INTRODUCTION idiopathic serous detachment of the maculaINTRODUCTION idiopathic serous detachment of the macula

INTRODUCTION 

Central serous chorioretinopathy (CSC) is an
idiopathic serous detachment of the macula caused by a focal leakage of the
choroidal interstitial fluid through the retinal pigment epithelium.1 It usually affects one eye of healthy young males and
symptoms consist mainly of loss of central vision, image distortion (primarily
micropsia), color desaturation and prolonged dark adaptation. Maumenee has
described the classic fluorescein angiographic appearance of central serous
chorioretinopathy a leak through the retinal pigment epithelium which is
evident as a focal point of hyperfluorescence that usually expands
symmetrically or less commonly asymmetrically with a ‘smoke stack’
configuration as the dye leaks into the subretinal space. Slow spontaneous
resolution with improvement in visual acuity usually occurs over a period of
few months. While the duration of detachment or the rate of recurrence may be
shortened by treatment with photocoagulation, the treatment does not have
any significant effect on visual acuity

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Review
of Literature

 

Central
serous chorioretinopathy (CSC) was first described by Von Graefe in 1866. He
named it recurrent central retinitis. Since then it has been variously named
and described by different authors as there has been a general disagreement
regarding the primary site and etiology of this disorder. Horniker named it
central angiospastic retinitis while Walsh and Sloane termed it
as idiopathic flat detachment of the macula. Klien attributed it to
autonomic nervous system dysfunction and classified the disease into three
groups : central angiospastic retinopathy, central angiospastic
chorioretinopathy and central angioneurotic chorioretinopathy. The name central
serous retinopathy, first used by Bennett in 1955, was the accepted term
for this disorder till 1965 when Maumenee utilising fluorescein angioscopy,
identified the retinal pigment epithelium(RPE) as the primary site of
pathology. Gass in 1967 suggested the term idiopathic central serous
choroidopathy for this condition based on the fluorescein angiographic
findings. Participation of the choroid as well as the retina (central
chorioretinopathy) is suggested by the presence of fluid, as seen by the
slit-lamp, between the retina and the pigment epithelium and by the early
appearance of pigment disturbances in the macular area, a feature which becomes
Striking soon after the resolution of the lesion. Histological examination
shows a localised exudative detachment of the retina from the pigment
epithelium and often a detachment of the latter from the choroid. 

 

CSC occurs in young to middle
aged individuals of about 20 – 45 years of age, with a male predominance of 8
to 10 : 1. The condition is common in whites, Hispanics and Asians and
relatively uncommon in blacks. Patients may have associated migraine like
headaches and may have various personality traits including type A personality,
hypochondria & hysteria. Patients present with complaints of blurred
vision, metamorphopsia, micropsia, paracentral scotoma and chromatopsia.
Visual acuity can range between 6/6 and 6/60, which typically improves
with a small hyperopic correction. Anterior segment and vitreous cavity
are normal. The condition is not associated with any other
recognized ocular or systemic disease. 

Gass in 1967 provided a classic description of
the disease. Fundus examination in typical cases shows a well defined round or
oval area of shallow serous retinal detachment in the macula associated with
attenuation or absence of the normal foveal reflex. The detached retina is
usually transparent and of normal thickness and the subretinal fluid is usually
clear. The posterior surface of the detached retina may be covered by multiple
yellowish dot like precipitates and in 10% of cases, the subretinal space
may be partly filled with a grey serofibrinous exudate.

 

One or more discrete round or
oval yellowish grey areas of detached RPE may be observed beneath the superior
half of macular detachment or may even be present above the macular detachment. Occasionally, instead
of a discrete RPE detachment, there may be an irregular round or flask shaped
area of varied depigmentation of the RPE beneath the retinal detachment which
is usually seen in recurrent forms
of the disease. In the fovea, a small yellow round spot may be seen due to increased visibility of
xanthophyll. 

