INTRODUCTION:
- Terms such as choroidal effusion,
ciliochoroidal effusion, choroidal detachment, and ciliochoroidal detachment
are used for somewhat similar entities and occasionally mentioned
interchangeably in the literature.
- However, choroidal detachment is
a broader term than choroidal effusion.
- The terms choroidal effusion,
ciliochoroidal effusion, and serous choroidal detachment describe the same
entity.
- A choroidal detachment (CD) is
defined as abnormal presence of fluid or blood in the suprachoroidal space.
- The suprachoroidal space is the
potential space between the choroid and the sclera.
- CD is of in two types—serous and haemorrhagic.
Serous choroidal detachments, also known as choroidal effusions, are a frequent
complication of glaucoma surgery.
- Glaucoma surgery is the most
common cause of choroidal detachments, which may occur in 3-34% of
trabeculectomies and 3%-35% of glaucoma implant procedures. Newer techniques
such as MIGS have lower incidence of CDs.
- Other causes of choroidal
detachment include infection (e.g., herpesviruses, human immunodeficiency
virus), inflammation (e.g., posterior scleritis, drug-induced cyclitis,
Vogt-Koyanagi-Harada syndrome), malignancy (e.g., primary intraocular lymphoma
or metastatic carcinoma), or episcleral venous congestion (e.g., Sturge-Weber
syndrome, dural arteriovenous fistula.
- Uveal effusion syndrome is a rare
cause of idiopathic choroidal effusions that may involve impaired posterior
segment drainage and congenital anomaly of the sclera resulting in scleral
thickening.
- Following glaucoma surgery
hypotony may occur, resulting in pressure-driven osmotic shifts of serous fluid
from the choroidal capillaries into the suprachoroidal space due to decreased
vascular permeability.
- Due to the increased use of antimetabolites, there
is increased incidence of persistent choroidals, complicating the postoperative
course with prolonged visual compromise, shallow anterior chambers, cataract
formation, and bleb failure.
- Choroidal effusions further potentiate
hypotony due to reduced aqueous humor production.
- Disturbances in the hydrostatic
and oncotic pressure gradients and high permeability of the choriocapillaris
result in serum or blood accumulation in the suprachoroidal space. This fluid
accumulation leads to thickening of the choroid and the formation of a
fluid-filled suprachoroidal layer.
- Low IOP or a disruption to
uveoscleral outflow also promotes fluid accumulation within the suprachoroidal
space.
SEROUS CHOROIDAL DETACHMENTS:
- Serous choroidal effusions result
from transudation of serum into the suprachoroidal space.
- Starling’s equation explains the
movement of fluid between the plasma and interstitium. According to this
equation, the movement is determined by the relative hydrostatic and oncotic
pressures of these compartments.
- Drastic fall in IOP such as that
occurring following incisional glaucoma surgery allows fluid to accumulate in
the interstitial space, due to a higher capillary pressure relative to
interstitial pressure.
- Other factors which can
contribute to the formation of choroidal effusions include:
- Inflammation-induced increases in
choroidal capillary permeability and high hydrostatic pressure in the choroidal
vascular plexus secondary to hypertension.
- Accumulation of proteinaceous
serum in the suprachoroidal space disturbs the equilibrium between the oncotic
pressure in the interstitium and plasma limits uveal resorption.
- These non-resolving choroidal
effusions may result in serous retinal detachment due to failure of the retinal
pigment epithelium pump mechanism.
RISK FACTORS FOR SEROUS CDs:
SURGERY
Glaucoma
filtration surgery (GFS) [e.g., trabeculectomy or MIGS implantation].
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Glaucoma
Drainage Device (GDD) implantation [especially valved devices].
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Laser
peripheral iridotomy.
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Retinal
surgery (pars plana vitrectomy or scleral buckling procedure).
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Any
glaucoma surgery with intraoperative or postoperative hypotony.
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OCULAR MEDICATIONS
Antimetabolite
(mitomycin C or 5-fluorouracil) augmented GFS especially in the setting of
prolonged hypotony.
|
Topical
aqueous suppressants (e.g., timolol and dorzolamide) after trabeculectomy or GDD
implantation.
|
Topical
prostaglandin analogs (e.g., latanoprost, travoprost, and bimatoprost) have
been associated with late choroidal effusions following cataract extraction
or GFS.
|
Intravitreal
injection of ocriplasmin has also been reported as a cause of choroidal
effusion.
|
SYSTEMIC MEDICATIONS
Carbonic
anhydrase inhibitors.
