Eye

The eye consists of many different structures. It contains the eyelid, cilia, lacrimal glands, drainage apparatus, and conjunctiva. 1  Cancers of the eye can include ocular malignancies, uveal and retinal tumors, optic glioma, and orbital malignancies. Overall, eye cancers can be caused by a variety of things including eye color, sun exposure, and even occupational exposure to certain chemicals. There are several factors that are associated with certain eye malignancies. Among them are the following: Common symptoms of the eye include: a growing dark spot on the iris, sensation of flashing lights, alteration in the shape of the pupil and blurring/loss of vision.
 * **Epidemiolgy:** || Spencer
 * **Epidemiolgy:** || Spencer
 * Ocular Malignancies: Basel and Squamous Cell Carcinoma of the Eyelid. Radiation therapy is used most often for these cases which have a 90% cure rate. 1
 * Uveal Tumors: The most common forms of these include metastatic tumors of the posterior uvea and malignant melanoma of the uvea. These specific forms account for 90% of all cases that present in the eye. 1
 * Retinal Tumors: This form of cancer is the most common intraocular malignancy in children and accounts for 25% of all primary malignant tumors of the eye. 1  This form also presents 1/3 bilateral, and 2/3 unilateral in most cases. 1
 * Optic Glioma: This form of eye cancer is most prevalent in children under 15 years of age. It also includes only 1% of all central nervous system tumors, of which 50% involve the optic chiasm. 1
 * Orbital Tumors: These types of tumors include RMS (Rhabdomyosarcoma), malignant lymphoma of the orbit, and lacrimal gland tumors.
 * <span style="color: #ff0300; font-family: Arial,Helvetica,sans-serif;">The overall 5 year survival rates from eye and orbital cancers taken from 18 geographical areas include 81.7%. <span style="color: #ff0300; font-family: Arial,Helvetica,sans-serif; vertical-align: super;">2 <span style="color: #ff0300; font-family: Arial,Helvetica,sans-serif;"> The overall lifetime risk that a person will end up with cancer of the eye and or orbit can include .08%. <span style="color: #ff0300; font-family: Arial,Helvetica,sans-serif; vertical-align: super;">2 ||
 * **Etiology:** || Pablo
 * Race and ethnicity: studies show that the incidence is much higher in whites than in African Americans or Asians.
 * Eye Color: people with lighter eye color are at higher risk of developing malignancies of the eye
 * Sun exposure
 * Occupation: Welders, chemical workers are also at a higher risk
 * Having other diseases like the human immunodeficiency virus / acquired immunodeficiency syndrome (HIV)/AIDS), the Humana Papillomavirus (HPV)
 * People on antirejection drugs for organ transplants
 * Inherited faulty genes 3 ||
 * **Signs & Symptoms:** || Becky

Signs & Symptoms of different types: ¨ Melanoma—loss of vision, detached retina, pain and bleeding ¨ Choroidal Nevus—loss of peripheral or central vision; can look like a mole ¨ Conjunctival Tumor—pain and loss of vision; grow on the external surface of the eye ¨ Eyelid Tumors—pain, swelling, vision loss and impairment of the tear duct ¨ Orbital Tumors—bulging of the eye, retinal detachment; usually develop over the eye socket ¨ Retinoblastoma—common in children; whiteness of pupil and swelling 4 || The following diagnostic tests are used for cancers of the eye: 5
 * **Diagnostic Procedures:** || Adam


 * Ultrasound
 * Fluorescein angiography
 * Fine needle biopsy
 * CT Scan
 * PET Scan