Yanuzzi et al have described extramacular
inferior hemispheric RPE atrophic tracts extending from the paracentral and
peripapillary areas to the equator or ora serrata related to an antecedent
retinal detachment. Such eyes are particularly prone to recurrent macular
detachments and are usually associated with retinal capillary telangiectasia,
retinal capillary leakage, cystoid macular oedema, choroidal neovascular
membrane (CNVM), disciform scar formation and poor visual prognosis. 

An atypical presentation of CSC is that of multiple
bullous serous retinal detachments with areas of shifting subretinal fluid
often associated with subretinal fibrinous exudate and multiple serous RPE
detachments. Chronic idiopathic CSC is characterized by multiple sites of
prolonged and recurrent serous retinal detachment in one or both eyes
which is initially juxta papillary, peripheral macular or extramacular and later progresses to form a localized
detachment of macula. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fluorescein angiography
features:

 

Maumenee first described the
classic RPE leak noted on fluorescein angiography. Early phases show a focal
dot like hyperfluorescence representing the leakage of dye from choroid through
the RPE which gradually accumulates beneath the sensory retinal detachment.

 

Two types of leakage may occur,
the first being the classic or ‘smoke stack’ type first described by Shimizu
& Tobari in 1971 which occurs in 7 – 20% cases. The dye first ascends
superiorly and then spreads laterally this occurs secondary to convection
currents and a specific gravity gradient existing because of different protein
concentrations between the subretinal fluid and the dye entering the detachment. The majority of cases (upto
93%) however show a Leakage point with uniform dye filling (ink blot
type).

Other rare leakage patterns include a diffuse
leakage without an obvious leakage point, a healed CSC scar that still leaks and a RPE detachment with a
leak. Failure to detect a leak angiographically may indicate presence of
an extramacular leak usually located
superiorly or a healed leak. 

Spitznas and Huke have studied the number, shape
and topography of leakage points in 430 eyes with CSC. Single point of leakage
was found in the majority of cases (71.6%) whereas upto 7 leakage points
were present in 0.2% cases. The most common location was in the upper
nasal quadrant (33.2%) followed by lower nasal (21.2%) upper temporal (19%) and
lower temporal (14.8%) quadrants. Most leakage points were within 1mm from the
fovea and in 10.3% cases, the leakage point was found in the papillomacular
bundle(PMB). In recurrent cases the new leakage point was within 1 mm of
initial leakage in 80% of cases. 

Other associated angiographic findings include a
mottled hyperfluorescence produced due to RPE changes secondary to old CSC
episodes and areas of well demarcated hyperfluorescence which does not
increase in size indicating an RPE detachment.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pathophysiology 

The pathophysiology of CSC is highly
controversial. There is also an uncertainty regarding the actual site of disease
the choroid or RPE. Spitznas suggested RPE damage via an immunologic,
infectious, circulatory or neuronal mechanism which causes the RPE to
secrete ions in a chorioretinal direction. Duke Elder believed the
condition to result from toxic and allergic phenomena. Marmor suggests that
central serous chorioretinopathy has more diffuse RPE abnormalities leading to
increased choroidal permeability which overwhelms the neighbouring RPE
cells. Yanuzzi suggests a multifactorial cause consisting of genetic, environmental and behavioural factors. Other
contributory factors like elevated catecholamine levels, pregnancy and organ
transplantation have also been reported. 

Gass believes that the transient neuroepithelial
detachment may result from physiologic decompensation at one or several focal
sites of minor congenital structural defects in the choriocapillaris and
Bruch’s membrane during vasomotor stress. The apparent propensity for these
lesions to occur in the macular region is probably related to differences in
haemodynamic stress occurring in this area as the result of abundant short
ciliary arterial blood supply to the capillary bed of the macular region.
Indocyanine green video angiography has provided additional evidence of
abnormal choriocapillary permeability that may be more extensive than that
indicated by fluorescein angiography. 

 

 

 

 

 

 

Natural History

 

The prognosis for the majority
of patients with CSC for spontaneous resolution of the detachment and
return of visual acuity is excellent. 