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Anticoagulants.
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Topiramate.
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Tamsulosin.
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Sulfonamides
(e.g., chlorthalidone, sulfamethoxazole-trimethoprim, indapamide)
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Antidepressants
(e.g., escitalopram, venlafaxine, bupropion)
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Angiotensin
receptor blockers (e.g., losartan)
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Chemotherapeutics
(e.g., docetaxol and gemcitabine)
|
Pergolide
(a dopamine agonist used to treat Parkinson’s disease)
|
Drugs
of abuse (e.g., 3,4-methylenedioxymethamphetamine a.k.a. “ecstasy” or MDMA)
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PRE-EXISTING CONDITIONS
Nanophthalmos
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Sturge-Weber
syndrome
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Hypermetropia
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Systemic
hypertension
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Atherosclerosis
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Diabetes
mellitus
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Prior
cataract surgery
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Glaucoma
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Diffuse
choroidal hemangioma
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Older
age
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History
of choroidal detachment in the other eye
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TREATMENT-RELATED FACTORS
Lower
postoperative IOP
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Full-thickness
filtration surgery
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Ocular
inflammation
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Aqueous
suppressant therapy
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PRIMARY PREVENTION OF CDs:
- Acute glaucoma surgery-related CDs
may be prevented by minimizing hypotony, bleeding, and inflammation
intra-operatively and post-operatively.
- Pre-operative medications
(Carbonic anhydrase inhibitors or osmotic agents) can be used to reduce IOP.
- Intra-operative proper and
meticulous surgical technique would avoid the development of CDs.
- The scleral flap should be constructed
at 50-75% scleral depth.
- To prevent early hypotony,
multiple sutures can be placed in the scleral flap.
- Suture release should be delayed
by at least one week.
- A stable anterior chamber can be
achieved with a cohesive ophthalmic viscosurgical device or anterior chamber
maintainer.
- Antimetabolites should be used
carefully, as their use can increase the risk of CD.
- When non-valved GDDs are
implanted, the tube should be ligated with dissolvable polyglactin suture intra-operatively,
or two-stage surgery should be performed with the tube remaining in the
subconjunctival space outside the eye and being placed into the anterior
chamber at a later time.
- Proper water-tight closure of the
conjunctiva should be done at the end of the surgery (it can be confirmed by
placing a fluorescein strip over the conjunctival wound and doing the Seidel’s
test)
- Releasable sutures and
restrictive devices may be used to reduce hypotony, but these tools do not
prevent choroidal detachment completely.
- Post-operative care: Topical and
systemic aqueous suppressants should be discontinued post-operatively, and early
laser suture lysis should be avoided.
DIAGNOSIS:
- Post-operative CDs develop around
2-5 days after surgery.
- Small, peripheral effusions are
asymptomatic and usually resolve spontaneously.
- Large effusions affect peripheral
vision and may occasionally be large enough to obstruct the visual axis.
- Anterior displacement of the
lens-iris diaphragm causes a myopic shift and results in secondary angle
closure. Appositional choroidal detachments, which extend from the optic nerve
to the lens, are more likely to obscure central vision and cause secondary
angle closure.
- Young patients are more prone to
develop hypotonic maculopathy.
- Persistent hypotonic maculopathy leads
to permanent vision loss.
SIGNS & INVESTIGATIONS:
- The AC can be of normal depth,
shallow, or flat.
- AC shallowing is typically
diffuse, as pressure from choroidal swelling is indirectly transmitted to the
posterior surface of the lens via the vitreous body.
- IOP can be normal, low, or
elevated in the setting of choroidal detachment. Typically, low IOP accompanies
serous choroidal detachments.
- Fundus examination reveals a multi-lobed
appearance. Up to four smooth lobes may be visualized, extending to the vortex
veins.
