David Sousa - Academia.edu (original) (raw)

Papers by David Sousa

Journal of Clinical Medicine, 2021

Background: The purpose of this prospective study was to evaluate the efficacy and safety of the ... more Background: The purpose of this prospective study was to evaluate the efficacy and safety of the Ultrasound Cyclo Plasty (UCP) procedure using high-intensity focused ultrasound in surgery-naïve open-angle glaucoma patients. Methods: prospective, non-randomized, single-arm, multicenter clinical trial. Sixty-six eyes with primary open-angle glaucoma, intraocular pressure (IOP) ≥21 mmHg and with no history of filtering surgery were enrolled. Patients were treated by UCP with a therapy probe comprising six piezoelectric transducers, consecutively activated for 8 s each. Complete ophthalmic examination was performed before the procedure, 1 day after the procedure, and 1, 3, 6, 12, 18 and 24 months after the procedure. Primary outcomes were complete success (defined as IOP lowering from baseline ≥20% without additional glaucoma medications) and vision-threatening complications. Secondary outcomes were the presence of complications and the reduction of the number of medications used. Resul...

Frontiers in Neuroscience, 2019

Sousa et al. OCT-Angiography and Retinal Vascular Changes using OCT-A technology. A vasodilatory ... more Sousa et al. OCT-Angiography and Retinal Vascular Changes using OCT-A technology. A vasodilatory response and a vasoconstriction response were observed in two physiologic conditions-mild hypoxia and isometric exercise, respectively. This protocol constitutes a new way of studying retinal vascular changes that may be applied in health and disease of multiple medical fields.

Journal of Glaucoma, 2018

PURPOSE: The XEN gel stent is a minimally invasive surgical device aimed at creating a subconjunc... more PURPOSE: The XEN gel stent is a minimally invasive surgical device aimed at creating a subconjunctival drainage of aqueous humor, thereby reducing intraocular pressure (IOP). Being a novel device, doubts remain with regard to the efficacy and safety of its implantation in the early stage of new users. This paper illustrates the XEN implantation learning curve, assessed through several surgeons of different expertise. METHODS: This was a retrospective study on the first 6 XEN implants performed by each of the 10 certified ophthalmic surgeons. Simultaneous cataract surgery was allowed (phaco-XEN). Primary outcomes were as follows: surgical time; intraoperative and postoperative surgical complications. Secondary outcomes were as follows: IOP; the number of topical drugs in use; the need for needling procedures. Outcome data were collected preoperatively and at postoperative days 1, 7, 15, 30, 60, and 90. Statistical analysis was performed with STATA 14.1 and SPSS. RESULTS: Sixty patients were included (56.7% female patients). Mean age was 73 years (45 to 89). Mean preoperative IOP was 23.8±8.95 mm Hg. From the included patients, 29 (48.3%) were submitted to simple XEN implant and 31 (51.7%) to phaco-XEN. In both groups, mean surgical time decreased by 9 minutes throughout the 6-implant learning curve. Final IOP was 15±7.27 mm Hg in the stent group (-43% than baseline) , and 14.92±3.32 mm Hg in the phaco-XEN group (-16% than baseline). On average, patients decreased 2 topical IOP-lowering drugs. Needling procedures were performed in 17 patients (28.3%). CONCLUSIONS: XEN gel stent was associated with a fast learning curve, by both experienced surgeons and novice residents. By the sixth implant, both groups had considerably decreased mean surgical time and complication rates.

European journal of ophthalmology, 2018

To compare the safety and efficacy profiles of Descemet membrane endothelial keratoplasty (DMEK) ... more To compare the safety and efficacy profiles of Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) in adult patients with Fuchs' endothelial dystrophy. Electronic database search on MEDLINE and CENTRAL from inception to August 2017. We included all comparative studies of DMEK versus DSAEK in patients with diagnosed Fuchs' endothelial dystrophy. Studies assessing rescue procedures were excluded to minimize bias. mean difference in best-corrected visual acuity (BCVA) at 3, 6, and 12 months postoperatively. rates of graft primary failure, rejection, and rebubbling; other graft-related issues; mean difference in endothelial cell density; subjective visual outcomes; and patient satisfaction. A total of 10 retrospective studies of moderate methodological quality were included (n = 947 eyes, 646 DMEK). BCVA was better with DMEK at all evaluated time points (0.16 logMAR at 12 months) comparing to DSAEK (0.30 logMAR; p &...

