RU2159599C1 - Method for correcting eye sight after penetrating keratotransplantation operation - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves applying transplants with stable properties retained unchanged after 18-24 months of penetrating keratotransplantation. Keratoablation is carried out in 3-5 weeks after forming flap on pedicle. EFFECT: increased reliability of operation; reduced risk of astigmatism to be occurred.

Description

 The invention relates to the field of ophthalmology and allows the operation of laser keratomileusis after surgery through keratotransplantation.

 There is a method of correcting vision after an earlier through keratotransplantation, in which laser keratoablation (LASIK) is performed (Arenas E., Maglione A. "Laser in situ keratomileusis for astigmatism and myopia after penetrating keratoplasty" J. Refrakt Surg. 1997, Jan-Feb, 13 (1) p. 27-32).

 In the known method, the corneal flap is formed on the pedicle simultaneously with excimer laser keratoablation.

The known method has the following disadvantages:
the dates after the operation of end-to-end keratotransplantation are not established, at which laser keratoablation is optimal;
there are cases of inducing astigmatism after LASIK surgery;
there are difficulties in calculating the algorithm of the operation due to an error in the readings of devices with through keratoplasty. Very often occurring astigmatism is incorrectly determined. There are differences in the preoperative and postoperative directions of astigmatism.

 The technical result of the proposed invention is to increase the reliability of the operation by reducing the possibility of astigmatism.

 The specified technical result is achieved in the method of vision correction after end-to-end keratotransplantation, and, on the one hand, the period through which laser keratoablation can be performed is clearly defined, it is 18-24 months after the operation of end-to-end keratotransplantation, and on the other hand, the formation of a corneal flap on the leg perform 3-5 weeks before laser keratoablation.

 In the proposed method for the correction of ametropia after end-to-end keratoplasty, a time period is determined at which laser keratoablation, or rather, refractive-correcting excimer laser intrastromal keratectomy (REIK) is safer due to the onset of stability of the corneal scar. This period is 18-24 months. It is this period that is necessary to complete the processes within the corneal reconstruction and stabilize refraction.

 If preliminary the formation of a corneal flap on the stalk is carried out 3-5 weeks before laser keratoablation, errors in determining the refraction algorithm can be avoided, since a sharp increase in intraocular pressure due to the action of the vacuum ring of microkeratome redistributes the tension in the cornea with a subsequent change in the direction of astigmatism. Therefore, if the operation is performed simultaneously, then during repositioning of the flap, astigmatism may occur in another meridian. A period of 3-5 weeks is sufficient for the changes in astigmatism data to stabilize. Since astigmatism data may differ during keratotopography, refractometry and subjective assessment of refraction after end-to-end keratoplasty, it will be more correct to use the average astigmatism value for the operational algorithm. In the proposed method, the corneal flap is formed on the leg in advance, and then after 3-5 weeks a refractive operation is performed. Thanks to such a delay, the graft is placed in the cornea in such a way that the astigmatism that arises does not change its direction, the graft flap is laid as if by itself in an optimal way.

 Example 1

 Patient Pavel V., 27 years old.

 He contacted the Novy Vzglyad Scientific Research Center with a diagnosis of OD — keratoconus of the II degree, OS — the state after end-to-end keratoplasty (UPC), postoperative irregular myopic astigmatism with complaints of insufficient visual acuity, and quick visual fatigue.

 From the anamnesis, it is known that the patient underwent end-to-end keratotransplantation on the OS for keratoconus in 1997. At the time of the inspection, 23 months passed after the specified operation.

On examination:
Visus OD = with hard contact lens = 0.9 - 1.0
OS = 0.05 sph - 1.75 cyl - 6.0 axis 150 = 0.6
Refractometry - Fails
Biomicroscopy - OD - is calm. The cornea is conical in shape. Keratoconus stage I according to Amsler. The front camera is deeper than usual, moisture is transparent. The structures of the anterior segment of the eye are preserved. OS - calm, no detachable. Corneal graft with a diameter of 8.0 mm is transparent. The anterior chamber is of medium depth, moisture is transparent. The iris is gray-blue, relief, basal iridectomy at 12 o’clock. The pupil in the center, reacts vividly to the light, round. The lens is transparent. Vitreous body - destructive changes.

 Ophthalmoscopy - OI - DZN - pale pink, the borders are clear, there is a myopic cone a: v as 2: 3. In the macular region - no change. Pachymetry - OS - 572 plural

Conclusion: Diagnosis - OD - Keratoconus II degree according to Amsler
OS - Condition after SP for keratoconus.

Postoperative irregular myopic astigmatism
Operation progress:
The operation was performed in 2 stages, the 1st stage included keratomileusis, the 2nd stage was performed after 1 month and included laser ablation
07/15/1999 - an operation was performed - stage 1 - carrying out a corneal section (keratomileusis) on the OS.

