visual acuity of 20/400 or worse before surgery. Our group had three eyes with visual acuity better than 20/ 400 before cataract extraction and all three of these eyes have maintained a significant improvement for at least 18 months. Also, six of seven eyes in the group presented by Augsburger and Shields'? had intracapsular cataract extractions, whereas all eyes in the present group had extracapsular cataract extractions. The extracapsular technique may reduce the incidence of severe cystoid macular
Table 4. Diagnoses before Cataract Extraction Uveitis Radiation retinopathy Vitreous hemorrhage
1 2 1
Table 5. Postoperative Complications Corneal edema (mild) Glaucoma (mild) Decentered lens CME (7 pseudophakic) Vitreitis Capsular opacity CME
=
1 1 1 1 1 2
cystoid macular edema.
edema'" and, similarly, the visual loss related to radiation retinopathy. Obviously, patient selection plays a role in the success of any surgical procedure. In our group, 13 patients developed cataracts and only 11 had cataract surgery. Not only is the number of patients very small, but care must be taken in extrapolating our experience to the entire population of patients who develop cataracts after brachytherapy for choroid melanoma. Careful preoperative evaluation with particular attention directed toward detecting radiation-induced optic neuropathy or retinop621
OPHTHALMOLOGY
•
MAY 1991
athy may allow the identification ofa subgroup of patients who would benefit from cataract extraction. The mortality rate for patients without cataracts was 14%,whereas those patients with cataracts had a mortality rate of 38%. Although these differences in such small groups are not statistically significant, the higher mortality in patients who developed cataracts might be influenced by the older age of these patients and the longer length of follow-up time that had elapsed since the treatment of their malignant melanoma. Additionally, patients developing cataracts had tumors that were larger and located more anteriorly, factors believed to be associated with a poorer prognosis for life.' 7 , 18 The small number of patients in our study precludes conclusive determination of whether cataract surgery played a role in mortality. A larger group of patients and careful matching of tumor characteristics between surgical and nonsurgical cases would be necessary to determine any potential role of cataract surgery in mortality. Although this study is retrospective, with only a 2-year average follow-up, we are encouraged by the fact that a significant number of patients have experienced and maintained visual improvement after cataract extraction. Augsburger and Shields'? reported that the visual acuity fell to the preoperative level or worse within 6 months of surgery in the six eyes that initially experienced improvement. Longer follow-up of our patients will be necessary to confirm our initial impression that selected patients may benefit from cataract extraction after brachytherapy for malignant melanoma of the choroid.
REFERENCES 1. Augsburger JJ, Gamel JW, Sardi VF, et al. Enucleation vs cobalt plaque radiotherapy for malignant melanomas of the choroid and ciliary body. Arch Ophthalmol1986; 104:655-61.
622
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2. Seddon JM, Gragoudas ES, Albert DM, et al. Comparison of survival rates for patients with uveal melanoma after treatment with proton beam irradiation or enucleation. Am J Ophthalmol 1985; 99:282-90. 3. Garretson BR, Robertson DM, Earle JD. Choroidal melanoma treatment with iodine 125 brachytherapy. Arch Ophthalmol1987; 105:1394-7. 4. Packer S, Rotman M, Salanitro P. lodine-125 irradiation of choroidal melanoma: clinical experience. Ophthalmology 1984;91: 1700-8. 5. Gragoudas ES, Goitein M, Koehler A, et al. Proton irradiation of choroidal melanomas: preliminary report. Arch Ophthalmol1978; 96:158391. 6. Packer S, Rotman M. Radiotherapy of choroidal melanoma with iodine125. Ophthalmology 1980; 87:582-90. 7. Gragoudas ES, Goitein M, Verhey L, et al. Proton beam irradiation: an altemative to enucleation for intraocular melanomas. Ophthalmology 1980; 87:571-81. 8. Wilkes SR, Gragoudas ES. Regression patterns of uveal melanomas after proton beam irradiation. Ophthalmology 1982; 89:840-4. 9. Packer S. lodine-125 radiation of posterior uveal melanoma. Ophthalmology 1987; 94:1621-6. 10. Cruess AF, Augsburger JJ, Shields JA, et al. Visual results following cobalt plaque radiotherapy for posterior uveal melanomas. Ophthalmology 1984; 91:131-6. 11. Shields JA, Augsburger JJ, Brady LW, Day JL. Cobalt plaque therapy of posterior uveal melanomas. Ophthalmology 1982; 89:1201-7. 12. Augsburger JJ, Shields JA. Cataract surgery following cobalt-50 plaque radiotherapy for posterior uveal malignant melanoma. Ophthalmology 1985; 92:815-22. 13. Shields JA. Diagnosis and management of intraocular tumors. Sf. Louis: CV Mosby, 1983; 46. 14. Westheimer GW. Scaling of visual acuity measurements. Arch Ophthalmol1979; 97:327-30. 15. Berson EL, Sandberg MA, Rosner B, et al. Natural course of retinitis pigmentosa over a three-year interval. Am J Ophthalmol 1985; 99: 240-51. 16. Bradford JD, Wilkinson CP, Bradford RH Jr. Cystoid macular edema following extracapsular cataract extraction and posterior chamber intraocular lens implantation. Retina 1988; 8:161-4. 17. Shammas HF, Blodi FC. Prognostic factors in choroidal and ciliary body melanomas. Arch OphthalmoI1977; 95:63-9. 18. McLean IW, Foster WD, Zimmerman LE. Uveal melanoma: location, size, cell type, and enucleation as risk factors in metastasis. Hum Patho11982; 13:123-32.
