【Disease Name】 【Disease Name
[Standard Name].
Large vesicular keratopathy.
【English Name】 【Disease Name
Bullous Keratopathy.
【ICD-10 Code
H18.101.
【Overview】.
The disease refers to corneal stromal edema and epithelial large vesicle-like changes resulting in vision loss due to a decrease in the number of endothelial cells caused by various reasons, which cannot maintain the normal physiological function of corneal dehydration. Since the corneal epithelium is rich in subepithelial nerve endings, epithelial blisters squeeze the nerve endings, or blister rupture leads to exposure of nerve endings, which can cause symptoms of corneal irritation (and vision loss) such as tearing, photophobia, and eye pain. (Figure 1)
Pathogenesis
Etiology
Mechanical injury: (1) Cataract extraction, IOL implantation, anti-glaucoma surgery, and other internal eye surgeries, resulting in corneal endothelial injury due to contact with various instruments, water flushing, and drugs during the surgery. (2) Ocular shock injury: shock waves or direct extrusion of endothelial cells can be formed in the eye, resulting in corneal endothelial cell injury. (3) Long-term foreign body retention in the anterior chamber angle damages the corneal endothelium
Ocular diseases: (1) long-term high intraocular pressure causes loss of corneal endothelial cell function, such as the absolute phase of glaucoma, which is often accompanied by large corneal vesicles in addition to persistent high intraocular pressure. (2) Iris implantation cyst: with the increase of the cyst, it can directly compress the corneal endothelium, causing limited endothelial cell function loss. (3) Herpes simplex virus keratitis (endotheliitis): the infection is not controlled in time, resulting in massive necrosis of corneal endothelial cells. (4) Anterior uveitis: endothelial KP and atrial fluid inflammatory cell stimulation due to recurrent inflammation, endothelial cell function decreases and the number is also significantly reduced. (5) Postoperative inflammatory reaction: inflammatory reaction can occur after inner eye surgery, which can lead to endothelial cell damage in severe cases. (6) Iris corneal endothelial syndrome: an unexplained peripheral iris anterior adhesion with loss of endothelial function of the cornea.
Chemical factors: Intraocular drug injection during inner eye surgery may have toxic damage to corneal endothelial cells, and fluids with acidic or alkaline pH values can cause endothelial cell damage. There is also ocular ganglion toxicity syndrome, which is also related to this.
[Pathology].
Corneal epithelial cells are edematous, with widened cell gaps and large subepithelial vesicles with irregular surfaces. The anterior elastic layer is swollen, and the local destruction disappears. The corneal stromal layer was thickened and edematous, the stromal fiber gap was widened, and in some cases, inflammatory cell infiltration was seen, along with neovascularization and fiber proliferation. The posterior elastic layer was slightly thickened, with uneven lamellar staining, and some cases could form a double-layered posterior elastic layer-like appearance. The endothelial cells are enlarged, degenerated, sparse or even disappeared.
Diagnosis
History
Most of them have a history of ocular trauma or surgery, or a history of glaucoma, uveitis and other ocular diseases, or a history of “morning fog and evening clearing” symptoms.
Key points of symptoms
Visual changes In the early stage, the symptoms can be morning fog and evening clearing, i.e. blurred vision and foreign body sensation in the morning, relieved in the afternoon and evening. With further reduction of corneal endothelial cell count, continuous vision loss may occur.
Ocular symptoms Early stage can have ocular foreign body sensation, late stage can have ocular pain, varying in severity, such as secondary infection at the time of large corneal vesicles, extremely easy to develop corneal ulcers.
Key points of physical examination
Slit lamp examination Early stage can be mild corneal edema, the cornea is foggy and cloudy (Figure 2) .
In the late stage, corneal edema and corneal epithelial (sub)blister-like changes can be seen. Further advanced stages can develop corneal epithelial hyperplasia clouding (Figure 3).