In addition to these tests, eye melanomas can be discovered during a regular eye examination. || This table explains the different types of histology's that can occur within the eye, and percentage frequency of occurrence. This table was found on nature.com explaining the incidence of eye cancer in Taiwan, and it was an 18 year review. 6 The longevity of the study and the number of cases studied increases both its validity and strength. ||~ Subsite ||~ Histology ||~ No. of cases ||~ Frequency (%) ||
 * **Histology:** || Megan
 * Eyeball (190.0)a || Melanoma || 51 || 83.6 ||
 * || Squamous cell carcinoma || 3 || 4.92 ||
 * || Other cell types || 7 || 11.5 ||
 * || Total histologically confirmed || 61 || 100 ||
 * Orbit (190.1)b || Lymphoma || 59 || 41.5 ||
 * || Squamous cell carcinoma || 19 || 13.4 ||
 * || Rhabdomyosarcoma || 10 || 7.04 ||
 * || Carcinoma NOS || 9 || 6.34 ||
 * || Adenocarcinoma || 8 || 5.63 ||
 * || Other cell types || 37 || 26.1 ||
 * || Total || 142 || 100 ||
 * Lacrimal gland (190.2) || Adenoid cystic carcinoma || 14 || 45.2 ||
 * || Lymphoma || 6 || 19.3 ||
 * || Adenocarcinoma || 4 || 12.9 ||
 * || Other cell types || 7 || 22.6 ||
 * || Total || 31 || 100 ||
 * Conjunctiva (190.3) || Squamous cell carcinoma || 50 || 43.5 ||
 * || Melanoma || 27 || 23.5 ||
 * || Lymphoma || 23 || 20.0 ||
 * || Carcinoma NOS || 12 || 10.4 ||
 * || Other cell types || 3 || 2.60 ||
 * || Total || 115 || 100 ||
 * Cornea (190.4) || Squamous cell carcinoma || 4 || 44.5 ||
 * || Carcinoma NOS || 3 || 33.3 ||
 * || Other cell types || 2 || 22.2 ||
 * || Total || 9 || 100 ||
 * Retina (190.5) || Retinoblastoma || 259 || 97.0 ||
 * || Other cell types || 8 || 3.00 ||
 * || Total || 267 || 100 ||
 * Choroid (190.6) || Melanoma || 32 || 88.9 ||
 * || Other cell types || 4 || 11.1 ||
 * || Total histologically confirmed || 36 || 100 ||
 * Lacrimal duct (190.7) || Carcinoma NOS || 4 || 28.6 ||
 * || Squamous cell carcinoma || 3 || 21.4 ||
 * || Adenocarcinoma || 3 || 21.4 ||
 * || Other cell types || 4 || 28.6 ||
 * || Total || 14 || 100 ||
 * Other sites (190.8, 190.9)c || Melanoma || 16 || 27.6 ||
 * || Squamous cell carcinoma || 14 || 24.1 ||
 * || Carcinomas NOS || 10 || 17.2 ||
 * || Adenocarcinoma || 4 || 6.90 ||
 * || Other cell types || 14 || 5.17 ||
 * || Total || 58 || 100 ||
 * **Lymph node drainage:** || Kevin Tsai
 * Other sites (190.8, 190.9)c || Melanoma || 16 || 27.6 ||
 * || Squamous cell carcinoma || 14 || 24.1 ||
 * || Carcinomas NOS || 10 || 17.2 ||
 * || Adenocarcinoma || 4 || 6.90 ||
 * || Other cell types || 14 || 5.17 ||
 * || Total || 58 || 100 ||
 * **Lymph node drainage:** || Kevin Tsai
 * **Lymph node drainage:** || Kevin Tsai

