Thiel cadaver eye as a training model for sub-Tenon's blocks: a feasibility study.

BACKGROUND: Regional anaesthesia education, especially for ocular procedures, necessitates reliable surgical training models. While cadaveric models offer anatomical fidelity, conventional embalming methods may compromise tissue integrity. We aimed to assess the effectiveness of Thiel cadavers for training in sub-Tenon's blocks by evaluating ocular tissues and measuring insertion forces. METHODS: Experimental design, using twenty eyes from ten Thiel cadaver heads. These cadavers were specifically prepared to test the administration of sub-Tenon's blocks. The research was conducted in a controlled laboratory setting appropriate for handling cadaveric materials and conducting precise measurements. Each cadaver eye underwent an initial ultrasound examination, and its axial length was noted. An intravitreal injection of heptastarch solution followed, to re-establish the eye's sphericity. After this volume injection, the axial length and intraocular pressure were measured again. Mock sub-Tenon's blocks were administered in 2 separate quadrants of the eye, with insertion forces measured using a pressure gauge. These were compared to a data set of insertion forces measured in a series of isolated pig's eyes on which STBs had been performed. Main outcome measurements were macroscopic assessment of the ocular tissue layers and the insertion forces required for the sub-Tenon's blocks. In a second set of 10 Thiel cadaver heads, 5 ml of sodium chloride were injected as sub-Tenon's blocks and the emergence of a periocular "T-sign" ascertained and measured by ultrasound. RESULTS: Four of twenty eyes (20%) retained near-natural sphericity, with the remaining requiring volume injection to approximate physiological shape and pressure. The conjunctiva and Tenon's layer were intact, and correct cannula placement was achieved in all cases. In 16 of 20 eyes where T-signs could be measured, the median thickness of the T-sign amounted to 2.72 mm (range 1.34 mm-5.28 mm). The average maximum cannula insertion force was 2.92 Newtons. Insertion forces in intact Thiel cadaver heads were consistently higher than in isolated pig's eyes (3.6 N vs 2.0 N). CONCLUSION: These findings suggest that Thiel cadavers are a promising model for training in sub-Tenon'sblocks, despite the challenge of often desiccated and involuted eyes.

A Modification of the Inverted Internal Limiting Membrane Flap Technique without Heavy Liquids and Prone Posturing. / Eine Modifikation der inversen Membrana-limitans-interna-Lappentechnik ohne Einsatz schwerer Flüssigkeiten und Bauchlagerung.

Primary closure of large macular holes remains challenging, and variations of inverted inner limiting membrane (ILM) flap surgery have been described. In the present retrospective, interventional, single-centre case series, we propose a superior flap design with minimal posturing. Eight eyes of eight patients (four women and four men) in the period between July 2020 and March 2022 underwent 23 G three-port vitrectomy with a superior inverted ILM flap and 20% SF6 endotamponade for a full thickness macular hole (MH) by the same experienced surgeon (F. M. H.). Seven MHs were classified as large (> 400 µm) and one as medium (250 - 400 µm). The mean MLD was 638.0 ± 166.4 µm (range: 353 - 851 µm). MH closure was achieved in all (8/8, 100%) patients with a single surgery. The median best-corrected visual acuity (BCVA) improved from 6/120 (Snellen) (range: finger counting [FC] to 6/19) preoperatively to 6/19 (range: FC to 6/9.5) after surgery, without any intra- or postoperative complications. The superior inverted ILM flap technique seems to be a safe and successful approach for the primary closure of large MHs. Further studies should investigate our proposed surgical technique on a larger population, potentially without air or gas endotamponade.

Retinal vessel diameter measurements by spectral domain optical coherence tomography.

