Die vitreoretinale Grenzfläche und ihre Rolle in der Pathogenese vitreomakulärer Erkrankungen

Pars plana vitrectomy for vitreoretinal interface disorders coincident with intermediate stage age-related macular degeneration

BACKGROUND AND AIMS

Currently around 67 million people in Europe are affected by some form of age-related macular degeneration (AMD). As most known types of vitreoretinal (VR) interface disorders can coexist with AMD and as we can favourably affect the former with vitreoretinal surgery, our goal was to evaluate the results of vitreoretinal interface disorder surgery with macular peeling in relation to coincident intermediate stage AMD.

METHODOLOGY

This was a retrospective evaluation of eyes operated with 25-gauge pars plana vitrectomy (PPV). The monitored parameters were anatomical and functional findings and, safety of the procedure. The surface of the macula was stained with trypan blue and treated (peeling) with a disposable microforceps. 10% perfluoropropane, or the air tamponade was used. Distance visual acuity was examined on the ETDRS chart, the macular finding was monitored by OCT and photodocumented. The post-operative face-down position was 3-5 days. The follow-up period was 6 months.

RESULTS

17 eyes (14 patients, woman 86%) mean age 74 years. The primary indications for the procedure were: idiopathic macular hole (IMD) 59%, epiretinal membrane 29% and vitreomacular traction syndrome 12%. Ophthalmoscopic and OCT findings of intermediate dry form of AMD (100%), in 24% was drusoid ablation of the pigment leaf. In all cases of IMD, primary closure occurred. Input visual acuity 0.1-0.6 improved to 0.2-0.9 at the end of the follow-up period (P<0.05). No complications during surgery or progression of AMD in the follow-up period were observed.

CONCLUSION

PPV for vitreoretinal interface disorders have similar anatomical results, whether the outer part of the retina is disrupted by intermediate AMD or not. Functional results are affected by possible disruption of the RPE or the outer layers of the neuroretina by AMD. The PPV procedure has a standard security profile. It is safe and does not affect the progression of AMD in the short term.

Bacterial endophthalmitis following anti-VEGF intravitreal injections: a retrospective case series

BACKGROUND

To describe the incidence of endophthalmitis and the treatment outcomes of acute bacterial endophthalmitis following intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections in a Brazilian hospital. The analysis was based on the timing of infection after intravitreal injection, culture results, visual acuity, and the presence of epiretinal membrane after a 1-year follow-up period, spanning nine years.

METHODS

This retrospective case series, conducted over a 9-year period, aimed to evaluate the treatment outcomes of acute endophthalmitis following intravitreal Bevacizumab injections. The inclusion criteria involved a chart review of 25 patients who presented clinical signs of acute endophthalmitis out of a total of 12,441 injections administered between January 2011 and December 2019. Negative culture results of vitreous samples or incomplete data were excluded. Ultimately, 23 patients were enrolled in the study. Eight patients were treated with intravitreal antibiotic injections (IVAI) using vancomycin 1.0 mg/0.05mL and ceftazidime 2.25 mg/0.05mL, while 15 patients underwent pars plana vitrectomy (PPV) followed by intravitreal antibiotic injections at the end of surgery (IVAIES). The main outcome measures were the efficacy of controlling the infection with IVAI as a standalone therapy compared to early PPV followed by IVAIES. Data collected included pre-infection and one-year post-treatment best corrected visual acuity (BCVA), optical coherence tomography (OCT) abnormalities, and enucleation/evisceration rates. To compare groups, Mann-Whitney and ANOVA tests were employed for statistical analysis.

