Intraocular irradiation administered for choroidal melanoma can result in a variety of ocular complications. The presence of certain risk factors can help identify a patient who may be at risk for vision loss in the treated eye. The authors are from the Massachusetts Eye and Ear Infirmary and Massachusetts General Hospital.
Adverse outcomes of intraocular irradiation:
(1) radiation vasculopathy
(2) radiation maculopathy
(3) radiation papillopathy
(4) vision loss
Risk factors for adverse effect:
(1) dose of radiation to site in CGE (cobalt Gy equivalent)
(2) presence of diabetes mellitus or other vascular disease
|
Target |
Radiation Dose |
Relative Risk for Radiation Vasculopathy |
|
macula |
<= 40 CGE |
1.0 |
|
|
41 – 65 CGE |
2.1 |
|
|
> 65 CGE |
2.6 |
|
optic disc |
<= 40 CGE |
1 |
|
|
41 – 65 CGE |
12.4 |
|
|
> 65 CGE |
36.0 |
from Table 2, page 1573
|
Dose to Macula in CGE |
Probability of Radiation Maculopathy |
|
10 |
24% |
|
20 |
33% |
|
30 |
39% |
|
40 |
46% |
|
50 |
50% |
|
60 |
52% |
|
70 |
54% |
from Figure 1, page 1573
|
Dose to Optic Disc in CGE |
Probability of Radiation Papillopathy |
|
10 |
7% |
|
20 |
7% |
|
30 |
7% |
|
40 |
21% |
|
50 |
34% |
|
60 |
48% |
|
70 |
75% |
from Figure 1, page 1573
Risk factors for vision loss:
(1) radiation dose to macula (relative risk 1.8 for 26-69 CGE; relative risk 2.5 for >= 70 CGE)
(2) pre-existing vision defect (relative risk 2.7 if visual acuity worse than 20/63)
(3) presence of diabetes (relative risk 2.7)
Purpose: To identify the risk of visual damage associated with intraocular irradiation using the study of Gragoudas et al.
Specialty: Hematology Oncology, Ophthalmology
Objective: risk factors, response to therapy, complication detection
ICD-10: C43, C44,