PURPOSE: To describe a spectral domain optical coherence (OCT)-assisted method of measuring retinal vessel diameters. METHODS: All Patients with an OCT circle scan centered at the optic nerve head using a Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) were retrospectively reviewed. Individual retinal vessels were identified on infrared reflectance (IR) images and given unique labels both on IR and spectral domain OCT (SD-OCT). Vessel width and vessel types obtained by IR were documented as ground truth. From OCT, measurements of each vessel, including horizontal vessel contour diameter, vertical vessel contour diameter, horizontal hyperreflective core diameter, and reflectance shadowing width, were assessed. RESULTS: A total of 220 vessels from 13 eyes of 12 patients were labeled, among which, 194 vessels (88 arteries and 65 veins confirmed from IR) larger than 40 microns were included in the study. The mean vessel width obtained from IR was 107.9 ± 36.1 microns. A mean vertical vessel contour diameter of 119.6 ± 29.9 microns and a mean horizontal vessel contour diameter of 124.1 ± 31.1 microns were measured by SD-OCT. Vertical vessel contour diameter did not differ from vessel width in all subgroup analysis. Horizontal vessel contour diameter was not significantly different from vessel width for arteries and had strong or very strong correlation with vessel width for veins. CONCLUSION: In our study, vertical vessel contour diameter measured by current commercially available SD-OCT was consistent with vessel width obtained by IR with good reproducibility. This SD-OCT based method could potentially be used as a standard measurement procedure to evaluate retinal vessel diameters and their changes in ocular and systemic disorders.

Postoperative anatomical and functional outcomes of different stages of high myopia macular hole.

BACKGROUND: Recently it was suggested that high myopia macular holes (HMMH) and macular holes accompanied by retinal detachment occur in the advanced stages of myopia traction maculopathy (MTM), while macular retinoschisis, shallow retinal detachment without holes, and lamellar macular holes occur in the early stages of MTM. Complete vitreous cortex removal associated with internal limiting membrane peeling is now widely used to treat HMMH. However, it remains uncertain at what HMMH stage patients would benefit most from surgical intervention. Our study was aimed to evaluate the postoperative anatomical changes and functional outcomes of high myopia macular holes (HMMH). METHODS: Patients were retrospectively collected between March 2009 and August 2011. Before and 1st, 3rd, and 9th month after 23G pars plana vitrectomy, all patients underwent a complete ophthalmologic examination, spectral domain optical coherence tomography (SD-OCT) and MP-1. At each follow-up, best-corrected visual acuity (BCVA), photoreceptor inner and outer segments (IS/OS) defects, and retinal sensitivity (RS) were investigated. According to different preoperative macular hole morphologies, patients were divided into three groups: Group 1, macular hole with epiretinal membrane (ERM) traction and macular retinoschisis; Group 2, full-thickness macular hole (FTMH); Group 3, FTMH with subretinal fluid. RESULTS: 43 eyes from 43 patients met the inclusion criteria. The mean age was 60 years. BCVA and RS were significantly improved after vitrectomy; the mean IS/OS defect was significantly reduced. At 9 postoperative months, 11 of 43 (25.6 %) eyes achieved IS/OS junction integrity; 9 of these 11 (81.8 %) eyes belonged to Group 1, 2 (18.2 %) belonged to Group 2. CONCLUSIONS: Pars plana vitrectomy combined with ILM peeling and gas tamponade results in limited functional outcomes in patients with HMMH. The appearance of subretinal fluid indicates a worse prognosis for surgical intervention.

Clinical outcomes after switching treatment from intravitreal ranibizumab to aflibercept in neovascular age-related macular degeneration.

PURPOSE: To describe the treatment response to aflibercept in patients with exudative age-related macular degeneration that showed insufficient or diminishing treatment effects under ranibizumab. METHODS: From December 2012 till June 2013 all patients receiving intravitreal injections of aflibercept after previous treatment with ranibizumab were collected in a database and retrospectively reviewed. Clinical data such as visual acuity or central subfield retinal thickness on optical coherence tomography (OCT) scans were analyzed for the time frame before, during, and shortly after the aflibercept injections. Of particular interest was the comparison of clinical features under ongoing ranibizumab treatment to the time during aflibercept treatment. RESULTS: Seventy-one eyes of 65 patients were included in the study. All eyes had previous ranibizumab injections in their medical history, the average number of which was nine (range 3-43). For the total group the mean visual acuity (VA) before the first ranibizumab injection was 0.54 logMAR, and after the last ranibizumab injection was 0.57 logMAR. Mean VA changed from 0.47 logMAR before the first aflibercept injection to 0.25 logMAR after the last aflibercept injection. Central subfield retinal thickness (CSRT) on OCT changed from a mean of 417.28 µm to 349.52 µm under ranibizumab treatment and from 338.76 µm to 272.00 µm under aflibercept treatment. Interestingly, 33 % of cases that did not show a functional improvement under ranibizumab therapy gained visual acuity after aflibercept treatment. CONCLUSION: Aflibercept appears to be an effective choice for patients with neovascular age-related macular degeneration who were resistant to previous therapy of ranibizumab. The longevity of this effect still remains questionable.

