Effects of a human amniotic membrane extract on ARPE-19 cells.

BACKGROUND: Human Amniotic Membrane (hAM) is endowed with several biological activities and might be considered an optimal tool in surgical treatment for different ophthalmic pathologies. We pioneered the surgical use of hAM to treat retinal pathologies such as macular holes, tears, and retinal detachments, and to overcome photoreceptor damage in age-related macular degeneration. Although hAM contributed to improved outcomes, the mechanisms of its effects are not yet fully understood. The characterization and explanation of the effects of hAM would allow the adoption of this new natural product in different retinal pathologies, operative contexts, and hAM formulations. At this end, we studied the properties of a hAM extract (hAME) on the ARPE-19 cells. METHODS AND RESULTS: A non-denaturing sonication-based technique was developed to obtain a suitable hAME. Viability, proliferation, apoptosis, oxidative stress, and epithelial-mesenchymal transition (EMT) were studied in hAME-treated ARPE-19 cells. The hAME was able to increase ARPE-19 cell viability even in the presence of oxidative stress (H2O2, TBHP). Moreover, hAME prevented the expression of EMT features, such as EMT-related proteins, fibrotic foci formation, and migration induced by different cytokines. CONCLUSIONS: Our results demonstrate that the hAME retains most of the properties observed in the whole tissue by others. The hAME, other than providing a manageable research tool, could represent a cost-effective and abundant drug to treat retinal pathologies in the future.

HUMAN AMNIOTIC MEMBRANE TO TREAT MACULAR HOLES THAT FAILED TO CLOSE, SULFUR HEXAFLUORIDE ENDOTAMPONADE VERSUS AIR ENDOTAMPONADE: A Prospective Comparative Study.

BACKGROUND/PURPOSE: To determinate the efficacy of the human amniotic membrane plugs with sulfur hexafluoride versus human amniotic membrane plug with air as endotamponade to treat macular holes that failed to close after vitrectomy plus internal limiting membrane peeling. Multimodal imaging was focused to evaluate preoperative features and postoperative changes. METHODS: Prospective interventional comparative study. Twenty eyes of 20 patients affected with macular hole that failed to close were divided into 2 groups: 10 eyes received an amniotic membrane plug with 20% sulfur hexafluoride tamponade and 10 eyes received an amniotic membrane plug with air tamponade. All eyes were studied using multimodal advanced diagnostic tools, such as spectral-domain optical coherence tomography, optical coherence tomography angiography, microperimetry, and adaptive optics to investigate the postoperative results. RESULTS: In both groups, all macular holes were found successfully closed after 12 months. Mean preoperative best-corrected visual acuity was 20/400 in the SF6 group and 20/250 in air group. Final mean best-corrected visual acuity was 20/63 in both groups. The superficial capillary plexus, studied using optical coherence tomography angiography, showed a statistically significant difference between the treated and the fellow eyes. Adaptive optics images revealed the presence of a photoreceptor cell mosaic in the area of the amniotic membrane plug. CONCLUSION: The human amniotic membrane combined with air endotamponade demonstrated its effectiveness to seal macular holes that failed to close after vitrectomy plus internal limiting membrane peeling. Advanced multimodal diagnostic imaging helped us to better understand the modifications associated with the use of the amniotic membrane in these cases.

VITRECTOMY WITH INTERNAL LIMITING MEMBRANE PEELING AND AIR TAMPONADE FOR MYOPIC FOVEOSCHISIS.

