Features in dynamics of macular pigment status and central retinal sensitivity in vitreoretinal surgery for diabetic macular edema

Purpose. To identify the features of macular pigment and sensitivity of the central retina in case of vitreoretinal surgery for diabetic macular edema. Material and methods. Vitreoretinal interventions were performed in 31 patients (31 eyes) with diabetic macular edema combined with vitreomacular traction syndrome. All patients underwent the seamless closed 3-port vitrectomy with peeling of internal limiting membrane using the 25G systems. The analysis of retinal changes was carried out according to results of evaluation of optical density of macular pigment and retinal sensitivity pre- and post-operatively. Results. There was revealed a sharp decrease in the parameters of the optical density of macular pigment (ODMP) associated, apparently, with their screening in case of vitreomacular traction syndrome combined with diabetic macular edema. Vitreoretinal intervention led to an increase in the average optical density of the macular pigment by 50.24% indicating a normalization of vitreoretinal interface. Correlative analysis between the parameters of retinal sensitivity and ODMP showed an average correlation (r=-0.66, p<0.05). This indicates a decrease in the functional activity of the retina with the development of the pathologic process in the macular zone. The light sensitivity of the central retina in the examined patients averaged 7.83±0.09 dB before the suergery, and 11.66±0.11 dB (p<0.05) after the surgery. Conclusion. Vitrectomy with peeling of internal limiting membrane depending on diabetic macular edema leads to an increase of light sensitivity and normalization of macular pigment status, that pathogenetically proves an advisability of this surgical technique

Intravitreal Dexamethasone Implant for the Treatment of Patient with Resistant to Anti-VEGF Diabetic Macular Edema

Purpose. To evaluate the effectiveness of intravitreal injection of biodegradable intravitreal implant containing dexamethasone (Ozurdex) in patients with resistant diabetic macular edema (DME).Material and methods. The study was conducted of 24 patients with diabetic macular edema resistant to therapy with angiogenesis inhibitors (3-5 intravitreal injections without a positive structural and functional result) on the background of compensated type 2 diabetes mellitus. A biodegradable intravitreal implant containing dexamethasone (Ozurdex) was injected once according to standard method at a dose of 0.7 mg. The follow-up period was 6 months.Results. According to optical coherence tomography of the macular area, within 6 months after intravitreal injection of Ozurdex implant, the retinal thickness in the fovea decreased on average from 558.4 ± 25.1 μm to 188.3 ± 18.4 μm, with partial restoration of the foveolar cavity. The maximum corrected visual acuity increased on average from 0,04±0,01 to 0,3±0,09, intraocular pressure did not exceed 18.0 mm Hg.Conclusion. If the anti-angiogenic therapy of DME is ineffective, the use of the biodegradable intravitreal implant containing dexamethasone (Ozurdex) is considered as an effective treatment method that provides a significant and stable (prolonged) improvement of the structural and functional parameters of the eye in 86,6% cases

EFFICIENCY OF VITRECTOMY IN COMBINATION WITH INTERNAL LIMITING MEMBRANE PEELING ASSOCIATED WITH THE GAS-AIR TAMPONADE OF THE VITREOUS CAVITY AT THE ADVANCED STAGE OF PROLIFERATIVE DIABETIC RETINOPATHY

