|Retinal Pigment Epithelium (RPE) Detachment
Signs and Symptoms
In most instances, serous detachment of the RPE occurs asymptomatically.
Only in those cases in which the macula is affected will patients report blurred vision,
metamorphopsia, micropsia, or positive scotomas. Other associated clinical findings may
include induced hyperopia and delayed retinal recovery time on the photostress test. Most
individuals with RPE detachment are male, between the ages of 20 and 60 years. The history
often reveals predisposing or concurrent ocular conditions such as macular degeneration,
idiopathic central serous chorioretinopathy (ICSC), angioid streaks, presumed ocular
histoplasmosis syndrome (POHS), or hereditary choroidal degeneration. In other cases, the
condition occurs idiopathically.
RPE detachment appears ophthalmoscopically as single or multiple,
well-circumscribed round or oval lesions within the posterior fundus. The lesions are
typically dome-shaped with slight elevation and appear yellow to orange in color. A
reddish "halo" is often seen around the base of the detachment, and overlying
pigment defects such as clumping or mottling are commonplace. Lesions may vary in size
from one-fifth to over 5 disc diameters (DD), but most are less than 1 DD. Fluorescein and
indocyanine green (ICG) angiography show early hyperfluorescence of the entire RPE
detachment, which persists throughout the angiogram demonstrating late pooling. Leakage
into the sensory retina occurs only in cases of concurrent serous retinal detachment.
RPE detachment is a non-specific anatomical alteration that may result from
any number of choroidal disorders that disrupt the normal junction between the basement
membrane of the RPE and the inner collagenous layer of Bruchs membrane. This
disruption permits serous fluid from the underlying choriocapillaris to gain access into
the sub-RPE space. Age-related macular degeneration, choroidal neovascular membranes, high
myopia, angioid streaks, hereditary choroidal degeneration, POHS, and tumors of the
choroid have all been identified as precipitating conditions in the development of RPE
detachment. Idiopathic cases are sometimes associated with ICSC; some believe these two
conditions to represent a continuum of a similar underlying pathology. Uncomplicated
idiopathic serous detachments of the RPE often resolve spontaneously, however, those
associated with more generalized damage to the choriocapillaris may be complicated by
hemorrhage, choroidal neovascular membrane formation, and disciform scarring.
Most patients under the age of 55 who present with small serous RPE
detachments without evidence of other retinal or choroidal disease enjoy an excellent
prognosis without intervention. This is particularly true if the lesion is outside of the
fovea and there is no associated subretinal fluid.
Older patients who manifest RPE detachment without angiographic evidence
of a choroidal neovascular membrane have a 25-30 percent chance of developing such
membranes during their lifetime, and therefore warrant careful observation as well as
weekly home monitoring with an Amsler grid.
Those patients over the age of 55 who present with associated choroidal
neovascular membranes and/or hemorrhagic RPE detachments have an exceedingly poor visual
prognosis. Focal laser photocoagulation is indicated for these patients.
Approximately 90 percent of cases of RPE detachment have
or will manifest concurrent serous retinal detachment over the natural history of the
disorder. In cases of idiopathic RPE detachment, a striking similarity with ICSC is seen
in the predisposed patient population; i.e. male, average age of 44 years, and a moderate
to severe emotional stress level.
The presentation of RPE detachment is quite
characteristic. Nonetheless, one must be sure to rule out other conditions that may appear
similar from an ophthalmoscopic perspective. These include: ICSC, malignant melanoma,
metastatic carcinoma, choroidal hemangioma, and Bests disease (vitelliform
dystrophy). History and angiography are the most helpful factors in making this
RPE detachment in patients over 55 years of age should be
considered secondary to choroidal neovascular membrane, rather than idiopathic, until
proven otherwise. Prompt fluorescein angiography is mandatory in these cases.
Other reports in this section