Drusen measurements comparison by fundus photograph manual delineation versus optical coherence tomography retinal pigment epithelial segmentation automated analysis.

PURPOSE: To compare drusen measurements obtained from color fundus and infrared retromode photographs with those derived from spectral-domain optical coherence tomography. METHODS: Drusen lesions identified on the planar (color and infrared) imaging modalities were manually segmented by two independent graders using previously described reading center software to produce quantitative measurements of drusen area and number. The corresponding volume Cirrus OCT datasets were analyzed using commercial retinal pigment epithelium analysis algorithms to segment the retinal pigment epithelium band and estimated the drusen area. Drusen numbers were extracted from retinal pigment epithelium elevation maps. Intraclass correlation coefficients assessed agreement between graders; graders' average measurements were compared with optical coherence tomography (OCT) using paired T-tests. RESULTS: Excellent agreement between graders was observed (r = 0.951-0.974). No statistical difference was found in the area values obtained by color (0.85 ± 0.26 mm(2), P = 0.43) or retromode (1.15 ± 0.32 mm(2), P = 0.35) compared with those obtained by OCT (0.98 ± 0.28 mm). The number of drusen identified by OCT (13.15 ± 3.19) was significantly lower than that determined by manual segmentation of color (53.7 ± 13.18) and retromode (100.13 ± 16.18) images. CONCLUSION: Although the number of drusen individualized by commercial OCT algorithms is significantly lower than by planar fundus imaging modalities, the OCT-measured drusen area is not affected, suggesting that the algorithm counts confluent drusen as a single drusen.

An easy method to differentiate retinal arteries from veins by spectral domain optical coherence tomography: retrospective, observational case series.

BACKGROUND: Recently it was shown that retinal vessel diameters could be measured using spectral domain optical coherence tomography (OCT). It has also been suggested that retinal vessels manifest different features on spectral domain OCT (SD-OCT) depending on whether they are arteries or veins. Our study was aimed to present a reliable SD-OCT assisted method of differentiating retinal arteries from veins. METHODS: Patients who underwent circular OCT scans centred at the optic disc using a Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) were retrospectively reviewed. Individual retinal vessels were identified on infrared reflectance (IR) images and given unique labels for subsequent grading. Vessel types (artery, vein or uncertain) assessed by IR and/or fluorescein angiography (FA) were referenced as ground truth. From OCT, presence/absence of the hyperreflective lower border reflectivity feature was assessed. Presence of this feature was considered indicative for retinal arteries and compared with the ground truth. RESULTS: A total of 452 vessels from 26 eyes of 18 patients were labelled and 398 with documented vessel type (302 by IR and 96 by FA only) were included in the study. Using SD-OCT, 338 vessels were assigned a final grade, of which, 86.4% (292 vessels) were classified correctly. Forty three vessels (15 arteries and 28 veins) that IR failed to differentiate were correctly classified by SD-OCT. When using only IR based ground truth for vessel type the SD-OCT based classification approach reached a sensitivity of 0.8758/0.9297, and a specificity of 0.9297/0.8758 for arteries/veins, respectively. CONCLUSION: Our method was able to classify retinal arteries and veins with a commercially available SD-OCT alone, and achieved high classification performance. Paired with OCT based vessel measurements, our study has expanded the potential clinical implication of SD-OCT in evaluation of a variety of retinal and systemic vascular diseases.

Aflibercept for central retinal vein occlusions: long-term outcomes of a 'Treat-and-Extend' regimen.

