Bullous keratopathy is a pathology of the cornea characterized by swelling of the shell, damage to the epithelial layer with the formation of specific “bulls”. Clinical symptoms are represented by a decrease in visual acuity, pain syndrome, sensation of a foreign body in the eye, photophobia, increased tearfulness. Biomicroscopy, keratopachimetry, ophthalmoscopy, ultrasound, visometry, tonometry, gonioscopy are performed for diagnosis. Conservative therapy is indicated on the I-II art. It is possible to use contact lenses, phototherapeutic keratectomy, crosslinking. Patients at stage III-V undergo layered or through keratoplasty.
H18.1 Bullous keratopathy
Bullous keratopathy (secondary endothelial-epithelial dystrophy) in 80% of cases is caused by surgical interventions on the anterior part of the eyeball. After IV-V art. treatment, visual acuity can be restored by no more than 30%. According to statistics, graft rejection reactions are observed in 6% of patients. It is possible to stop the pain syndrome in 91% of cases. For 8% of patients, a recurrent course of pathology is characteristic, which is manifested by the formation of single bullae and erosive defects on the surface of the cornea. The disease is widespread everywhere. Men and women get sick with the same frequency.
Pathology has an acquired character, but it is often possible to establish a hereditary predisposition to this disease. Genetic mutations and the type of inheritance of keratopathy have not been studied. The main causes of development:
- Fuchs endothelial dystrophy. There is a genetically determined apoptosis of the cells of the posterior epithelium, which leads to an increase in its permeability and the appearance of pathology.
- Eye infections. The disease develops when the cornea is affected by herpetic or syphilitic nature. The detection of specific turbidity in newborns suggests intrauterine infection.
- Corneal injury. Damage due to mechanical injury or burn provokes increased exudation, which causes the formation of typical “bulls”.
- Iatrogenic effects. Pathology may occur in the early postoperative period after cataract phacoemulsification or implantation of intraocular lenses.
The mechanism of the disease development is based on a violation of the function of the endothelial and epithelial layers of the cornea. An increase in the permeability of the endothelium leads to the impregnation of tissues with intraocular fluid from the anterior chamber. Due to the accumulation of transudate on the surface layer, specific bubbles or “bulls” are formed. Chronic edema significantly disrupts trophic processes. When an inflammatory component is attached, the organization of the exudate leads to the formation of persistent turbidity. Thickening of the cornea entails secondary damage to nerve fibers, pain syndrome occurs. The decrease in visual acuity is caused, on the one hand, by a violation of the permeability of the optical media of the eye, on the other hand, by narrowing and deformation of the pupil.
There are congenital and acquired forms. The risk group for the development of pathology includes persons who have a transparent cornea of normal thickness with an endotheliocyte density of 320-510 cells / mm2. In clinical ophthalmology, a classification is used, according to which the following stages of the disease are distinguished:
- I – small areas with reduced corneal transparency and uneven arrangement of endothelial cells are visualized. The thickness of the shell does not exceed 0.7 mm.
- II – transparency is reduced moderately at a thickness of 0.7-0.79 mm. The cornea is evenly covered with an endothelial layer due to pronounced cell hypertrophy. The number of endotheliocytes is reduced.
- III – significant violation of transparency. The average thickness exceeds 0.8 millimeters. Endothelial cells connect to each other only thanks to the processes.
- IV – the average thickness is 0.97 mm. Separate groups of endotheliocytes are identified. Transparency is drastically reduced.
- V – pronounced corneal opacity is visualized, the thickness of which exceeds 1.15 mm. Single cells are determined.
At the first stage, patients occasionally note a feeling of discomfort in the eye socket, accompanied by tearfulness. Visual dysfunction does not occur. There are no external changes in the iris. The second stage is characterized by a feeling of a foreign body, periodic redness of the orbital conjunctiva. There is a slight decrease in visual functions. At 3 art. patients complain of increased lacrimation, photophobia. There is discomfort resembling a feeling of pain, a foreign body or “sand” in the eyes and under the eyelids. Stretching of nerve fibers leads to a pronounced pain syndrome of a stabbing nature. Visual acuity is sharply reduced.
At stage 4, a severe headache joins, which radiates into the brow arches, temporal and frontal lobes. The progression of visual dysfunction leads to the appearance of “fog” or “shroud” in front of the eyes. The terminal stage is accompanied by a pronounced pain syndrome, a decrease in visual functions up to light perception. Patients note that the use of contact methods of correction of visual impairment does not make it possible to achieve the desired results. In addition to the general symptoms, due to pronounced edema, conjunctival hyperemia and pupil deformation, a cosmetic defect is formed.
At stage 1, the development of complications is not characteristic. At stage 2, recurrent iritis is often diagnosed. Stage 3 is complicated by iridocyclitis, stage 4 – clouding of the lens, retrocorneal film. A common phenomenon in bullous keratopathy is superficial keratitis. When the posterior segment of the eye is affected, multiple synechiae are formed, there is a detachment of the retina. Secondary glaucoma develops at the terminal stage. The most unfavorable outcome of the disease is complete blindness, which, under the condition of severe pain syndrome, requires enucleation.
