Silicone oil insulation effects on flash electroretinogram and visual evoked potential in patients with retinal detachment / Efectos del aislamiento del aceite de silicona sobre el electrorretinograma flash y el potencial evocado visual en pacientes con desprendimiento de retina

Background: Silicone oil is used as endotamponade following vitreoretinal surgery to maintain the retina reattached when indicated. This study investigates the hypothesis that silicone oil causes insulation effects on the retina by affecting its response to light. Methods: Electrophysiological responses to a flash stimulus were recorded using full-field electroretinography (ERG) and visual evoked potentials (VEP). Recordings were performed in 9 patients who underwent surgery for retinal detachment, before (1–2 days) and after (2–3 weeks) silicone oil removal (SOR) in both the study and the control eye. Flash ERG and VEP recordings were performed according to the ISCEV standard protocol. Results: Statistically significant differences were found in the study eye in the amplitudes of the ERG responses and their corresponding ratios, i.e. the amplitude after SOR over the amplitude before SOR, in all conditions tested. No differences were observed in the control eye. The mean ratio of photopic ERG response was 3.4 ± 2.4 for the study and 1.0 ± 0.3 for the control eye (p<0.001). The mean ratio of ERG flicker response was 3.1 ± 2.4 and 1.0 ± 0.3, respectively (p = 0.003). Scotopic flash ERG ratio was 5.0 ± 4.4 for the study and 1.3 ± 0.6 for the control eye (p = 0.012). No differences were observed for the amplitude and latency of flash VEP response after SOR. Conclusions: Silicone oil causes a reduction in flash ERG responses; no effect was found on flash VEP responses. ERGs in eyes filled with silicone oil should not be considered representative of retinal functionality, in contrast to VEPs, which are not affected by silicone oil presence.(AU)

A novel vector field analysis for quantitative structure changes after macular epiretinal membrane surgery.

The aim of this study was to introduce novel vector field analysis for the quantitative measurement of retinal displacement after epiretinal membrane (ERM) removal. We developed a novel framework to measure retinal displacement from retinal fundus images as follows: (1) rigid registration of preoperative retinal fundus images in reference to postoperative retinal fundus images, (2) extraction of retinal vessel segmentation masks from these retinal fundus images, (3) non-rigid registration of preoperative vessel masks in reference to postoperative vessel masks, and (4) calculation of the transformation matrix required for non-rigid registration for each pixel. These pixel-wise vector field results were summarized according to predefined 24 sectors after standardization. We applied this framework to 20 patients who underwent ERM removal to obtain their retinal displacement vector fields between retinal fundus images taken preoperatively and at postoperative 1, 4, 10, and 22 months. The mean direction of displacement vectors was in the nasal direction. The mean standardized magnitudes of retinal displacement between preoperative and postoperative 1 month, postoperative 1 and 4, 4 and 10, and 10 and 22 months were 38.6, 14.9, 7.6, and 5.4, respectively. In conclusion, the proposed method provides a computerized, reproducible, and scalable way to analyze structural changes in the retina with a powerful visualization tool. Retinal structural changes were mostly concentrated in the early postoperative period and tended to move nasally.

Real-Time Temperature-Controlled Retinal Laser Irradiation in Rabbits.

Purpose: Subdamaging thermal retinal laser therapy has the potential to induce regenerative stimuli in retinal diseases, but validated dosimetry is missing. Real-time optoacoustic temperature determination and control could close this gap. This study investigates a first in vivo application. Methods: Two iterations of a control module that were optically coupled in between a continuous-wave commercial laser source and a commercial slit lamp were evaluated on chinchilla rabbits. The module allows extraction of the temperature rise in real time and can control the power of the therapy laser such that a predefined temperature rise at the retina is quickly achieved and held constant. Irradiations with aim temperatures from 45°C to 69°C were performed on a diameter of 200 µm and a heating time of 100 ms. Results: We analyzed 424 temperature-guided irradiations in nine eyes of five rabbits. The mean difference between the measured and aim temperature was -0.04°C ± 0.98°C. The following ED50 values for visibility thresholds could be determined: 58.6°C for funduscopic visibility, 57.7°C for fluorescein angiography, and 57.0°C for OCT. In all measurements, the correlation of tissue effect was higher to the temperature than to the average heating laser power used. Conclusions: The system was able to reliably perform temperature-guided irradiations, which allowed for better tissue effect control than simple power control. This approach could enhance the accuracy, safety, and reproducibility of thermal stimulating laser therapy. Translational Relevance: This study is a bridge between preclinical ex vivo experiments and a pilot clinical study.

