Antonio Ferreras

Background: Diabetic retinopathy (DR) is the leading cause of legal blindness in the working population in developed countries. Optical coherence tomography (OCT) angiography (OCTA) has risen as an essential tool in the diagnosis and control of diabetic patients, with and without DR, allowing visualisation of the retinal and choroidal microvasculature, their qualitative and quantitative changes, the progression of vascular disease, quantification of ischaemic areas, and the detection of preclinical changes. The aim of this article is to analyse the current applications of OCTA and provide an updated overview of them in the evaluation of DR. Methods: A systematic literature search was performed in PubMed and Embase, including the keywords “OCTA” OR “OCT angiography” OR “optical coherence tomography angiography” AND “diabetes” OR “diabetes mellitus” OR “diabetic retinopathy” OR “diabetic maculopathy” OR “diabetic macular oedema” OR “diabetic macular ischaemia”. Of the 1456 studies initially identified, 107 studies were screened after duplication, and those articles that did not meet the selection criteria were removed. Finally, after looking for missing data, we included 135 studies in this review. Results: We present the common and distinctive findings in the analysed papers after the literature search including the diagnostic use of OCTA in diabetes mellitus (DM) patients. We describe previous findings in retinal vascularization, including microaneurysms, foveal avascular zone (FAZ) changes in both size and morphology, changes in vascular perfusion, the appearance of retinal microvascular abnormalities or new vessels, and diabetic macular oedema (DME) and the use of deep learning technology applied to this disease. Conclusion: OCTA findings enable the diagnosis and follow-up of DM patients, including those with no detectable lesions with other devices. The evaluation of retinal and choroidal plexuses using OCTA is a fundamental tool for the diagnosis and prognosis of DR.

Introduction: This study aimed to investigate the relationship between the choroidal circulation and glaucoma, assessing macular choroidal thickness (MCT) as a predictive value of glaucomatous visual field damage. Methods: Twenty primary open-angle glaucoma patients were recruited. Patients underwent 2 SS-OCT scans: one with DRI OCT (Topcon) and the other with PLEX Elite 9000 (Zeiss). Standard OCT parameters were acquired by DRI OCT, while MCT was manually measured in 5 points on Plex ELITE 9000 images. The relationship among MCT, standard OCT parameters, and visual field indices was evaluated. Pearson’s r correlation was calculated to evaluate these relationships. Reproducibility of measurements was analyzed. Results: MCT measurements showed a good intra- and interobserver repeatability. A negative correlation appeared between MCT and BMI (r = −0.518, p = 0.023). Mean deviation showed a statistically significant correlation with MCT measured at subfoveal and at 1,000 μm nasally (r = 0.50, p = 0.03, and r = 0.52, p = 0.023). A correlation was found between the 2 MCT (Zeiss vs. Topcon) measurements and between MCT and peripapillary choroidal thickness (r = 0.944 and r = 0.740, p < 0.001, respectively). Conclusions: A good intra- and interobserver reproducibility was found. MCT showed a weak predictive value of glaucomatous visual field damage. A significant correlation was found between MCT and BMI.

Background: We study the retinal function measured by macular integrity assessment microperimetry (MAIA) and structural changes assessed by scanning swept source optical coherence tomography (SS-OCT) between healthy individuals and patients undergoing pars plana vitrectomy (PPV) after rhegmatogenous retinal detachment (RRD). Methods: Cross-sectional study. Early Treatment Diabetic Retinopathy Study (ETDRS) grids were measured by SS-OCT and compared with the MAIA parameters. Results: Thirty-eight eyes with RRD (19 macula-on and 19 macula-off) were compared with 113 healthy eyes. The retinal sensitivity and average total threshold were reduced in all sectors in the RRD group; macular integrity index was increased. Macular thicknesses in total retina and ganglion cell layer (GCL)++ protocols were higher in the RRD group in nasal outer (NO) and central (C) sectors and only in C sector for GCL+ protocol. Thicknesses were lower in total retina, GCL++ protocols in the temporal outer (TO) sector and in the GCL+ protocol in NO sector. Best-corrected visual acuity (BCVA) correlated moderately with retinal sensitivity in all sectors and in just several sectors with time between the date of surgery and the test. The central nasal (CN) sector thickness and the average total threshold were higher in the macula-on subgroup. Conclusions: RRD and subsequent surgery results in functional and structural changes, especially in individuals with macular detachment.

