Iurii Belyi_SCIENTIFIC POSTER 2015_1

Purpose:

To develop an optimized mechanical method of internal limiting membrane peeling.

Method:

We observed 3 patients with cystic macular edema of various etiologies. All patients were examined before and after the operation for: best corrected visual acuity (BCVA), intraocular pressure, perimetry, optical coherence tomography (OCT) (Stratus, Carl Zeiss Meditec) and retina photography. According to the data from OCT all patients suffered from initial stage of fibrosis of internal limiting membrane. Taking into consideration high visual function (0.4-0.6 decimal), the decision was made to carry out delicate ILM peeling in order to minimize traumas of interference. Operation technique. In all cases a standard transconjunctival 3-port 25 gauge pars plana vitrectomy has been done, with a cutting rate from 2500 to 5000 cuts per minute, vacuum from 5 to 400 mmHg. The separation of posterior hyaloid membrane was carried out with the help of aspiration technique, starting from the disk of optic nerve, then continually lifting it up to the sides. ILM peeling procedure was carried out in the following manner. Stepping back from the center of fovea 2.0-2.5 mm to the lower temporal arcade, we defined the part of retina for the first action. Then with a vitreoretinal forceps we separated the ILM from retina. Taken hold of the edge of ILM, in circular movement, keeping an equal distance from the center, we carried out undermine the membrane at 2-3 meridian hours, controlling the distance from intact fovea area. Then we strangulated circled separated ILM close to the non-separated ILM and moved to the center backwards. Reaching a point of 0.5-0. 8 mm from the center we carried out next interception and changed the direction circularly, thereby the center was left intact. Separation of the given part of ILM was finished by connecting the edge of still attached ILM with the radial part. Then, following to the described methodology, in roundabout movements we carried out the peeling of particular parts of ILM, the number of which differed from 5 to 7 depending on the adhesion density to the retina, the intensity of fibrosis of ILM and the presence of epiretinal membranes tightly connected with the ILM. In the process of the last part removal, before interlocking circle edges we left a small intersection to prevent spontaneous peeling of central part of ILM. Remained part of intersection was lifted up carefully by a forceps holding the edge, moving from periphery to the center and finalize the peeling at the distance of 0.5-0.8 mm from fovea. This method reminds the process of removal petals from a flower. Upon completing the formation of central circle of remained part of ILM we carried out separation of its edges in the direction of center in the form of «basket». Then using the head of vitreous cutter 25 gauge (frequency 5000 cuts per minutes, vacuum 5 mmHg) we lifted and connected the edges of separated ILM in the center very carefully. The operation was completed by transconjunctival scleral suturing of the sclerotomies with 8-00 vicryl material. In one case fluid – air – SF6 gas exchange was made through a 30 gauge needle in order to achieve a light postoperative hypertension.

Results:

In all cases surgical procedures were made according to the developed technology. One patient developed small preretinal hemorrhages, appeared as a result of mechanical pickups of ILM, which disappeared in a week by itself. In the one month follow up examination one patient improved BCVA from 0.4 to 0.7. In all other cases BCVA remained the same. According to the data fovea structures could not been clearly differentiated, with different reflectivity levels in the photoreceptor layer from higher reflectivity of inner layers to low reflectivity of photoreceptor layer in foveola.

Conclusion:

The suggested methodology could help minimise the traumatic interference and represents an additional tool in the hands of vitreoretinal surgeon for safer ILM removal.

Contact Details:

Email: nauka@mntk.kaluga.ru
Cell Phone: +74842505795