PURPOSE: To evaluate the functional and anatomical outcomes of 23-gauge or 25-gauge pars plana vitrectomy with internal limiting membrane peeling and air tamponade for the treatment of myopic foveoschisis. METHODS: Retrospective, noncomparative, interventional case series. The records of 29 patients (32 eyes), with myopic foveoschisis who were treated by 23-gauge or 25-gauge 3-port pars plana vitrectomy with internal limiting membrane peeling and air tamponade, were reviewed. At each visit, a complete ophthalmic examination, intraocular pressure, best-corrected visual acuity, and central foveal thickness measured using optical coherence tomography were assessed. RESULTS: Twenty-five eyes of 23 patients (M:F = 4:19) matched the inclusion criteria, whereas 7 eyes of 6 patients were excluded. The mean logarithm of the minimum angle of resolution best-corrected visual acuity (Snellen equivalent) was 0.62 (20/80) (SE: 0.061), and the mean preoperative central foveal thickness was 619.5 µm (SE: 16.38) at baseline. Visual acuity significantly improved of 5 Early Treatment Diabetic Retinopathy Study letters (45 letters) at the 1-month follow-up (P < 0.001), 2 lines (50 Early Treatment Diabetic Retinopathy Study letters) at the 6-month follow-up (P < 0.001), and it reached 55 Early Treatment Diabetic Retinopathy Study letters at the 1-year follow-up visit (P < 0.001). Central foveal thickness decreased to 292.4 µm (SE: 15.93), to 227.3 µm (SE: 14.05), and to 208.8 µm (SE: 12.86), respectively, at the 1-, 6-, and 12-month follow-ups (for each P < 0.001). There were no differences in best-corrected visual acuity or central foveal thickness changes between the foveal detachment group and the nonfoveal detachment group (P > 0.05). CONCLUSION: Small-gauge vitrectomy with internal limiting membrane peeling and air tamponade results in favorable anatomical and functional outcomes for patients affected by myopic macular foveoschisis.

INTERNAL LIMITING MEMBRANE PEELING VERSUS INVERTED FLAP TECHNIQUE FOR TREATMENT OF FULL-THICKNESS MACULAR HOLES: A COMPARATIVE STUDY IN A LARGE SERIES OF PATIENTS.

BACKGROUND: The inverted flap (IF) technique has recently been introduced in macular hole (MH) surgery. The IF technique has shown an increase of the success rate in the case of large MHs and in MHs associated with high myopia. This study reports the anatomical and functional results in a large series of patients affected by MH treated using pars plana vitrectomy and gas tamponade combined with internal limiting membrane (ILM) peeling or IF. METHODS: This is a retrospective, consecutive, nonrandomized comparative study of patients affected by idiopathic or myopic MH treated using small-gauge pars plana vitrectomy (25- or 23-gauge) between January 2011 and May 2016. The patients were divided into two groups according to the ILM removal technique (complete removal vs. IF). A subgroup analysis was performed according to the MH diameter (MH < 400 µm and MH ≥ 400 µm), axial length (AL < 26 mm and AL ≥ 26 mm), and the presence of chorioretinal atrophy in the macular area (present or absent). RESULTS: We included 620 eyes of 570 patients affected by an MH, 300 patients underwent pars plana vitrectomy and ILM peeling and 320 patients underwent pars plana vitrectomy and IF. Overall, 84.94% of the patients had complete anatomical success characterized by MH closure after the operation. In particular, among the patients who underwent only ILM peeling the closure rate was 78.75%; among the patients who underwent the IF technique, it was 91.93% (P = 0.001); and among the patients affected by full-thickness MH ≥400 µm, success was achieved in 95.6% of the cases in the IF group and in 78.6% in the ILM peeling group (P = 0.001); among the patients with an axial length ≥26 mm, success was achieved in 88.4% of the cases in the IF group and in 38.9% in the ILM peeling group (P = 0.001). Average preoperative best-corrected visual acuity was 0.77 (SD = 0.32) logarithm of the minimum angle of resolution (20/118 Snellen) in the peeling group and 0.74 (SD = 0.33) logarithm of the minimum angle of resolution (20/110 Snellen) in the IF group (P = 0.31). Mean postoperative best-corrected visual acuity was 0.52 (SD = 0.42) logarithm of the minimum angle of resolution (20/66 Snellen) in the peeling group and 0.43 (SD = 0.31) logarithm of the minimum angle of resolution (20/53 Snellen) in the IF group (P = 0.003). CONCLUSION: Vitrectomy associated with the inverted ILM flap technique seems to be effective surgery for idiopathic and myopic large MHs, improving both functional and anatomical outcomes.

Descemet stripping automated endothelial keratoplasty in Fuchs' corneal endothelial dystrophy: anterior segment optical coherence tomography and in vivo confocal microscopy analysis.

