RU2120268C1 - Method for performing eximer phototherapeutical stroma keratectomy in treating the cases of bullous keratopathy - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves applying eximer laser cornea ablation to a large depth of down to 120 mcm all over the whole cornea surface excluding peripheral zone of 1.0 mm width. Soft bandage contact lens is used during 2-6 weeks of postoperative period for stabilizing regenerating epithelium layer. EFFECT: prevented cicatricial barrier formation in anterior corneal stroma.

Description

 Bullous (edematous) chronic keratopathy is a polyetiological disease, which is one of the progressive corneal lesions associated with the loss of endothelial cells (Fuchs endothelial-epithelial dystrophy, secondary postoperative, post-traumatic, post-inflammatory keratopathy). Stage III-IV (according to the Payrau classification, 1973) of chronic bullous keratopathy are characterized by the appearance of many vesicles in the epithelium against the background of increasing edema of the stroma, its vascularization and the development of gross turbidity. Violation of the endothelial barrier leads to the formation of chronic corneal edema, to reduce visual acuity up to blindness. In 50% of cases, bullous keratopathy is accompanied by the development of a pain syndrome of varying severity (from a sensation of a foreign body to severe pain associated with the appearance of blisters in the epithelium and their periodic rupture). In this situation, a secondary infection is easily attached, which is often the cause of eye death.

 In the treatment of chronic bullous keratopathy, conservative treatment, including the use of hyperosmotic and vitamin agents, soft therapeutic contact lenses (MKL), and helium-neon laser stimulation are ineffective. In the surgical treatment system, various types of keratoplasty (microdermatocoagulation with MKL, interamellar keratocapsuloplasty according to M. M. Krasnov, reconstructive penetrating keratoplasty, cryokeratoplasty, layer-by-layer keratoplasty in the modification of the inverse fungus) and keratoplasty are significantly more effective and widely used. However, given the usually advanced age of patients with bullous chronic keratopathy, their often burdened general somatic status, surgical treatment may not be recommended to everyone. Difficulties in surgical treatment are often exacerbated by the lack of quality donor material.

 In recent years, there have been reports of the use of microdermatocoagulation with therapeutic MKL (2) and excimer laser superficial phototherapeutic keratectomy (4,5) in the treatment of bullous chronic keratopathy, carried out to relieve pain, as well as in situations where through keratoplasty is not possible due to a number of reasons (difficult general somatic status, difficulties with donor material, etc.).

 Microdermatocoagulation gives a good decongestant effect due to the development of scar tissue in the stroma of the cornea and eliminates unpleasant sensations in the patient, however, it does not have an optical effect due to the development of severe corneal opacity (2).

 Excinative phototherapeutic keratectomy (FTK) according to Austin (4), undertaken after preliminary abrasion of the epithelium, is performed to a depth of 6 - 9 microns, which is about 1/2 the thickness of the Bowman shell and does not capture the stroma.

 The technical result achieved by our FTK method involves deeper ablation, which extends not only to the Bowman shell, but also to the stroma of the cornea. This leads to the formation of a more reliable barrier than the Austin method for moisture seeping from the anterior chamber of the eye. The cicatricial barrier created in the stroma prevents the swelling of the corneal epithelium and prevents pain arising from bursting epithelial blisters (boules).

 The essence of the method is to achieve the aforementioned technical result by conducting photoablation over the entire surface of the cornea except for the peripheral zone 1.0 wide with the capture of not only the entire Bowman shell, but also the anterior stroma layers to a depth of not more than 80 - 120 microns. In the postoperative period, the cornea is covered with a bandage soft contact lens for 2-6 weeks in order to stabilize the growing layer of the epithelium in the conditions of ongoing flooding of the stroma and prevention of recurrent erosion.