Role of Optical Coherence Tomography in Predicting Visual Outcome after Surgery for Sellar and Supra-Sellar Tumors.

BACKGROUND: Almost one-fifth of patients undergoing surgery for sellar/supra-sellar tumors do not gain a significant improvement in their vision. Various methods have been described to predict prospective visual outcomes in them, although they lack uniformity. OBJECTIVE: The study was conducted to predict visual outcomes following surgery for sellar and supra-sellar tumors compressing the anterior optic pathway based on pre-operative optical coherence tomography (OCT) parameters. METHODS AND MATERIALS: This was a record-based observational descriptive longitudinal study done in a tertiary care center in India. Thirty-seven patients (74 eyes) diagnosed with sellar supra-sellar lesions were included in the study. Patients' ophthalmic evaluations, done pre-operatively and 3 months post-operatively, were reviewed. Spectral-domain OCT and segmentation were done using the automated segmentation technology of Spectralis software. The thickness of the respective layers was measured. RESULTS AND CONCLUSIONS: The mean age of the study population was 42.68 years. Eyes with a pre-operative visual acuity component of VIS (visual impairment score) ≤61, pre-operative ganglion cell layer thickness ≥26.31 um, a pre-operative inner plexiform layer thickness of ≥25.69 um, a pre-operative ganglion cell inner plexiform layer thickness of 52.00 um, pre-operative ganglion cell complex thickness ≥84.47 µm, and a pre-operative inner retinal layer thickness of ≥205.25 µm were more likely to have an improved visual outcome. Eyes with a pre-operative duration of visual symptoms of ≥15 months, VIS ≥126.50, a pre-operative decimal visual acuity of <0.035, a pre-operative visual field index of ≤8%, a pre-operative macular thickness of ≤287.06 um, a pre-operative macular RNFL (retinal nerve fiber layer) thickness ≤66.00 µm, and a pre-operative peri-papillary RNFL thickness ≤64.62 µm were unlikely to have visual improvement.

Comparison of effect of machine muteness to reduce noise anxiety vs regular settings on patient compliance during pan-retinal photocoagulation.

This Quasi Experimental study was conducted at Major Eye Clinic, Gujranwala, from January to December 2022, to study the effect of muting the sound of Argon Laser machine on patient compliance and the pain felt during pan-retinal photocoagulation (PRP). Eighty patients were included in the study with proliferative diabetic retinopathy (PDR), retinal breaks, lattice and myopic fundus degenerations for which PRP was performed. A total of 80 patients were enrolled, who were divided in two groups with 40 patients in each group. Group A patients received muted machine settings, while group B underwent regular PRP. The mean age was 54.6±3.4 years. Sixty-eight (85%) cases were of PDR, 4 (5%) of retinal breaks, 3 (3.75%) of lattice degenerations associated with breaks, and 5 (6.25%) of laser barrage. In group A, 28 (70%) patients had grade 1 and grade 2 pain score, while in group B, 26 (65%) had grade 3 and grade 4 pain score. It was concluded that by eliminating machine sound, noise anxiety can be greatly reduced ensuring better patient cooperation.

Pars Plana Vitrectomy in the Treatment of Rhegmatogenous Retinal Detachment.

