RU2807860C1 - Method of combined fixation of amniotic membrane for treatment of chronic corneaal erosions - Google Patents

Abstract

FIELD: medicine; ophthalmology.

SUBSTANCE: preliminary epibulbar anesthesia is performed, the amniotic membrane is prepared and a flap is formed from it using scissors, the diameter corresponding to the diameter of a soft contact lens. Next, the first and second components of two-component autologous fibrin glue (TAFG) in a volume of 0.1 ml are sequentially instilled onto the deepithelialized surface of the cornea. After this, a rounded flap of amniotic membrane is moved and straightened using a microspatula on the surface of the cornea, followed by a 2-minute exposure and additional fixation by applying a continuous suture of 10-0 nylon, fixing the amniotic membrane flap to the conjunctiva. Next, the first and second components of TAFG in a volume of 0.1 ml are sequentially instilled onto the surface of the amniotic membrane; after a 2-minute exposure, the operation is completed by applying a soft contact lens to the ocular surface.

EFFECT: method allows to perform durable and low-traumatic fixation of the amniotic membrane to the surface of the cornea in the treatment of chronic corneal erosions.

1 cl, 12 dwg, 2 ex

Description

The invention relates to medicine, namely to ophthalmic surgery, and can be used as an effective and reliable method for fixing the amniotic membrane in the treatment of chronic corneal erosions.

The issue of effective treatment of chronic corneal erosions requires special attention, since the long-term existence of an epithelial defect ensures proliferation of myofibroblasts in the corneal stroma and disorganization of the extracellular matrix, which leads to the formation of persistent opacities of the corneal stroma, a significant decrease in visual acuity, and, as a consequence, a decrease in the quality of life of patients [ Wilson S.E., Medeiros C.S., Santhiago M.R. Pathophysiology of Corneal Scarring in Persistent Epithelial Defects after PRK and Other Corneal Injuries. J Refract Surg. 2018;34(1):59-64]. Monocular blindness after injuries, erosions and ulcers of the cornea is the outcome of 1.5-2 million people annually in the world [Kulikov A.N., Chernysh V.F., Churashov S.V., Gavrilyuk I.O. On the use of amniotic membrane to optimize epithelization of the cornea in the early stages of a severe eye burn (clinical observation) // Modern technologies in ophthalmology. - 2017. - No. 3. - P. 130-132].

In addition, the presence of chronic (persistent) erosion of the corneal graft is a frequent (up to 19.2% of cases) complication of penetrating keratoplasty, which can in turn be complicated by the development of secondary infection, ulcers and perforation of the cornea, neovascularization, which will require repeat keratoplasty and lead to increasing length of hospital stay [Chen H.F., Yeung L., Yang K.J., Sun C.C. Persistent corneal epithelial defect after pars plana vitrectomy. Retina. 2016;36(1):148-155].

Polymorphism of etiological factors and clinical course in this pathology sometimes complicates timely diagnosis and prevents the implementation of effective therapeutic measures aimed at stopping the inflammatory process and enhancing corneal regeneration processes [Kasparova E.A., Kasparov A.A., Amir M.R. Α. N., Marchenko N.R., Makarova M.A., Borodina N.R., Fedorov A.A., Smirennaja E.V. Recurrent corneal erosion // Recidivirujushhaja jerozija rogovicy. [Cataract & Refractive Surgery]. Kataraktal'naja i refrakcionnaja hirurgija. - 2010. - T. 1. - P 51-53; Trufanov S.V., Malozhen S.A., Polunina E.G. and others. Recurrent corneal erosion syndrome (review) // Ophthalmology. - 2015. - T. 12. - No. 2. – P. 4-12].

It is known that covering the ocular surface with the amniotic membrane promotes epithelization of the cornea. This effect is associated with the biological properties of the amniotic membrane, namely the prevention of epithelial apoptosis, improvement of migration and differentiation of epithelial cells, inhibition of neovascularization [Skachkov D.P., Shtilerman A.L., Skachkova O.V. Application of the biological properties of the amniotic membrane in the surgical treatment of corneal pathology // Far Eastern Medical Journal. 2013. No. 4]. In addition, covering the cornea with the amniotic membrane has a significant analgesic effect and reduces the severity of the inflammatory process [Chernysh V.F., Boyko E.V. Eye burns – state of the problem and new approaches. – St. Petersburg: VMedA, 2008. – 135 p.]. In this regard, the use of amniotic membrane in the treatment of chronic corneal erosions is a promising area of ophthalmic surgery.