BACKGROUND: To evaluate the in vivo corneal changes using in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) in patients with Fuchs' dystrophy who underwent Descemet stripping automated endothelial keratoplasty (DSAEK) and the relationship between these changes and the postoperative visual recovery up to 1-year follow-up. METHODS: Before DSAEK and 1 day, 3, 6 and 12 months after surgery 31 patients (39 pseudophakic eyes) underwent a complete ophthalmological evaluation including best corrected visual acuity (BCVA), IVCM (subepithelial haze, interface haze, graft thickness) and AS-OCT (graft thickness). RESULTS: Graft thickness measurements by AS-OCT were strongly correlated to those obtained using IVCM at every follow-up stage (intraclass correlation coefficient = 0.95 to 0.97 between 3 and 12 months, P < 0.001 for all coefficients). No correlation between BCVA and graft thickness measured by AS-OCT at any follow-up stage was found, while at 3 and 6 postoperative months the correlations between BCVA and preoperative subepithelial haze (r = 0.61, P < 0.001 and r = 0.46, P = 0.002), interface haze (r = 0.51, P < 0.001 and r = 0.46, P = 0.003), postoperative subepithelial haze (r = 0.43, P = 0.004 and r = 0.39, P = 0.001) were significant. CONCLUSIONS: The study confirmed corneal subepithelial haze and interface haze as important factors limiting visual acuity after DSAEK, while graft thickness was not related to BCVA.

Reproducibility of SIMPLE classification for diabetic retinopathy screening and its comparison to current Italian guidelines.

PURPOSE: To evaluate the reproducibility of SIMPLE (Single field Image Multi Parameters defined Lesions Extent), a new Diabetic Retinopathy (DR) classification for screening of 45° single field fundus pictures of patients with diabetes (PwDM), assessing DR, Diabetic Maculopathy (DMac) and referral rate agreement and comparing it to current Italian Guidelines (IG). MATERIALS AND METHODS: We conducted a retrospective, observational, multicentre study, collecting 1000 retinal 45° single field images of PwDM obtained during routine visits in two diabetes clinics. Three ophthalmologists evaluated each image, determining the presence and number of specific DR lesions and then assigning a stage according to the current IG for screening. SIMPLE staging was performed automatically via Excel software, based on the pre-specified DR characteristics observed by the graders. We analysed intra-centre, inter-centre and total inter-grader agreement for DR and DMac stage and referral rate of the two classifications. RESULTS: Agreement amongst the three graders was consistently higher when using SIMPLE classification than when using current IG classification. For DR, kappa (k) was 0.86 with IG and 0.95 with SIMPLE classification; for DMac, k-IG was 0.78, while k-SIMPLE was 0.96; concordance on the referral rate was 0.91 with IG and 0.99 with SIMPLE. Similar results were obtained in sub-analyses for the evaluation of intra-centre and inter-centre concordance. CONCLUSIONS: Our results suggest that the new SIMPLE classification has an excellent reproducibility amongst graders, comparable or superior to the current IG for DR screening proposed in 2015, improving the standardisation of the decision on referability.

Management of submacular massive haemorrhage in age-related macular degeneration: comparison between subretinal transplant of human amniotic membrane and subretinal injection of tissue plasminogen activator.

PURPOSE: Macular neovascularization (MNV) can complicate age-related macular degeneration (AMD) and lead to severe visual acuity reduction. Massive submacular haemorrhage (SMH) is a sight-threatening complication of MNV and a challenge in the management of complications related to MNV in AMD since the effects of anti-vascular endothelial growth factor treatment alone are insufficient. Here, we evaluate the different postoperative outcomes of patients affected by MNV complicated by SMH that underwent subretinal implant of human amniotic membrane (hAM) or subretinal injection of tissue plasminogen activator (tPA). METHODS: This is a retrospective, consecutive, comparative, non-randomized interventional study. We included 44 eyes of 44 patients affected by AMD complicated by MNV and SMH. Twenty-two eyes underwent a pars plana vitrectomy (PPV), SMH and neovascular membrane removal, with a subretinal implant of hAM and silicone oil, and 22 eyes underwent PPV, subretinal injection of tPA, and 20% sulphur hexafluoride. The primary study outcome was visual acuity improvement. Secondary outcomes were postoperative complications, and MNV recurrence and optical coherence tomography (OCT)-Angiography parameters correlated with best-corrected visual acuity (BCVA). RESULTS: Mean preoperative BCVA was 1.9 logarithm of the minimal angle of resolution (logMAR) in the amniotic membrane-group and 2 logMAR in the tPA-group. The mean final BCVA values were 1.25 and 1.4 logMAR, respectively, with a statistically significant difference. Optical coherence tomography (OCT)-Angiography scan was be used to evaluate the retinal vascularization in the treated eye. CONCLUSION: Both techniques report similar VA improvements and postoperative complications. However, transplantation of hAM seems to have a significant benefit in inhibiting MNV recurrence.