Examination of a patient with a bullous form of keratopathy involves an external examination and the use of special diagnostic methods. Visually, the ophthalmologist determines persistent opacity of the anterior part of the eyes, often in combination with hyperemia of the orbital conjunctiva. The complex of ophthalmological studies includes:
- Biomicroscopy of the eye. At the initial stage, local edema of the endothelial layer, single folds on the descement membrane are detected. 2 art. is characterized by persistent limited swelling, diffuse spraying of pigment, multiple folds. At the next stage, in addition to the above-described manifestations, there is an injection of conjunctival vessels, signs of superficial keratitis, erosive defects, increased neovascularization. At 4 tbsp. edema spreads to all layers. The final stage is characterized by vascular opacities of different densities. The cornea is replaced by dense scar tissue with focal ulceration.
- Keratopachimetry. Signs of local or diffuse edema are determined. The thickness of the cornea in the central part varies from 600 to 1500 microns.
- Gonioscopy. At the fifth stage, obliteration of the anterior chamber angle is detected, which is caused by the organization of exudate and the deposition of pigment granules. Iridocorneal junctions are visualized. Watery moisture is transparent, contains vitreous fibrils.
- Visometry. Visual acuity is often in the range of 0.1-0.3 dptr. With a severe lesion, only light perception is preserved.
- Ophthalmoscopy. Ophthalmoscopic examination is possible only at stages 1-3 of the disease. The reflex received from the fundus is pink, less often gray. Signs of retinal detachment are characteristic.
- Ultrasound of the eyes. Posterior synechiae and pupillary exudative film are visualized at stage 3. It is used in all patients for 5 art. due to the overgrowth of the pupillary opening. Turbidity or destruction of the vitreous body may be detected.
- Non-contact tonometry. With a total lesion, there is an increase in IOP, which is due to a violation of the outflow of intraocular fluid.
Differential diagnosis is performed with primary Fuchs keratopathy and keratitis. In Fuchs’ disease, the process is two-sided, there are no surgical interventions in the anamnesis, there is a genetic predisposition. During ultrasound, signs of damage to the eyeballs are not detected. Unlike bullous keratopathy in keratitis, edema is local, an inflammatory infiltrate is detected. The epithelium is absent only in the infiltrate area. According to keratopachimetry, the thickness of the cornea does not exceed 800-1000 microns, signs of its thinning are less often determined. Patients often note the relationship between the development of keratitis and inflammatory diseases, micro-injuries, non-compliance with hygiene rules.
Therapeutic tactics are determined by the stage of pathology and the severity of secondary changes in the eyeball. All patients with bullous keratopathy are shown keratoprotective therapy, which is based on the appointment of artificial tear preparations, sodium hyaluronate, dexpanthenol. An important role is assigned to the prevention of infection. The treatment package includes:
- Drug therapy. Antibacterial and antihypertensive drugs are used. Instillations of antibiotics are carried out throughout the entire period of the disease to prevent keratitis. Local hypotensive therapy is indicated with an increase in intraocular pressure, the development of a clinical picture of ocular hypertension and secondary glaucoma. Instillations of glucocorticosteroids allow to stop the symptoms of inflammation. Conservative therapy is used in stages 1-2.
- Contact correction methods. Soft contact lenses promote the regeneration of the epithelial layer. Patients should prefer lenses with a hydrophilic or silicone-hydrogel structure. Thanks to their change 1 time in 2 weeks, it is possible to slightly stop the pain syndrome. This type of lens is used in the formation of erosive defects on the cornea and resistance to drug treatment.
- Phototherapeutic keratectomy. It is used in the absence of the effect of conservative therapy in patients with persistent pain syndrome. With a shell thickness of less than 450 microns, infectious complications, decompensated glaucoma, keratectomy is contraindicated. An alternative to this intervention is corneal collagen crosslinking with riboflavin.
- Keratoplasty. Indications for end-to-end or layer-by-layer corneal plastic surgery: lack of vision, severe pain syndrome for 3-5 art. Surgery is contraindicated with a high risk of graft rejection or retinal detachment, subatrophy of the eyeball.
- Physical therapy. The appointment of a helium-neon laser is recommended. The technique has an anti-edematous and anti-inflammatory effect.
Along with the main treatment for narrowing of the pupillary opening, prolonged-acting M-cholinolytics are used. With the development of inflammatory complications, the use of antimicrobial drugs from the fluoroquinolone groups is indicated. If the disease is accompanied by severe pain, local anesthetics and opioid narcotic analgesics are prescribed. Preparation for surgery includes the appointment of antibacterial agents, glucocorticosteroids and premedication.
Prognosis and prevention
The prognosis for bullous retinopathy is determined by the severity of the course. In stage I-II of the disease, timely treatment ensures complete restoration of the functions of the cornea. Stage III is characterized by a relatively favorable prognosis. At IV-V art., dysfunction can be eliminated only by keratoplasty or keratoprosthetics. There are no specific preventive measures. Nonspecific prevention is reduced to the treatment of infectious and inflammatory pathologies of the anterior segment of the eye, compliance with the rules of asepsis and antiseptics during surgical intervention on the cornea.