Definition and Overview
Retinal lesions are tumours that form in the eyes. They are treated with radiation therapy.
The most common eye lesion is choroidal nevus, a benign growth that forms at the back of the eyes when pigment cells accumulate. Its development is associated with some systemic conditions, such as choroidal neurofibroma. Although it is believed to be congenital, it rarely affects children and is often diagnosed in adulthood.
Who Should Undergo and Expected Results
Patients with macular lesions on the eye, lesions on the retina, or choroidal nevus should seek medical attention. Although choroidal nevus treatment is not always immediately necessary because the lesions are usually benign, it is important that patients undergo constant monitoring to ensure that their condition is not progressing. If the nevus is small and does not show signs of growth or other significant change, no treatment is recommended. However, it is continuously checked because there is a risk that it will develop into melanoma.
Studies show that one in every 500 cases of choroidal nevus of the eye become malignant within ten years. When this happens, patients may experience the following:
Vision loss or decreasing vision
Abnormal blood vessel growth
If a choroidal nevus is confirmed to be malignant, the patient has to undergo treatment as soon as possible. Seeking immediate medical attention provides the best chance of preserving their vision and preventing serious complications, such as metastatic melanoma.
Treatment, however, does not produce instant results. It may take between 3 and 6 months of treatment before the lesion is removed. In some cases, the growth does not completely disappear, leaving behind a benign residual lump.
How is the Procedure Performed?
Prior to undergoing any treatment for retinal lesions, various eye tests, such as photographic imaging, ultrasonography, and ocular coherence tomography, are performed. These tests are used to monitor the status of a detected choroidal nevus. Once treatment is prescribed, patients may undergo plaque radiation therapy. Also known as radioactive plaque therapy, this treatment uses a sealed device that delivers high doses of radiation directly to the tumour to avoid damaging the eye.
The device, which is called the plaque, is positioned over the tumour on the surface of the eyeball. It is implanted and removed while the patient is under sedation or local anaesthesia. Patients who undergo this therapy are expected to feel some pain and discomfort within 24-48 hours after the procedure. They are usually advised to stay in the hospital during this time and are provided with pain medications.
Possible Risks and Complications
Patients who undergo treatment of retinal lesion commonly experience the following:
Pain and discomfort
Itchy and red eyes
These symptoms may persist for around two weeks, but most patients can resume their normal activities within a week after being discharged from the hospital.
Although radiation therapy for retinal lesions is generally safe, patients still face a minimal risk of complications, such as:
Treatment-related vision loss – Patients may experience blurring, dimming, or total vision loss in the affected eye depending on the size and location of the tumour.
These, however, can be treated with anti-VEGF agents.
“Understanding Choroidal Nevi.” Ocular Melanoma Foundation. http://www.ocularmelanoma.org/choroidalnevus.htm
Finger PT. “Small choroidal melanoma: To treat or not to treat, that is the question!” New York Eye Cancer Center. https://eyecancer.com/eye-cancer/research-articles/small-choroidal-melanoma-to-treat-or-not-to-treat-that-is-the-question/
JI Hui et al. “Radioactive plaque therapy.” Int Ophthal Clin. 46(1), 51-68. Winter 2006. https://www.ncbi.nlm.nih.gov/labs/articles/16365555/
Finger PT. “Eye and vision sparing radiation therapy for intraocular tumors.” New York Eye Cancer Center. https://eyecancer.com/eye-cancer/treatments/eye-and-vision-sparing-radiation-therapy-for-intraocular-tumors/
C Stannard, W Sauerwein, G Maree, K Lecuona. “Radiotherapy for ocular tumors.” Eye (2013) 27, 119-127. http://www.nature.com/eye/journal/v27/n2/full/eye2012241a.html