RESULTS

The incidence rate of bacterial endophthalmitis was 0.185% (1/541 anti-VEGF injections), with the highest infection rates observed in 2014 and 2017. Patients presented clinical symptoms between 2 and 7 days after injection. The most common isolated organisms were coagulase-negative Staphylococci and Streptococci spp. Treatment outcomes showed that both IVAI and PPV + IVAIES effectively controlled the infection and prevented globe atrophy. After one year, the PPV group with BCVA better than Light Perception had a significantly better BCVA compared to the IVAI group (p 0.003). However, PPV group had higher incidence of epiretinal membranes formation compared to the IVAI group. (P 0.035) CONCLUSION: Anti-VEGF injections carry a risk of developing acute bacterial endophthalmitis. Isolated antibiotic therapy could be an effective treatment to control the infection, but performing PPV + IVAIES as a primary treatment showed promising results in terms of improving BCVA after one year, despite a higher rate of epiretinal membrane formation. Further studies are needed to confirm these findings.

3-D OCT imaging of hyalocytes in partial posterior vitreous detachment and vaso-occlusive retinal disease

Purpose

To describe the spatial distribution and morphologic characteristics of macrophage-like cells called hyalocytes in the posterior vitreous cortex of a patient with unilateral partial posterior vitreous detachment (PVD) using coronal plane en face optical coherence tomography (OCT).

Observations

A 54-year-old male with sickle cell disease (HbSC genotype) presented with a partial PVD in one eye. Rendered volumes of a slab extending from 600 μm to 3 μm anterior to the inner limiting membrane (ILM) revealed hyperreflective foci in the detached posterior vitreous cortex suspended anterior to the macula, likely representing hyalocytes. In the fellow eye without PVD, hyperreflective foci were located 3 μm anterior to the ILM. The morphology of the cells in the eye with PVD varied between a ramified state with multiple elongated processes and a more activated state characterized by a plump cell body with fewer retracted processes. In the same anatomical location, the hyperreflective foci were 10-fold more numerous in the patient with vaso-occlusive disease than in an unaffected, age-matched control.

Conclusions and Importance

Direct, non-invasive, and label-free techniques of imaging cells at the vitreoretinal interface and within the vitreous body is an emerging field. The findings from this case report suggest that coronal plane en face OCT can be used to provide a detailed and quantitative characterization of cells at the human vitreo-retinal interface in vivo. Importantly, this case report demonstrates that 3D-OCT renderings can enhance visualization of these cells in relation to the ILM, which may provide clues concerning the identity and contribution of these cells to the pathogenesis of vitreo-retinal diseases.

Retinal Vascular Tortuosity Index Change after Idiopathic Epiretinal Membrane Surgery: Does Internal Limiting Membrane Peeling Affect Retinal Vascular Tortuosity?

BACKGROUND

Idiopathic epiretinal membrane (iERM) surgery is one of the most commonly performed vitreoretinal surgeries, and the issue of internal limiting membrane (ILM) peeling in ERM surgery is still controversial. The aims of this study are to evaluate the changes in retinal vascular tortuosity index (RVTI) after pars plana vitrectomy for the iERM using optical coherence tomography angiography (OCTA) and to assess whether ILM peeling has an additional effect on RVTI reduction.

METHODS

This study included25 eyes of 25 iERM patients who underwent ERM surgery. The ERM was removed without ILM peeling in 10 eyes (40.0%), and the ILM was peeled in addition to the ERM in 15 eyes (60.0%). The existence of the ILM after ERM peeling was checked with second staining in all eyes. Best corrected visual acuity (BCVA) and 6 × 6 mm en-face OCTA images were recorded before surgery and at the first month postoperatively. A skeleton model of the retinal vascular structure was created following Otsu binarization of en-face OCTA images using ImageJ software (1.52U). RVTI was calculated as the ratio of each vessel length to its Euclidean distance on the skeleton model using the Analyze Skeleton plug-in.

RESULTS

The mean RVTI declined from 1.220 ± 0.017 to 1.201 ± 0.020 (p = 0.036) in eyes with ILM peeling and from 1.230 ± 0.038 to 1.195 ± 0.024 in eyes without ILM peeling (p = 0.037). There was no difference between the groups in terms of postoperative RVTI (p = 0.494). A statistically significant correlation was found between postoperative RVTI and postoperative BCVA (rho = 0.408, p = 0.043).

