Swept-source OCT reduces the risk of axial length measurement errors in eyes with cataract and epiretinal membranes

Aims: To compare the biometric data from partial coherence interferometry (PCI) and swept-source OCT (SS-OCT) in patients with age-related cataract and epiretinal membrane (ERM): ERM, ERM with foveoschisis and macular pseudohole. Methods: 49 eyes of 49 subjects including 36 ERM, 9 ERM foveoschisis and 4 macular pseudohole were analysed to evaluate the axial length (AL) measurements and the presence of AL measurement errors, defined basing on the shape of the biometric output graphs and on the concordance of AL values between instruments. Eyes with ERM were divided in four stages according to OCT features (i.e. presence/absence of the foveal pit, presence of ectopic inner foveal layers, disrupted retinal layers). Results: The devices provided similar mean AL measurements in all subgroups, with differences <0.1 mm in 41/49 cases (83.6%). AL measurement errors were observed in ERM stages 3 and 4, characterized by ectopic inner foveal layers, and were significantly more frequent with the PCI (8/17, 47%) as compared with the SS-OCT device (2/17, 12%), p = 0.02. The refractive prediction error in cases with AL measurement errors was significantly greater using the PCI compared to the SS-OCT device (p<0.05). Conclusion: Both devices provide reliable biometric data in the majority of patients and can be used in the preoperative assessment of patients with age-related cataract and ERM. In eyes with ectopic inner foveal layers, attention should be paid as AL measurement and refractive prediction errors may occur, more frequently with the PCI device

Morpho-Functional Evaluation of Full-Thickness Macular Holes by the Integration of Optical Coherence Tomography Angiography and Microperimetry

(1) Objective: To use optical coherence tomography angiography (OCTA) and microperimetry (MP) to evaluate the correlation between retinal structure and function in patients with idiopathic, full-thickness macular holes (FTMHs) (2) Methods: This prospective, observational study included 11 eyes of 10 patients with FTMHs evaluated before surgery using OCTA and MP. MP sensitivity maps were superimposed and registered on slabs corresponding to superficial capillary plexus (SCP) and deep capillary plexus (DCP) on OCTA, and on the outer plexiform layer (OPL) and the Henle fiber layer (HFL) complex in en face OCT. On these maps, mean retinal sensitivity was calculated at 2 degrees and 4 degrees, all centered on the FTMH. Cystic cavity extension was assessed on the slab corresponding to the OPL + HFL complex in en face OCT and DCP in OCTA using the Image J software (Version 1.49v; National Institutes of Health, Bethesda, MD, USA); (3) Results: Absolute scotomas were observed corresponding to the FTMH. Additionally, rings of relative scotoma in the perilesional area were detected and correlated to the cystic spaces on en face OCT and OCTA. There was a significant correlation between reduced retinal sensitivity at 2 degrees and 4 degrees diameters around the FTMH and the extension of cystic areas (p < 0.01). There was a significant correlation between the extension of cystic cavities and BCVA (p < 0.01). (4) Conclusions: Morpho-functional analysis of FTMH using OCTA and MP, and the correlation between vascular abnormalities and impaired retinal sensitivity, may provide new, useful information. This integrated evaluation of FTMH may be useful to determine the function-structure correlation before and after vitreoretinal surgery, in order to gain a better understanding of the functional consequences induced by the morphological alterations, assessing outcomes in a more objective way, and potentially adding new surgical prognostic factors

Femtosecond laser-assisted cataract in vitreoretinal surgery

To assess the safety and surgical results of femtosecond laser-assisted phacovitrectomy

Scleral Buckling Using Chandelier and Releasable Suture: A Useful Surgical Variant

PURPOSE: To describe a surgical variant for scleral buckling technique using a chandelier and scleral releasable suture.METHODS: We collected retrospectively 20 eyes of 20 patients who underwent to scleral buckling for retinal detachment. In all cases, the surgeons performed the surgical variant of scleral buckling using a 27-gauge (G) chandelier as endoillumination and releasable 7.0 vicryl scleral suture.RESULTS: None of the operated eyes developed lens opacity or lens marks at the entrance site of the chandelier used during the surgery, and no cataract development was observed as well, during the follow-up. Retinal reattachment was achieved in 19 out of 20 eyes at the first surgery in the follow-up time of 6 months.CONCLUSION: The association of chandelier and releasable suture was a useful surgical variant when performing scleral buckling technique for retinal detachment. Complications like lens opacity or lens marks at the entrance site of the chandelier due to the use of chandelier itself can be greatly reduced, as well as complications due to vitreous prolapse from the sclerotomy by using releasable scleral suture

Choriocapillaris vascular density changes: healthy vs. advanced exudative age-related macular degeneration previously treated with multiple anti-VEGF intravitreal injections

Purpose: To assess choriocapillaris vascular density (VD) in healthy and advanced exudative age-related macular degeneration (ae-AMD) patients by new full-range optical coherence tomography angiography (OCT-A). Method: In this observational, cross-sectional study, 21 healthy and 21 ae-AMD eyes, already treated with anti-VEGF, were enrolled. Angio-View retina patterns centered on fovea (6.4 × 6.4 mm) were acquired for all participants using Solix full-range OCT (Optovue Inc., Freemont, CA, USA). The main outcome was to compare choriocapillaris VD between healthy and ae-AMD eyes. Automated measurements of whole image choriocapillaris VD (%) and fovea grid-based (%) were collected for the analysis. Angio-View patterns were used to assess the flow area (mm2) of macular neovascularization (MNV) by contour flow measure algorithm. Best-corrected visual acuity (BCVA) of both groups was also used for the statistical analysis. Results: The mean age was 60.9 (±8.3) in healthy and 73.33 (±15.05) in ae-AMD eyes. The mean BCVA (ETDRS letters) was 98.47 (±1.50) in healthy and 7.04 (±5.96) in ae-AMD eyes. The Mann-Whitney test comparing choriocapillaries VD for whole and fovea healthy and ae-AMD eyes showed statistical significance (p < 0.0001 (t = 4.91; df = 40) and p < 0.0001 (t = 6.84; df = 40), respectively). Regarding, the correlation between MNV and VD of choriocapillaries, neither whole nor fovea areas were statistically significant (F = 0.38 (R2 = 0.01) and 1.68 (R2 = 0.08), respectively). Conclusions: Choriocapillaris VD showed a statistically significant reduction in comparison to healthy eyes in ae-AMD eyes. Choriocapillaris impairment can be seen in the early phase of MNV pathogenesis

