1,721,085 research outputs found
Early retinal flow changes after vitreoretinal surgery in idiopathic epiretinal membrane using swept source optical coherence tomography angiography
Full text linkIntroduzione: Lo scopo di questo studio osservazionale è di valutare per mezzo di Swept Source OCT Angiografia (SS-OCTA) le modificazioni retiniche vascolari precoci in pazienti sottoposti a chirurgia per rimozione di membrane epiretinica idiopatica (iERM).
Metodi: sono stati esaminati 24 occhi di 24 pazienti sottoposti a vitrectomia e rimozione di membrana limitante interna. Le valutazioni pre e post operatorie sono state effettuate con SS-OCTA (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). Due operatori hanno acquisito 5 scansioni OCTA di 6x6-mm per ogni occhio. Le analisi sono state effettuate esportando le immagini en face del plesso capillare superficiale (SCP) sul programma Image J ed usando algoritmi semiautomatici. Sono stati studiati, sia nell’area parafoveale (2.5 mm di diametro) che in quella perifoveale (5.5 mm di diametro): la densità di perfusione (PD), la densità di lunghezza vascolare (VLD), l’indice di diametro vascolare (VDI) e la tortuosità vascolare (VT)
Risultati: sono state trovate differenze statisticamente significative tra il gruppo controllo ed i pazienti affetti da iERM per ogni parametro (parafoveale e perifoveale) eccettuato il VLD perifoveale. Al Follow up di 1 mese, SCP VLD e VT risultavano significativamente aumentati rispetto ai valori preoperatori nella regione parafoveale (p= 0.043 e p= 0.045)
Conclusioni: L’analisi quantitativa e qualitativa del plesso capillare superficiale con SS-OCTA consente la valutazione di variazioni vascolari precoci in pazienti sottoposti ad intervento chirurgico per iERMBackground: The aim of this observational cross-sectional work was to investigate early retinal vascular changes in patients undergoing idiopathic epiretinal membrane (iERM) surgery using swept source optical coherence tomography angiography (SS-OCTA).
Methods: 24 eyes of 24 patients who underwent vitrectomy with inner limiting membrane (ILM) peeling were evaluated pre- and postoperatively using SS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). For each eye, five 6x6-mm OCTA volume scans were acquired by two observers independently. The en face images of superficial capillary plexus (SCP) were then exported to imageJ and a semi-automated algorithm was used for subsequent quantitative analysis. Perfusion density (PD), vessel length density (VLD), vessel diameter index (VDI) and vessel tortuosity (VT) of SCP were evaluated in both the parafoveal (2.5 mm diameter) and perifoveal areas (5.5 mm diameter);
Results: At OCTA analysis statistically significant differences were found between controls and diseased eyes for all parameters in parafoveal and perifoveal regions (p<0.001; p<0.05) except for perifoveal VLD. 1 month after surgery, SCP VLD and VT significantly increased in parafoveal region (p= 0.043 and p= 0.045 respectively) compared to preoperative values.
Conclusions: SS-OCTA provides a quantitative and qualitative analysis of the superficial capillary plexus allowing for early vascular changes assessment after vitrectomy with iERM and ILM peeling
The expression of LGR5 in healthy human stem cell niches and its modulation in inflamed conditions
Full text linkPurpose: The aims of this study are to investigate the expression of leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) protein in the normal human cornea and limbus and to analyze modifications of this expression under inflammatory conditions. Methods: The expression of LGR5 was evaluated in seven limbal epithelial crypts (LECs), collected from healthy cadaver donors, and five inflamed LECs obtained from enucleated eyes. Central corneal buttons were used as controls. LGR5 protein distribution was determined by immunohistochemistry staining analysis. Results: The cytoplasmic expression of LGR5 protein was observed in 100% of healthy LECs. Three out of five inflamed tissues analyzed were completely negative, while in the two remaining cases, we observed a moderate positivity in the basal cells of LECs. No relation was found between the expression of LGR5 and the grade of inflammatory cells. Conclusions: These findings demonstrate the presence of LGR5-positive cells in human LECs and their decrease in inflamed conditions, which suggests a critical role of this protein during inflammation and its possible use as a marker in normal crypts
Bilateral macular hemorrhage in a patient with COVID-19
Full text linkPurpose: We report a case of a patient with a known hereditary spherocytosis who developed a bilateral macular hemorrhage in concurrence with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related respiratory syndrome. Observations: Blood tests showed severe hemolytic anemia. Interestingly, the peripheral blood smear demonstrated a mixed pathogenesis of the hemolytic process (cold-agglutinin-mediated and non-immune-mediated due to spherocytosis). Conclusions and importance: We argue that SARS-CoV-2 could have triggered the hemolytic process, which led to retinal hemorrhages due to endothelial anoxia from the low oxygen carrying capacity
