RU2804717C1 - Method for removing the internal limiting membrane of the retina - Google Patents

Abstract

FIELD: ophthalmology.

SUBSTANCE: used to remove the internal limiting membrane of the retina (ILM). For this purpose, subtotal vitrectomy is performed. The ILM is stained, peeled from the periphery to the center. During peeling, an OCT scan of the retina is performed in a plane perpendicular to the peeling direction. The degree of neuroepithelial detachment in the area of the separation point of the ILM from the retina is determined. If the neuroepithelium is detached with a height of less than ½ of the retinal thickness, peeling is continued in the same direction until the ILM is completely separated and the ILM is removed as a single unit. When the neuroepithelium is detached with a height of ½ or more of the retinal thickness, peeling in this zone is stopped and it is carried out in the same way further sequentially in adjacent quadrants.

EFFECT: prevention of ruptures and atrophic changes in the retina in the postoperative period while maintaining central vision and increasing visual acuity after surgery.

1 cl, 4 ex

Description

The invention relates to the field of medicine, namely to ophthalmology, and can be used to remove the internal limiting membrane of the retina.

Peeling of the internal limiting membrane (ILM) is a technically complex manipulation that is performed during the surgical treatment of macular pathology. The internal limiting membrane preserved during surgery can serve as a matrix for the development of the epiretinal membrane or the development of relapse of epimacular fibrosis [Zakharov V.D., Shkvorchenko D.O., Kakunina S.A., Norman K.S., Fozilova F.F. The effectiveness of peeling of the internal limiting membrane against the background of silicone tamponade in rhegmatogenous retinal detachment. Tauride Medical-Biological Bulletin. 2018; 21(4): 23-27].

During visual inspection during ILM removal, it is not always possible to assess the degree of ILM adhesion to the retina, and this seems necessary, since excessive traction during ILM peeling can lead to the formation of hemorrhages and iatrogenic retinal tears. Recently, the use of intraoperative OCT monitoring has become increasingly popular. I-OCT control makes it possible to prevent such complications of ILM peeling as detachment of the “lid” of retinal cysts, detachment of the layer of nerve fibers tightly attached to the ILM and to assess the degree of ILM adhesion to the retina [Ashurov A, Chronopoulos A, Heim J, Schutz JS, Arndt C , Hattenbach LO. Real-Time (iOCT) Guided Epiretinal Membrane Surgery Using a Novel Forceps with Laser-Ablated Microstructure Tip Surface. Clin Pract. 2022 Oct 10; 12(5):818-825. doi: 10.3390/clinpractl2050086. PMID: 36286072; PMCID: PMC9599977; Tuifua TS, Sood AB, Abraham JR, Srivastava SK, Kaiser PK, Sharma S, Rachitskaya A, Singh RP, Reese J, Ehlers JP. Epiretinal Membrane Surgery Using Intraoperative OCT-Guided Membrane Removal in the DISCOVER Study versus Conventional Membrane Removal. Ophthalmol Retina. 2021 Dec; 5(12):1254-1262. doi: 10.1016/j.oret.2021.02.013. Epub 2021 Feb 27. PMID: 33647472; PMCID: PMC8390556].

There is a known method of peeling the ILM in the surgical treatment of macular edema, which is carried out as follows: stain with Membrane Blue Dual dye and remove the posterior hyaloid, epiretinal and internal limiting membranes under intraoperative OCT control in order to minimize trauma to the retina in the projection of intraretinal cysts. Peeling of the ILM is performed circularly, starting from the place with the lowest photosensitivity according to microperimetry data. Having grabbed the ILM with tweezers, it is separated over 2-3 hour meridians with a movement directed along the arc of an imaginary circle with the center in the foveola. The ILM isolated along the arc is intercepted and its further separation is carried out in a circular motion. If, according to intraoperative OCT data, a hyporeflective formation (cyst) with a diameter of more than 200 μm is detected in the foveal projection, ILM peeling is completed at the site of the beginning of the cyst in order to neutralize the risk of developing a lamellar macular hole. The flap of the separated ILM is removed with a vitreotome. The disadvantage of this method is that it only monitors the condition of the inner layer of the retina, to prevent the removal of the “lid” of the intraretinal cyst; the degree of traction when peeling the ILM to the retina outside the area of intraretinal cysts is not assessed (Patent RU 2687592, 08/12/2018).