Abstract: Thirteen eyes of 55 consecutive patients treated with brachytherapy for malignant melanoma of the choroid developed postirradiation cataracts. Cataract development was more common in older patients and in patients with larger and more anterior tumors. Eleven eyes had extracapsular cataract extraction and intraocular lens implantation. Initial visual improvement occurred in 91 % of eyes, with an average improvement of 5.5 lines. Visual acuity was maintained at 20/60 or better in 55% of the eyes over an average period of follow-up of 24 months (range, 6 to 40 months). These data suggest that, visually, cataract extraction can be helpful in selected patients who develop a cataract after brachytherapy for malignant melanoma of the choroid. Ophthalmology 1991 ,. 98:619-622
Melanoma of the choroid is treated most often by either enucleation or irradiation of the tumor. Frequently, irradiation is effective in controlling th e tumor within the globe. I - I I To date, studies comparing sur vival between patients treated with enucleation and th ose treated with irradiation ha ve not shown either therapy to be more effective.l -' Th e Collaborative Ocular Melanoma Study is now attempting to pro vide an answer to the important question regarding th e best management of choroidal melanoma. Irradiation can be achieved by external beam (H + or He ++)or brachytherapy using a plaque source (cobalt 60, ruthenium 106, iodine 125). Complications of radiation to the globe include radiation retinopathy, neuropathy, rubeosis, loss oflashes, and radiation-induced cataract. A previous report indicated that cataract extraction in eyes
Originally received : Octob er 31, 1990. Revision accepted : January 15, 1991. 1
2
3
Texas Retina Associates , Dallas. Department of Ophthalmology, University of Texas Southwestern Medical School, Dallas. Retina Found ation of the Southwest, Dallas.
Presented at the American Academy of Ophthalmology Ann ual Meeting, Atlanta, October / Novembe r 1990. Reprint requests to Gary Edd Fish, MD , 7150 Greenville Ave, Suite 400, Dallas, TX 75231.
that had developed a mature radiation cataract after cobalt 60 plaque radiotherapy did not seem to improve visual function .' ? We reviewed the visual function and survival of II patients who had cataract extraction for symptomatic lens opa cities after bra chytherapy for choroidal melanoma. In addition, we compared the eyes that developed cataracts with those th at did not to see if factors could be identified that related to cataract form ation.
MATERIALS AND METHODS We reviewed the records of 55 consecutive phakic patients who presented between January 1981 and April 1987 with brachytherapy for malignant melanoma of th e choroid. Th e age, sex, eye involvement, location of anterior border of tumor, maximal basal diameter of tumor, tumor height , type of plaque used to treat the tumor, and total radiation dose to the tumor apex were analyzed. The surgical technique of brachytherapy for choroidal melanoma has been described previously and consists of localizing the tumor and placing the plaque on the sclera immediately adjacent to the tumor.':' Irradiation was delivered eith er with a cobalt 60 or iodin e 125 plaque. All tumors received approximately 8000 rad to the tumor ape x. The plaque selected was determined by the tumor diameter, height, and date of treatment. Larger tumors were mu ch more likely to ha ve been treated with cobalt 6 19
OPHTHALMOLOGY
•
MAY 1991
Table 1. Patient Profile Average Age, yrs (range)
Lens Status No cataract (n = 42) Cataract (n = 13) Cataract extraction (n
=
11)
59.0 (35-84) 65.6 (54-77) 63.8 (54-73)
Sex
Eye
22F/20M 1700/250S 7F/6M 700/60S 6F/5M 600/50S
00 = right eye; OS = left eye.