Up to now lymphatics of the eye could not be pointed out. Research is still underway to determine the role of lymphatics of eye cancer. || <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif;">Secondary Intraocular tumors are those that start somewhere else and then spread to the eye. <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; vertical-align: super;">7 <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif;"> These are actually more common than primary eye tumors. The most common cancers that spread to the eye are breast and lung cancer. Less common sites of origin include the prostate, kidney, thyroid, and gastrointestinal tract. <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif; vertical-align: super;">8 <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif;"> Lymphoma and leukemia can also spread to the eye and orbit. The most common area for ocular metastasis is in the choroid (vascular layer) of the eye. || <span style="color: #f44743; font-family: Arial,Helvetica,sans-serif;">The most common forms of cellular classifications of the eye include Spindle-A cells, Spindle-B Cells, Epithelioid cells, and Intermediate cells. <span style="color: #f44743; font-family: Arial,Helvetica,sans-serif; vertical-align: super;">2 <span style="color: #f44743; font-family: Arial,Helvetica,sans-serif;"> The tumor is given a grade (G) to describe the composition of its cells. Usually a lower grade indicates a better prognosis. <span style="color: #f44743; font-family: Arial,Helvetica,sans-serif; vertical-align: super;">9
 * <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif;">Metastatic spread: || <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif;">Erin
 * **Grading:** || <span style="color: #f44743; font-family: Arial,Helvetica,sans-serif;">Spencer
 * <span style="color: #f44743; font-family: Arial,Helvetica,sans-serif;">GX - The grade cannot be evaluated.
 * <span style="color: #f44743; font-family: Arial,Helvetica,sans-serif;">G1 – A Spindle Cell Melanoma
 * <span style="color: #f44743; font-family: Arial,Helvetica,sans-serif;">G2 – A Mixed Cell Melanoma
 * <span style="color: #f44743; font-family: Arial,Helvetica,sans-serif;">G3 – An Epithelioid Melanoma ||
 * **Staging:** || Pablo
 * __ The American Joint Committee on Cancer (AJCC) advocates the TNM staging system. This system is based on the following information. __**


 * T used to describe the size of the primary tumor and if adjacent structures have been invaded
 * N indicates if the disease has spread to regional lymphatics
 * M gives information on whether the tumor has spread to distant organs 10

This system was developed by the Collaborative Ocular Melanoma Study (COMS) group and as implied by its name, it focuses on intraocular melanoma. This system divides eye melanomas into small, medium, and large. Tumor size classifications according to boundary lines used in a Collaborative Ocular Melanoma Study (COMS) are as follows:
 * __The COMS staging system.__ **


 * Small: Range from 1.0 mm to 3.0 mm in apical height and largest basal diameter of 5.0 to 16.0 mm.[[|1]]
 * Medium: Range from 3.1 to 8.0 mm in apical height and a basal diameter of not more than 16.0 mm.[[|2]]
 * Large: Greater than 8.0 mm in apical height or a basal diameter more than 16.0 mm, when the apical height is at least 2.0 mm. 10

Developed in the 1960’s, the Reese-Ellsworth staging system is used to classify retinoblastomas that have not metastasize to other parts of the body. This system includes terms such as favorable or unfavorable and doubtful used to describe the like hood of the disease treated effectively while the affected eye is preserved. It is divided into 5 categories or groups, each one representing the probability of preserving the eye and sight while controlling the disease.
 * __ The Reese-Ellsworth staging system __**


 * Group 1 (very favorable for saving or preserving the eye)
 * Group 2 (favorable for saving or preserving the eye)
 * Group 3 (doubtful for saving or preserving the eye)
 * Group 4 (unfavorable for saving or preserving the eye)
 * Group 5 (very unfavorable for saving or preserving the eye) 11

