RU2828698C1 - Method for penetrating keratoplasty after ocular surface reconstruction in patients with limbal insufficiency syndrome - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to ophthalmology, and can be used for perforating keratoplasty after ocular surface reconstruction in patients with limbal insufficiency syndrome for unilateral limbal insufficiency syndrome (LIS). For this purpose, the locations of limbal micrografts are marked on the patient’s cornea with a marker. At a distance from them within 1-2 mm to the centre of the cornea, making a mark with diameter of 6.0 to 8.5 mm. A through corneal trepanation is performed until moisture appears from the anterior chamber. In case of moderate disturbance of corneal transparency, in which iris details are visualized, corneal removal is performed with the help of femtosecond laser (FSL). For this purpose, vacuum ring is fixed to eye surface and FSL head is attached to it. During this process, the corneal surface is levelled over the entire applanation area, the diameter of which is 6-8.5 mm. Thereafter, the cornea is scanned with the help of an OCT laser built into the handle; the micrografts locations, the configuration and depth of the through cut are specified. Diameter of the through circular cut is set in range of 6-8.5 mm. Laser is activated and circular cut is made. Laser operation time is 1.5-2.0 minutes. Further, the vacuum is deactivated and the laser head with the vacuum ring is detached from the cornea. Donor cornea is placed into the prepared surgical bed, 4 fixing sutures are applied, silk 8-0, and then continuous or 12-18-knot suture, nylon 10-0, avoiding the area of limbal micrografts. Finally, a soft contact lens is applied.

EFFECT: invention provides reducing the number of intra- and postoperative complications due to excision of the affected cornea of a smaller diameter, relative to limbal micrografts, which, in turn, provides safe excision of the cornea and subsequent epithelisation of micrografts and, as a result, the possibility of obtaining high clinical and functional results.

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Description

Method of performing penetrating keratoplasty after reconstruction of the ocular surface in patients with limbal insufficiency syndrome.

The invention relates to medicine, and more specifically to ophthalmology, and can be used to restore corneal transparency in patients operated on using the Glueless Simple Limbal Epithelial Transplantation (GSLET) technology for unilateral limbal insufficiency syndrome (UIS) [1. Malyugin, M. Glueless Simple Limbal Epithelial Transplantation: The Report of the First 2 Cases / B.E. Malyugin, M.Y. Gerasimov, S.A. Borzenok. - DOI: 10.1097/ICO.0000000000002467. - Text : electronic // Cornea. - 2020. - Vol. 39, N 12. - P. 1588-1591. – URL: https://journals.lww.com/corneajrnl/Abstract/2020/12000/Glue (date of treatment: 04/07/2023). 2. Diagnostic Algorithm for Surgical Management of Limbal Stem Cell Deficiency / B. Malyugin; S. Kalinnikova; R. Isabekov [et al.]. –. DOI: 10.3390/ diagnostics13020199. – Text: electronic // Diagnostics. – 2023. N 13. – P. 199. 3. Malyugin, B.; Kalinnikova, S.; Knyazer, B.; Gerasimov, M. Midterm outcomes of autologous glueless simple limbal epithelial transplantation for unilateral limbal stem cell deficiency. – Cornea. - 2023. No. 4. – doi: 10.1097/ICO.0000000000003279].

It is known that the development of SLN is associated with damage and/or death of limbal stem cells (LSC) located in the limbal zone along the periphery of the cornea. Etiological SLN is a consequence of burns, injuries, keratitis, systemic autoimmune and inflammatory diseases. With the loss of functional activity of LSCs responsible for the regeneration and restoration of the epithelial layer, there is an increase in the conjunctival epithelium with newly formed vessels on the surface of the cornea, fibrosis of the Bowman's membrane is formed, as a result of which the thickness and transparency of the cornea changes. GSLET technology, which consists in autologous transplantation of LSCs from a healthy eye into tunnels located along the periphery of the cornea of the affected eye, allows restoring the lost function of LSCs, which contributes to persistent re-epithelialization of the cornea. However, due to the presence of deep stromal opacities of the cornea, such patients have a low functional result, which does not allow achieving high visual acuity.

A method for performing penetrating keratoplasty (PK) in patients after ocular surface reconstruction using simple limbal epithelial transplantation (SLET) technology is known [3. Sangwan VS, Basu S, MacNeil S, Balasubramanian D. Simple limbal epithelial transplantation (SLET): a novel surgical technique for the treatment of unilateral limbal stem cell deficiency. Br J Ophthalmol. 2012;96(7):931-934. doi:10.1136/bjophthalmol-2011-301164. 4. Gupta N, Farooqui JH, Patel N, Mathur U. Early Results of Penetrating Keratoplasty in Patients With Unilateral Chemical Injury After Simple Limbal Epithelial Transplantation. Cornea. 2018;37(10):1249-1254. doi:10.1097/ICO.00000000000001681], in which the recipient's cornea is excised using a disposable hand trephine, then the donor cornea measuring 0.50 mm is sutured to the recipient's cornea with interrupted sutures (nylon 10-0). This method is the closest analogue of the claimed invention.