60 plaques. Our use of iodine 125 plaques began in December 1984, whereas cobalt 60 plaques were used exclusively before that date. Thirty-five patients were treated with cobalt 60 plaques and 20 patients were treated with iodine 125 plaques. Visually significant cataracts developed in 13 patients after irradiation. These 13 patients were compared with those patients in whom cataracts did not develop. Eleven patients underwent cataract extraction after brachytherapy. The II cataract extractions were performed by II different ophthalmologists. Extracapsular extraction with intraocular lens implantation was used in each case. Ten eyes received a posterior chamber lens and one eye received an anterior chamber lens. Preoperative conditions that were potentially vision limiting were assessed in these patients along with preoperative visual acuity, type of intraocular lens implanted, intraoperative complications, early postoperative visual acuity, postoperative complications, and long-term visual acuity. Snellen acuity values were converted to log minimum angle of resolution (IogMAR) to facilitate quantitative analysis. The 10gMAR scale represents steps of equal discriminability so that, for example , a 0.3 change in 10gMAR value is equivalent to a doubling of the visual angle regardless of the initial visual acuity (20/200 to 20/400 = 20/20 to 20/40).14An improvement of 0.115 in the 10gMAR value was considered to be a significant improvement. IS In addition, a "tumor size factor" was calculated by multiplying the longest tumor diameter by the tumor height. Survival data and evidence of metastatic disease were determined for all 55 patients.
RESULTS The characteristics of the patients with cataracts and those without cataracts were similar except for age (Table I). The average age of patients in whom cataracts developed was 65.6 years, and the average age of those without cataracts was 59 years. Eyes that developed cataracts were more likely to have tumors with a larger diameter (average, 14.54 mm versus 11.45 mm), greater height (average, 7.35 mm versus 5.89 mm) and more anterior location (Table 2). Eyes that developed cataracts were significantly more likely to have tumors with a maximal basal diameter of 12 mm or greater (chi-square = 4.123, P::; 0.05). Although eyes with cataracts tended to have tumors with greater height and more anterior location, these differences did 620
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not attain statistical significance. Eyes that developed cataracts also were more likely to have been treated with larger cobalt plaques (92% versus 52%). The average time between irradiation for the melanoma and development ofa significant cataract was 40 months (12 to 73 months). In contrast, patients who are cataract free have an average follow-up from the time of irradiation of only 26 months (range, 2 to 70 months). Five of 13 patients who developed cataracts have died (two with metastases) compared with 6 of 42 (three with metastases) in the noncataract group. Of those patients having cataract extraction, 3 of II have died (two with metastases). The visual results after cataract extraction in II patients are shown in Table 3. Eight of II patients had visual acuity of finger counting or worse before cataract extraction. None of the eyes experienced worsened visual acuity after surgery. Seven eyes had an initial improvement to 20/50 or better, and six of these eyes have maintained visual acuity of 20/60 or better at the most recent followup or until the time of death (average follow-up, 24 months) . One patient was lost to follow-up after 5 months, and two patients, who initially improved, worsened significantly over time . Of the four patients who were either not helped visually by cataract extraction or did not maintain an initial improvement, two had radiation retinopathy and two had notable vitreous opacities believed to be vitreous hemorrhage. The average 10gMAR value before surgery was 1.3 (20/400), 0.59 (20/80) shortly after surgery, and 0.67 (20/90) after an average of 24 months. Average initial improvement was 0.71 10gMAR(approximately 5.5 Snellen lines). The average maintained improvement (24 months) was 0.63 10gMAR(approximately 4.5 Snellen lines). Eyes that maintained visual improvement had an average tumor size factor (longest diameter X height) of 65, while those that were either not improved or had deteriorated over time had an average tumor size factor of 182. The critical'tumor size factor in this small series was between 102 (largest tumor that maintained visual improvement) and 145 (the smallest tumor that did not experience improvement). Several patients were known to have diagnoses that were potentially vision-limiting before cataract surgery (Table 4). All patients had extracapsular cataract extraction, and intraoperative complications were not seen in any of the patients. A wide range of postoperative complications were seen, although none of them were severe (Table 5).