 Keratomileusis was performed using a Hansatome Vision NT-230 microkeratome, which kit includes fixing vacuum rings of different diameters, an electric motor, a set of interchangeable heads for conducting slices of various depths and an adapter. Microkeratum is equipped with disposable interchangeable blades that are inserted into the head immediately before surgery. Keratom movement and pressure in the vacuum ring are controlled by pedals. Before each operation, a keratoma was technically controlled, which included checking the course of keratoma in both translational and reverse directions. In between operations, the microkerate was thoroughly cleaned with special fluids and sterilized.

 The preoperative preparation of the patient included double treatment of the eyelid skin with 70% alcohol and instillation of the anesthetic (propakain 0.5%, leocain 0.3%, lidocaine 2%) 3-5 minutes before surgery and directly on the operating table. After installing a rigid blepharostat and removing moisture from the surface of the corneal graft using a surgical sponge, a marking was made on the corneal graft with a special radial taper with three radii at 3, 6 and 9 hours, as well as in the optical zone of 3 mm. A vacuum ring was applied around the periphery of the corneal graft, centered according to the location of the pupil. A vacuum was created and the intraocular pressure was monitored by a Barraquer applanation tonometer. IOP should be at least 65 mm Hg. Art. The pre-assembled cutting part of the keratome head was mounted on the pin of the vacuum ring, and after turning on the moving mechanism, the corneal transplant was cut round and diameter 9.0 mm, 160 microns thick with a base for 12 hours. The primary flap adhesion was monitored for 3-5 minutes. After instillations in the conjunctival sac of an antibiotic (tobrex, colbiozion, cypromed) and an anti-inflammatory non-steroid drug (nakloff, diclofenac) blepharostat was recovered. No blindfold was applied. After 30-60 minutes after the operation, a control examination was performed using a slit lamp.

 The next examination was scheduled after 24 hours, then after 4 days. After this, the patient was asked to come to the clinic 1 month after keratomileusis. Within a month, the patient instilled preparations of artificial tears "Lacrisin", "Lacrisifi" 3-4 times a day.

 Stage II was carried out after 1 month and included laser keratoablation with preliminary additional verification of visual acuity, refractometry, computer topography, pachymetry and biomicroscopy.

 Laser keratoablation was performed using an EC-5000 excimer laser, NIDEK, which was calibrated before surgery.

 Using a flat spatula, the corneal flap was gently separated from the stroma and reclined on the leg. After the flap was raised and laid, the stromal surface of the cornea was thoroughly dried using a microsurgical sponge and laser ablation was performed according to the optical correction of this patient. After the ablation was completed, the stroma surface was washed with saline and reposition of the flap with a spatula. The primary adhesion of the flap was monitored for 3-5 minutes. After instillations in the conjunctival sac of an antibiotic (tobrex, colbiocin, cypromed) and an anti-inflammatory non-steroid drug (nakloff, diclofenac) blepharostat was recovered. No blindfold was applied. 30-60 minutes after the operation, a control examination was performed using a slit lamp. Then the patient visited the clinic every other day, 4 days, 1 month. Further, the patient was constantly observed in the clinic for a year, attending examinations after 2-3 months.

The first inspection in a day
Visus OS = 0.4
Biomicroscopy: OS is calm. There is no detachable. The corneal graft is clear. The flap is adapted. Front section structures saved.

Inspection after 4 days
Visus OS = 0.4-0.5 s corr. sph - 2.5 = 0.7-0.8
Inspection after 1 month
Visus OS = 0.8-0.9
Inspection after 1 year
Visus OS = 0.8-0.9
Example 2

 Patient Sergey P., 31 years old. In November 1997, he received a penetrating mechanical injury to the cornea OD with a cat's claw. The primary surgical treatment was carried out at the medical institution at the place of work and included the application of a corneal suture. A dense scar has formed in the central optical zone, which captures all layers of the stroma and significantly reduces visual acuity.

 In April 1998, an end-to-end keratotransplantation of OD with a diameter of 7.5 mm was performed in the central optical zone. In January 1999, a continuous suture was removed from the cornea.

 In December, 1999, the Novy Vzglyad Scientific Research Center, the patient, complained of insufficient visual acuity, acute eye fatigue, and the impossibility of full binocular vision.

Visus OD = 0.3
OS = 0.1
Refractometry - Fails
Biomicroscopy - OD - is calm. The corneal graft is clear. The anterior chamber is of medium depth, moisture is transparent. The iris is gray-green. The pupil in the center, reacts vividly to the light, round. The lens is transparent. The vitreous is transparent.