Background: to compare the extent of the detached retina and retinal tears location in rhegmatogenous retinal detachment (RRD) among non-mydriatic ultra-wide field (UWF) imaging, dilated fundus exam (DFE), and intraoperative evaluation. Methods: this retrospective chart review comprised 123 patients undergoing surgery for RRD. A masked retina specialist analyzed the UWF fundus images for RRD area, status of the macula, and presence and location of retinal breaks. The same variables were collected from a database including DFE and intraoperative recordings. Evaluation methods were compared. Results: mean age was 59.8 ± 14.9 years. Best-corrected visual acuity improved from 0.25 ± 0.3 (Snellen) to 0.67 ± 0.3 at 12 months (p = 0.009). The RRD description and assessment of macula status (34.5% macula-on) did not differ between UWF, DFE, and intraoperative examination. The inferior quadrant was involved most frequently (41.5%), followed by the superior (38.9%), temporal (27.8%) and nasal quadrant (14.8%). Intraoperative exam detected 96.7% of retinal tears compared with DFE (73.2%, p = 0.008) and UWF imaging (65%, p=0.003). UWF imaging and DFE did not differ significantly. Conclusion: RRD extent on DFE and UWF images was consistent with intraoperative findings. UWF and DFE detection of peripheral retinal tears was similar, but 25% of retinal breaks were missed until intraoperative evaluation.

Background: This study compared functional and structural visual changes in Friedreich ataxia (FRDA) patients with healthy controls (HC) and correlated these changes with neurological disability. Methods: Eight FRDA Spanish patients and eight HC were selected from 2014 to 2018. Best corrected visual acuity (BCVA), visual field (VF), optic coherence tomography (OCT), and neurological disability measured by “scale for the assessment and rating of ataxia” (SARA) were taken in a basal exploration and repeated after 6 months. A linear mixed analysis and Bonferroni p-value correction were performed. Results: FRDA baseline and follow-up patients showed statistically significant decreases in BCVA, VF, and OCT parameters compared with the HC. Some of the VF measurements and most of the OCT parameters had an inverse mild-to-strong correlation with SARA. Moreover, the analysis of the ROC curve demonstrated that the peripapillary retinal nerve fiber layer (pRNFL) average thickness was the best parameter to discriminate between FRDA patients and HC. Conclusions: The follow-up study showed a progression in OCT parameters. Findings showed a sequential effect in pRNFL, ganglion cell complex (GCC), and macula. The VF and the OCT could be useful biomarkers in FRDA, both for their correlation with neurological disease as well as for their ability to evaluate disease progression.

Background: To compare early visual changes in amyotrophic lateral sclerosis (ALS) patients with healthy controls in a baseline exploration, to follow-up the patients after 6 months, and to correlate these visual changes with neurological disability. Methods: All patients underwent a comprehensive neurological and ophthalmological examination. A linear mixed analysis and Bonferroni p-value correction were performed, testing four comparisons as follows: Control baseline vs. control follow-up, control baseline vs. ALS baseline, control follow-up vs. ALS follow-up, and ALS baseline vs. ALS follow-up. Results: The mean time from the diagnosis was 10.80 ± 5.5 months. The analysis of the optical coherence tomography (OCT) showed: (1) In ALS baseline vs. control baseline, a macular significantly increased thickness of the inner macular ring temporal and inferior areas; (2) in ALS follow-up vs. ALS baseline, a significant macular thinning in the inner and outer macular ring inferior areas; (3) in ALS follow-up vs. ALS baseline, a significant peripapillary retinal nerve fiber layer (pRNFL) thinning in the superior and inferior quadrants; and (4) ALS patients showed a moderate correlation between some OCT pRNFL parameters and Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) score. Conclusion: The OCT showed retinal changes in patients with motoneuron disease and could serve as a complementary tool for studying ALS.