BACKGROUND/AIMS: This study reports on the long-term functional and anatomical outcomes of patients with central retinal vein occlusion (CRVO) treated under the Bern treat-and-extend (T&E) protocol. METHODS: Observational study. Treatment-naive patients with CRVO and consecutive macular oedema treated with aflibercept were included. The T&E protocol involved 2 monthly injections followed by an extension based on individual assessments. At each visit, best-corrected visual acuity (BCVA), optical coherence tomography imaging and a 2 mg aflibercept injection were administered. Changes in BCVA, proportion of patients gaining ≥15 letters, central subfield thickness (CST) and treatment intervals were analysed. RESULTS: Out of 173 patients, 64 had a follow-up of at least 2 years. BCVA improved from 46.7±25.3 at baseline to 78.3±0.5 at year 9. The proportion of patients with ≥15 letters gained was 56%, 53%, 56%, 62%, 52%, 52%, 43%, 50% and 33% at years 1-9, respectively. CST decreased significantly from 660±242 µm at baseline to 359±63 µm at year 9. Treatment intervals extended from 4 weeks initially to an average of 13.0±4.1 weeks by year 8. CONCLUSIONS: The T&E regimen for CRVO shows sustained visual improvements and reduced CST over time. Patients maintained stable visual gains for many years, demonstrating the effectiveness of this treatment approach. However, no control group was available to compare our T&E regimen with other strategies.

Comparison of Surgical Times Between Manual and Robot-Assisted Epiretinal Membrane Peeling.

Purpose: Epiretinal membranes (ERM) pose a common challenge in vitreoretinal pathology, often causing vision impairment in older adults. The Preceyes Surgical System (PSS) supports the surgical removal of ERM through robot-assisted membrane peeling (RA-MP). This study compares surgical times and iatrogenic hemorrhages between manual membrane peeling (MMP) and RA-MP using PSS. Methods: Nine patients underwent RA-MP with PSS, whereas 16 patients (18 eyes) underwent MMP for comparative analysis. Surgical durations were categorized into RA-MP, manual forceps utilization in PSS surgeries (mRA-MP), and traditional MMP. Cumulative manual manipulation duration (cMMP), instrument grasps, and intraoperative hemorrhages were statistically analyzed using the Mann-Whitney U test. Results: RA-MP showed significantly longer peeling times compared to MMP (P < 0.001). Flap initiation grasps were similar between methods (P = 0.86), RA-MP demonstrated a significant reduction in peeling grasps (P = 0.01) and mean grasps per minute (P < 0.001). Although RA-MP resulted in fewer hemorrhages, the difference did not reach statistical significance relative to MMP (P = 0.08). Discussion: Although RA-MP tended to extend surgical time, it offered advantages in reducing tissue trauma and intraoperative hemorrhages. Further research is needed to explore the learning curve for novice surgeons and evaluate the safety profile of RA-MP. Translational Relevance: RA-MP may offer potential advantages over manual surgery, particularly in terms of reduced tissue trauma and intraoperative hemorrhages. Despite its longer duration compared with manual techniques, RA-MP may lead to fewer grasping maneuvers and lower rates of hemorrhages, thereby enhancing the safety and precision of vitreoretinal surgeries.

Peripheral autofluorescence and clinical findings in neovascular and non-neovascular age-related macular degeneration.

PURPOSE: To characterize peripheral fundus autofluorescence (FAF) abnormalities in patients with age-related macular degeneration (AMD), correlate these with clinical findings, and identify risk factors associated with these FAF abnormalities. DESIGN: Clinic-based, cross-sectional study. PARTICIPANTS: A total of 119 consecutive patients: 100 patients with AMD (200 eyes) and 19 patients without AMD (38 eyes). METHODS: In a prospective study performed at the Doheny Eye Institute, University of Southern California, widefield 200-degree FAF and color images were obtained by the Optos 200Tx Ultra-Widefield device (Optos, Dunfermline, Scotland) using a standardized imaging protocol. The FAF images were captured centered on the fovea, and additional images were captured after steering the field of view inferiorly and superiorly. All FAF and color images were graded independently by 2 masked ophthalmologists with respect to the presence, location, extent, and type of peripheral (defined as outside the central 30 degrees) FAF abnormality. MAIN OUTCOME MEASURES: Presence and type of peripheral FAF abnormalities. RESULTS: Peripheral FAF abnormalities were evident in 164 eyes (68.9%), with several distinct FAF patterns identified: granular (46.2%), mottled (34.0%), and nummular (18.1%). A 90% concordance of FAF patterns was observed between both eyes. Abnormal FAF occurred more frequently in neovascular compared with non-neovascular AMD or normal eyes (86% vs. 72.8% vs. 18.4%, respectively, P<0.001). Significant risk factors for peripheral FAF abnormalities were AMD type (neovascular AMD odds ratio [OR], 12.7 and non-neovascular AMD OR, 6.2 compared with normal eyes, P<0.001), older age (OR, 6.5; 95% confidence interval [CI], 2.4-17.8; P<0.001 for the oldest quartile compared with the youngest), and female sex (OR, 4.1; 95% CI, 1.9-8.9; P<0.001). Clinical features on color photography were detected in 174 eyes (73.1%): peripheral drusen (51.7%), retinal pigment epithelium (RPE) depigmentation (34.9%), RPE hyperpigmentation (branching reticular pigmentation) (22.7%), and atrophic patches (16.8%). There was a high correlation between specific FAF and clinical findings: granular FAF with peripheral drusen (P<0.001) and mottled FAF with RPE depigmentation (P<0.001). CONCLUSIONS: Several distinct patterns of peripheral FAF abnormalities were observed in 68.9% of patients, with AMD type, female sex, and age being independent risk factors. The peripheral FAF patterns correlate strongly with specific clinical features seen in eyes with AMD. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Optical coherence tomography-based observation of the natural history of drusenoid lesion in eyes with dry age-related macular degeneration.