Refractive error after combined phaco-vitrectomy: A multicentric study.

PURPOSE: To study the post-operative refractive error (RE) of patients undergoing combined phaco-vitrectomy and to find out which intraocular lens (IOL)-power formula had the best refractive outcomes. METHODS: In this retrospective multicentric study we compared the preoperative expected target with the postoperative RE of patients undergoing combined phaco-vitrectomy due to vitreomacular traction, macular pucker, full thickness macular hole or lamellar macular hole. A multinomial logistic regression was performed to compare the postoperative REs and the differences between expected and postoperative REs among the SRK-T, Olsen's and Holladay-2 formulas. The correlation between the difference in REs and IOL-power was also studied. RESULTS: Sixty-seven eyes with a mean axial length of 23.73 ± 1.21 mm were included. Forty-two (63%), 14 (21%) and 11 (16%) eyes were implanted with an IOL that was calculated respectively with SRK-T, Olsen's and the Holladay-2 formula. The mean preoperative expected- and post-operative REs were -0.16 ± 0.12D and -0.48 ± 0.17, respectively (p = 0.045). SRK-T and Holladay-2 formulas led to a significant myopic shift whereas Olsen's caused a significant hyperopic error, independently from the IOL power. CONCLUSION: Independently from the IOL power, none of the analyzed formulas is precise at calculating the post-operative RE.

Optic Disk Pit Maculopathy Treatment Using a Human Amniotic Membrane Patch: One-Year Results.

PURPOSE: To report the 1-year results of human amniotic membrane patch implantation for optic disc pit maculopathy. DESIGN: A prospective, consecutive, interventional study. METHODS: Eleven eyes of 11 patients affected by optic disc pit maculopathy associated with subretinal/intraretinal fluid were included in this single-institution study. A 25-gauge pars plana vitrectomy was performed in all cases, with an implant of a human amniotic membrane patch into the optic disc pit and air was injected as endotamponade. The primary study outcome was the subretinal and intraretinal fluid reabsorption. Secondary outcomes were visual acuity improvement and postoperative complications. RESULTS: Mean central retinal thickness gradually diminished from 512 ± 137 µm to 243 ± 19 µm, at the 12-month follow-up. The mean visual acuity improved from 20/80 at baseline to 20/32 at the 12-month follow-up. Complete fluid resorption occurred in 9 of 11 (81.8%) eyes and there was partial resorption in 2 eyes (18%). No subretinal fluid recurrence was observed during the 12-month follow-up. No intraoperative or postoperative complications were reported during the follow-ups. The amniotic membrane patch remained detectable inside the pit for the entire follow-up time. CONCLUSION: An amniotic membrane plug may be effective for improving optic disc pit maculopathy. All cases had an anatomical improvement and encouraging visual acuity recovery.

Via pars plana anterior iris enclavation IOL fixation.

AIM: To describe a via pars plana anterior iris enclavation intraocular lens (IOL) fixation technique. METHODS: A total of 35 consecutive aphakic vitrectomised patients (average age 71.12±10.12y) underwent pars plana vitrectomy (PPV) and via pars plana anterior iris enclavation IOL fixation. RESULTS: The mean preoperative best corrected visual acuity (BCVA) was 0.11±0.14 logMAR, the mean postoperative BCVA was 0.07±0.11 logMAR. The preoperative mean spherical equivalent was 7.22±4.21 D. The final mean spherical equivalent was -0.25±0.15 D. No eyes had hypotony, retinal or choroidal detachment or endophthalmitis. CONCLUSION: This technique may be a safe and useful in the case of aphakia, and a prospective study would be useful to confirm this findings.

Combining cataract surgery with 25-gauge high-speed pars plana vitrectomy: A prospective study.