There is a known method of ILM peeling, in which 5-7 consecutive series are performed, each of which includes the following set of actions: 2.0-2.5 mm to the inferotemporal arcade from the foveola, the tip of the internal limiting membrane (ILM) is separated from the retina. Next, grasping the tip of the ILM with tweezers, the membrane is separated over 2-3 hour meridians with a movement directed along the arc of an imaginary circle with the center in the foveola. Make sure that the area of the retina at a distance of 1.0-1.2 mm from the foveola is intact. The ILM separated along the arc is intercepted at the end point and, moving along the radius of the circle, the ILM is separated, not reaching the foveola 0.5-0.8 mm. An interception is performed at the end point and the ILM is separated over 2-3 hour meridians in the opposite direction. The separation of this section of the ILM is completed with a movement directed along the radius, thus arriving at the initial point. Thus, a foveal fragment of the ILM is formed around the fovea, surrounded by a retinal zone without the ILM in the form of an open ring. The last section of the ILM is removed so as to prevent the ring from closing. The remaining jumper is lifted with microtweezers by the edge at the outer border and separated towards the center, stopping at a distance of 0.5-0.8 mm from the foveola, and the jumper is removed using a vitreotome. The disadvantage of this method is the lack of assessment of the degree of adhesion of the ILM to the adjacent retina and the force of traction on the inner layers of the retina (Patent RU 2563438, 10/15/2014).

This method is accepted as the closest analogue.

The objective of this invention is to develop a method for removing (peeling) the ILM with minimal risk of developing intra- and postoperative complications.

The technical result of the method is the prevention of ruptures and atrophic changes in the retina in the postoperative period while maintaining central vision and increasing visual acuity after surgery.

The technical result is achieved by determining the degree of neuroepithelial detachment in the area of the “point of separation” of the ILM from the retina using intraoperative OCT to determine further tactics for removing the ILM.

The method is carried out as follows

Subtotal vitrectomy, ILM staining, and ILM peeling from the periphery to the center are performed. During peeling, an OCT scan of the retina is performed in a plane perpendicular to the peeling direction. The degree of neuroepithelial detachment in the area of the “separation point” of the ILM from the retina is determined. If the neuroepithelium is detached with a height of less than ½ of the retinal thickness, peeling is continued in the same direction until the ILM is completely separated. Thus, the ILM is removed en bloc. When the neuroepithelium is detached with a height of ½ or more of the retinal thickness, peeling in this zone is stopped and it is carried out in the same way further sequentially in adjacent quadrants.

This method was used during surgical treatment of 10 patients. The postoperative period was uneventful, the patients' visual acuity improved. There were no breaks or atrophic changes in the retina. The method is illustrated by clinical examples.

Clinical example 1

Patient G., 52 years old, was admitted with a diagnosis of proliferative diabetic retinopathy, epimacular fibrosis, and initial cataract of the left eye. The maximum corrected visual acuity of the left eye (BCVA) was 0.6. According to OCT data, the profile of the fovea is smoothed, the heterogeneity of the inner and outer layers of the retina is visualized, and a hyperreflective membrane is visualized on the surface of the retina in the macular zone. Under local anesthesia, surgical treatment was performed on the left eye according to the proposed method: subtotal vitrectomy, staining of the ILM, peeling of the ILM from the periphery to the center was performed. During peeling, an OCT scan of the retina was performed in a plane perpendicular to the peeling direction. The degree of neuroepithelial detachment in the area of the “separation point” of the ILM from the retina was determined. The degree of neuroepithelial detachment in the area of the “point of separation” of the ILM from the retina was less than ½ the thickness of the retina, so peeling was continued in the same direction until the ILM was completely separated. Thus, the ILM was removed en bloc. The operation was completed by tamponade of the vitreal cavity with a gas-air mixture (sulfur hexafluoride - 20%), suturing the sclerostome. 1 week after surgery, BCVA of the left eye was 0.6. The patient was observed for 3 months. When examined after 3 months. after surgery, BCVA was 0.9. According to OCT data - no negative dynamics, no iatrogenic breaks, no atrophic changes in the retinal neuroepithelium.

Clinical example 2

Patient G., 52 years old, was admitted with a diagnosis of proliferative diabetic retinopathy, partial hemophthalmos, and initial cataract of the left eye. Maximum corrected visual acuity of the left eye (BCVA) 0.01. Preoperative OCT was not possible due to the opacity of the optical media. Under local anesthesia, surgical treatment was performed on the left eye according to the proposed method: subtotal vitrectomy, staining of the ILM, peeling of the ILM from the periphery to the center was performed. During peeling, an OCT scan of the retina was performed in a plane perpendicular to the peeling direction. The degree of neuroepithelial detachment in the area of the “separation point” of the ILM from the retina was determined. The degree of neuroepithelial detachment in the area of the “separation point” of the ILM from the retina was more than ½ the thickness of the retina, so peeling in this quadrant was stopped and moved to the adjacent quadrant. During peeling of the ILM in the adjacent quadrant, an OCT scan of the retina was performed in a plane perpendicular to the direction of peeling. The degree of neuroepithelial detachment in the area of the “separation point” of the ILM from the retina was determined. The degree of neuroepithelial detachment in the area of the “point of separation” of the ILM from the retina was ½ the thickness of the retina, so peeling in this quadrant was stopped and moved to the adjacent quadrant. During peeling of the ILM in the adjacent quadrant, an OCT scan of the retina was performed in a plane perpendicular to the direction of peeling. The degree of neuroepithelial detachment in the area of the “separation point” of the ILM from the retina was determined. The degree of neuroepithelial detachment in the area of the “separation point” of the ILM from the retina was less than ½ the thickness of the retina, so peeling was continued in the same direction until the ILM was completely separated. The separated ILM was cut off using a vitreotome. The operation was completed by tamponade of the vitreal cavity with a gas-air mixture (sulfur hexafluoride - 20%), suturing the sclerostome. 1 week after surgery, BCVA of the left eye was 0.5. The patient was observed for 3 months. When examined after 3 months. after surgery, BCVA was 0.6. According to OCT data, the foveal profile is preserved, the parafoveal section of the ILM is preserved, there are no signs of iatrogenic ruptures or atrophic changes in the retinal neuroepithelium.