AIM: The aim of the study is to retrospectively evaluate the anatomical success rate and functional results of 25G+ PPV in the treatment of newly diagnosed rhegmatogenous retinal detachment (RRD). MATERIAL AND METHODS: The set consists of 152 eyes of 152 patients, of which 71 (47%) were men, average age 54 years, operated on by one surgeon for RRD at the Eye Clinic of the University Hospital and Medical Faculty of Masaryk University Brno from 1.7.2019 to 4.5.2021 using the 25G+ PPV technique. 25G+ PPV with pre-equatorial cerclage was performed on 7 patients. The patients' anamnesis included blunt ocular trauma and uncomplicated cataract surgery with implantation of a posterior chamber intraocular lens. The cause of RRD was retinal tear/s, regardless of their number and location. The transparency of the anterior segment of the eye enabled reliable visualization of the posterior segment. Preoperative proliferative vitreoretinopathy (PVR) grade A-D2 was admissible. Patients with a history of penetrating ocular trauma were excluded. The postoperative findings and functional outcomes of the patients were evaluated 1-3 months after PPV. The operation was anatomically successful if the retina was fully attached. Final visual acuity (VA) was evaluated for each patient. The final visual acuity examination was carried out typically on a Snellen optotype, either without correction, with the patient's own spectacle correction or with correction according to the current values on the autorefractometer. The arithmetic average was used for the numerical expression of the attained results, and the numerical values were also expressed in percentages. Since the different groups were not compared with each other, no statistical test was necessary to analyze the results. RESULTS: In 150 (98.7%) of the 152 patients in the group, we achieved complete retinal reattachment, in 2 (1.3%) patients the retina remained detached, and we recorded anatomical failure of the treatment. Fifty (33%) patients achieved VA ≥ 4/8. CONCLUSION: In 133 (87.5%) patients, we are able to state anatomical success even without the presence of intraocular tamponade in the operated eye. These patients can be considered completely cured. 25G+ PPV has demonstrated its contribution to resolving RRD.

Retinal Oxygenation With Conventional 100-ms Versus Short-Pulse Pan-Retinal Laser Photocoagulation.

BACKGROUND AND OBJECTIVE: Conventional (100 ms) pan-retinal photocoagulation (PRP) laser burns are larger than short-pulse (10 ms to 20 ms) PRP burns. This study investigates the effect of PRP burns of different sizes on retinal oxygenation. METHOD: A mathematical model using COMSOL Multiphysics 6 was used to create a three-dimensional abstraction of the coupled biology of the choroid, photoreceptor, and retinal tissues. Laser burn sizes were varied in the model, specifically considering burn diameters of 500 µm, 250 µm, and 125 µm, while keeping the total burn area constant. RESULTS: Total increase in retinal oxygenation was the same for different burn sizes, but the oxygen distribution differed. Smaller burns resulted in a more even lateral oxygen distribution but with reduced penetration into the inner retina. CONCLUSIONS: Conventional and short-pulse PRP may affect retinal oxygenation differently, even when total burn area is the same. Further investigation into optimum burn size and pattern is required. [Ophthalmic Surg Lasers Imaging Retina 2024;55:40-45.].

Aniseikonia and retinal morphological changes in eyes undergoing macular hole surgery.

Even after idiopathic macular hole (MH) surgery and with successful closure of MH, aniseikonia is a common postoperative symptom. We investigated the correlation of MH diameter, retinal displacement and retinal layer thicknesses with aniseikonia in 41 eyes of 41 patients undergoing MH surgery with internal limiting membrane peeling. Aniseikonia was measured with the New Aniseikonia Test. Retinal displacement (RD%) was defined as change of retinal distance between the temporal margin of the optic papilla and the intersection of the retinal vessels. Changes of thicknesses of the inner nuclear layer (INL%) and the outer retinal layer (OR%) were calculated. Aniseikonia improved postoperatively. Preoperative aniseikonia and their improvement at 6 months correlated with MH diameters (P = 0.004-0.046). Improvement of aniseikonia correlated with temporal RD% (P = 0.002-0.012). Improvement of vertical aniseikonia correlated with INL% at 2 weeks and with the nasal OR% at 1, 3, and 6 months (P = < 0.001-0.028). MH diameter and age were significant predictors for improvement of aniseikonia. The greater the temporal retina displacement, and the thinner the postoperative INL and OR, the greater the improvement of aniseikonia. MH diameter and age are strong predictors for improvement of aniseikonia after MH surgery.

Relaxing radial retinal incisions for the treatment of persistent macular holes.