DISCUSSION Brachytherapy, the placement of the radioactive source near a tumor, relies on proximity for tumor kill. Irradiation influences normal tissue close to the tumor site as well as the tumor tissue itself. Larger and more anteriorly located tumors in this study were more prone to develop cataracts after irradiation. These tumors required larger plaques placed nearer to the lens, necessitating a significant
FISH et al
•
CATARACT EXTRACTION AFTER BRACHYTHERAPY
Table 2. Tumor Profile Lens Status
Anterior Border of Tumor
Average Longest Basal Diameter (range)
Average Height (range)
Plaque
No cataract (n = 42) Cataract (n = 13) Cataract extraction (n = 11)
15P/18E/90ra 1P/5E/70ra 1P/3E/70ra
11.45 mm (4.5-24) 14.54 mm (9-20) 14.27 mm (9-20)
5.89 mm (1.6-12.4) 7.35 mm (3-13) 7.11 mm (3-13)
191/22C2/1 C1 11/12C2 11/10C2
P = posterior to equator; E = equator to ora; I.= iodine 125; C1 = 7.5 mm cobalt 60; C2 = 10 to 15 mm cobalt 60.
Table 3. Cataract Surgery Patient No.
Preoperative Visual Acuity
Early Postoperative Visual Acuity
1 2 3 4 5 6 7 8 9 10 11
20/60 20/100 FC 20/200 FC FC FC FC HM FC FC
20/50 20/25 20/400 20/20 20/80 20/30 20/50 20/70 FC 20/40 20/40
FC
=
finger counting; HM
=
Long-term Visual Acuity
Follow-up (mos)
20/40 20/60 20/200 20/25 20/300 20/50 20/200
25 18 36 25 15 18 39 5 9 19 36
HM 20/40 20/40
Comments Deceased Cystoid macular edema Radiation retinopathy Deceased Posterior capsule opacity, potential acuity 20/25 Radiation retinopathy Lost to foliow-u P Moderate vitreous hemorrhage Deceased
hand motions.
dose to the lens to permit an adequate dose to be delivered to the tumor apex. Accordingly, these plaques were farther from the fovea and optic nerve, and thus led to relative sparing of these structures. Tumor size was the parameter most important in determining whether an eye would have improved visual acuity after cataract surgery and maintain this improvement over time. Large tumors required larger plaques and higher doses of radiation. Therefore, the likelihood of radiation to other parts of the eye was increased. In a previous report, Augsburger and Shields" suggested that cataract extraction after brachytherapy for malignant melanoma ofthe choroid is unrewarding because of macular or optic nerve damage, cystoid macular edema, or choroidal hemorrhage precluding long-term improvement of reasonable visual function. They reported on seven eyes with mature radiation-induced cataracts, all with visual acuity of 20/400 or worse, that had cataract extraction. Direct comparison between their study group and the present study group is impossible. All of their patients had visual acuity of 20/400 or worse before surgery. Our group had three eyes with visual acuity better than 20/ 400 before cataract extraction and all three of these eyes have maintained a significant improvement for at least 18 months. Also, six of seven eyes in the group presented by Augsburger and Shields'? had intracapsular cataract extractions, whereas all eyes in the present group had extracapsular cataract extractions. The extracapsular technique may reduce the incidence of severe cystoid macular
Table 4. Diagnoses before Cataract Extraction Uveitis Radiation retinopathy Vitreous hemorrhage
1 2 1
Table 5. Postoperative Complications Corneal edema (mild) Glaucoma (mild) Decentered lens CME (7 pseudophakic) Vitreitis Capsular opacity CME
=
1 1 1 1 1 2
cystoid macular edema.