CONCLUSIONS

The RVTI is an indirect indicator of the traction created by the iERM on retinal microvascular structures, and it was effectively reduced after iERM surgery. The postoperative RVTIs were similar in cases who underwent iERM surgery with or without ILM peeling. Therefore, ILM peeling may not have an additive effect on the loosening of microvascular traction and thus may be reserved for recurrent ERM surgeries.

Deciphering the Molecular Signature of Human Hyalocytes in Relation to Other Innate Immune Cell Populations

Purpose

Hyalocytes are the tissue-resident innate immune cell population of the vitreous body with important functions in health and vitreoretinal disease. The purpose of this study is to gain new insights into the biology and function of human hyalocytes in comparison to other innate immune cells.

Methods

The present study applies fluorescence-activated cell sorting and RNA sequencing to compare the transcriptional profiles of human hyalocytes, retinal microglia (rMG) and classical, intermediate, and non-classical monocytes isolated from the same patients. Immunohistochemistry was applied for morphological characterization of human hyalocytes.

Results

Pairwise analysis indicates distinct differences between hyalocytes and monocytes, whereas a high degree of similarity to rMG is apparent, with comparable expression levels of established microglia markers, such as TREM2, P2RY12, and TMEM119. Among the top expressed genes in hyalocytes, SPP1, CD74, and C3, were significantly upregulated when compared with monocytes. Despite the high level of similarity of hyalocytes and rMG, ten highly expressed genes in hyalocytes compared to microglia were identified, among them FOS, DUSP1, and EGR2.

Conclusions

This study reveals a high degree of similarity between hyalocytes and retinal microglia. Nevertheless, hyalocytes exhibit some expression differences that may adapt them to the specific needs of the vitreous and provide the basis for deciphering the multiple roles of this fascinating cell population in health and vitreoretinal diseases.

Epiretinal membrane: A review

The prevalence of epiretinal membrane (ERM) is 7% to 11.8%, with increasing age being the most important risk factor. Although most ERM is idiopathic, common secondary causes include cataract surgery, retinal vascular disease, uveitis and retinal tears. The myofibroblastic pre-retinal cells are thought to transdifferentiate from glial and retinal pigment epithelial cells that reach the retinal surface via defects in the internal limiting membrane (ILM) or from the vitreous cavity. Grading schemes have evolved from clinical signs to ocular coherence tomography (OCT) based classification with associated features such as the cotton ball sign. Features predictive of better prognosis include absence of ectopic inner foveal layers, cystoid macular oedema, acquired vitelliform lesions and ellipsoid and cone outer segment termination defects. OCT-angiography shows reduced size of the foveal avascular zone. Vitrectomy with membrane peeling remains the mainstay of treatment for symptomatic ERMs. Additional ILM peeling reduces recurrence but is associated with anatomical changes including inner retinal dimpling.

The vitreopapillary interface in healthy and glaucoma: posterior vitreous detachment in the vitreopapillary interface study

PURPOSE

To investigate the vitreopapillary interface (VPI) in health and glaucoma according to the different stages of posterior vitreous detachment (PVD) formation.

METHODS

Prospective single centre study including healthy subjects and glaucoma patients. PVD staging was performed with spectral domain optical coherence tomography. Gender, age, lens status and refractive error were assessed in both groups. Glaucoma patients additionally had a comprehensive ophthalmological investigation including intraocular pressure measurement, visual field testing and confocal imaging of the optic nerve head.

RESULTS

Data on 523 subjects (993 eyes) were included from the VPI study (clinicaltrials.gov NCT02290795) database (493 eyes of 258 healthy subjects and 500 eyes of 265 glaucoma patients). Healthy subjects were significantly younger than primary open angle glaucoma patients (59.7 ± 14.81 versus 70.0 ± 10.78 years, p < 0.001), but were otherwise matched for refractive error and gender. Significantly more glaucomatous eyes were pseudophakic (26.6% versus 5.1%). Including only phakic nonoperated eyes from subjects between 50 and 80 years old decreased the age difference between healthy and open angle glaucoma (64.1 ± 8.0 versus 65.9 ± 6.7 years, p = 0.051). Comparing these subgroups rendered similar average ages for PVD stages 0 and 4, in contrast to the significant older age for the glaucoma subgroup in stage 1 (64.1 ± 6.01 versus 61.4 ± 8.38 years, p < 0.001) and a trend towards significance in stage 3 (70.8 ± 69.8 versus 67.5 ± 5.92 years, p = 0.051).