OS - front section structures saved
Ophthalmoscopy - OI - DZN - pale pink, the borders are clear, a: v as 2: 3. In the macular region - unchanged.

Pachymetry - OD - 586 mn
The operation was performed according to the method described above.
Inspection after stage 1
II stage
The first inspection in a day
Visus OS = 0.4
Biomicroscopy: OS is calm, there is no discharge. The corneal graft is clear. The flap is adapted. Front section structures saved.

Inspection after 4 days
Visus OS = 0.7-0.8
Inspection after 1 month
Visus OS = 1.0
Inspection after 1 year
Visus OS = 1.0
Example 3

 Patient Nadezhda D., 45 years old. In November 1993 she underwent herpetic keratoiridocyclitis OS. After the transferred herpetic keratitis, an intense clouding of the cornea formed, significantly reducing visual acuity.

 In March 1995, a through keratotransplantation with a diameter of 7.0 mm was performed. Despite the transparent graft engraftment, visual acuity remained insufficiently high due to postoperative astigmatism.

 At the Novy Vzglyad Research Center, the patient complained of insufficient OS visual acuity, rapid visual fatigue, and the impossibility of full binocular vision.

Visus OD = 0.4 s corr sf - 1.0 = 1.0
OS = 0.1 s corr SF + 3.0 cyl - 1.5 ax 12 = 0.5
Refractometry OS-sf + 3.5 cyl - 2.0 ax 10
Biomicroscopy - OS - is calm. The corneal graft is clear. The anterior chamber is of medium depth, moisture is transparent. The iris is brown, there is a basal irrectomy at 12 o’clock. The pupil in the center, reacts vividly to the light, round. The lens is a slight clouding of the anterior layers.

OS - front section structures saved
Ophthalmoscopy - OI - DZN - pale pink, the borders are clear, there is a small myopic cone, a: v as 2: 4. In the macular region - no change.

Pachymetry - OD - 563 mn
The operation was performed according to the method described above.
The therapy included antiviral therapy (Zovirax ointment - 2 times a day, half-day - 4 times a day) and preliminary (before surgery) the next course of antiherpetic vaccination.

Inspection after stage 1
Inspection after stage II
The first inspection in a day
Visus OS = 0.2-0.3
Biomicroscopy: OS is calm, there is no discharge. The corneal graft is clear. The flap is adapted. Front section structures saved.

Inspection after 4 days
Visus OS = 0.4
Inspection after 1 month
Visus OS = 0.5-0.6
Inspection after 1 year
Visus OS = 0.75
Example 4

 Patient Alexandra B., 62 years old.

 About 7 years ago, she underwent cataract extraction with implantation of a posterior chamber intraocular OD lens. Within a year after the operation, secondary epithelial-endothelial dystrophy (bullous keratopathy) developed, accompanied by severe pain, severe blepharospasm, lacrimation and photophobia.

 During the year, the patient underwent conservative treatment.

 Due to the ineffectiveness of conservative therapy and an increase in pain, in 1996 cryokeratoplasty OD was performed. Despite the transparent graft engraftment, visual acuity remained insufficiently high due to postoperative astigmatism.

Visus OD = 0.1 n / corr
OS = 0.3 s corr sf - 1.75 = 0.5
OS Refractometry - Fails
Biomicroscopy - OS - is calm. The corneal graft is clear. The anterior chamber is of medium depth, moisture is transparent. Iris - pale gray, basal irrectomy at 12 o’clock. The pupil in the center is round, the reaction to the light is sluggish. IOL - stands well, its surface is clean. Vitreous - there is a "golden rain", floating opacities. OS - the cornea is transparent. The anterior chamber is of medium depth, the iris is calm. The lens is an immature cataract.

 Ophthalmoscopy - OI - DZN - pale pink, clear borders, angiosclerosis. Sclerotic macular degeneration.

OS - ophthalmoscopy is difficult
Pachymetry - OD - 532 mn
The operation was performed according to the method described above.
Inspection after stage 1
Inspection after stage II
The first inspection in a day
Visus OS = 0.2
Biomicroscopy: OS is calm, there is no discharge. The corneal graft is clear. The flap is adapted. Front section structures saved.

Inspection after 4 days
Visus OS = 0.2-0.3
Inspection after 1 month
Visus OS = 0.35-0.4
Inspection after 1 year
Visus OS = 0.45-0.5
Visual acuity in the last 2 cases is associated with opacities in the vitreous body and lens, as well as with changes in the retina.

Claims (1)

 A method of vision correction after end-to-end keratotransplantation, including the formation of a flap on the leg and laser stromal keratoablation, characterized in that the vision correction is performed while maintaining stable transplant performance after 24 months of end-to-end keratotransplantation, while keratoablation is carried out 3 to 5 weeks after the formation of the graft leg.