ULTRASOUND IN VITRECTOMY

Purpose: To study a prototype of an ultrasound-based vitrector, and to try to understand the physical phenomena underlying this new technology. Methods: We tested the ultrasound-based vitrector prototype (UV) (ultrasonically-driven handpiece obtained from a modified version of the Alcon CONSTELLATION Vision System [Alcon]) using an automatic experimental setup. Balanced saline solution (BSS) and vitreous (from fresh postmortem enucleated porcine eyes) flow rates were analyzed using three different tips. Results: In general, BSS solution flow rates increased with increasing aspiration levels and decreased when we used % US power. Vitreous flow rates were influenced by aspiration levels, % US power, and ultrasound-related phenomena: cavitation phenomenon and “jet streaming.” Conclusion: Ultrasound-based vitrectomy may represent an important alternative to traditional vitrectomy. Such a tool, capable of liquefying and excising the vitreous body using ultrasound, could overcome all the limits of the guillotine-based technique (GV). Knowledge of the physical phenomena underlying ultrasound-based technology is a necessary prerequisite for further development of this new technology

Scanning Laser Ophthalmoscopy Retromode Imaging Compared to Fundus Autofluorescence in Detecting Outer Retinal Features in Central Serous Chorioretinopathy

Central serous chorioretinopathy (CSCR) is a retinal disease characterized by a heterogeneous clinical phenotype, depending on the influence of different factors in its pathogenesis, including the presence of subretinal fluid (SRF), trophism of the retinal pigmented epithelium (RPE) and choroidal hyper-permeability. Our study has the purpose of assessing the ability of scanning laser ophthalmoscopy (SLO) retromode imaging, compared to fundus autofluorescence (FAF), to identify outer retinal features in a cohort of patients with a diagnosis of CSCR. A total of 27 eyes of 21 patients were enrolled in our study. All patients underwent full ophthalmological examination, including fundus retinography, fundus fluorescein angiography, optical coherence tomography (OCT), FAF and SLO retromode imaging. For each patient, the following features were evaluated: SRF, the presence of pigmented epithelium detachment (PED), RPE dystrophy, and RPE atrophy. RPE dystrophy was further characterized according to the appearance in FAF of iso-, hyper- and hypo-autofluorescent dystrophy. The ability to identify each feature was evaluated for FAF and SLO retromode alone, compared to a multimodal imaging approach. FAF identified SRF in 11/14 eyes (78%), PED in 14/19 (74%), RPE dystrophy with iso-autofluorescence in 0/13 (0%), hyper-autofluorescence in 18/19 (95%), hypo-autofluorescence in 20/20 (100%), and RPE atrophy in 7/7 (100%). SLO retromode imaging identified SRF in 13/14 eyes (93%), PED in 15/19 (79%), RPE dystrophy with iso-autofluorescence in 13/13 (100%), hyper-autofluorescence in 13/19 (68%), hypo-autofluorescent in 18/20 (90%), and RPE atrophy in 4/7 (57%). SLO retromode imaging is able to detect retinal and RPE changes in CSCR patients with a higher sensitivity than FAF, while it is not able to identify the depth of lesions or supply qualitative information about RPE cells' health status, meaning that it is less specific. SLO retromode imaging may have a promising role in the assessment of patients with CSCR, but always combined with other imaging modalities such as OCT and FAF

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

The Role of OCT Angiography in the Assessment of Epiretinal Macular Membrane

Background: The aim of this observational study is to assess pre- and postoperative retinochoroidal vascular changes in patients undergoing epiretinal macular membrane (ERM) surgery by using optical coherence tomography angiography (OCTA).Materials and Methods: 23 eyes affected by ERM and those which underwent phacovitrectomy associated with ERM peeling were enrolled. They were evaluated using structural OCT and OCTA before surgery and at 1, 3, and 6 months postoperatively.Results: We found a statistically significant (p<0.05) increase in the superficial capillary plexus vessel density (VD) from baseline to the 6-month follow-up. We observed a large increase in both the perfusion density (PD) and the VD of the deep capillary plexus between baseline and the 6-month follow-up (p<0.001). A significant decrease in the VD and PD of the choriocapillaris (CC) from baseline to the 1st month and a significant increase in CC perfusion density at the 6-month follow-up compared to the preoperative value were revealed. The FAZ area and perimeter after surgery significantly increased during the follow-up (p<0.001) at baseline retinal and choroidal plexi with a lower PD or VD correlated with worse visual acuity (p<0.05 for all plexi). At baseline and at the 1-month follow-up, a significant correlation was found with the FAZ area and the FAZ perimeter: a smaller FAZ area or a smaller FAZ perimeter was correlated to a lower visual acuity. Before surgery, negative correlations (p<0.05) were found between the Govetto ERM stages and perfusion density of the SCP and the DCP and between the Govetto stages and vessel density of the DCP.Conclusions: In our study, OCTA detected vascular alterations induced by the presence of the ERM, allowing several correlations with functional data. In these patients, OCTA may be useful to add new potential surgical prognostic factors