Cornea, Jan 20, 2018

To compare intracameral 20% sulfur hexafluoride (SF6) versus 100% air as tamponade for graft atta... more To compare intracameral 20% sulfur hexafluoride (SF6) versus 100% air as tamponade for graft attachment in Descemet membrane endothelial keratoplasty (DMEK). Using an electronic database search on MEDLINE and CENTRAL from inception to December 2017, we performed a literature review and meta-analysis including all comparative studies of SF6 at a 20% concentration (20% SF6) versus pure air (100% air) for anterior chamber tamponade in DMEK. The primary outcome was the rebubbling rate at the final observation. The secondary outcomes were 1) the graft detachment rate, 2) mean difference (MD) in best-corrected visual acuity (BCVA), 3) manifest refraction spherical equivalent, 4) central corneal thickness (CCT), 5) percentage of endothelial cell loss (ECL), and 6) rate of pupillary block by the final observation. Statistical analysis was performed using RevMan5.3 software. Five retrospective studies were included, assessing 1195 eyes (SF6 277; air 918). The main indication for surgery was ...

Acta ophthalmologica, Jan 21, 2017

Previous studies report that the response of retinal vessels to a decrease in oxygen (hypoxia) is... more Previous studies report that the response of retinal vessels to a decrease in oxygen (hypoxia) is vasodilation, thus increasing blood flow. We aimed to characterize the changes in retinal microvasculature induced by a mild hypoxia stress test in a healthy population, using ocular coherence tomography angiography (OCT-A) technology. Interventional repeated-measures study. The standardized hypoxia challenge test (HCT) was performed to all volunteers, according to the British Thoracic Society protocol. Ocular coherence tomography angiography (OCT-A) was performed at three time-points (baseline, during HCT and 30' posthypoxia). Macular and peripapillary vessel densities were assessed using the built-in software. To minimize bias, analysis was performed separately in right (OD) and left (OS) eyes. Repeated-measures anova and mean comparison analysis were used as statistical tests (stata v13). Studied population included 30 healthy subjects (14 women), with a mean age of 28.8 ± 4.2 [r...

European journal of ophthalmology, Jan 16, 2017

To provide a spectral-domain optical coherence tomography (SD-OCT)-based analysis of retinal laye... more To provide a spectral-domain optical coherence tomography (SD-OCT)-based analysis of retinal layers thickness and nasal displacement of closed macular hole after internal limiting membrane peeling in macular hole surgery. In this nonrandomized prospective interventional study, 36 eyes of 32 patients were subjected to pars plana vitrectomy and 3.5 mm diameter internal limiting membrane (ILM) peeling for idiopathic macular hole (IMH). Nasal and temporal internal retinal layer thickness were assessed with SD-OCT. Each scan included optic disc border so that distance between optic disc border and fovea were measured. Thirty-six eyes had a successful surgery with macular hole closure. Total nasal retinal thickening (p<0.001) and total temporal retinal thinning (p<0.0001) were observed. Outer retinal layers increased thickness after surgery (nasal p<0.05 and temporal p<0.01). Middle part of inner retinal layers (mIRL) had nasal thickening (p<0.001) and temporal thinning (p&...

Acta Ophthalmologica, 2017

The aim of this study is to assess the agreement between manual and automated gonioscopy for irid... more The aim of this study is to assess the agreement between manual and automated gonioscopy for iridocorneal angle opening. Methods: The research is a cross-sectional observational study. Manual and automated gonioscopy were performed to consecutive patients in a glaucoma clinic. Iridocorneal angle opening grading was performed according to Shaffer's classification. Automated gonioscopy was performed with NGS-1 automated gonioscope (NIDEK Co., Gamagori, Japan). The automated gonio-photos were graded by two independent observers. Agreement between automated and manual gonioscopy and also among raters was ascertained by Fleiss' kappa statistic and comparison of area under curve. Results: In total, 88 eyes of 47 subjects were analysed. Mean age was 63 ± 10 years. Twenty eyes (22.7%) were excluded from grading due to poor quality images. Angle closure was detected in 23.4% with dynamic gonioscopy in comparison with 4.3% using automated image grading. The agreement for angle closure diagnosis between dynamic and automated gonioscopy was low (κ = 0.09 ± 0.10; p = 0.18). The area under curve for detecting eyes with angle closure showed poor accuracy between automated and manual methods (area under curve: 0.53 ± 0.05, 95% confidence interval: 0.44-0.62). There was modest inter-rater agreement for angle opening assessment of automated images with Fleiss' kappa of 0.17 (95% confidence interval: 0.035-0.238). Conclusion: Manual and automated gonioscopy showed only slight agreement for the assessment of iridocorneal angle opening status. Further improvements of the NGS-1 automated gonioscopy and technique are desired for widespread use in a real-life setting.