The disadvantage of this method is that it does not take into account the presence of previously implanted limbal autografts in pockets located on the periphery of the cornea, and therefore is not suitable for patients after reconstruction of the ocular surface using the GSLET technology. The SLET technique initially used in this case involves gluing the amniotic membrane to the corneal surface of the affected eye, followed by adhesive fixation of randomly located limbal autografts on its surface, then a soft contact lens (SCL) is put on.

Using this method of SCP after GSLET, there is a high risk of damaging the tunnels at the stage of corneal trepanation and traumatizing the LSC depots located in them. This can also lead to maladaptation of the corneal transplant and the recipient bed.

A method for reconstructing the corneal epithelial layer in patients with thin corneas is also known in SLN, which involves superficial keratectomy of the cornea and peeling off the superficial stromal layers from the deep ones. Then, radial incisions are made in the paralimbal zone of the cornea, an oblique or horizontal tunnel up to 1.0 mm long is formed in each incision with a peeler, and one microfragment of the limbus taken from a healthy eye (n=8) is placed in each tunnel. An amniotic membrane is applied to the entire surface of the cornea as a protective coating and fixed with a continuous suture outside the limbus (Patent of the Russian Federation for Invention No. 2766166).

The disadvantage of this method is that it involves a one-stage transplantation of limbal fragments using GSLET technology and performing anterior lamellar keratoplasty of the cornea. That is, this technology is not suitable for patients with deep corneal opacities who require SKP.

The objective of this invention is to create a safe and effective method for performing SCP in patients who have undergone epithelial reconstruction using GSLET technology, by mechanical or laser (using a low-energy femtosecond laser, FSL) excision of the affected cornea with a minimum diameter that does not affect the tunnels with limbal micro-grafts.

The technical result of the proposed method is a reduction in the number of intra- and postoperative complications due to excision of the affected cornea of a smaller (relative to limbal microtransplants) diameter and provision of dosed laser operation at the stage of cutting out the cornea, as well as the possibility of controlling the depth of the cut due to the intraoperative optical coherence tomography (OCT) built into the laser. This in turn ensures safe excision of the cornea and subsequent epithelialization of the transplant.

The technical result is achieved by performing retrobulbar anesthesia of the eye before the operation, then treating the surgical field of the recipient eye with a 0.5% chlorhexidine solution or a 5% povidone-iodine solution. The locations of the limbal microtransplants are marked on the patient's cornea with a marker, then, retreating from them within 1-2 mm to the center of the cornea, a mark with a diameter of 6.0 to 8.5 mm is made, depending on the original size of the cornea. Using a trephine from Moria (France) or similar, a through trephine of the cornea is performed until moisture appears from the anterior chamber, then the cornea is cut along the entire circumference with microsurgical scissors and removed. In case of moderate impairment of corneal transparency, in which details of the iris are visualized, this stage can be performed using FSL. To do this, fix the vacuum ring to the eye surface and attach the FSL head to it. During this, the corneal surface is leveled over the entire applanation area, the diameter of which is 6 - 8.5 mm. After that, scan the cornea using the OCT laser built into the handle, specify the location of the microtransplants, the configuration and depth of the through cut. Set the diameter of the through circular cut within 6 - 8.5 mm. Activate the laser and perform a circular cut. The laser operating time is on average 1.5-2.0 minutes. Then deactivate the vacuum and smoothly disconnect the laser head with the vacuum ring from the cornea. The donor cornea is placed in the prepared surgical bed, 4 fixing sutures "silk 8-0" are applied, and then a continuous or 12-18 interrupted suture "nylon 10-0", avoiding the zone of limbal microtransplants. Finally, the CL is applied.

There is a cause-and-effect relationship between the set of essential features and the achieved technical result.

Corneal SKP is the only way to restore vision in patients with SLN and deep corneal opacities. The presence of limbal microtransplants in corneal tunnels along the periphery of the cornea creates risks of additional perforation in the projection of the tunnel and damage to the LSC. The use of FSL and safe excision of the cornea within the limits not affecting stem cells reduces intraoperative risks to minimum values. Thus, due to the LSC, epithelialization of the transplant occurs, which is one of the main conditions for its transparent engraftment and the ability to obtain high clinical and functional results.

The method is illustrated with clinical examples.

Example 1

Patient A., 27 years old, diagnosis: OD Corneal degeneration (condition after glueless simple limbal epithelial transplantation).

During examination: Vis OS 1.0. Vis OD 0.1, does not correct.

OCT of the cornea: OS without pathology. OD - regular epithelium, deep fibrous changes in the stroma, hyperreflective formations (limbal transplants) are visualized in the stromal pockets along the periphery of the cornea.

A penetrating keratoplasty operation was performed according to the proposed method, whereby the locations of the limbal microtransplants are marked within 8.0 mm, then, retreating from them within 2 mm to the center of the cornea, a mark with a diameter of 6.0 mm is made. Using a trephine, penetrating trephination of the cornea is performed until moisture appears from the anterior chamber. A pre-cut donor cornea with a diameter of 6.0 mm is placed in the prepared surgical bed, 4 fixing sutures "silk 8-0" are applied, and then a continuous suture "nylon 10-0", avoiding the zone of the limbal microtransplants. Then the MKL is applied.