It is also important to look for the cause of the disease, whether there is an abnormal position of the IOL, whether there is an anterior chamber implant such as an antiglaucoma valve in contact with the corneal endothelium; whether there is a history of trauma resulting in the retention of microscopic foreign bodies in the anterior chamber; and whether there is an inflammatory response in the affected eye and whether there is corneal endothelial dystrophy in the contralateral eye.
Measure intraocular pressure.
Observe for glaucomatous fundus changes; observe for macular cystoid edema or vitreous inflammation.
[Auxiliary examination
Corneal endothelioscopy or confocal microscopy Corneal endothelial cell count is reduced to varying degrees and cell morphology loses its hexagonal shape.
Ultrasonic corneal thickening When corneal edema and clouding are obvious, and endothelial examination by corneal endothelial microscopy is not possible, ultrasonic corneal thickening is very important, and the disease can be diagnosed when the central corneal thickness is generally >620 μm.
[Differential diagnosis
Acute hypertension: This can be acute closed-angle glaucoma or other causes of acute elevation of intraocular pressure, which can lead to corneal foggy edema. These edemas can be transient, and the cornea will return to clarity after the IOP is controlled. If the IOP is chronically high, it can also lead to corneal endothelial dysfunction, again requiring treatment.
Herpes simplex virus endotheliitis: The endothelial form of herpes simplex virus keratitis can cause corneal disc edema, mostly centrally located, with clear peripheral corneas. KP is visible and will regain transparency with hormonal and antiviral medications. There is a history of recurrent episodes (Figure 4).
Fuchs’ corneal dystrophy: It occurs mostly in the 50s and 60s, is more common in women, and is often autosomal dominant, but can also be recessive. The posterior elastic layer is seen as a tiny redundant mass called corneal droplets, which fuse to form a gold leaf-like appearance or an orange peel-like appearance.
Posterior polymorphic corneal dystrophy: an uncommon autosomal dominant disorder with significant diversity of lesions in the posterior elastic lamina and endothelium, with significant variation in patient signs and symptoms.
Iris corneal endothelial syndrome: often monocular, non-hereditary, commonly seen in middle-aged women. It is a group of secondary closed-angle glaucoma with the same features, and is associated with typical iris abnormalities in addition to corneal endothelial lesions.
【Treatment
【Drug treatment】.
Treatment of primary disease: endothelial loss of compensation due to high intraocular pressure should be controlled before further treatment. Those with anterior chamber inflammation should have the inflammation controlled first. Surgical removal of foreign body with anterior chamber foreign body
Symptomatic treatment: Mild cases can be treated with local application of hypertonic agents and corneal nutrients, such as topical 5% sodium chloride eye drops or hypertonic glucose water dots; if combined with high intraocular pressure, anti-glaucoma drugs can be applied in combination. If the corneal epithelial vesicle ruptures and corneal epithelial defect occurs, topical antibiotic eye ointment can be applied to the eye; corneal bandage lens can be worn to reduce symptoms and promote epithelial repair.
[Surgical treatment
Penetrating keratoplasty or corneal endothelial transplantation can effectively treat large vesicular keratopathy; conjunctival flap masking or amniotic membrane masking is usually indicated for cases with painful eyes and low latent visual acuity.
Other treatments]
There are also treatments such as PTK laser photocoagulation combined with amniotic membrane coverage, lamellar keratoplasty, and interlaminar biofilm implantation in the cornea.
Common complications
Large corneal vesicles, especially when they rupture, can be followed by corneal infection and prone to corneal ulcers.
Prognosis]
The prognosis of corneal transplantation is generally good, especially for corneal endothelial transplantation, which has emerged in recent years, with low incidence of immune rejection and better recovery of vision (Figure 5, 6).
[Follow-up].
The corneal macula was reviewed 24-48 h after rupture until the epithelial defect healed. Then it was reviewed every 1-6 months according to the symptoms.
【Prevention】
Glaucoma, patients with high intraocular pressure should have timely and effective control of intraocular pressure, and the operation time in the anterior chamber should be minimized during internal eye surgery, and perfusion solution containing endothelial cell protective components can be applied.