PURPOSE: Various surgical techniques have been described for managing persistent macular holes after an unsuccessful vitrectomy with internal limiting membrane (ILM) peeling. However, the closure and functional improvement rates after these procedures are limited. Therefore, the aim of this study was to evaluate the usefulness of radial retinal incisions (retinotomies) in eyes with persistent large macula holes despite previous vitrectomy with ILM peeling. DESIGN: In a retrospective case series, closure rate and best-corrected visual acuity (BCVA) were evaluated in eyes with persistent macular holes after an unsuccessful vitrectomy that included posterior vitreous detachment and ILM peeling. SUBJECTS: 22 eyes of 22 patients (10 men and 12 women) underwent re-vitrectomy with radial retinal incisions. All the patients had undergone an unsuccessful surgery before. METHODS: Small-incision re-vitrectomy with radial retinal incisions (retinotomies) and air tamponade was performed. MAIN OUTCOME MEASUREMENTS: For all eyes, high-definition SD-OCT scans (SD-OCT Spectralis, Heidelberg Engineering GmbH, Germany) of the macula were routinely performed before surgery; 1 week and 1 month after surgery; and at final follow-up. Additionally, age, gender, axial length, macular hole diameter, biomicroscopic fundus evaluation and best-corrected visual acuity (BCVA) in logMAR and Snellen at baseline, 1 and 4 months after operation, and at the final follow-up visit were analyzed. RESULTS: The mean baseline macular hole diameter was 668.5 ± 226.8 µm. At the final examination, 16 (72.72%) of the 22 macula holes were closed. Visual acuity increased in 17 eyes, was stable in 3 eyes, and decreased in 2 eyes owing to central retinal atrophy in both. The mean BCVA increased from logMAR 1.04 ± 0.29 at baseline to 0.57 ± 0.31 (Snellen 0.11 ± 0.05 to 0.33 ± 0.18). In all successful cases, macula hole closure was attained after 3 days, and none of the eyes showed macula hole recurrence. CONCLUSION: The results of this limited case series suggest that radial retinal incisions of the rim in persistent macula holes after initial surgery with ILM peeling increase the success rate of macula hole closure and results in a relevant increase in BCVA. However, as the number of eyes included in this series is limited, the results must be confirmed in a study with a larger sample size.

Correlation between Anatomical and Functional Outcomes in Patients with Idiopathic Epiretinal Membrane after Vitrectomy.

BACKGROUND: Idiopathic epiretinal membrane (iERM) is a common disorder of the vitreomacular interface characterized by decreased visual acuity and metamorphopsia. This study aimed to analyze the association between the anatomical change of the retina and functional outcomes in iERM patients so as to derive the prognostic factors of visual acuity (VA) and metamorphopsia. METHODS: Forty-five patients (one eye per patient; 45 eyes in total) who underwent pars plana vitrectomy and membrane peeling for iERM by a single surgeon were enrolled in this retrospective study. The results on best-corrected visual acuity (BCVA) and metamorphopsia as well as retinal images were obtained before the surgery and 1, 3, 6 months after the surgery. The BCVA and retinal microstructure, including central retinal thickness (CRT), ganglion cell layer (GCL) thickness, inner nuclear layer (INL) and outer nuclear layer + outer plexiform layer (ONL+OPL), and continuity of photoreceptor inner/outer segment (IS/OS) junction before and after iERM surgery were compared using paired samples t-test (continuous variables) or Chi-square test (categorical variables). Multiple regression analysis was carried out to explore the association among BCVA, M-score, and the parameters derived from optical coherence tomography. RESULTS: Compared with preoperative data, a significant improvement in BCVA was observed 1, 3, and 6 months postoperatively (t = 5.37, p < 0.0001; t = 7.29, p < 0.0001; t = 6.44, p < 0.0001 for 1, 3, and 6 months postoperatively, respectively), whereas the M-score only decreased significantly 3 and 6 months after the surgery (t = 2.36, p = 0.02; t = 5.00, p < 0.0001, respectively). In comparison with the baseline, the CRT, INL, and ONL+OPL thickness showed a significant decrease at each postoperative follow-up time, and GCL thickness (t = 3.86, p = 0.0002) and IS/OS disruption ratio (χ2 = 4.86, p = 0.027) were markedly reduced only 6 months postoperatively. Six-month postoperative BCVA was considerably associated with preoperative CRT and ONL+OPL thickness, as well as postoperative CRT, ONL+OPL thickness, and severity of IS/OS disruption. Moreover, the M-score after surgery was markedly correlated with both the preoperative and postoperative INL and CRT thickness. CONCLUSIONS: Both VA and M-score in iERM patients were significantly improved after vitrectomy. Pre- and post-operative CRT was significantly associated with both postoperative BCVA and M-score. Besides, pre- and post-operative INL thickness was correlated to postoperative metamorphopsia, and postoperative BCVA was associated with postoperative ONL+OPL thickness and IS/OS integrity.