In addition to the classical fixation of the amniotic membrane using suture material, alternative methods have now been developed, which are not always reliable and may be accompanied by displacement of the amniotic membrane in the postoperative period, and, consequently, a decrease in the effectiveness of treatment. This fact dictates the need to find a way for reliable and long-term fixation of the amniotic membrane to the surface of the cornea with minimal risk of dislocation and the development of complications in the postoperative period.

There is a known method of fixing the amniotic membrane using suture material [Milyudin E.S. Restoration of the corneal epithelium under the silicon-dried plasticized amniotic membrane in patients with pathology of the anterior segment of the eye // Bulletin of SamSU. 2006. No. 9]. The essence of the technique is as follows. The deepithelialized surface of the cornea is covered with silicon-dried plasticized amniotic membrane. The amniotic membrane is secured to the edges of the epithelial defect with interrupted sutures (8-0 or 10-0 nylon) followed by coverage with a soft contact lens. This method has established itself as a simple, affordable and reliable method of fixing the amniotic membrane.

However, despite the success of the proposed method, the use of interrupted sutures to fix the amniotic membrane takes a lot of operating time, is associated with the risk of intraoperative bleeding, and requires the surgeon’s care and attention to avoid excessive tension of the amniotic membrane and its further eruption. In addition, suture knots can provoke trauma to the cornea and amniotic membrane when blinking, which can lead to inflammation and fragmentation of the flap. When using suture material, there is a risk of subsequent weakening, sagging of the sutures, and the formation of folds of the amniotic membrane in the postoperative period, which also reduces the effectiveness of treatment. Interrupted sutures in the postoperative period cause severe discomfort (foreign body sensation, lacrimation). Upon reaching the expected epithelization of the cornea, a procedure for removing sutures is necessary; this is accompanied by additional trauma to the surface of the cornea and takes a lot of the surgeon’s time [Szurman, P., Warga, M., Grisanti, S. Sutureless amniotic membrane fixation using fibrin glue for ocular surface reconstruction in a rabbit model Cornea, 2006. No. 25(4), P. 460–466].

These disadvantages are partially eliminated in the method of fixing the amniotic membrane using a soft contact lens and viscoelastic [RF patent No. RU 2 321 379 C1 IPC, publ. 04/10/2008].

This method differs from the previous one in that viscoelastic in a volume of 0.2 ml is applied to the inner surface of a soft contact lens (for example, “Maxima-55”), a fragment of silicon-dried amniotic membrane cut to the diameter of the lens is placed on top using tweezers and spread with a spatula over the entire surface of the lens. During surgery, the patient's eyelids are secured with an eyelid speculum (or an assistant's fingers) and an amnion (viscoelastic) lens is placed on the damaged cornea. After 6-7 days, the lens is removed; if there is no epithelization of the corneal defect, the manipulation is repeated. The advantages of this method of fixation are: the ability to perform manipulation outside the operating room, simplicity and accessibility, no need for microsurgery skills, reduced patient discomfort in the postoperative period (no foreign body sensation and pain), no need to remove sutures and associated trauma to the surface of the cornea and amniotic membrane.

In turn, the use of this fixation method has its disadvantages, namely:

1) insufficiently strong fixation of the amniotic membrane to the soft contact lens;

2) the soft consistency of the viscoelastic leads to its partial drainage from the lens, and, consequently, to an even greater weakening of the flap fixation;

3) microtraumas caused by displacement of the amniotic membrane flap, especially during blinking, can slow down the epithelization of the cornea under the amniotic membrane;

4) insufficient fixation of the amniotic membrane leads to its premature sliding from the surface of the cornea, which reduces the time of epithelization and reduces the effectiveness of the treatment;

5) early dislocation of the amniotic membrane dictates the need for repeated intervention in order to achieve complete epithelization.