Klein et al, noted spontaneous resolution
without any treatment in all the 34 eyes in their prospective study. The
average resolution time was 3 months. All patients had visual acuity of 20/40
or better at presentation and 94% eyes had visual acuity of 20/30 or
better at follow-up examination (average 23 months). These authors concluded
that CSC was a benign and self limiting condition which seldom required
laser PHC. In a similar study by Gilbert and associates, approximately 75% of their
patients had 20/20 vision at follow-up examination. Patients with initial
visual acuity of 20/20 remained at that level and patients with initial visual
acuity of less than 20/30 gained an average of 2 – 3 Snellen lines
at follow up. 

Resolution of the detachment occurs by 3 to 4
months. An improvement in visual acuity can occur upto 12 months following
resolution of the detachment. Even after complete resolution, patients may
still have minor visual complaints like decreased color vision, relative
scotomas, metamorphopsia, decreased contrast sensitivity and nyctalopia. There
is a great variability in the biomicroscopic appearance of the macula after
resolution of the retinal detachment. In some patients, fundus may regain a
normal appearance. Most patients, however, demonstrate evidence of irregular
depigmentation and atrophy of the RPE in the area of the detachment
especially in recurrent cases. 

In a small number of cases, the visual outcome
may not be as favourable. After a long term study of 14 eyes, Levine and associates
concluded that CSC may be a diffuse progressive bilateral RPE disorder, with
non-leaking RPE defects present in the affected eye in all cases and in fellow
eyes in 42% of cases. In a series by Yanuzzi et a1,out of 32 CSC eyes with
peripheral RPE atrophic tracts, 25% had final visual acuity of 20/200 or
worse. 

 

Recurrences are an additional
problem in CSC with 20 – 30% 0f patients having one or more recurrences.
Klein et a1 recorded historical and clinically documented recurrences in 45
percent of patients in their series. Gilbert and associates reported that about
half of both treated and untreated patients in their study had recurrent or
presumed persistent detachments.

Thus although the visual
prognosis is usually very good, a small subset of patients may have a poor
visual outcome because of uncommon complications of the disease such as
peripheral tracts and detachments, macular oedema,
choroidal neovascularization and RPE atrophy.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Differential Diagnosis 

Although the clinical and fluorescein angiographic
features of CSC are often classic, several other conditions should be
considered in the differential diagnosis. Serous detachment of retina in
the macular region may develop secondary to ocular conditions like : 

Optic disc pit. 

Choroidal tumors (eg. haemangioma, metastatic carcinoma,
melanoma)

Choroidal inflammatory diseases (eg.
Sarcoidosis, Harada’s disease, sympathetic ophthalmia, presumed ocular
histoplasmosis syndrome, posterior scleritis)

 

Traction maculopathy caused by incomplete posterior
vitreous detachment.

 

Ocular hypotony, macular hole

 

Senile macular degeneration

 

Following ocular contusion and scleral buckling
procedures.

 

Transient exudative macular detachment can also occur
in association with systemic conditions like malignant hypertension, toxaemia
of pregnancy, collagen vascular diseases and disseminated intravascular
coagulopathy.

 

 

 

 

 

 

 

 

Treatment 

No medical treatment has been shown to be
effective for patients with CSC. Tranquilizers, sedatives and barbiturates have
been advocated to reduce the psychogenic component of this disorder.
Acetazolamide therapy may cause earlier resolution either by increasing
RPE pump or by altering choroidal haemodynamics. Systemic administration
of corticosteroids appears to aggravate or even precipitate CSC in some
patients particularly those receiving corticosteroids for the treatment of
collagen vascular or other systemic diseases.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Laser
photocoagulation : 

The role of laser photocoagulation in the
treatment of CSC is highly controversial. Photocoagulation acts by
altering the diffusion barrier of the retinal Pigment epithelium which
hastens movement of protein and fluid out of subretinal Space into choroid.
Laser destroys the unhealthy RPE thus stopping the secretion of fluid from beneath the neurosensory retina.
It permits ingrowth of surrounding healthy RPE which pumps out the subretinal
fluid to cause resolution of the detachment. The resulting scar also helps
to transport fluid back in to the choriocapillaris.