A Literary Pediatric Retina Fellowship With Michael T. Trese, MD.

Michael T. Trese, MD (1946-2022), a vitreoretinal surgeon, made significant contributions to the field of retina. Although most known for his work in pediatric retina surgery, he was a pioneer in areas such as medical retina, translational research, and telemedicine. This article reviews his major contributions to spread his knowledge more widely to vitreoretinal trainees and specialists. We discuss six areas where Trese made a lasting impact: lens-sparing vitrectomy, familial exudative vitreoretinopathy, congenital X-linked retinoschisis, autologous plasmin enzyme, regenerative medicine, and telemedicine. [Ophthalmic Surg Lasers Imaging Retina 2023;54:701-712.].

[Primary vitrectomy in the treatment of retinopathy of prematurity with unfavorable progression]. / Pervichnaya vitrektomiya v lechenii retinopatii nedonoshennykh neblagopriyatnogo tipa techeniya.

PURPOSE: The study aims to determine the indications and evaluate the results of primary vitrectomy in unfavorable progression of stage III active retinopathy of prematurity (ROP). MATERIAL AND METHODS: The control group consisted of 17 patients (28 eyes) with unfavorable progression of stage III ROP, who had the disease progress after coagulation of the avascular retina and underwent the second stage of treatment - vitrectomy. The main group consisted of 5 patients (10 eyes) with unfavorable progression of stage III ROP, who underwent primary vitrectomy. Gestational age at birth was 24-30 weeks, body weight ranged from 680 to 1250 g. According to spectral optical coherence tomography (SOCT) and OCT angiography (OCT-A), the initial state of the retina and vitreoretinal interface in patients of the main and control groups were identical. RESULTS: A retrospective analysis of control patients, according to SOCT and OCT-A data, showed the spread of neovascularization beyond the retinal plane, its interaction with the posterior hyaloid membrane and vitreous body structures in the early stages of the disease, traction changes in the underlying retina, areas of retinoschisis, as well as thickening of the posterior hyaloid membrane. The tactics of treating patients with unfavorable progression of stage III ROP has changed since 2020. Primary vitrectomy was performed in case the signs listed above were identified. The transition of the disease to the inactive stage was recorded in all cases one month after primary vitrectomy. After one year the pathological process did not reactivate in any of the cases, and no pathological changes were found in the projection of the former proliferation ridge. CONCLUSIONS: Extraretinal retinovitreal neovascularization, according to multimodal preoperative diagnostics, indicates the need for vitreoretinal surgery as a pathogenetically substantiated method of treatment for unfavorable progression of stage III active ROP.

Obtaining High-Quality Cryosections of Whole Rabbit Eye.

This protocol describes how to obtain high-quality retinal cryosections in larger animals, such as rabbits. After enucleation, the eye is briefly immersed in the fixative. Then, the cornea and iris are removed and the eye is left overnight for additional fixation at 4 °C. Following fixation, the lens is removed. The eye is then placed in a cryomold and filled with an embedding medium. By removing the lens, the embedding medium has better access to the vitreous and leads to better retinal stability. Importantly, the eye should be incubated in embedding medium overnight to allow complete infiltration throughout the vitreous. Following overnight incubation, the eye is frozen on dry ice and sectioned. Whole retinal sections may be obtained for use in immunohistochemistry. Standard staining protocols may be utilized to study the localization of antigens within the retinal tissue. Adherence to this protocol results in high-quality retinal cryosections that may be used in any experiment utilizing immunohistochemistry.