These disadvantages are partially eliminated in the method of treating inflammatory and trophic lesions of the cornea [RF patent No. 2481087 C1, publ. 05/10/2013]. The technique consists in taking the amniotic membrane with tweezers using curved Vanassa-type scissors, and cutting out a flap with a diameter smaller than the diameter of a soft contact lens, for example, Riga Vision. A polyacrylamide (PAA) film is applied to the inner surface of the contact lens, saturated, depending on the desired effect, with an anti-inflammatory or regenerating agent. Next, the amnion is placed on the lens with the PAA film using tweezers, which is straightened with a spatula, the patient’s eyelids are fixed with an eyelid speculum (or the assistant’s fingers) and the lens with the amnion (fixed with the polyacrylamide film) is placed on the damaged cornea. Depending on the predominance of inflammatory or trophic lesions, PAA film is used, saturated, for example, with diclofenac or solcoseryl. The manipulation takes 1-2 minutes. After 6-7 days, the lens is removed; if the corneal defect has not epithelialized, then the manipulation is repeated. The advantages of this fixation method include minimizing the dislocation of the AM fragment due to better capillary attraction of its edges, maintaining high concentrations of the drug through the use of PAA film and increasing the efficiency of surgical treatment.

This method of fixation is not without its disadvantages, which include:

1) insufficient fixation of a fragment of the amniotic membrane due to the lack of suture material or viscous substance that ensures tight adhesion of the flap to the surface of the cornea;

2) the risk of dislocation of the amniotic membrane in the postoperative period and a possible reduction in the time of epithelization;

3) early displacement of the amniotic membrane before the onset of complete epithelization of the cornea, this requires repeated manipulation, and therefore repeated traumatization of the de-epithelialized surface;

4) shortage of PAA films in each hospital;

5) production of PAA films from natural, as well as artificial and synthetic polymers, which can lead to toxic side effects of treatment, and, as a result, slow down regeneration and epithelization [Seitkhan G.S., Iminova R.S. Film materials based on some nonionic polymers and clay-containing films. News of the scientific and technical society “Kahak”, 2020, No. 2 (69)];

6) there is no need to perform manipulations in sterile operating room conditions; this can contribute to the development of pathogenic microflora, which can subsequently lead to postoperative inflammatory complications.

The above disadvantages have been eliminated in the method of surgical treatment of corneal defects of various origins [RF patent No. 2607163 C1, publ. 01/10/2017], which consists of fixing the silicon-dried amniotic membrane with continuous U-shaped sutures around the entire circumference of the cornea, followed by putting on a soft contact lens and performing lateral blepharorrhaphy. The method is carried out as follows: the surgical field is treated, anesthesia is instilled with alcaine, and a blepharostat is applied. A fragment of silicon-dried plasticized amniotic membrane is taken with tweezers, curved Vanassa-type scissors, and a flap is cut out of it with a diameter smaller than the diameter of a soft contact lens (for example, “Pure Vision”). The cut amnion flap is straightened with a spatula and placed on the damaged cornea, and sutured to the limbal zone with continuous U-shaped 10-0 sutures along the entire circumference of the amnion. A suture is then placed on the lateral edge of the eyelid (tarsorrhaphy). After 5-7 days, the suture is removed from the eyelid and the lens is removed. If the corneal defect is not epithelialized, then the manipulation is repeated. The main advantage of this method is the strong fixation of a fragment of the amniotic membrane to the cornea due to a continuous suture and lateral blepharorrhaphy. However, this method has a number of disadvantages, namely:

1) the risk of sagging sutures cannot be excluded, and at the same time – displacement of the amniotic membrane, slowing down the timing of epithelization and re-intervention;

2) the application of lateral blepharorrhaphy requires precision and basic microsurgical skills and cannot always be performed in a hospital setting;

3) the process of suturing the eyelids is accompanied by bleeding due to their abundant vascularization and increases the time of surgical intervention;

4) lateral blepharorrhaphy can cause both external discomfort to the patient and pain in the postoperative period;

5) subsequent removal of continuous sutures and blepharorrhaphy are traumatic for the patient.