 Methodology Instillation anesthesia with 1% dicaine solution (3 times), eyelid fixation with an eyelid expander. Scraping of the epithelium with a scraper from the entire surface of the cornea with the exception of the peripheral germinal zone 1.0 mm wide. The Nidek EC-5000 excimer laser is calibrated prior to the procedure to an expanded zone of 9.0 mm with a transition zone and ablated in it (beam energy - 30 millijoules at the output, pulse frequency - 30 Hz). The peripheral zone is additionally exposed by circular motions of the laser beam with a spot with a diameter of 3 mm. After the laser procedure is completed, 0.25% solution of chloramphenicol is instilled into the conjunctival cavity and MKL is applied. In a number of patients, MKL is applied to the cornea for 3-4 days, and immediately after the procedure, treatment is started with the application of an antibiotic ointment (colbyacin, tetracycline, etc.) under a bandage.

 We provide extracts from case histories of two patients with bullous painful keratopathy who underwent FTK according to the Austin method and the proposed method. FTK allowed postponing end-to-end keratoplasty, which he ultimately performed 2 months after FTK. Disks of corneas excised during surgery were subjected to pathomorphological examination.

Clinical example I (Austin method)
Patient T., born in 1925, medical history N 552/97, noted the deterioration of vision and pain in OD that appeared 1.5 years ago and received medical treatment.

On examination 02.17.97:
Visual acuity OD = 0.02 - 0.03 n / corr.

OS = 0.6 - 0.7 spheres. +0.75 = 0.7 - 0.8
IOP of both eyes is normal (palpation)
Indicators of electrophysiological studies of both eyes are within normal limits.

 OD biomicroscopy: eyelid edema, blepharospasm, lacrimation, photophobia, conjunctiva friable, mixed eyeball injection The cornea is translucent, diffuse epithelial edema and stroma, the corneal section is thickened, individual blisters, the anterior chamber is of medium depth, its moisture is clear, the iris is transparent, the iris is transparent, the iris is round shape.

 Diagnosis: OD-Bullous painful keratopathy (III art.). 02/18/97, on OD was made FTK, according to the method of Austin, to a depth of 10 microns, a diameter of 8.0 mm and a transition zone of 9.0 mm after removal of the epithelium. In the postoperative period the following drug therapy was carried out: 0.25% levomecitin solution, 20% solcoseryl gel, tetracycline ointment) 4% taufon solution, table. indomethacin 0.1 g. On the third day wearing a bandage lens.

Visual acuity of OD (after 14 days) = 0.06 - 0.07 spheres. + 2.5D = 0.1
OD (after 2 months) = 0.09 - 0.1 spheres. - 3,5D = 0,2
Corneal permeability rate = 3'40 '' (after 2 months) increased.

 Biomicroscopy (after 2 months): the edema of the epithelium was preserved, separate large vesicles appeared.

 Clinical example II (the proposed method of deep ablation of the stroma).

 Patient U., born in 1920 EED suffers during the last 2 years. Received medical treatment. In the last 6 months, pain has appeared.

When examined before surgery:
Visual acuity OD: = 0.01 n / corr.

IOP OD normal (palpation)
ROS = 0.12
EFI - indicators within normal limits.

Endothelial Microscopy:
OD - inspection not possible
OS - 2750 - 2800 cells in mm
Corneal permeability index = 2'45 '' (keratopenefluorometry method).

 OD biomicroscopy: edema of the eyelids, blepharospasm, lacrimation, photophobia, pericorneal mixed injection of the eyeball, the epithelium is edematous, in places peeled, the corneal section is thickened. The cornea is translucent, the anterior chamber is deep, its moisture is transparent, the iris is calm, the posterior segment is not visible.

 Diagnosis: OD - Bullous, painful keratopathy.

 03/27/97, on OD made FTK according to the proposed methodology.

 Photoablation was performed after removal of the epithelium to a depth of 100 microns with a diameter of 8.0 mm with a transition zone of 9.0 mm. Wearing a bandage lens. In the postoperative period, the following drug therapy was carried out: 0.25% chloramphenicol solution, solcoseryl solution, taufon solution.