PURPOSE: To compare visual outcome and postoperative complications of combined 25-gauge pars plana vitrectomy and phacoemulsification with vitrectomy alone surgery in patients with epiretinal membrane and macular hole. METHODS: A total of 110 eyes (73 eyes with epiretinal membrane and 37 eyes with macular hole) were enrolled in this prospective study. The eyes were divided into two groups: Group A included 55 eyes which underwent phacovitrectomy at the same time and Group B included 55 eyes which underwent vitrectomy alone. Follow-up visits were at 1, 3, and 6 months. RESULTS: The best-corrected visual acuity correlation by analysis of variance measurement showed statistically non-significant differences between the two groups (p = 0.32). The post hoc analysis from baseline, 1°, 2°, and 3° follow-ups was not statistically significant (p > 0.05). The most common postoperative complication was cystoid macular edema that has been detected in 11 patients (10%) (seven eyes in Group A and four eyes in Group B): 2 patients (1.8%) developed a chronic macular edema. Intraocular hypertension occurred in five eyes (4.5%) (three in Group A and two in Group B). Four eyes (3.6%) underwent another surgical procedure for a persistent macular hole (two in Group A and two in Group B). The intraocular lens repositioning was performed one day after surgery in three eyes (2.7%) (Group A). The mean preoperative visual acuity was not different between the two groups (p = 0.80). CONCLUSION: No significative differences between combined surgery and vitrectomy alone have been detected, in terms of postoperative complications and visual outcome.

Human Amniotic Membrane Plug to Restore Age-Related Macular Degeneration Photoreceptor Damage.

PURPOSE: Age-related macular degeneration (AMD) is the leading cause of legal blindness in adults 65 years of age and older. Choroidal neovascularization (CNV) can complicate AMD and lead to severe visual acuity reduction. Despite the several treatments available, if the retinal pigment epithelium is damaged, we have to cope with the impossibility of restoring acceptable visual acuity using only medical treatments. DESIGN: Prospective, consecutive, interventional study. PARTICIPANTS: Eleven patients affected by AMD, 6 patients affected by CNV, and 5 patients affected by geographic atrophy. METHODS: All patients underwent a pars plana vitrectomy with subretinal implantation of human amniotic membrane (hAM) to induce photoreceptor regeneration and partial visual acuity restoration. MAIN OUTCOME MEASURES: Primary study outcome was visual acuity improvement. Secondary outcomes were multimodal imaging results. RESULTS: Mean preoperative best-corrected visual acuity (BCVA) was 20/2000 (2 logarithm of the minimum angle of resolution [logMAR]), and all the patients showed a BCVA of counting fingers or less. Mean final BCVA was 20/400 (1.31 logMAR), ranging from 20/2000 to 20/100 (2-0.7 logMAR). OCT angiography was used to measure retinal vascularization in the treated eye compared with the fellow eye. A high correlation between BCVA and deep vascular density was evidenced. Adaptive optics findings, obtained over the retinal area where the highest functionality was observed, were evaluated using microperimetry. The images showed possible photoreceptor presence over the hAM membrane. CONCLUSIONS: This work supports the feasibility and safety of the hAM to promote partial retinal function restoration 6 months after surgery with visual acuity improvement. The advanced diagnostics help to understand the interaction between the hAM and photoreceptors and suggest that photoreceptor regeneration may occur.

A human Amniotic Membrane plug to manage high myopic macular hole associated with retinal detachment.

OBJECTIVE: To assess the efficacy of the human amniotic membrane (hAM) to treat (HMMH) associated with retinal detachment (RD). MATERIAL AND METHODS: Ten eyes of 10 patients with recurrent HMMH and RD, who had already undergone one or more pars plana vitrectomy (PPV), underwent a PPV with an hAM plug implanted in the macular hole. The initial five patients enrolled were tamponaded with (SO) while the subsequent five patients with 10% octafluoropropane (C3 F8 ). Silicon oil was removed in all five patients 2 months later. No statistical differences were reported between the two groups. RESULTS: Final retinal reattachment was achieved in all the patients. BCVA improved from 1.73 logMAR to 0.94 logMAR after 6 months. No adverse events were registered during follow-up. CONCLUSION: An hAM plug is an efficient substrate to manage HMMH associated with RD resulting in encouraging visual acuity recovery.

Applications of the Amniotic Membrane in Vitreoretinal Surgery.

Recently, the use of the human amniotic membrane (hAM) has been extended to treat retinal disorders, such as macular holes that failed to close and retinal tears. The hAM has demonstrated the induction of a recovery process of the external retinal layers involving the external limiting membrane (ELM) and the ellipsoid zone (EZ). After that, the application of the hAM for retinal pathologies was extended to large macular tears, high myopic retinal detachment associated with MH, paravascular tears, serous macular detachment associated with optic pit, complicated retinal detachment and advanced age-related macular degeneration (AMD). The hAM has shown a potential in repairing retinal tissue through a regeneration process. This review aims to highlight the use of the hAM in various vitreo-retinal surgical fields, and to confront it with other cutting-edge surgical techniques used to treat challenging vitreo-retinal pathologies.