Clinical Case 3

Patient B., 63 years old, was admitted with a diagnosis of epiretinal fibrosis, nonproliferative diabetic retinopathy, and diabetic macular edema of the left eye. The maximum corrected visual acuity of the left eye (BCVA) was 0.08. According to OCT data, the profile of the fovea is smoothed, the heterogeneity of the inner and outer layers of the retina is visualized, there are multiple hypoechoic cavities in the neuroepithelium, and a hyperreflective membrane is visualized on the surface of the retina in the macular zone. Under local anesthesia, surgical treatment was performed on the left eye: three-port vitrectomy with removal of epimacular fibrosis and ILM. During the operation, pronounced traction was visually observed at the point of application of the tweezers, but the ILM was removed completely within the vascular arcades. The operation was completed by tamponade of the vitreal cavity with a gas-air mixture (sulfur hexafluoride - 20%), suturing the sclerostome. 1 week after surgery, BCVA was 0.2; According to ophthalmoscopy and OCT, the retina in the macular zone straightened, the size of hypoechoic inclusions decreased significantly. The patient was observed for 3 months. When examined after 3 months. after surgery, BCVA was 0.1. According to OCT data, there is a decrease in the central thickness of the retina to 220 µm, and in the neuroepithelium there is heterogeneity of layers. In the absence of proper control over the adhesion of the ILM to the retina, it was not possible to exclude the development of neuroepithelial subatrophy in the long-term postoperative period.

Clinical Case 4

Patient S., 67 years old, was admitted with a diagnosis of epimacular fibrosis and an emerging lamellar rupture in the left eye. Maximum corrected visual acuity of the left eye (BCVA) 0.5. According to OCT data, the surface of the retina has folds of the inner layers, single hypoechoic cavities in the neuroepithelium parafoveolar and in the fovea, on the surface of the retina there is a hyperreflective dense membrane with a tangential traction component. Under local anesthesia, a surgical procedure was performed on the left eye: three-port vitrectomy for epimacular fibrosis and ILM, with i-OCT control. During the operation, pronounced traction was visually observed at the point of application of the tweezers during peeling of the ILM in the foveal region, but the ILM was removed completely within the vascular arcades. The operation was completed by tamponade of the vitreal cavity with a gas-air mixture (sulfur hexafluoride - 20%), suturing the sclerostome. 1 week after surgery, BCVA was 0.4; According to ophthalmoscopy and OCT, the retina in the macular zone straightened, the size of hypoechoic inclusions decreased significantly, but a lamellar retinal break was visualized in the foveal zone. The patient was observed for 3 months. When examined after 3 months. after surgery, BCVA was 0.5. According to OCT data, a lamellar rupture was diagnosed. Thus, with uncontrolled removal of the ILM in the foveal area in the presence of neuroepithelial cysts, the development of a lamellar rupture due to the separation of the “lid” of the cyst cannot be ruled out.

Thus, the proposed method for removing the ILM under intraoperative OCT control, taking into account the degree of neuroepithelial detachment in the area of the “point of separation” of the ILM from the retina, makes it possible to prevent ruptures and atrophic changes in the retina in the postoperative period and preserve central vision and increase visual acuity after surgery.

Claims (1)

A method for removing the internal limiting membrane of the retina (ILM), including performing subtotal vitrectomy, staining the ILM, peeling the ILM from the periphery to the center, characterized in that during peeling an OCT scan of the retina is performed in a plane perpendicular to the direction of peeling and the degree of neuroepithelial detachment in the area is determined “points of separation” of the ILM from the retina and when the neuroepithelium is detached with a height of less than ½ of the retinal thickness, peeling is continued in the same direction until the ILM is completely separated; if the neuroepithelium is detached with a height of ½ or more of the retinal thickness, peeling in this area is stopped and it is carried out in the same way further sequentially in adjacent quadrants.