The closest to the claimed invention is the method we chose as a prototype and consists in using a thrombofibrin clot to close erosions and perforations of the eyeball, covered on top with an AM fragment, additionally fixed with suture material [Alio J.L., Arnalich-Montiel F., Rodriguez A.E. The role of “eye platelet rich plasma” (E-PRP) for wound healing in ophthalmology // Curr Pharm Biotechnol. 2012 Jun; 13(7): 1257-65].

The authors propose using a clot of platelet-rich plasma from the patient as additional protection for the corneal surface defect, as well as to enhance the reparative and regenerative effects of the amniotic membrane due to the content of a large number of growth factors. The following technique for preparing a clot is described: immediately before the operation, 40-60 ml of venous blood is taken from the patient; after one-step centrifugation, plasma enriched with platelets is collected, the concentration of which is 2-3 times higher than the concentration of platelets in whole blood. One milliliter of the resulting plasma was placed in each well of a 4-well flat-bottom plate and 50 μl of a 10% calcium chloride solution was added to activate the solution. After gentle mixing using a sterile pipette, the solution was incubated at 37°C for 30 minutes. After 30 minutes, a clot of platelet-rich plasma has formed, ready to be applied to the corneal surface defect. After placing the clot, a fragment of the amniotic membrane is placed on it, which is fixed to the conjunctiva using a continuous suture (nylon 10-0), as well as using an additional purse-string suture. The final stage of the operation is the application of temporary blepharorrhaphy.

The disadvantages of this method include:

1) lack of reliable data on the effective use of thrombofibrin clot, its effects and ability to ensure tissue adhesion and stimulation of regeneration and epithelization;

2) long-term preparation of a thrombofibrin clot;

3) the need for special equipment (incubator) to comply with temperature conditions during the preparation of the clot;

4) the use of a thrombofibrin clot to protect the surface of the cornea, which does not provide reliable fixation of a fragment of the amniotic membrane;

5) lack of reliably complete adherence of a fragment of the amniotic membrane to the surface of the cornea due to the shape and size of the clot;

6) applying an additional purse-string suture to fix the amniotic membrane is labor-intensive and increases the operation time;

7) the risk of dislocation and the formation of tears in a fragment of the amniotic membrane during suturing requires the surgeon’s accuracy and increases the operation time;

8) the presence of fixation with suture material and blepharorrhaphy does not eliminate the risk of dislocation, sagging sutures and sliding of a fragment of the amniotic membrane in the postoperative period;

9) the application of blepharorrhaphy requires basic microsurgical skills and cannot always be performed in a hospital setting;

10) the process of suturing the eyelids is accompanied by bleeding due to their abundant vascularization, which leads to an increase in the time of surgical intervention;

11) blood trapped under the flap of the amniotic membrane provokes the activation of pro-inflammatory cytokines and neutrophils, which leads to more rapid lysis of the amniotic membrane;

12) inaccurate application of blepharorrhaphy as the final stage of the operation can lead to dislocation or tears of the amniotic membrane in the area of the sutures;

13) the presence of sutures on the eyelids can cause both external discomfort to the patient and pain in the postoperative period;

14) subsequent removal of continuous sutures and blepharorrhaphy is traumatic for the patient.

The present invention is based on the idea of creating a durable and low-traumatic method for combined fixation of the amniotic membrane to the surface of the cornea, and, as a result, an effective method for treating chronic corneal erosions. This is achieved by using the biological properties of the developed and patented [RF patent No. 2704256 C1, publ. 02/18/2019] two-component autofibrin glue (DAFK), suture material and a soft contact lens.

The method we propose for combined fixation of the amniotic membrane in the treatment of chronic corneal erosions consists of installing a blepharostat, preliminary epibulbar anesthesia (inocaine solution), then using scissors to form a flap from the amniotic membrane, the diameter of which is comparable to the diameter of a soft contact lens. The first and second components of DAPC are instilled onto the deepithelialized surface of the cornea in a volume of 2-3 drops (0.1 ml); using a microspatula, a flap of amniotic membrane is placed on the surface of the cornea and straightened. After a 2-minute exposure, the amniotic membrane flap is sutured to the conjunctiva using a continuous suture (10-0 nylon suture). The first and second components of DAPC are re-instilled onto the surface of the amniotic membrane in a volume of 2-3 drops (0.1 ml), after a 2-minute exposure, a soft contact lens is applied to the ocular surface, the operation is completed by removing the blepharostat.