PURPOSE: To use spectral domain optical coherence tomography (SD-OCT) to investigate risk factors predictive for the development of atrophy of drusenoid lesions (DLs) (drusen and drusenoid pigment epithelium detachment) in eyes with non-neovascular age-related macular degeneration (NNVAMD). DESIGN: Cohort study. PARTICIPANTS: Forty-one eyes from 29 patients with NNVAMD. METHODS: Patients with NNVAMD who underwent registered SD-OCT imaging over a minimum period of 6 months were reviewed. Drusenoid lesions that were accompanied by new atrophy onset at 6 months or last follow-up (FUL) were further analyzed. Detailed lesion change was described throughout the study period. Odds ratios (ORs) and risk for new local atrophy onset were calculated. MAIN OUTCOME MEASURES: Drusenoid lesion features and longitudinal changes in features, including maximum lesion height, lesion diameter, lesion internal reflectivity, and presence and extent of overlying intraretinal hyperreflective foci (HRF). Subfoveal choroidal thickness (SFCT) and choroidal thickness (CT) were measured below each lesion. RESULTS: A total of 543 individual DLs were identified at baseline, and 28 lesions developed during follow-up. The mean follow-up time was 21.3±8.6 months (range, 6-44 months). Some 3.2% of DLs (18/571) progressed to atrophy within 18.3 ± 9.5 months (range, 5-28 months) of the initial visit. Drusenoid lesions with heterogeneous internal reflectivity were significantly associated with new atrophy onset at 6 months (OR, 5.614; 95% confidence interval [CI], 1.277-24.673) and new atrophy onset at FUL (OR, 7.005; 95% CI, 2.300-21.337). Lesions with the presence of HRF were significant predictors of new atrophy onset at 6 months (OR, 30.161; 95% CI, 4.766-190.860) and FUL (OR, 11.211; 95% CI, 2.513-50.019). Lesions with a baseline maximum height >80 µm or CT ≤ 135 µm showed a positive association with the new atrophy onset at FUL (OR, 7.886; 95% CI, 2.105-29.538 and OR, 3.796; 95% CI, 1.154-12.481, respectively). CONCLUSIONS: The presence of HRF overlying DLs, a heterogeneous internal reflectivity of these lesions, was found consistently to be predictive of local atrophy onset in the ensuing months. These findings provide further insight into the natural history of anatomic change occurring in patients with NNVAMD.

Different phenotypes of the appearance of the outer plexiform layer on optical coherence tomography.