Deep learning-based prediction of the retinal structural alterations after epiretinal membrane surgery.

To generate and evaluate synthesized postoperative OCT images of epiretinal membrane (ERM) based on preoperative OCT images using deep learning methodology. This study included a total 500 pairs of preoperative and postoperative optical coherence tomography (OCT) images for training a neural network. 60 preoperative OCT images were used to test the neural networks performance, and the corresponding postoperative OCT images were used to evaluate the synthesized images in terms of structural similarity index measure (SSIM). The SSIM was used to quantify how similar the synthesized postoperative OCT image was to the actual postoperative OCT image. The Pix2Pix GAN model was used to generate synthesized postoperative OCT images. Total 60 synthesized OCT images were generated with training values at 800 epochs. The mean SSIM of synthesized postoperative OCT to the actual postoperative OCT was 0.913. Pix2Pix GAN model has a possibility to generate predictive postoperative OCT images following ERM removal surgery.

Vitrectomy and tumor endoresection for the diagnosis and treatment of focal nodular retinal gliosis.

We report the case of a 60-year-old woman who presented with metamorphopsia and progressive vision loss in the right eye. Fundus examination revealed an elevated, white-yellow mass in the peripheral inferotemporal retina, with massive retinal exudation, proliferative vitreoretinopathy, and retinal detachment. Pars plana vitrectomy with tumor endoresection was performed, and a complete excisional biopsy of the lesion was obtained by removing the tumor through the anterior chamber. Histopathological analysis of the specimen confirmed a diagnosis of peripheral, focal, nodular retinal gliosis. Postoperatively, visual function improved greatly, with no recurrence of the disease at 12 months' follow-up. Focal nodular retinal gliosis is a rare, non-neoplastic proliferation of retinal glial cells, with a vascular component. In our case, surgical treatment with pars plana vitrectomy facilitated accurate diagnosis and resulted in effective management of the retinal tumor and associated complications.

[Autologous neurosensory retinal transplantation.] / Autológ neuroszenzoros retinatranszplantáció.

Macular hole is a full-thickness neuroretinal defect in the fovea. The surgical solution is the removal of the internal limiting membrane (ILM) during vitrectomy with gas filling. Several surgical techniques have been described for the closure of refractory macular holes (about 5%), that reappear after successful surgery or do not close despite surgery. This article presents the first autologous neurosensory retina transplantation performed in Hungary for a large, refractory, full-thickness macular hole, with a brief overview of macular hole surgery. In September 2022, we performed a combined phacovitrectomy with ERM/ILM peeling and SF6 gas filling due to cataract, epiretinal membrane (ERM), and large macular hole due to the deterioration of vision in our patient's left eye for months, with a visual acuity of 6%. We drew the patient's attention to the importance of postoperative head positioning, which she ignored. With a visual acuity of 4%, due to a refractive macular hole (at the base: 983 µm, at the smallest diameter: 609 µm), on December 14, 2022, autologous neurosensory retina transplantation was performed using intraoperative OCT (Zeiss ARTEVO 800). At the end of the surgery, decalin was left in the eye to keep the graft in place, and the patient spent 5 days in a supine position. The decalin was removed with another operation, followed by C3F8 gas filling. 8 weeks after surgery, we documented a closed macular hole with 20% visual acuity, which was stable during the 6-month follow-up. Among the options considered for the resolution of refractory macular holes, autologous neurosensory retinal transplantation, which results in a visual improvement of our patient, is an intervention worth considering. Intraoperative OCT was a great help in performing the surgery. Although the decalin left temporarily in the eye helps to keep the transplant in place, it requires a continuous supine position and another operation is essential to remove it. Further experience is needed to establish the exact indication for autologous neurosensory retinal transplantation. Orv Hetil. 2023; 164(38): 1511-1517.

Fundamental and State-of-the-Art Technologies In Retinal Studies and Disease Repair.