After 6 days, the MKL was removed, the transplant was adapted, the sutures were sound, epithelialization was complete, the epithelium was loose.

After 12 months, the stitches were removed, the transplant is transparent, the scar is healthy, epithelialization is complete, the epithelium is regular.

Example 2

Patient V., 43 years old, was hospitalized with the diagnosis:

OS Corneal degeneration (condition after glueless simple limbal epithelial transplantation).

On examination: Vis OD 1.0. Vis OS 0.04.

OCT of the cornea: OD without pathology. OS - regular epithelium, deep fibrous changes in the stroma, hyperreflective formations (limbal transplants) are visualized in the stromal pockets along the periphery of the cornea.

Penetrating keratoplasty was performed according to the proposed method, whereby the locations of the limbal microtransplants are marked within 8.0 mm, then, retreating from them within 1 mm to the center of the cornea, a mark with a diameter of 7.0 mm is made. Then, a vacuum ring is fixed to the surface of the eye on the cornea and the FSL head is attached to it. During this, the corneal surface is leveled over the entire applanation area, the diameter of which is 7.0 mm. After that, the cornea is scanned using the OCT laser built into the handle, the locations of the microtransplants, the configuration and depth of the through cut are specified. The diameter of the through circular cut is set within 7.0 mm. The laser is activated and a circular cut is made. The laser operating time is 2.0 min. Then the vacuum is deactivated and the laser head with the vacuum ring is smoothly disconnected from the cornea. The donor cornea is placed in the prepared surgical bed, 4 fixing sutures "silk 8-0" are applied, and then 12 interrupted sutures "nylon 10-0", avoiding the area of the limbal microtransplants. Then the CL is applied.

After 4 days, the MKL was removed, the transplant was adapted, the sutures were sound, epithelialization was complete, the epithelium was loose.

After 12 months, the stitches were removed, the transplant is transparent, the scar is healthy, epithelialization is complete, the epithelium is regular.

Example 3

Patient L., 37 years old, was hospitalized with a diagnosis of:

OS Corneal degeneration (condition after glueless simple limbal epithelial transplantation).

On examination: Vis OD 1.0. Vis OS 0.05.

OCT of the cornea: OD without pathology. OS - regular epithelium, deep fibrous changes in the stroma, hyperreflective formations (limbal transplants) are visualized in the stromal pockets along the periphery of the cornea.

Penetrating keratoplasty was performed according to the proposed method, marking the locations of the limbal microtransplants within 9.5 mm, then stepping back from them within 1 mm to the center of the cornea, making a mark with a diameter of 8.5 mm. Then, a vacuum ring is fixed to the surface of the eye on the cornea and the FSL head is attached to it. During this, the surface of the cornea is leveled over the entire applanation area, the diameter of which is 8.5 mm. After that, the cornea is scanned using the OCT laser built into the handle, specifying the locations of the microtransplants, the configuration and depth of the through cut. The diameter of the through circular cut is set within 8.5 mm. The laser is activated and a circular cut is made. The laser operating time is 1.5 minutes. Then the vacuum is deactivated and the laser head with the vacuum ring is smoothly disconnected from the cornea. The donor cornea is placed in the prepared surgical bed, 4 fixing sutures "silk 8-0" are applied, and then 18 interrupted sutures "nylon 10-0", avoiding the area of the limbal microtransplants. Then the CL is applied.

After 5 days, the MKL was removed, the transplant was adapted, the sutures were sound, epithelialization was complete, the epithelium was loose.

After 12 days, the stitches are removed, the transplant is transparent, the scar is healthy, epithelialization is complete, the epithelium is regular.

Claims (3)

1. A method for performing penetrating keratoplasty after reconstruction of the ocular surface in patients with limbal insufficiency syndrome, characterized by performing penetrating keratoplasty, distinguished in that the locations of the limbal micrografts are marked on the patient's cornea with a marker, then, stepping back from them within 1-2 mm towards the center of the cornea, a mark with a diameter of 6.0 to 8.5 mm is made, then penetrating trepanation of the cornea is performed until moisture appears from the anterior chamber, at the end of the operation, the donor cornea is placed in the prepared surgical bed, 4 fixing sutures are applied, silk 8-0, and then a continuous or 12-18-node suture, nylon 10-0, avoiding the zone of the limbal micrografts, then a soft contact lens is applied. 2. The method according to item 1, characterized in that the cornea is removed using a trephine and microsurgical scissors. 3. The method according to item 1, characterized in that in case of moderate impairment of corneal transparency, its removal is performed using a femtosecond laser (FSL), for this purpose a vacuum ring is fixed to the surface of the eye and the FSL head is attached to it, after which the cornea is scanned using optical coherence tomography built into the laser handle, the locations of the microtransplants, the configuration and depth of the through cut are specified, the diameter of the through circular cut is set within 6-8.5 mm, the laser is activated and a circular cut is performed, while the laser operating time is 1.5-2.0 min.