PURPOSE: To present a selected case series of different phenotypes of the normal outer plexiform layer (OPL) visualized by optical coherence tomography (OCT). METHODS: Five cases were selected to represent the spectrum of appearances of the OPL in this case series. Categorical descriptions of each manifestation were then developed. Additional SD-OCT scans were obtained from a normal volunteer to further support the hypothesis. RESULTS: The inner one-third of the OPL typically appears hyperreflective on OCT, while the outer two-thirds (Henle fiber layer) may have a more varied appearance. Six different phenotypes of Henle fiber layer reflectivity were noted in this series, and classified as: bright, columnar, dentate, delimited, indistinct, and dark. The brightness of the Henle fiber layer appears to depend on the geometric angle between the OCT light beam and the axonal fibers in this portion of the OPL. This angle appears to be a function of the natural orientation of the Henle fiber layer tissue (θN), the existence of subretinal pathology that alters the angle of the neurosensory retina (θ(P)), and the tilt angle of the tissue on the B-scan (θ(T)) due to decentered OCT acquisition. CONCLUSIONS: Since accurate interpretation of the OPL/ONL boundary is of vital importance to study the thickness of ONL, location of cystoid lesions, hyperreflective crescents over drusen, et al., our case series may aid better understanding of the OPL appearance in SD-OCT. In the absence of clear delineation, it may be most correct to refer to indistinct OPL and ONL together as the photoreceptor nuclear axonal complex (PNAC).

Evaluation of the axial location of cystoid spaces in retinal vein occlusion using optical coherence tomography.

PURPOSE: To analyze the axial distribution of intraretinal cystoid changes in patients with retinal vein occlusion (RVO), incorporating a new hypothesis about the optical coherence tomographic boundary between the outer nuclear layer and the outer plexiform layer. METHODS: Data were collected from patients with RVO who underwent spectral domain coherence tomography imaging. For each image set, certified graders evaluated each retinal layer for cystoid macular edema, defined as hyporeflective intraretinal cystoid spaces. Subretinal fluid, if present, was also noted. RESULTS: Forty-eight eyes were evaluated (24 branch RVO, 18 central RVO, 6 hemiretinal vein occlusion). Cystoid macular edema was present in 30.8% of eyes in outer nuclear layer, 77.9 % in outer plexiform layer, 77.9 % in inner nuclear layer, 36.9 % in inner plexiform layer, 48.8 % in ganglion cell layer, and 4.9% in nerve fiber layer. Subretinal fluid was assessed as present in 23.8% of patients. The presence of subretinal fluid correlated most strongly with cystoid changes in the outer nuclear layer (r = 0.514, P = 0.001) but was not significantly correlated with these changes in the superficial retina. CONCLUSION: Use of spectral domain coherence tomography allows precise characterization of the axial location of cystoid spaces in RVO and highlights the frequency of fluid accumulation in the outer plexiform layer and inner nuclear layer. Using updated definitions, cystoid macular edema seems to occur less frequently in the outer nuclear layer, but when it does so, it is often associated with subretinal fluid. Future longitudinal studies, documenting the axial progression of such changes, and their response to treatment, may be of clinical relevance as pharmacotherapeutic options evolve.

Robot-Assisted Epiretinal Membrane Peeling: A Prospective Assessment of Pre- and Intra-Operative Times and of Surgeons' Subjective Perceptions.

PURPOSE: The Preceyes Surgical System (PSS) is a robotic assistive device that may enhance surgical precision. This study assessed pre- and intra-operative times and surgeons' perceptions of robot-assisted epiretinal membrane peeling (RA-MP). METHODS: We analyzed the time requirement of three main tasks: the preparation of the PSS (I), patient preparation (II), and surgery (III). Following surgery, the surgeons were asked questions about their experience. RESULTS: RA-MP was performed in nine eyes of nine patients. Task I required an average time of 12.3 min, initially taking 15 min but decreasing to 6 min in the last surgery. Task II showed a mean time of 47.2 (range of 36-65) min. Task III had a mean time of 72.4 (range of 57-100) min. A mean time of 27.9 (range of 9-46) min was necessary for RA-MP. The responses to the questionnaire revealed a trend towards increasing ease and reduced stress as familiarity with the PSS increased. CONCLUSIONS: A substantial reduction in pre- and intra-operative times, decreasing to a total of 115 min, was demonstrated. RA-MP was positively anticipated by the surgeons and led to no hand or arm strain while being more complex than manual MP.

Microperimetry as a routine diagnostic test in the follow-up of retinal vein occlusion?