edema'" and, similarly, the visual loss related to radiation retinopathy. Obviously, patient selection plays a role in the success of any surgical procedure. In our group, 13 patients developed cataracts and only 11 had cataract surgery. Not only is the number of patients very small, but care must be taken in extrapolating our experience to the entire population of patients who develop cataracts after brachytherapy for choroid melanoma. Careful preoperative evaluation with particular attention directed toward detecting radiation-induced optic neuropathy or retinop621
OPHTHALMOLOGY
•
MAY 1991
athy may allow the identification ofa subgroup of patients who would benefit from cataract extraction. The mortality rate for patients without cataracts was 14%,whereas those patients with cataracts had a mortality rate of 38%. Although these differences in such small groups are not statistically significant, the higher mortality in patients who developed cataracts might be influenced by the older age of these patients and the longer length of follow-up time that had elapsed since the treatment of their malignant melanoma. Additionally, patients developing cataracts had tumors that were larger and located more anteriorly, factors believed to be associated with a poorer prognosis for life.' 7 , 18 The small number of patients in our study precludes conclusive determination of whether cataract surgery played a role in mortality. A larger group of patients and careful matching of tumor characteristics between surgical and nonsurgical cases would be necessary to determine any potential role of cataract surgery in mortality. Although this study is retrospective, with only a 2-year average follow-up, we are encouraged by the fact that a significant number of patients have experienced and maintained visual improvement after cataract extraction. Augsburger and Shields'? reported that the visual acuity fell to the preoperative level or worse within 6 months of surgery in the six eyes that initially experienced improvement. Longer follow-up of our patients will be necessary to confirm our initial impression that selected patients may benefit from cataract extraction after brachytherapy for malignant melanoma of the choroid.
REFERENCES 1. Augsburger JJ, Gamel JW, Sardi VF, et al. Enucleation vs cobalt plaque radiotherapy for malignant melanomas of the choroid and ciliary body. Arch Ophthalmol1986; 104:655-61.
622
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2. Seddon JM, Gragoudas ES, Albert DM, et al. Comparison of survival rates for patients with uveal melanoma after treatment with proton beam irradiation or enucleation. Am J Ophthalmol 1985; 99:282-90. 3. Garretson BR, Robertson DM, Earle JD. Choroidal melanoma treatment with iodine 125 brachytherapy. Arch Ophthalmol1987; 105:1394-7. 4. Packer S, Rotman M, Salanitro P. lodine-125 irradiation of choroidal melanoma: clinical experience. Ophthalmology 1984;91: 1700-8. 5. Gragoudas ES, Goitein M, Koehler A, et al. Proton irradiation of choroidal melanomas: preliminary report. Arch Ophthalmol1978; 96:158391. 6. Packer S, Rotman M. Radiotherapy of choroidal melanoma with iodine125. Ophthalmology 1980; 87:582-90. 7. Gragoudas ES, Goitein M, Verhey L, et al. Proton beam irradiation: an altemative to enucleation for intraocular melanomas. Ophthalmology 1980; 87:571-81. 8. Wilkes SR, Gragoudas ES. Regression patterns of uveal melanomas after proton beam irradiation. Ophthalmology 1982; 89:840-4. 9. Packer S. lodine-125 radiation of posterior uveal melanoma. Ophthalmology 1987; 94:1621-6. 10. Cruess AF, Augsburger JJ, Shields JA, et al. Visual results following cobalt plaque radiotherapy for posterior uveal melanomas. Ophthalmology 1984; 91:131-6. 11. Shields JA, Augsburger JJ, Brady LW, Day JL. Cobalt plaque therapy of posterior uveal melanomas. Ophthalmology 1982; 89:1201-7. 12. Augsburger JJ, Shields JA. Cataract surgery following cobalt-50 plaque radiotherapy for posterior uveal malignant melanoma. Ophthalmology 1985; 92:815-22. 13. Shields JA. Diagnosis and management of intraocular tumors. Sf. Louis: CV Mosby, 1983; 46. 14. Westheimer GW. Scaling of visual acuity measurements. Arch Ophthalmol1979; 97:327-30. 15. Berson EL, Sandberg MA, Rosner B, et al. Natural course of retinitis pigmentosa over a three-year interval. Am J Ophthalmol 1985; 99: 240-51. 16. Bradford JD, Wilkinson CP, Bradford RH Jr. Cystoid macular edema following extracapsular cataract extraction and posterior chamber intraocular lens implantation. Retina 1988; 8:161-4. 17. Shammas HF, Blodi FC. Prognostic factors in choroidal and ciliary body melanomas. Arch OphthalmoI1977; 95:63-9. 18. McLean IW, Foster WD, Zimmerman LE. Uveal melanoma: location, size, cell type, and enucleation as risk factors in metastasis. Hum Patho11982; 13:123-32.