The expression of LGR5 in healthy human stem cell niches and its modulation in inflamed conditions
No full textPurpose: The aims of this study are to investigate the expression of leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) protein in the normal human cornea and limbus and to analyze modifications of this expression under inflammatory conditions.Methods: The expression of LGR5 was evaluated in seven limbal epithelial crypts (LECs), collected from healthy cadaver donors, and five inflamed LECs obtained from enucleated eyes. Central corneal buttons were used as controls. LGR5 protein distribution was determined by immunohistochemistry staining analysis.Results: The cytoplasmic expression of LGR5 protein was observed in 100% of healthy LECs. Three out of five inflamed tissues analyzed were completely negative, while in the two remaining cases, we observed a moderate positivity in the basal cells of LECs. No relation was found between the expression of LGR5 and the grade of inflammatory cells.Conclusions: These findings demonstrate the presence of LGR5-positive cells in human LECs and their decrease in inflamed conditions, which suggests a critical role of this protein during inflammation and its possible use as a marker in normal crypts
Femtosecond Laser–Assisted Stromal Lenticule Addition Keratoplasty for the Treatment of Advanced Keratoconus: A Preliminary Study
No full textPURPOSE: To investigate the in vivo effect of a novel femtosecond laser-assisted procedure termed stromal lenticule addition keratoplasty for advanced keratoconus.
METHODS: Ten patients with stage III and IV stable keratoconus were included. Negative meniscus-shaped stromal lenticules were produced from corneoscleral eye bank buttons with a refractive lenticule extraction procedure with a 500-kHz VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Recipient corneas underwent a modified femtosecond laser flap-cut procedure to produce an intrastromal pocket and lenticules were implanted. Patients were followed up for 6 months after surgery with determination of uncorrected (UDVA) and corrected (CDVA) distance visual acuity, subjective refraction and topographic corneal curvature changes, anterior segment optical coherence tomography (AS-OCT), and in vivo confocal microscopy.
RESULTS: Comparison of preoperative and 6-month postoperative UDVA and CDVA showed statistically significant improvements (P = .024 and .007, respectively) from 1.58 ± 0.36 to 1.22 ± 0.37 and from 1.07 ± 0.17 to 0.70 ± 0.23 logMAR. Eight of 10 eyes showed an improvement in UDVA (P < .001) that ranged between one and three lines, whereas all but one eye presented improved CDVA. Corneal topography documented a decrease between preoperative and 6-month postoperative anterior mean curvature (AVG-K at 3 mm) and anterior Q values (P = .005). AS-OCT showed a significant increase in thickness of the central and mid-peripheral cornea produced by the lenticule implantation (P = .005).
CONCLUSIONS: The stromal lenticule addition keratoplasty procedure was clinically efficient in improving the corneal shape and vision in patients with keratoconus. Negative meniscus-shaped lenticule addition induced a flattening of the cone while increasing corneal thickness
Optical coherence tomography angiography assessment of vascular effects occurring after Aflibercept intravitreal injections in treatment-naive patients with wet AMD
No full textPURPOSE: To investigate vessel changes occurring after aflibercept injections in treatment-naive exudative age-related macular degeneration patients. METHODS: Fifteen eyes of 15 patients affected by wet age-related macular degeneration were enrolled in the study. All the patients had a diagnosis of Type 1 choroidal neovascularization and were treated with 3 monthly aflibercept intravitreal injections (IVI). Subjects were evaluated by means of optical coherence tomography angiography at baseline, the day after the first injection and one month after both the first and the second IVI. At last, all the patients were followed up to 2 months after the third IVI. RESULTS: Foveal superficial vascular plexus flow density was 29.01% (21.13-37.32%) at baseline and was significantly reduced as soon as 1 month after the first IVI (median: 20.78%; interquartile range: 14.75-23.13%; P = 0.017). Parafoveal superficial vascular plexus flow density was 47.09% (44.91-51.72%) at baseline and significantly decreased as soon as 1 month after the second IVI (median: 44.40%; interquartile range: 41.59-49.29%; P = 0.034). Choroidal neovascularization lesion area remained stable throughout the follow-up. Nevertheless, interestingly, choroidal neovascularization flow area was significantly reduced as soon as the next day the first IVI (median: 0.37 mm and interquartile range: 0.27-0.72 mm at baseline; median: 0.30 mm and interquartile range: 0.24-0.64 mm at 1 day after the first IVI; P = 0.047). CONCLUSION: Intravitreal aflibercept injections are associated with a significant change in native retinal and choroidal vasculature. Moreover, the treatment did not cause a reduction in lesion area, but rather reduced the flow in the choroidal neovascularization
Myopia onset and progression: can it be prevented?