Arquivos brasileiros de oftalmologia, 2017

Studies have suggested that corneal biomechanical properties influence intraocular pressure (IOP)... more Studies have suggested that corneal biomechanical properties influence intraocular pressure (IOP) measurements, namely central corneal thickness (CCT) and corneal hysteresis (CH). The present study aimed to investigate the associations of CH and CCT with glaucoma development. We performed a review of the literature and meta-analysis of observational studies (2006-2016) that included both adult glaucoma patients and controls and reported CCT and CH as outcomes. Nineteen studies were conside red eligible, and the mean difference (MD) between groups (patient and control) for both variables was used for statistical analyses. A total of 1,213 glaucoma and 1,055 healthy eyes were studied. Quan titative analysis suggested that CH was significantly lower in the glaucoma group than in the control group (MD=-1.54 mmHg, 95% CI [-1.68, -1.41], P<0.0001). Additionally, CCT was significantly lower in the glaucoma group than in the control group (MD=-8.49 µm, 95% CI [-11.36, -5.62], P<0.001)...

European Journal of Ophthalmology, 2016

Purpose To investigate the association between anterior lamina cribrosa depth (ALCD), determined ... more Purpose To investigate the association between anterior lamina cribrosa depth (ALCD), determined with enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT), and intraocular pressure (IOP) in a healthy Portuguese population. Methods In this cross-sectional observational study conducted between January and July 2015, 2 optic nerve head (ONH)–centered EDI-OCT cross-scans were performed and ALCD was defined as the perpendicular distance between the line connecting both edges of Bruch's membrane opening and the anterior border of the lamina cribrosa at the maximum depth point. A multivariate regression model was performed to assess the association of IOP and ALCD. Results The studied population included 59 subjects (35 women) with a mean age of 61.7 ± 15.1 years. Mean vertical and horizontal maximum ALCD was 444.5 ± 92.2 μm and 427.6 ± 82.7 μm, respectively. When controlling for age and spherical equivalent, maximum vertical and horizontal ALCD were positively...

Journal of current glaucoma practice

To report a case of a patient who developed uveitis-glaucoma-hyphema (UGH) syndrome after an unev... more To report a case of a patient who developed uveitis-glaucoma-hyphema (UGH) syndrome after an uneventful cataract surgery and to discuss risk factors, diagnostic challenges, management options, and clinical implications. Uveitis-glaucoma-hyphema syndrome is a rare but potentially serious cataract surgery complication. Clinical manifestations include increased intraocular pressure (IOP), anterior chamber inflammation, and recurrent hyphema or microhyphema. Uveitis-glaucoma-hyphema Plus syndrome also includes accompanying vitreous hemorrhage. Although classically associated with rigid anterior chamber intraocular lenses (lOLs), cases of malpositioning and subluxated posterior chamber lOLs have also been described as possible triggers. We report a case of a 70-year-old Caucasian man who developed UGH Plus syndrome after an uneventful cataract surgery with an lOL implanted in the capsular bag. During postoperative follow-up, persistent intraocular inflammation, increased IOP, hyphema, an...

BMJ, 2016

A 25 year old African man presented with reduced vision and headache lasting three hours. His blo... more A 25 year old African man presented with reduced vision and headache lasting three hours. His blood pressure was 228/132 mm Hg (normal: <140/90 mm Hg1). Best corrected visual acuity was 20/80 in the right eye and 20/120 in the left eye (normal: 20/20). The figure shows the fundus of the right eye (fig 1). Fig 1 Colour fundus photography of right eye, …

Investigative Opthalmology & Visual Science, 2020

We hypothesize that patients with type 1 diabetes (T1D) may have abnormal retinal vascular respon... more We hypothesize that patients with type 1 diabetes (T1D) may have abnormal retinal vascular responses before diabetic retinopathy (DR) is clinically evident. Optical coherence tomography angiography (OCTA) was used to dynamically assess the retinal microvasculature of diabetic patients with no clinically visible retinopathy. METHODS. Controlled nonrandomized interventional study. The studied population included 48 eyes of 24 T1D patients and 24 demographically similar healthy volunteers. A commercial OCTA device (AngioVue) was used, and two tests were applied: (1) the hypoxia challenge test (HCT) and (2) the handgrip test to induce a vasodilatory or vasoconstrictive response, respectively. The HCT is a standardized test that creates a mild hypoxic environment equivalent to a flight cabin. The handgrip test (i.e., isometric exercise) induces a sympathetic autonomic response. Changes in the parafoveal superficial and deep capillary plexuses in both tests were compared in each group. Systemic cardiovascular responses were also comparatively evaluated. RESULTS. In the control cohort, the vessel density of the median parafoveal superficial and deep plexuses increased during hypoxia (F 1,23 = 15.69, P < 0.001 and F 1,23 = 16.26, P < 0.001, respectively). In the T1D group, this physiological response was not observed in either the superficial or the deep retinal plexuses. Isometric exercise elicited a significant decrease in vessel density in both superficial and deep plexuses in the control group (F 1,23 = 27.37, P < 0.0001 and F 1,23 = 27.90, P < 0.0001, respectively). In the T1D group, this response was noted only in the deep plexus (F 1,23 = 11.04, P < 0.01). CONCLUSIONS. Our work suggests there is an early impairment of the physiological retinal vascular response in patients with T1D without clinical diabetic retinopathy.