BACKGROUND: In the follow-up of retinal vein occlusions, a patient's subjective change in vision frequently cannot be confirmed by objective measurements. Furthermore, contradictory results of OCT and distance visual acuity give the impression that current routine diagnostic tests might not be satisfying for patients with retinal vein occlusions. This prospective case series analyses the value of microperimetry as a routine diagnostic test in the follow-up of patients with retinal vein occlusions during therapy. METHODS: In a prospective case series, we tested microperimetry as a functional measure in comparison to distance visual acuity, reading ability, and OCT, on 13 patients treated for central or branch retinal vein occlusions. Treatment consisted of intravitreal bevacizumab injections combined with panretinal laser coagulation in cases of peripheral ischemia. If macular edema persisted, bevacizumab injection was repeated, or instead of this intravitreal triamcinolone or focal laser coagulation was applicated. Follow-up ranged from 6-14 months. An interim analysis was performed for the 6-month follow-up. RESULTS: In the branch retinal vein occlusion group, the average of the retinal thickness measured by OCT was 502.22 µm (±SD 217.75 µm) at baseline and changed to 396.38 ± 154.38 at the 6-month follow-up (p = 0.121). Mean distance visual acuity stayed similar to the study entrance with 0.41 ± 0.34 at the 6-month follow-up (p = 0.944) Mean reading ability improved to 0.51 ± 0.52 at the 6-month follow-up but was not statistically significant (p = 0.435). The mean light sensitivity of microperimetry improved from baseline to the 6-month follow-up: the 40-points group improved from 8.62 ± 5.69 dB to 10.98 ± 5.42 (p = 0.060) and the 8-points group from 6.27 dB to 9.6 dB (p = 0.07) but missed statistical significance. The sector group showed in contrast to this an improvement from 6.02 ± 5.71 dB to 9 ± 6.07 dB (p = 0.025), which was statistically significant. Changes in the central vein occlusion group were not statistically significant but changes for both groups together showed statistical significance. CONCLUSIONS: In the present case series, microperimetry was more convenient to detect, even the subtle functional changes during the disease course of branch retinal vein occlusions than distance and reading visual acuity. This indicates that microperimetry could be a possible valuable tool in the follow-up of branch retinal vein occlusions.

Structural and functional implications of severe foveal dystopia in epiretinal membranes.

PURPOSE: The purpose of this study was to examine the functional and structural correlates of severe foveal dystopia in patients with epiretinal membranes. METHODS: For this retrospective study of 29 eyes with epiretinal membrane, we identified 7 eyes that had severe foveal dystopia (defined as fovea located >200 µm from its expected location) and followed the direction and rate of foveal movement pre- and postoperatively. RESULTS: Epiretinal membrane traction caused the fovea to move preoperatively at a rate of 275 µm/month from its anatomical location in 2 patients. The final preoperative foveal location was, on average, 1,217 ± 683 µm away from its expected location. Postoperatively, foveal movement toward its expected location was largest during the first month after surgery (mean = 547 ± 340 µm) and slowed down until the final follow-up position was achieved (mean = 301 ± 131 µm). Overall, the fovea moved a total of 848 ± 445 µm, allowing the fovea to correct only 32.8 ± 22.1% of the total displacement from its expected location. A univariate regression model confirmed a linear relationship between preoperative visual acuity and preoperative foveal distance from its expected anatomical location with an R of 0.759 (P = 0.0107). CONCLUSION: The extent of tractional foveal dystopia correlates with decreased visual acuity. Although all patients experienced functional and anatomical improvements with surgery, long-standing or severe foveal dystopia may be associated with permanent structural changes that limit functional outcome. Cases with extreme degrees of foveal dystopia may benefit from early intervention to prevent irreversible structural and functional changes.

Multimodal Imaging in a Case of Presumed Solitary Circumscribed Retinal Astrocytic Proliferation.

Provisionally referred to as presumed solitary circumscribed retinal astrocytic proliferation (PSCRAP), the lesion is a rare, benign retinal tumour that typically presents as white-yellow, opaque, and well circumscribed. Typically, the lesion is stable or may regress spontaneously. In light of the adjacent pigmentation of the tumour and from our retinal imaging, we suggest that the lesion originates from the deep neurosensory retina or the retinal pigment epithelium. Herein, we present a case of this entity in a 36-year-old man with a roundish, parapapillary tumour in his right eye and share its characteristics in the different diagnostic imaging modalities.

Incidence of severe rise in intraocular pressure after intravitreous injection of aflibercept with prefilled syringes.

