Download Yousef, Delilah

Delilah Yousef, OD
Ocular Disease Resident
Submission date: 08/28/2009
A case on proliferative radiation retinopathy in the right eye after radiation therapy
secondary to brain metastasis
Abstract
A 59-year old male received whole brain radiation therapy after metastasis of small cell
lung cancer to the frontal lobe. After examination, we diagnosed him as proliferative
radiation retinopathy and referred him for laser treatments.
Case Report Outline
I. Case History
a) Patient demographics: 59 year old, African American male
b) Chief Complaint: sudden decrease in vision of the right eye, began approximately
two months prior; patient reports condition is worsening; also reports associated
pain in the right eye that began one week prior
c) Ocular History
 Primary Open Angle Glaucoma: Diagnosed in 1988
d) Medical History
 Hypertension: Diagnosed in 1988
 Small cell lung cancer: Diagnosed in August 2007
 Stomach surgery in August 2007: clot removed
 Cancer metastasis to brain: November 2008
e) Medications
 Amlodipine 5mg tab, po qd
 Timolol maleate 0.5%ophthalmic solution, 1 gtt bid ou
 Travoprost 0.004%, 1 gtt qhs ou
f) Other salient information
 Chemotherapy (etoposide and cisplatin) 6 cycles completed in August
2008
 A course of pallative whole-brain radiation therapy of 3000 cGY (30
Gy) over 10 cycles on consecutive days beginning in November 2008
II. Pertinent Findings
a) Clinical
 Best-corrected visual acuities
– OD: LP (light perception)
– OS: 20/30
 Intraocular pressures (Goldmann) at 12:08p
– OD: 38mmHg, reduced to 23 mmHg with Azopt in office
– OS: 20 mmHg
 Neovascular vessels on inferior, nasal bed of the right iris
 Gonioscopy showed both angles were open to ciliary body OU;
however blood was noted in schlemn’s canal 360 of the right eye,
without use of the compression technique
 Episcleral vessels engorged and dilated in the right eye
 Several intraretinal hemorrhages of various diameters, extending into
peripheral retina with juxtafoveal neovascularization of the right eye
 A disappearance of the foveal depression was noted in the right eye,
with associated macular thickening
 Optic nerve head appearance was normal
b) Physical features
Delilah Yousef, OD
Ocular Disease Resident
Submission date: 08/28/2009
 Facial swelling secondary from superior vena cava compression
 Left lower extremity weakness
c) Radiology studies
 CT abdomen/pelvis with IV and PO contrast
– Low attenuation of soft tissue extending between the right upper
lobe and the right paratracheal mediastinum, consistent with
small-cell lung cancer. After completion of chemotherapy the
mass has decreased from the size of 58 X 48 mm to 38 X 45 mm
– Superior vena cava is constricted, however still patent
 CT brain
– Multiple hemorrhages in the left frontal lobe and right frontal
lobe with associated edema; hemorrhages were also seen in the
right occipital lobe
 MRI
– Confirmed numerous metastatic lesions in both cerebral
hemispheres, the largest measuring 2.7 X 3.2 X 3.2 cm in the
right frontal lobe
III. Differential Diagnosis
a) Primary/leading
 Branch or central vein occlusion (#1 DDx was CRVO)
b) Others
 Diabetic Retinopathy, any stage
 Accelerated hypertensive retinopathy
 Coat’s disease
 Perifoveal telangiectasia
 Ischemic optic neuropathy
 Papilledema
 Optic neuritis
IV. Diagnosis and Discussion
a) Condition: usually develops after treatment of intraocular tumors via plaque
therapy or external beam irradiation due to malignancies.
 Pathogenesis
– Histopathological evidence suggests retinal vascular endothelial
cells are damaged first, which is the starting point for radiation
retinopathy. Radiation auses cells to undergo miotic death;
therefore, compromising vascular endothelial integrity initiating
the clotting cascade.
– Microvascular abnormalities develop due to the alteration of
local metabolism. Capillary occlusions normally lead to
formation of smaller dilated collateral channels that will bypass
the area of ischemia. High doses of radiation can cause
vasculopathy of choroidal circulation and can also compromise
the microcirculation of the optic nerve head.