CONCLUSION

The VPI study is a large clinical trial investigating the VPI in health and glaucoma. A subset of glaucoma patients seems to experience stages 1-3 of PVD formation at older age compared to healthy subjects.

Long-term follow-up of fellow eye in patients with lamellar macular hole

BACKGROUND

To evaluate macular changes in fellow eyes of patients diagnosed with lamellar macular hole (LMH) using spectral-domain optical coherence tomography (SD-OCT) and blue fundus autofluorescence (B-FAF).

METHODS

Fellow eyes of patients diagnosed with a LMH were retrospectively evaluated on OCT. Best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were recorded. Corresponding B-FAF images, vitreo-macular relations, and type of epiretinal membranes (ERMs) were also examined.

RESULTS

Thirty-five patients were included. At baseline, six fellow eyes (17%) showed a normal foveal profile, 26 (74%) had a tractional ERM, and three cases (9%) revealed a bilateral LMH, one of them with a lamellar hole-associated epiretinal proliferation (LHEP). A posterior vitreous detachment (PVD) was present in 29 patients (83%), four (11%) had only a vitreo-papillary adhesion (VPA), and two (6%) had both vitreo-macular adhesion (VMA) and VPA. After a mean follow-up of 4.6 ± 1.9 years, one eye (3%) developed a vitreous detachment from the macula with persistent VPA, and one developed a PVD from a VPA with subsequent ERM formation. BCVA and mean CFT remained stable in 35 eyes (100%). Likewise, no B-FAF signal variations were detected. One patient developed a LMH during the 3rd year of follow-up.

CONCLUSIONS

Our data suggest that the presence of a LMH in one eye does not increase significantly the risk of developing the same condition in the fellow eye after 4 years. Bilateral condition is uncommon, and an ERM is often detected in the fellow eye. LHEPs were not observed in fellow eyes with foveal integrity, and all LHEPs observed (in main and fellow eyes) were always associated with LMHs; this supports the hypothesis that LHEP is a consequence and not a causative factor for LMHs. The occurrence of a LMH in one fellow eye after 3 years follow-up may suggest that a higher incidence of bilateral disease could develop in a longer time span.

IMAGING AND MEASUREMENT OF THE PRERETINAL SPACE IN VITREOMACULAR ADHESION AND VITREOMACULAR TRACTION BY A NEW SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY ANALYSIS

PURPOSE

To evaluate a new method for volumetric imaging of the preretinal space (also known as the subhyaloid, subcortical, or retrocortical space) and investigate differences in preretinal space volume in vitreomacular adhesion (VMA) and vitreomacular traction (VMT).

METHODS

Nine patients with VMA and 13 with VMT were prospectively evaluated. Automatic inner limiting membrane line segmentation, which exploits graph search theory implementation, and posterior cortical vitreous line segmentation were performed on 141 horizontal spectral domain optical coherence tomography B-scans per patient. Vertical distances (depths) between the posterior cortical vitreous and inner limiting membrane lines were calculated for each optical coherence tomography B-scan acquired. The derived distances were merged and visualized as a color depth map that represented the preretinal space between the posterior surface of the hyaloid and the anterior surface of the retina. The early treatment d retinopathy study macular map was overlaid onto final virtual maps, and preretinal space volumes were calculated for each early treatment diabetic retinopathy study map sector.