Purpose. To evaluate the effectiveness of vitrectomy in combination with internal limiting membrane peeling associated with the gas-air tamponade of the vitreous cavity at the advanced stage of proliferative diabetic retinopathy. Material and methods. The study involved 52 patients (52 eyes) with diabetes mellitus of type 2, who underwent the vitreoretinal surgery with a preliminary antivasoproliferative therapy. In all cases, a traction syndrome was found only from the side of posterior hyaloid proliferative tissue with gliosis of degree II-III, without signs of an epiretinal membrane. In the first group of patients (n=28) the 27-Gauge vitrectomy was performed, with the removal of only posterior hyaloid proliferative tissue followed by a tamponade of the vitreous cavity with a gas-air mixture, and in the second group (n=24) a similar volume of vitreoretinal surgery combined with peeling of the internal limiting membrane was carried out. Results. In all patients, before the combined surgical treatment, the visual acuity averaged 0.06±0.02. Before the treatment in patients of both groups according to optical coherence tomography the thickness of zone «nerve fibers layer – internal limiting membrane» in the macular area averaged 25.38±3.11μm, in the fovea and parafovea – 457.41±36μm and 701.51±24μm, respectively. The mean value of the optical density of the macular pigment before the treatment was 0.094±0.01 du. After the performed vitreoretinal intervention, the visual acuity in patients of the group 1 improved up to 0.10±0.02 (p<0.05), in the group 2 – up to 0.25±0.05 (р1-2><0.05). Six months after vitrectomy, the thickness of zone «nerve fibers layer – internal limiting membrane» in the macular area in patients of the group 1 increased 1.6 times (p><0.05), due to the formation of a secondary epiretinal membrane, which occurred in >< 0.05), in the group 2 – up to 0.25±0.05 (р1-2<0.05). Six months after vitrectomy, the thickness of zone «nerve fibers layer – internal limiting membrane» in the macular area in patients of the group 1 increased 1.6 times (p><0.05), due to the formation of a secondary epiretinal membrane, which occurred in >< 0.05). Six months after vitrectomy, the thickness of zone «nerve fibers layer – internal limiting membrane» in the macular area in patients of the group 1 increased 1.6 times (p< 0.05), due to the formation of a secondary epiretinal membrane, which occurred in 39.2% cases (11/28), 54.5% of cases (6/11) showed traction macular edema, and diabetic macular edema (without epiretinal membrane) was detercted in 28.5% of cases (8/28). In the group 2 of patients, the «nerve fibers layer» zone decreased by 1.5 times (р1-2<0.05), the epiretinal membrane and the traction macular edema were not diagnosed in any case (0/24), but 5 patients (20.8%) had diabetic macular edema (5/24). >< 0.05), the epiretinal membrane and the traction macular edema were not diagnosed in any case (0/24), but 5 patients (20.8%) had diabetic macular edema (5/24).  According to the data of optical coherence tomography, the thickness of the retina in the fovea and parafovea after the combined surgical treatment in patients of the group 1 averaged 212.49±36μm and 365.74±28μm, in the group 2 – 190.11±24μm and 334.18±21μm, respectively (р1-2<0.05). The average value of macular pigment optical density after treatment was 0.109±0.01 du in the group 1 and 0.122 ± >< 0.05). The average value of macular pigment optical density after treatment was 0.109±0.01 du in the group 1 and 0.122 ± 0.01 du in the group 2.  Conclusion. Vitrectomy combined with peeling of the inner limiting membrane in patients with advanced proliferative diabetic retinopathy contributes to obtain a higher visual acuity minimizing a risk of secondary epiretinal membrane and diabetic macular edema

COMPARATIVE ANALYSIS OF AUTOMATIC LAYER-BY-LAYER SEGMENTATION USING OPTICAL COHERENT TOMOGRAPHS DRI OCT AND RETINASCAN-3000 IN HEALTHY PATIENTS

The aim was to determine different possibilities and the operating principle of modern optical coherent tomographs OCT RETINASCAN-3000 and  DRI OCT TRITON in automatic layer-by-layer segmentation of the  retina  and  perioretinal  structures. Methods. The study involved 31 patients (31  eyes) with no retinal pathology in the  macular area. Of these, there were  13 men,  18 women.  The average age  of the  patients was  55.8±3.65  years. Each patient  was  followed by a layered  automatic structuring of the  central  retina  with the help of RetinaScan-3000 (Nidek Technologies)  (1st  group,  n = 31)  and DRI OCT Triton (Topcon Japan) (2nd group,  n = 31)  of the right eye only. The OST device RetinaScan-3000 used  the  mode  macula  multi cross 6 mm,  the  DRI OCT Triton used  the  5 line cross 6 mm mode.Results: The difference in the automatic layer-by-layer segmentation between the optical coherent tomographs DRI OCT TRITON and OCT RETINASCAN-3000 is, first of all, in the unequal coverage of the retina  layers and the preand subretinal space and the number of automatically layered zones.  For example,  OCT RETINASCAN-3000 (SD-OCT) suggests the separation of the transverse optical  section  of the  structures of the  posterior segment of the  eyeball into 5 structural zones  when,  as  DRI OCT TRITON in (SSOCT), further  clearly  isolates  the  preretinal structures  and  the  choroid,  delineating  the  border of the  sclero-choroidal Articulation. The DRI OCT Triton device in the  SS-OCT system allowed for a more  complete differentiation from the  position of layered  delimitation of the  retina  covering  6 retinal  zones  to obtain  digital values  for  coverage of 5 layers  on RetinaScan-3000 (SD OCT).Conclutions: The DRI OCT Triton device with SS-OCT technology has  more  possibilities for topical diagnostics of the  posterior eyeball structures in the autonomous mode  relative to the Retinascan-3000 with SD-OCT technology

Macular oedema as manifestation of diabetic retinopathy

Diabetes mellitus is the third most dangerous disease of our time preceded by cardiovascular diseases and oncologic pathology. According to the International Diabetes Federation (January 1, 2016), worldwide approximately 415 million people aged 2079 years suffer from diabetes. The most significant manifestations of diabetes mellitus are lesions of the retina and blood vessels, which manifest as diabetic retinopathy and macular oedema, which lead to the inevitable loss of vision and disability in patients of working age. The existence of multile diagnostic methods and a broad classification provide an evidence of the complex nature of the pathological process of the macular zone in diabetes mellitus. However, to date, a single, generalised and accepted classification does not exist. Difficulties in the treatment of diabetic maculopathy are attributed to various forms of retinal lesions and ambiguities in the approach used to choose the disease management. It determines the importance of the development of diagnostic methods for the further correction of the standard treatment approach. New directions of surgical treatment allow relying on the best results of diabetic maculopathy treatment