Our aim was to analyze the intraocular pressure (IOP) changes following different intravitreous injection (IVI) procedures with or without prefilled syringes (PFS) and to elaborate their possible causes. Clinical study and laboratory assessment. 173 eyes of 141 patients. The IOP was prospectively measured pre- and postoperatively in three groups of patients receiving IVI either with ranibizumab (RP), aflibercept PFS (AP) or aflibercept vials (AV). The AP emptying volume (EV) was assessed using 40 aflibercept PFS vials: the plunger was aligned precisely (normal volume, NV) or right below the indication line (high volume, HV) and the drug was ejected with (wP) or without forced pressure (nP). Primary outcome was post-treatment IOP with type of IVI and pre-treatment IOP as fixed factors. Secondary outcome was identification of possibly confounding factors (age, sex, pathology, presence of pseudophakia, spherical error, and number of injections) and IOP > 30 mmHg post-treatment. An IOP rise above 30 mmHg was observed in 8/38 (22%), 16/51 (31%) and 35/86 (41%) cases in the RP, AV and AP groups, respectively (p = 0.129). Pre-treatment IOP was the only predictive variable for IOP rise (p < 0.001). The EV values in the NVnP, NVwP, HVnP and HVwP groups were 56.06 ± 10.32, 70.69 ± 4.56, 74.22 ± 7.41 and 81.63 ± 3.67 µl, respectively (p < 0.001). We observed a marked, although not significantly higher incidence of IOP elevations with the aflibercept PFS. One possible reason may be the error-proneness of administering the correct volume with the AP. Caution should be taken when using the aflibercept PFS in order to prevent potential optic nerve damage in cases with marked elevation in IOP.

Heavy silicone oil tamponade: a multicentre experience.

OBJECTIVE: To report multicentred use of the heavy silicone oil Densiron 68 for anatomical reattachment following rhegmatogenous retinal detachment (RRD) repair and its associated complications. METHODS AND ANALYSIS: Patients from seven vitreoretinal units within the UK that underwent RRD repair with Densiron 68 between January 2015 and December 2019 were identified. Primary outcome measures were primary and final reattachment rate, retained Densiron and failure rate. Secondary outcome measures were duration of tamponade, final visual acuity (VA) and complications of heavy silicone oil. RESULTS: 134 eyes of 134 patients were involved in the study. Primary surgical success was achieved in 48.5%, while a final reattachment rate of 73.4% was observed. The mean duration of Densiron 68 tamponade was 139.5 days. Mean final VA was 1.01 (range 0-2.9). 8 eyes (6.0%) required long-term topical steroids for anterior uveitis, whereas none of the eyes required long-term pressure-lowering treatment. Emulsification rate was 10.7% (6 eyes). CONCLUSION: This is the largest real-world study on Densiron 68 in the UK. Densiron 68 facilitates tamponade of inferior retinal pathology and may be considered as an option for tamponade of inferior retinal pathologies.

OCT changes in peri-tumour normal retina following ruthenium-106 and proton beam radiotherapy for uveal melanoma.

INTRODUCTION: Uveal melanoma is most commonly treated with radiotherapy, destroying the tumour cells with adequate safety margins and limiting collateral damage to surrounding structures to preserve maximal vision. We used optical coherence tomography (OCT) to study the effects of radiotherapy on the retina. METHODS: Patients with posteriorly located choroidal melanoma treated with proton beam radiotherapy (PBR) and ruthenium-106 brachytherapy between January 2010 and June 2014 underwent spectral domain OCT. RESULTS: Images of 32 patients following ruthenium-106 brachytherapy and 44 patients following proton beam teletherapy were analysed. Following plaque brachytherapy, an early marked disruption of the outer retinal layers could be observed in 30 cases (94%) with retinal atrophy evident in 26 cases (81%). In contrast, the images from patients who underwent PBR showed subtle outer retinal layer change with 16 cases (36%) showing some inner-outer segment junction disruption by 6 months and 63%  by 24 months with minimal atrophy. In cases with tumours <2 mm from the fovea, the visual loss was significantly less at 6 and 12 months in the proton beam group. CONCLUSION: In comparison to ruthenium-106 plaque brachytherapy, PBR leads to more subtle and slower changes in the outer retinal layers enabling retention of visual function for longer. The difference in dosing regime and dose distribution across the tumour is likely to be causative for this structural differential.