RESULTS

Volumetric maps representing preretinal space volumes were created for each patient in the VMA and VMT groups. Preretinal space volumes were larger in all early treatment diabetic retinopathy study map macular regions in the VMT group compared with those in the VMA group. The differences reached statistical significance in all early treatment diabetic retinopathy study sectors, except for the superior outer macula and temporal outer macula where significance values were P = 0.05 and P = 0.08, respectively. Overall, the relative differences in preretinal space volumes between the VMT and VMA groups varied from 2.7 to 4.3 in inner regions and 1.8 to 2.9 in outer regions.

CONCLUSION

Our study provides evidence of significant differences in preretinal space volume between eyes with VMA and those with VMT. This may be useful not only in the investigation of preretinal space properties in VMA and VMT, but also in other conditions, such as age-related macular degeneration, diabetic retinopathy, and central retinal vein occlusion.

[Effect of autologous platelet concentrates on the anatomical and functional outcome of late stage macular hole surgery: A retrospective analysis]

BACKGROUND

The macular hole (MH) is a disorder of the visual center of the retina in humans. An untreated MH leads to loss of central visual acuity and reading ability. Surgery for early-stage macular holes has been very successful for many years and leads to very good anatomical and functional results. Despite continuous improvement of surgical procedures, the outcome for the later stages of MH is still unsatisfactory.

METHOD

In a retrospective analysis, we investigated the effect of autologous platelet concentrates in patients presenting later stages of MHs (stage III-IV) with respect to anatomic success (hole closure) and recovery of vision. The application of platelets was performed during retinal surgery (pars plana vitrectomy, ppV). In addition, selected platelet concentrates were qualitatively analysed for growth factors and platelet adhesion.

RESULTS

In the first group, 74% of the patients showed a good anatomical macular hole closure. The analyses of the platelet concentrates indicated a possible wound-healing effect due to growth factors (e.g. the platelet-derived growth factor, PDGF) and lesser to the ability of the platelets to adhere after ristocetin administration. Further optimization of the production process of platelet concentrates and of the surgical procedure in the second group of patients showed an increase of the anatomical success (92%) and a very rapid increase of visual acuity within six weeks.

DISCUSSION

In the past, the primary goal of MH surgery was to optimize the surgical procedures. Only few concepts focused on wound healing. Based on our data, we postulate the use of autologous platelet concentrates in MH surgery as a healing concept, which helps to increase the functional success of late-stage macular hole surgery.

Functional and Morphological Correlations before and after Video-Documented 23-Gauge Pars Plana Vitrectomy with Membrane and ILM Peeling in Patients with Macular Pucker

Purpose. To assess functional and morphological alterations following video-documented surgery for epiretinal membranes. Methods. Forty-two patients underwent video-documented 23-gauge vitrectomy with peeling of epiretinal (ERM) and inner limiting membrane (ILM). Patient assessment was performed before and 3 and 6 months including best corrected visual acuity (BCVA), slit lamp biomicroscopy, SD-OCT, and central 2° and 18° microperimetry. In addition, all video-documented areas of peeling on the retinal surface were evaluated postoperatively using an additional focal 2° microperimetry. Retinal sensitivity and BCVA were correlated with morphological changes (EZ and ELM) in the foveal region and in regions of membrane peeling. Results. Overall, BCVA increased from 0.6 (±0.2) to 0.2 (±0.2) logMAR after 6 months with an increase in retinal sensitivity (17.9 ± 2.7 dB to 26.8 ± 3.1 dB, p < 0.01). We observed a significant correlation between the integrity of the EZ but not of the ELM and the retinal sensitivity, overall and in peeling areas (p < 0.05). However, no significant correlation between alterations in the area of peeling and overall retinal sensitivity regarding visual acuity gain could be observed after 6 months (p > 0.05). In contrast, overall postoperative retinal sensitivity was significantly decreased in patients with a visual acuity gain lower than 2 lines (p < 0.05) correlating with EZ defects seen in OCT. Conclusions. Mechanical trauma of epiretinal membrane and ILM peeling due to the use of intraocular forceps may affect the outer retinal structure. Nevertheless, these changes seem to have no significant impact on postoperative functional outcome.