The main advantages of our proposed method of fixing the amniotic membrane to the surface of the cornea are:

1) use of patented [RF patent No. 2704256 C1, publ. 02/18/2019] DAPC, which contains live platelets that produce various growth factors and adhesive molecules, and create conditions for faster regeneration of the corneal epithelium, as well as stopping inflammation at the site of its application, which ensures the effectiveness of treatment and reduces the time of epithelization;

2) a simple and quick method for preparing DAPC, which consists of collecting the patient’s venous blood and centrifuging it for 4 minutes;

3) no need for an incubator to maintain the temperature during the preparation of DAPC;

4) strong adhesion of the amniotic membrane to the de-epithelialized surface of the cornea due to living platelets, growth factors and adhesive molecules contained in the 1st component, as well as a solution of calcium chloride and thrombin in the 2nd component of DAPC, which allows you to regulate the hardening time and degree of adhesion ;

5) intraoperative application of DAPC components in a liquid state from sterile syringes allows the resulting adhesive composition to be evenly distributed on the surface of the cornea, which ensures reliably complete and strong adhesion of the amniotic membrane to the cornea over its entire area;

6) reliable fixation of the amniotic membrane using DAFC and a continuous suture does not require additional sutures;

7) strong fixation with DAFC facilitates further application of a continuous suture by preventing displacement and the formation of tears in the flap when the conjunctiva is pierced with a needle, thus reducing the operation time;

8) fixation of the amniotic membrane with DAFC eliminates the dislocation of the fragment in the postoperative period, and therefore provides a prolonged effect of the amniotic membrane, stimulation of epithelization and increasing the effectiveness of the treatment;

9) the use of DAFC, suture material and a soft contact lens eliminates the need for blepharorrhaphy;

10) rapid adhesion of the amniotic membrane to the surface of the cornea within 2 minutes and the application of one continuous suture significantly reduces the time of surgical intervention;

11) strong adhesion of the amniotic membrane to the surface of the cornea prevents blood from entering under the flap, which reduces the likelihood of premature lysis of the amniotic membrane;

12) the absence of the need for blepharorrhaphy as the final stage of the operation eliminates the risks of dislocation and tears of the amniotic membrane flap;

13) the absence of stitches on the eyelids and the usual appearance of the eye in the postoperative period do not cause discomfort for the patient;

14) removal of a single continuous suture after epithelization of the cornea is achieved does not cause such discomfort as removal of blepharorrhaphy.

The invention is illustrated in Fig. 1 and Fig. 2, which show photographs of the ocular surface of patients at the ophthalmology clinic of the VmedA in dynamics. Figure 3 and Figure 4 show the preparation of the amniotic membrane and the formation of the flap using scissors. Figures 5 and Figure 6 show the instillation of the first component (Figure 5) and the second component (Figure 6) of DAPC in a volume of 2-3 drops (0.1 ml). Figure 7 shows the movement of a flap of amniotic membrane of a round shape, the diameter corresponding to the diameter of a soft contact lens, onto the de-epithelialized surface of the cornea. Figure 8 shows the application of a continuous suture (suture material - 10-0 nylon) after 2 minutes (exposure time of the DAPC components), fixing the amniotic membrane flap to the conjunctiva. Figures 9 and Figure 10 show re-instillation of the first (Figure 9) and second (Figure 10) components of DAPC in a volume of 2-3 drops (0.1 ml), exposure of the components of DAPC for 2 minutes. Figure 11 shows the application of a soft contact lens to the ocular surface. Figure 12 shows a view of the ocular surface after surgery.

The effectiveness of our proposed method of combined fixation of the amniotic membrane to the surface of the cornea is illustrated by the following clinical cases.