Laser PHC to the leakage site has been advocated
for CSC patients. Gass is regarded as one of the pioneers to recommend the use
of PHC to the site of RPE detachment or RPE leak in CSC as it was shown to produce
resolution of the detachment within 3 – 4 weeks in most patients. 

Watzke et al showed that ruby laser could
shorten the duration of disease by 2 months but had no effect on final
visual acuity or recurrence rate. 

Spitznas conducted a non-randomized study of 139
untreated and 109 xenon arc treated cases of CSC. Treatment was applied
directly to leakage site or indirectly to the edge of the detachment. The final
visual acuity (median 20/25) was identical in all the three groups. The
duration of detachment was 80 days in the untreated group compared to only 10
days in the treated group. Recurrences were noted in 45% of untreated patients,
38% of indirectly coagulated patients and only 8.8% of directly treated
patients. He concluded that directly treated patients had a shortened
duration of disease and five times less recurrence rate. 

 

Similar results
were reported by Robertson and Ilstrup who carried out a prospective randomized
trial of argon laser PHC in 42 eyes with CSC. The average duration of
detachment was reduced to about 2 months in directly treated cases. 

Gilbert et a1 did not find any difference in
final visual acuity or recurrence rate in argon laser treated and
untreated patients in their series. 

Indirect treatment has also been advocated for
CSC patients especially if the leak is near the foveola or in the PMB. However,
Robertson and Ilstrup have demonstrated the inefficacy of indirect treatment.
Watzke and colleagues have shown that indirect PHC was inferior to direct
treatment. This has been corroborated by Spitznas in his study where the
duration of disease was less in indirectly treated patients when compared to
untreated individuals but the recurrence rate was lower only for directly
treated patients. 

The consensus from the preceding studies is that
direct laser debridement of the RPE in the area of leakage shortens the course
of the disease but does not affect the final Visual acuity or recurrence
rate. 

Gass has defined the following criteria for
photocoagulation in CSC:

 

1. 
Allow
4 months for spontaneous resolution if the patient has had no
previous history or ophthalmoscopic evidence of previous detachment.

 

2. 
Wait
6 months or longer before PHC if the RPE leak is less than ¼ DD from the
fovea. 

 

3. 
Allow
1 month for spontaneous resolution in patients with a history of several episodes
of detachment in the same eye, if after each episode the patient has regained
normal macular function. 

 

4. 
When
the leak is at least ¼ DD away from the centre of the fovea, prompt PHC is
justified 

a. If detachment has been present for 4 months
or longer. 

b. If the patient has evidence of permanent loss
of acuity or paracentral visual field in either eye secondary to previous
episodes of detachment. 

c. If for occupational reasons the patient
cannot work because of the visual dysfunction caused by the
detachment. 

The leakage point must be well defined and
should be at least 400 microns from centre of the foveal avascular zone (FAZ).
Low intensity burns (100 – 200 micron Spot size, 0.1 – 0.2 second duration, 100
– 200 mw ) should be applied to avoid risk of post treatment
complications. To avoid large paracentral scotomas, a large RPE detachment
extending within 750 microns of the central foveal area should not be
completely covered with PHC. Small applications of moderately intense PHC
applied to the extrafoveal margins of the RPE detachment usually cause
resolution of the pigment epithelial and retinal detachment. Presence of
choroidal neovascularization should be ruled out before treatment as it
requires more intense treatment. Xenon arc, ruby laser and argon laser
have all been used to treat CSC. Kryton may also be beneficial as it is more
tissue selective.

 

Laser treatment itself can
result in complications like traction lines and iatrogenic CNVM apart from the
potential of foveal damage. There is a danger of coagulating a macular
venule or arteriole, resulting in foveal ischemia and intraretinal fibrosis.
Choroidal neovascular membranes have been known to occur following laser PHC as
seen by Schatz in 27 cases in his study. Tsukahara et al have reported
haemorrhagic and exudative detachment of the posterior pole after
photocoagulation for CSC. However such complications have not
been reported in other large series of treated CSC cases.