Glaucoma is a progressive, chronic optic neuropathy characterized by a typical visual field defects. Four main classes of topical medication are actually available on the market: beta-blockers, prostaglandins, alpha2-agonists, and topical carbonic anhydrase inhibitor to treat intraocular pressure (IOP). The aim of this review is to outline the efficacy of timolol and to evaluate the impact of this treatment on patients’ quality of life. Among beta-blockers, timolol is most used at three different concentrations: 0.1%, 0.25%, and 0.5%. While the first one is a gel, the other two products are solution. Timolol has few topical side effects, while it has some important systemic side effects on the cardiac and respiratory systems. The balance between efficacy and safety is always the main aspect to care patients. Because of the less efficacy of timolol 0.1% solution, the possibility to use carbomers as vehicle in the gel drops helped timolol 0.1 to be used in clinics, extending the time contact between the active ingredient and the surface of the cornea. Using preservative-free timolol 0.1 for treatment, IOP was at the same level of the other beta-blockers at higher concentration, but it was better tolerated. Preservative-free treatment improved the quality of life reducing dry-eye like symptoms; furthermore, the presence of an artificial tear in the medication bottle could help adherence. The once daily dosing improves compliance.

Purpose: To assess the intrasession repeatability of choroidal thickness measurements obtained using swept-source optical coherence tomography in Type 2 diabetic (T2D) patients and healthy controls. Methods: This was a single-center, prospective, observational, cross-sectional study with consecutive inclusion of 33 healthy subjects and 43 T2D patients. Subjects underwent three consecutive swept-source optical coherence tomography scans in a single session. After automatic delineation of the choroid, subfoveal choroidal thickness, and thickness at 500-μm intervals up to 2,500 μm nasal and temporal from the fovea were measured using the software caliper by the same operator. Intraclass correlation coefficients (ICCs), coefficients of variation, and test-retest variability were calculated. Results: Mean subfoveal choroidal thickness in healthy subjects and in T2D patients was 229.97 ± 79.9 and 192.67 ± 74.3 μm, respectively (P = 0.013). All intrasession intraclass correlation coefficients were higher than 0.95 and 0.99, respectively. Coefficients of variations were less than 4.4% and 1.8%, respectively. Test-retest variability ranged from 0.76 μm to 11.12 μm and 0.64 μm to 6.29 μm, respectively. No significant differences were found in the intrasession repeatability of any choroidal measurement between healthy subjects and T2D patients. Conclusion: Swept-source optical coherence tomography provided excellent intrasession repeatability of choroidal thickness measurements in healthy subjects and T2D patients.

Purpose: To analyze the effects of a dexamethasone intravitreal implant (DEX; Ozurdex 700 μg; Allergan) administered immediately after cataract surgery in diabetic patients. Methods: This prospective, single-arm, open label study (NCT01748487 at ClinicalTrials.gov) involved Type 2 diabetic patients with at least mild diabetic retinopathy (DR) who underwent cataract surgery and DEX insertion after phacoemulsification, and intraocular lens implantation were enrolled. Best-corrected visual acuity and central retinal thickness (CRT) measured by spectral-domain optical coherence tomography were recorded at 1 week preoperatively, and 1 week, 1 month, and 3 months after surgery. Adverse events were also recorded. Results: Twenty-four eyes of 24 patients (17 [70.8%] men; mean age 63.7 ± 8.7 years) with mild nonproliferative DR (41.7%), moderate nonproliferative DR (33.3%), severe nonproliferative DR (16.7%), or treated proliferative DR (8.3%) were selected. After DEX treatment, mean CRT changed from 241.1 μm (95% confidence interval, 227.5–254.6 μm) at baseline to 236.9 μm (95% confidence interval, 223.9–249.9 μm) at 1 week (P = 0.09), 238.9 μm (95% confidence interval, 225.5–252.3 μm) at 1 month (P = 0.44), and 248 μm (95% confidence interval, 232.4–260.8 μm) at 3 months (P = 0.15). No eyes showed a postoperative increase >50 μm in the CRT at any visit. A 10% increase in CRT was found in 8.3% of eyes. Mean best-corrected visual acuity significantly improved from 0.37 (20/50) at baseline to 0.19 (20/30) at 1 week, 0.12 (20/25) at 1 month, and 0.12 (20/25) at 3 months (P < 0.001 for each comparison). Mean intraocular pressure before surgery was 13.8 mmHg, and none of the patients developed an intraocular pressure ≥22 mmHg at any visit. None of the patients developed any serious adverse events during the follow-up. Conclusion: These short-term results suggest that a single DEX injection intraoperatively after phacoemulsification could avoid an increase in CRT after cataract surgery in diabetic patients.