ARTICLES DISCUSSED: Ma, Y., Li., T. Monitoring dynamic growth of retinal vessels in oxygen-induced retinopathy mouse model. Journal of Visualized Experiments. (170), e62410 (2021). Guan, Y., Xie, B. Zhong, X. Retinal organoid induction system for derivation of 3D retinal tissues from human pluripotent stem cells. Journal of Visualized Experiments. (170), e62435 (2021). Rose, K., Lokappa, S. Chen, J. Two peeling methods for the isolation of photoreceptor cell compartments in the mouse retina for protein analysis. Journal of Visualized Experiments. (178), e62977 (2021). Ye., Q. et al. In vivo methods to assess retinal ganglion cell and optic nerve function and structure in large animals. Journal of Visualized Experiments. (180), e62879 (2022). Abbas, F., Vinberg, F., Becker, S. Optimizing the setup and conditions for ex vivo electroretinogram to study retina function in small and large eyes. Journal of Visualized Experiments. (184), e62763 (2022). Okan, I., Ahmadian, M., Tutuncu, Y., Altay, H., Agca, C. Digital droplet PCR method for the quantification of AAV transduction efficiency in murine retina. Journal of Visualized Experiments. (178), e63038 (2021).

Association between severe retinopathy of prematurity (ROP) and poor motor neurodevelopmental outcome.

During the final (third) trimester outside of the womb, the retina develops significantly and is vulnerable to problems. Similar to how the cerebral cortex does, the cerebellum also grows quickly during this time and is susceptible to upsetting environmental influences. The only factors that show promise for lowering the incidence and retinopathy of prematurity (ROP) severity among high-risk infants are prematurity prevention, preeclampsia control, and prudent use of oxygen therapy and ventilation. The third trimester is when the cerebral cortex, cerebellum, and retina develop. These areas are vulnerable to environmental influences if their development is interrupted. Throughout childhood and adolescence, neurodevelopmental defects have been linked to impaired cortical development and smaller brain volumes. Reduced cerebellar volumes have been linked to an increased risk of autism spectrum disorder, lower motor performance, impaired executive functioning, and poorer cognitive outcomes. The complete avascular retina, as well as the peripheral retina, should be treated during retinal ablation with laser photocoagulation (using a transpupillary diode, 11 argon, and three FD-YAG) or cryoablation as failing to do so promotes disease progression and results in unfavorable anatomical and refractive outcomes.

Twelve-Month Clinical and Histopathological Performance of a Novel Synthetic Cornea Device in Rabbit Model.

Purpose: To report the biological stability and postoperative outcomes of a second-generation, single-piece, flexible synthetic cornea in a rabbit model. Methods: Device materials and design were amended to enhance biointegration. Optic skirt design devices were made from compact perfluoroalkoxy alkane with porous expanded polytetrafluoroethylene ingrowth surface overlying the skirt and optic wall. Sixteen devices were implanted into intrastromal pocket in rabbit eyes. Rabbits were randomly assigned to 6- and 12-month follow-up cohorts (n = 8 in each) postoperatively. Monthly examinations and optical coherence tomography assessed cornea-device integration, iridocorneal angle, optic nerve, and retina. Results: There were no intraoperative complications. All devices were in situ at exit, with clear optics. No retroprosthetic membrane, glaucoma, cataract formation, or retinal detachment was observed. Two rabbits in the 6-month group had mild, focal anterior lamella thinning without retraction adjacent to the optic near tight sutures. Three postoperative complications occurred in the 12-month group. One rabbit diagnosed with endophthalmitis was euthanized on day 228. Mild sterile focal retraction of anterior lamella occurred in two rabbits, which were terminated on days 225 and 315. Light microscopic examination of enucleated globes demonstrated fibroplasia with new collagen deposition into the porous scaffold without significant inflammation, encapsulation, or granuloma formation. Conclusions: Clinical evaluations, imaging, and histopathological findings indicate favorable outcomes of this synthetic corneal device in a rabbit model. Early feasibility studies in humans are being planned. Translational Relevance: Favorable 12-month results of the device in rabbits demonstrate vision-restoring potential in corneally blind individuals at high risk of failure with donor keratoplasty.