 After a month, visual acuity OD = 0.01 - 0.02 is not corr.

After 54 days: corneal permeability = 3'30 ''
Biomicroscopy after 55 days: the eye is calm, the cornea is translucent, the epithelium is smooth, and slight stromal edema.

The results of a pathomorphological study of excised corneal discs:
I clinical example:
60 days after refractive keratectomy to a depth of 10 μm, a patient with bullous keratopathy histologically reveals the remains of a bowman membrane of uneven thickness with single cell inclusions, presumably fibroblast. The epithelium of uneven thickness (thinner than normal) with impaired cell row. In the basal layer of epithelial cells, the phenomena of perinuclear vacuolization are evidence of a violation of metabolic functions in the cell. In the middle and surface layers of the epithelium, the cells are distinguished by polymorphism, different susceptibility to dyes, weakened by intercellular contacts.

II clinical example:
54 days after FTK to a depth of 110 μm, almost complete differentiation of the re-epithelized layer is noted. There is a propping basement membrane of the epithelium in direct contact with the stroma. In its surface layers, a concentration of proliferating fibroblasts is uneven in length. In the epithelium, the layer of spike (pterygoid) cells is well differentiated. In the surface layers, the phenomena of the highest concentration of superficial stromal fibroblasts (when we can talk about the formation of a fibrocellular membrane replacing the Bowman's membrane) are often observed, the overlying epithelial layer is relatively thinner. Perhaps, in this case, we can talk about the barrier functions of the newly formed fibrocellular membrane, which prevents the swelling of the epithelium and contributes to the formation of full-fledged epithelial and stromal contacts.

 The advantages of the method.

 FTK according to the proposed method was carried out in 20 patients and 3 patients according to the Austin method from 29 to 84 years old with chronic bullous keratopathy with accompanying pain syndrome (Payrau stage III-IV). The disease developed in 5 as a result of EED of the Fuchs cornea, in 5 after an injury, in 13 after abdominal eye operations. Observation of patients was carried out in the period from 1.5 to 9 months.

 10 patients with keratofluopenetometry using local fluorescence electrophoresis studied the permeability of the cornea before and after FTK. Permeability of the cornea was evaluated by determining the time of penetration of fluorescein through all layers of the cornea.

 Corneal permeability in patients with stage III-IV chronic bullous keratopathy is significantly increased. After phototherapeutic stromal keratectomy, corneal permeability decreased and tended to normalize.

 All 20 patients operated on by the proposed method at the indicated follow-up periods showed an increase in visual acuity, a suspension in the progression of chronic bullous keratopathy and the elimination of its accompanying pain. In 2 out of 3 patients operated on by Austin's method at the same time of observation, a relapse of bullous changes in the corneal epithelium was established.

Sources of information
1. Gorgiladze T.U., Ivanovskaya E.V., Gorgiladze L.T. Ophthalmological Journal, 1992, N 3, p.129-133.

 2. Kasparov A.A., Kasyanova N.S., Oganesyants V.A. Reconstructive Ophthalmosurgery, 1970, p. 44-47.

 3. Kasyanova N. S, Churkina MN, Kasparov A.A., Polunin G.S. Reconstructive Microsurgery, 1979, p. 48-52.

 4. Austin O. Lecture in the medical research ophthalmological center "New Look", M., 1996.

 5. Thomann U., Neiser U., Schipper I. Refract.Surg., 1986, Feb. 12: 2, P. 290-292.

Claims (1)

 A method of treating chronic bullous keratopathy by excimer laser ablation, characterized in that, in order to eliminate reported changes in the epithelium and associated pain, photoablation is carried out over the entire surface of the cornea except for the peripheral zone 1.0 mm wide and capture the anterior stroma to a depth of not more than 120 microns, and in the postoperative period, to stabilize the regenerating layer of the corneal epithelium, use a soft contact medical lens for 2-6 weeks.