- The fluid-filled lobes of serous
detachments demonstrate transillumination. Conversely, hemorrhagic detachments
do not transilluminate. Choroidal detachments can be distinguished from retinal
detachments based on their more anterior location, extension to the ora
serrata, and unique morphology resulting from the choroid’s strong attachments
at the sites of the vortex veins.
- B-scan ultrasonography can
distinguish serous vs. hemorrhagic CD. Serous detachments appear as rounded,
peripheral lobes filled with echo-lucent fluid.
- Ultrasound biomicroscopy (UBM)
can be used to visualize anterior rotation of the ciliary body associated with
CDs.
- UBM can serve a helpful
diagnostic role in confusing cases, as it can distinguish secondary angle
closure due to choroidal effusions or a choroidal tumor from a pupillary block
angle-closure mechanism.
- Occasionally, wide field fundus
photography and swept source optical coherence tomography can also be used to
detect and monitor choroidal detachments, with improved detection of peripheral
CD.
DIFFERENTIAL DIAGNOSIS:
Retinal
detachment
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Choroiditis
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Central
serous chorioretinopathy
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Choroidal
melanoma
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Uveal
effusion syndrome
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Idiopathic
ciliochoroidal effusion
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Pseudophakic
or aphakic pupillary block
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Malignant
glaucoma
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MANAGEMENT:
MEDICAL MANAGEMENT
Most CDs resolve spontaneously.
Surgical interventions have been found to cause more visual worsening compared
to conservative/medical treatment.
Initially, CDs can be treated
with steroids and long-acting cycloplegics such as atropine and
cyclopentolate).
Topical steroids are used in an
effort to increase IOP and control any inflammation which may be contributing
to CD. In severe cases that are refractory to topical medications, systemic
steroids may be used.
Any medications promoting ocular
inflammation should be discontinued.
SURGICAL MANAGEMENT
In case of wound leaks, a bandage
contact lens or suture(s) placed with a tapered (blood vessel) needle can be
used to close leaking areas, if the AC is still formed and deep.
If there is an over-filtrating
trabeculectomy, transconjunctival sutures may be placed using a tapering needle
to secure the scleral flap.
The AC can be reformed by
inserting a cohesive or ultracohesive viscoelastic material (e.g., Healon 5 or
Healon GV, respectively) through the already-formed intraoperative paracentesis
track. In some instances, multiple viscoelastic injections may be necessary to
maintain AC depth and IOP.
Injections are performed under
topical anesthesia, and IOP should be measured afterward to monitor for ocular
hypertension due to over-installation of viscoelastic.
SURGICAL DRAINAGE OF CHOROIDAL
DETACHMENTS IS INDICATED IN THE FOLLOWING CASES
Flat
anterior chamber
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Persistent
corneal edema with a shallow anterior chamber
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Significant
eye pain
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Elevated
IOP refractory to medical management
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Longstanding
choroidal effusion
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Appositional
choroidal effusion and/or apposition of the central retina
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Hemorrhagic
choroidal detachment
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Decreased
vision
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- Drainage procedures involve
deepening the AC while choroidal fluid egresses out of a full-thickness scleral
incision behind the limbus.
- First, a tangential conjunctival
incision is made 3-6 mm from the limbus in the quadrant where the effusion is
most substantial; a 2-3 mm radial sclerectomy is then placed 3-4 mm posterior
to the limbus.
- Choroidal fluid egresses
spontaneously and/or with assistance by holding the incision open with forceps
or gently depressing the adjacent sclera with a cyclodialysis spatula.
- Finally, the AC is deepened by
injecting saline solution via a paracentesis incision.
- This procedure has a reported 77%
success rate by 12 months follow-up, defined as complete resolution of the
choroidal detachment, normalization of anterior chamber depth, and resolution
of hypotony. Most patients had improved visual acuity as well.
- Cataract extraction is part of
treating CD. When a visually significant cataract is present in combination
with CD, then combined cataract extraction and CD drainage should be performed.
Cataract extraction may be considered for non-resolving choroidal detachment,
as this may in some cases result in resolution.
PROGNOSIS:
Serous choroidal effusions are
usually benign and do not significantly reduce visual acuity.
A large, persistent effusion,
however, may cause significant morbidity, particularly when it is associated
with hypotony maculopathy or serous retinal detachment.