Macular Hemorrhage Due to Age-Related Macular Degeneration or Retinal Arterial Macroaneurysm: Predictive Factors of Surgical Outcome

Objective: The study aimed to determine the outcomes and prognostic factors of vitrectomy, subretinal injection of tissue-plasminogen activator and gas tamponade in macular hemorrhage (MaH) due to age-related macular degeneration (AMD) or retinal arterial macroaneurysm (RAM). Methods: The study design utilized a multicentric retrospective case series design of consecutive patients undergoing surgery between 2014 and 2019. Results: A total of 65 eyes from 65 patients were included in the study. Surgery was performed after a mean period of 7.1 days. Displacement of MaH was achieved in 82% of the eyes. Mean best-corrected visual acuity (BCVA) improved from 20/500 to 20/125 at month(M)1 and M6 (p < 0.05). At M6, BCVA worsening was associated with an older age at diagnosis (p = 0.0002) and higher subretinal OCT elevation of MaH (p = 0.03). The use of treat and extend (TE) (OR = 16.7, p = 0.001) and small MaH fundus size (OR = 0.64 and 0.74 for horizontal and vertical fundus size, p < 0.05) were predictive of a higher likelihood of obtaining a countable BCVA at M1. Baseline BCVA was predictive of postoperative BCVA (p < 0.05). Retinal detachment and MaH recurrence occurred in 3% and 9.3% of cases at M6. Conclusion: MaH surgery stabilizes or improves BCVA in 85% of cases. Younger age at diagnosis, better baseline BCVA figures, smaller subretinal MaH height and use of TE regime were predictive of the best postoperative outcomes.

Two-step versus 1-step subretinal injection to compare subretinal drug delivery: a randomised study protocol

IntroductionThere is increasing interest in subretinal injections as a surgical procedure, largely as a result of emerging treatments for ocular diseases which necessitate this manoeuvre. However, surgical variables in the efficacy of such treatments have to date been largely overlooked and the proportion of drug which reaches the intended compartment of the subretinal space remains unknown. Our aims are twofold: first, to determine the proportion of subretinally injected medication retained following surgical delivery and second, to compare two different techniques of injection (‘1-step’ vs ‘2-step’).MethodsWe outline a randomised controlled trial of subretinal injection of alteplase following vitrectomy for the management of submacular haemorrhage secondary to age-related macular degeneration. Patients will be randomised to receive either 1-step injection, where the therapeutic solution simultaneously defines the surgical plane or 2-step injection, where the surgical plane is first identified with balanced salt solution prior to injection of subretinal alteplase, as outlined below. Sodium fluorescein will be used as an optical label to track drug reflux into the vitreous cavity using quantitative protocols established in our laboratory. All patients will undergo fluid air exchange at the completion of surgery, with injection of bevacizumab 1.25 mg and 20% sulfahexafluoride gas as the vitreous substitute (both of which may help improve outcomes). Alteplase, sodium fluorescein and bevacizumab will all be used for off-label indications in the trial.Ethics and disseminationEthical approval has been obtained from the South Eastern Sydney Local Health District’s Human Research Ethics Committee (HREC 17/092). The results of this trial will be disseminated in peer-reviewed proceedings (associated with conference presentation) and in scholarly journals.Trial registration numberACTRN12619001121156.

The learning curve of murine subretinal injection among clinically trained ophthalmic surgeons

PURPOSE: Subretinal injection (SRI) in mice is widely used in retinal research, yet the learning curve (LC) of this surgically challenging technique is unknown. METHODS: To evaluate the LC for SRI in a murine model, we analyzed training data from 3 clinically trained ophthalmic surgeons from 2018 to 2020. Successful SRI was defined as either the absence of retinal pigment epithelium (RPE) degeneration after phosphate buffer saline injection and the presence of RPE degeneration after Alu RNA injection. Multivariable survival-time regression models were used to evaluate the association between surgeon experience and success rate, with adjustment for injection agents, and to calculate an approximate case number to achieve a 95% success rate. A Cumulative Sum (CUSUM) analysis was performed and plotted individually to monitor each surgeon's simultaneous performance. RESULTS: Despite prior microsurgery experience, the combined average success rate of the first 50 cases in mice was only 27%. The predicted SRI success rate did not reach a plateau above 95% until approximately 364 prior cases. Using the 364-training case as a "cutoff" point, the predicted probability of success before and after the 364th case was 65.38% and 99.32%, respectively (P < 0.0001). CUSUM analysis showed an initial upward slope and then remained within the decision intervals with an acceptable success rate set at 95% in the late stage. CONCLUSIONS: This study demonstrates the complexity and substantial LC for successful SRI in mice with high confidence. A systematic training system could improve the reliability and reproducibility of SRI-related experiments and improve the interpretation of experimental results using this technique. Translational Relevance: Our prediction model and monitor system allow objective quantification of technical proficiency in the field of subretinal drug delivery and gene therapy for the first time.