A newer classification for retinoblastoma is divided into 5 groups labeled A through E Radiation side effects of treatment to the eye can range from cataracts, gradual vision loss, and optic nerve damage and perhaps in extreme cases blindness. || The prognosis for cancers of the eye depend primarily on the size of the tumor, the location of the tumor, and the extent of extraocular invasion. 12 The general 5 year survival rate for non-metastatic cancers of the eye sits at 80%. However, due to the rarity of eye cancers, the data on this isn't as extensive as many other types of cancers. 12 || As with all radiation treatments, the intention is to design a conformal treatment regimen that treats the tumor at an optimal dose with minimal normal tissue toxicity. 13 But, when treating the eye, the entire retinal area must be treated to eliminate the recurrence possibilities in the anterior of the eye. If instead of treating the whole, a lens sparing treatment is used, the chances for recurrence increases from 1.4% to 19%.2 Beam arrangements are typically laterals, a single anterior, a single lateral, or a combination of the two. 13 Left picture represents an anterior beam only and the right depicts an anterior combined with a lateral. If laterals are chosen the 5-10 degree posterior gantry tilts should be added to avoid dose to the contralateral lens, cornea, and brain.2 D shaped blocks are typically the outcome when avoiding these areas. This is a picture of the D shaped block often used with ocular radiation. Retinoblastoma can be adequately treated if a dose of 40-45 gray (Gy) is administered in 1.5-2.0 Gy fractions when external beam is used alone.2 This dose can be reached using 15-18 MeV beams or 4-6 MV. If chemo and radiation are combined, the a reduction in radiation is required to 35-40 Gy.2 || <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif;"> || Back to Week 2
 * __The International Classification for Intraocular Retinoblastoma__ **
 * Group A: Small tumors (3 mm across or less) that are confined to the retina and are not near important structures such as the optic disk (where the optic nerve enters the retina) or the foveola (the center of vision).
 * Group B: All other tumors (either larger than 3 mm or small but close to the optic disk or foveola) that are still confined to the retina.
 * Group C: Well-defined tumors with small amounts of spread under the retina (subretinal seeding) or into the gelatinous material that fills the eye (vitreous seeding).
 * Group D: Large or poorly defined tumors with widespread vitreous or subretinal seeding. The retina may have become detached from the back of the eye.
 * Group E: The tumor is very large, extends near the front of the eye, is bleeding or causing glaucoma (high pressure inside the eye), or has other features that mean there is almost no chance the eye can be saved. 11 ||
 * **Radiation side effects:** || Becky
 * **Prognosis:** || Adam
 * **Treatments:** || Megan
 * **TD 5/5:** || Kevin Tsai
 * Lens 1000 cGy – Cataract. 14
 * Retina 4500 cGy - Blindness
 * Optic Chiasm 4500 cGy – Blindness
 * Optic Nerve 5000 cGy – Blindness ||
 * **References:** || # <span style="color: #ff0300; font-family: Arial,Helvetica,sans-serif;">Chao C, Perez C, Brady L. Radiation Oncology Management Decisions. 3rd ed. PA: Lippincott Williams and Wilkins; 2011:193-202.
 * 1) <span style="color: #ff0300; font-family: Arial,Helvetica,sans-serif;">National Cancer Institute. National Cancer Institute Web Site. http://seer.cancer.gov/statfacts/html/eye.html. Accessed June 3, 2013.
 * 2) American Cancer Society. Web Site. []. Accessed June 1, 2013.
 * 3) Eye Cancer. Eye Cancer Symptoms Web site. [] Accessed June 3, 2013
 * 4) Eye Cancer. Cancer.Net Web Site. http://www.cancer.net/cancer-types/eye-cancer/diagnosis. Accessed, June 6, 2013.
 * 5) Chao KS, Perez CA, Brady LW. Radiation Oncology Management Decisions. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2002:178-179
 * 6) <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif;">American Cancer Society. Eye Cancer (Melanoma and Lymphoma). American Cancer Society. [] . Revised January 18, 2013. Accessed June 5, 2013.
 * 7) <span style="color: #ff00ff; font-family: 'Times New Roman',Times,serif;">The Eye Cancer Foundation. Chorodial Metastasis. Eye Cancer Network. [] . Accessed June 5, 2013.
 * 8) <span style="color: #ff0300; font-family: Arial,Helvetica,sans-serif;">Eye Cancer Stages and Grades. Cancer.Net Web Site. http://www.cancer.net/cancer-types/eye-cancer/staging-and-grading. Accessed June 3, 2013.
 * 9) American Cancer Society. Web Site. [] . Accessed June 2, 2013.
 * 10) American Cancer Society. Web Site. [] . Accessed June 2, 2013.
 * 11) Ocular Cancer. MD Anderson Web Site. http://www2.mdanderson.org/depts/oncolog/articles/10/1-jan/1-10-1.html. Accessed June 6, 2013.
 * 12) Cheng CY, Hsu WM. Incidence of eye cancer in Taiwan: an 18-year review. Nature publishing group. [|http://www.nature.com/eye/journal/v18/n2/fig_tab/6700619t3.html#figure-title]. Accessed June 5, 2013.
 * 13) Washington CM, Leaver D. Principles and Practice of Radiation Therapy. 3rd ed. St. Louis, MO: Mosby-Elsvier; 2010:739-743.