 Radiation dose
– The most important risk factors for retinopathy from radiation
will occur are the total dose of radiation administered to the
retina and the fraction size for cases involving teletherapy
a. It has been reported that the higher the total exposed
radiation dose and fraction dose, the higher the
frequency of development of radiation retinopathy.
Delilah Yousef, OD
Ocular Disease Resident
Submission date: 08/28/2009
–
Thresholds for teletherapy are less understood. However,
estimates fall in the range of 1500 to 6000 rad (15-60 Gy). In
general, 35 Gy is the highest limit of safe radiation dose, with a
50% chance of developing radiation retinopathy with dosages
greater than 60Gy and a 85-90% chance with a dose 70-80 Gy.
b) Unique features
 Ocular manifestations
– Earliest clinical appearance occurs at the posterior fundus where
areas of focal occluded capillaries and irregular dilation of the
microvasculature occur. This is more easily appreciated with the
use of fluorescein angiography.
– Later, microaneurysms and telangietctatic channels appear along
with retinal exudation and small intraretinal or nerve fiber
hemorrhages. Collateral vessels seen on the optic nerve are also
a common feature at this stage of the retinopathy. At this point,
there is little effect on vision.
– The capillary damage can worsen with more substantial radiation
insult, thereby affecting vision due to macular edema and
exudation.
– In acute phases, severe swelling of the optic nerve head along
with hemorrhages and cotton wool spots can be appreciated.
This phase can mimic acute papilledema or severe hypertensive
retinopathy.
– Proliferative radiation retinopathy can develop, but it usually not
until two years after the initial retinopathy occurs. Severe
complications include: vitreous hemorrhages, tractional
detachments, rubeosis iridis, and phthisis bulbi.
 Risk factors
– Chemotherapeutic drugs may potentiate the damage of ionizing
radiation by having effects on DNA synthesis and vascular
endothelial cell repair and division.
– Clinical evidence suggests that coexisting diabetes mellitus
increases the patient’s risk of developing radiation retinopathy;
they are also more likely to undergo severe complications such
as extensive retinal ischemia and neovascularization.
V. Treatment and Management
a) Treatment/ response to treatment
 If the patient has macular edema and/ or has developed to the
proliferative stage, studies suggest that focal or grid photocoagulation
has a favorable effect.
– In one case report, intravitreal injections of triamcinolone
acetonide was used for the treatment of macular edema; within
two weeks vision in the affected eye went from 20/60 to 20/30
acuity with an associated decrease in retinal thickening seen with
optical coherence tomography.
Delilah Yousef, OD
Ocular Disease Resident
Submission date: 08/28/2009

Panretinal photocoagulation has been used to successfully contain
preretinal and papillary neovascularization as well as reducing the
incidence of vitreous hemorrhages and retinal detachments.
 Research has found that less intense photocoagulation is required to
contain the radiation retinopathy when compared to similar findings
caused by diabetic retinopathy. However, most studies and clinical data
use diabetic retinopathy management as a gold standard for treatment
of radiation retinopathy.
 Retinal cryoablation has been shown to contain neovascularization in
the presence of a dense vitreous hemorrhage, although conventional
treatments like a vitrectomy have also proven useful.
b) Bibliography
1) Hong K, Chang S. A case of radiation retinopathy of left eye after
radiation therapy of right brain metastasis. Korean Journal
Ophthalmology 2009; 23:114-117.
2) Mao XW. A quantitative study of the effects of ionizing radiation
on endothelial cells and capillary-like network formation. Technol
Cancer Res Treat. 2006 Apr; 5(2):127-34.
3) Kinyoun J. Long-term visual acuity results of treated and untreated
radiation retinopathy. Trans Am Ophthalmol Soc 2008:106; 325335.
VI. Conclusion
a) Clinical pearls/ take home message
 Many studies have shown that the addition of chemotherapy to
radiation treatments can dramatically increase the risk of developing
severe retinopathy, especially advancing to the proliferative stage. The
practitioner needs to take this into account and adjust the patient follow
up period accordingly.
 If the patient has vascular disease, especially diabetes, along with
radiation treatments, the incidence of retinopathy developing increases.
 Studies have shown photocoagulation therapy as well as intravitreal
steroid injections to be useful in slowing and reducing retinopathy and
macular edema associated with radiation therapy; however, it is
important to understand that these treatments are not nearly as
beneficial or reliable to radiation retinopathy patients as they are with
patients who have diabetic retinopathy.