EXAMINING LOCALLY EXPRESSED mRNA OF INFLAMMATORY MEDIATOR GENES IN A MODEL OF RETINAL PIGMENT EPITHELIUM ATROPHY AND RETINAL DEGENERATION INDUCED BY SUBRETINAL SALINE INJECTION IN RABBITS

Degenerative-dystrophic retinal diseases, particularly age-related macular degeneration (AMD), are now considered to be the lead cause of blindness and low vision in developed countries, with a steadily increasing trend. Recent publications provide evidence for the involvement of inflammatory mechanisms in TMD development and progression unveiled due to advances in innate and adaptive immunity research. However, the immunopathogenesis of atrophic AMD form, “geographic atrophy” (GA) remains largely unstudied. Objective: to investigate local mRNA expression of inflammatory cytokines IL-1β, IL-18, CCL2/MCP-1 in a model of RPE atrophy induced after subretinal injection of 0.9% sodium chloride solution in experimental rabbits. The investigation was carried out in tissue complex retina-RPE-choroid (TC) samples isolated from eyes of 23 albino New Zealand rabbits after modeling RPE atrophy by subretinal injection of 0.9% sodium chloride solution and 5 healthy rabbits lacking eye lesions. Animals in the experimental group (one week before surgical intervention, in the early period, and in the period of sustained RPE atrophy formation) and controls were subjected to optical coherence tomography (OCT) and ocular fundus autofluorescence (FAF). Evaluation of proinflammatory cytokine gene expression levels in TC was performed by RT-PCR. Results. Subretinal injection of 0.01 ml of 0.9% sodium chloride solution induced experimental RPE atrophy development in rabbits vs. control that was associated with multidirectional changes of IL-1β, IL-18, MCP-1/CCL2 gene mRNA expression. Three types of response in the TC, formed during development of atrophic changes and determined by the value of local cytokine gene expression were characterized: 1) hypo/ no response – decreased/no expression; 2) normal response – moderate increase; 3) hyper response – overexpression. 69.6% of animals with persistent atrophy had a moderate to hypertrophic increase in locally expressed mRNA MCP-1/CCL2, whereas 30% cases had significantly increased IL-1β mRNA expression – factors damaging the blood-retinal barrier and contributing to posterior segment immune privilege. It should be taken into account while developing new strategies for treatment of ophthalmic pathology, in particular the currently actively studied and tested options for RPE stem cell transplantation into subretinal space. The data obtained may be useful to investigate various types of RPE atrophy and develop new strategies of ophthalmopathology treatment in preclinical studies.

Subretinal injection of prourokinase in the treatment of large subretinal hemorrhages

8 patients were treated in the Regional State ophthalmologic clinical hospital of Public Health Ministry of Udmurt Republic with subretinal hemorrhage. All performed 25-gage vitrectomy with removal of the posterior hyaloid membrane, subretinal injection of 500 ME prourokinase and air tamponade of the vitreous cavity. In the postoperative period, patients occupied a forced position of the body face up for 2 hours, then were transferred to an upright position for 1 day face down. All patients had resorption of subretinal hemorrhage, visual acuity from 0,009±0,005 improved to 0,15±0,05 (p<0.05; U-criterion). The technique proved to be a highly effective method of rehabilitation of patients with extensive subretinal hemorrhage. Key words: subretinal hemorrhage, prourokinase, vitrectomy.

Local photoreceptor cell death differences in the murine model of retinal detachment

To investigate local cell death differences in the attached and detached retina at different regions in a murine experimental retinal detachment model. Subretinal injection of sodium hyaluronate was performed in eight-week-old C57BL/6J mice. Retinal regions of interest were defined in relation to their distance from the peak of the retinal detachment, as follows: (1) attached central; (2) attached paracentral; (3) detached apex; and (4) detached base. At day 0, the outer nuclear layer cell count for the attached central, attached paracentral, detached apex, and detached base was 1247.60 ± 64.62, 1157.80 ± 163.33, 1264.00 ± 150.7, and 1013.80 ± 67.16 cells, respectively. There were significant differences between the detached base vs. attached central, and between detached base vs. detached apex at day 0. The detached apex region displayed a significant and progressive cell count reduction from day 0 to 14. In contrast, the detached base region did not show progressive retinal degeneration in this model. Moreover, only the detached apex region had a significant and progressive cell death rate compared to baseline. Immediate confounding changes with dramatic differences in cell death rates are present across regions of the detached retina. We speculate that mechanical and regional differences in the bullous detached retina can modify the rate of cell death in this model.

Surgical treatment of extensive submacular hemorrhage in patient with exudative age-related macular degeneration (clinical case)

Purpose. To evaluate the result of surgical treatment of submacular hemorrhage in patient with exudative age-related macular degeneration (AMD) by subretinal injection Gemase® and pneumatic retinopexy of blood clot. Material and methods. The article presents a clinical case of surgical treatment of submacular hemorrhage in patient with exudative AMD. The patient underwent three-port 25G vitrectomy, subretinal injection Gemase® 2000 ME by 38G needle, after which pneumatic retinopexy was performed. Results. Next day after the operation, there was displacement of subretinal blood clot from macula beyond out the lower vascular arcade. When observed after 6 months, the subretinal hemorrhage completely resolved, there was a regression of activity of subretinal neovascular membrane and macular edema, the retina was adherent in all cases. Visual acuity has improved. There was no recurrence of hemorrhage. Conclusion. This method of treatment allows you to increase and maintain the central visual acuity, as well as significantly reduce size of absolute central scotoma. Key words: submacular hemorrhage, recombinant prourokinase, Gemase®, exudative age-related macular degeneration, choroidal neovascularization, subretinal neovascular membrane.