Clinical case No. 1. Patient A. applied to the ophthalmology clinic of the V.Med. CM. Kirov with complaints of decreased visual acuity in the left eye. From the anamnesis it is known that 6 months ago he suffered from keratitis of unknown etiology in the left eye. Biomicroscopy reveals a cloud-like opacification in the optical zone of the cornea; fluorescein staining reveals no areas of deepithelialization. Due to superficial opacification of the cornea, the patient underwent anterior deep lamellar keratoplasty with femtolaser assistance on the left eye. In the postoperative period, biomicroscopy revealed that the keratograft was moderately edematous, with single folds of Descemet's membrane, fixed with a blanket suture. When stained with a fluorescein solution, deepithelialization is determined over the entire surface of the graft (Fig. 1). Due to the absence of a tendency to epithelization, on the 14th day after surgery, the graft was covered with an amniotic membrane with fixation of DAFC and suture material. In the postoperative period, a flap of amniotic membrane is securely fixed on the SCL eyeball. On the 7th day, the formation of folds of the amniotic membrane flap was noted; on the 8th day, the soft contact lens was removed, the continuous suture and flap were removed, and when stained with a fluorescein solution, complete epithelization of the graft was performed (Fig. 1).

Clinical case No. 2. Patient T. was hospitalized at the Ophthalmology Clinic of the V.Med. CM. Kirov as part of a follow-up examination 2 months after penetrating keratoplasty for a severe thermochemical (alkali) burn of the cornea of the right eye. With biomicroscopy: the keratograft is edematous, fixed with a blanket suture; when stained with a fluorescein solution, there is an irregularly shaped area of de-epithelialization measuring 1.5×3 mm, dye retention over the entire surface of the graft (Fig. 2). The patient underwent graft coverage with amniotic membrane with DAFK fixation and suture material. In the postoperative period, a flap of amniotic membrane is securely fixed on the SCL eyeball. On the 7th day, the soft contact lens was removed, the continuous suture and flap were removed, and when stained with a fluorescein solution, complete epithelization of the graft was performed (Fig. 2).

The technical result is a more durable fixation of the amniotic membrane to the de-epithelialized surface of the cornea, reducing the time of epithelization and increasing the effectiveness of the treatment due to live platelets producing growth factors and adhesive molecules included in DAPC, as well as the use of suture material and a soft contact lens for additional fixation amniotic membrane.

The technical result is achieved by the fact that the amniotic membrane is prepared in advance and the flap is formed using scissors (Fig. 3 and Fig. 4). On the deepithelialized surface of the cornea, the first (Fig. 5) and second (Fig. 6) components of DAPC are sequentially instilled in a volume of 2-3 drops (0.1 ml). After this, a round-shaped flap of amniotic membrane, corresponding in diameter to the diameter of a soft contact lens, is moved and straightened using a microspatula on the surface of the cornea (Fig. 7). After 2 minutes (exposure time of the DAPC components), a continuous suture is applied using suture material (nylon 10-0), fixing the flap of the amniotic membrane to the conjunctiva (Fig. 8). The first (Fig. 9) and second (Fig. 10) components of DAPC are re-instilled onto the surface of the amniotic membrane in a volume of 2-3 drops (0.1 ml), exposure of the components of DAPC for 2 minutes. The operation is completed by applying a soft contact lens to the ocular surface (Fig. 11, 12).

This method has proven itself as a simple and reliable combined method of fixing the amniotic membrane in the treatment of chronic corneal erosions.

Claims (1)

A method of combined fixation of the amniotic membrane, characterized in that preliminary epibulbar anesthesia is performed, the amniotic membrane is prepared and a flap is formed from it using scissors, the diameter corresponding to the diameter of a soft contact lens, then the first and second components of a two-component autologous fibrin are sequentially instilled onto the de-epithelialized surface of the cornea glue (DAFC) in a volume of 0.1 ml, after which a round-shaped flap of amniotic membrane is moved and straightened using a microspatula on the surface of the cornea, followed by a 2-minute exposure and additional fixation by applying a continuous 10-0 nylon suture, fixing the amniotic membrane flap to the conjunctiva, then the first and second components of DAPC in a volume of 0.1 ml are sequentially instilled onto the surface of the amniotic membrane; after a 2-minute exposure, the operation is completed by applying a soft contact lens to the ocular surface.