No full textMyopia is the commonest ocular abnormality and the high and growing prevalence of myopia, especially but not only in Asian populations, as well as its progressive nature in children, has contributed to a recent surge in interest. Such worldwide growing prevalence seems to be associated with increasing educational pressures, combined with life-style changes, which have reduced the time that children spend outdoors. Highly nearsighted people are at greater risk for several vision-threatening problems such as retinal detachments, choroidal neovascularization, cataracts and glaucoma, thus the potential benefits of interventions that can limit or prevent myopia progression would be of remarkable social impact. Our understanding of the regulatory processes that lead an eye to refractive errors is undoubtedly incomplete but has grown enormously in the last decades thanks to the animal studies, observational clinical studies, and randomized clinical trials recently published. In this review we assess the effects of several types of life-style and interventions, including outdoor activities, eye drops, undercorrection of myopia, multifocal spectacles, contact lenses, and refractive surgery on the onset and progression of nearsightedness
Subthreshold micropulse yellow laser for the management of refractory cystoid macular edema consequent to complicated cataract surgery
Full text linkPurpose:To report the safety and efficacy of subthreshold micropulse yellow laser of 577 nm for a complex case of refractory pseudophakic cystoid macular edema.Methods:A retrospective chart review of an interventional case report of three subthreshold micropulse yellow laser interventions for refractory pseudophakic cystoid macular edema.Patient:A 77-year-old healthy female underwent pseudoexfoliative cataract surgery complicated by posterior capsule rupture and sulcus intraocular lens implantation. After 3 months, she required a scleral fixation of the same lens, due to a lack of capsular support and decentration of the intraocular lens. One month later, she experienced a severe pseudophakic cystoid macular edema (foveal thickness of 399 mu m and best-corrected visual acuity of 20/80 Snellen). The condition was refractory to conventional treatments prior to subthreshold micropulse yellow laser interventions, including non-steroidal anti-inflammatory eye drops, topical steroids, oral indomethacin and three sub-Tenon's triamcinolone injections, attempted over a 14-month period.Results:Subthreshold micropulse yellow laser treatment was performed and immediate resolution was achieved and maintained for 2 months. Two cases of edema relapse were observed at 3 months from initial laser treatment and again at 4 months from the second laser treatment. Final patient's follow-up at 6 months from the third laser treatment evidenced the absence of edema, improved visual acuity (foveal thickness of 265 mu m/best-corrected visual acuity of 20/30 Snellen) and the absence of complications.Conclusions:Subthreshold micropulse yellow laser seems to be a safe and effective treatment for short-term resolution of refractory pseudophakic cystoid macular edema after complicated cataract surgery and represents a useful alternative to expensive and invasive therapies. A trend towards a longer duration of edema resolution with every subthreshold micropulse yellow laser repetition was observed
In Vivo Confocal Microscopy of the Corneal Sub-Basal Nerve plexus in Medically Controlled Glaucoma
Full text link: The present study investigated the corneal sub-basal nerve plexus (SNP) modifications in glaucoma. Ninety-five glaucomatous patients were enrolled and divided into Group 1 and 2, preserved and preservative-free mono-therapy (30 and 28 patients), and Group 3, multi-therapy (37). Thirty patients with dry eye disease (DED) and 32 healthy subjects (HC) served as controls. In vivo confocal microscopy evaluated the nerve fibers density (CNFD), length (CNFL), thickness (CNFT), branching density (CNBD), and dendritic cell density (DCD). CNFD, CNFL, and CNBD were reduced in Group 3 and DED compared to HC (p < 0.05). CNFL was reduced in Group 3 compared to Group 2 (p < 0.05), and in Group 1 compared to HC (p < 0.001). CNFD, CNBD, and CNFT did not differ between glaucomatous groups. DCD was higher in Group 3 and DED compared to HC and Group 2 (p < 0.01). Group 3 showed worse ocular surface disease index (OSDI) scores compared to Group 1, 2, and HC (p < 0.05). CNFL and DCD correlated with OSDI score in Group 3 (r = −0.658, p < 0.001; r = 0.699, p = 0.002). Medical therapy for glaucoma harms the corneal nerves, especially in multi-therapy regimens. Given the relations with the OSDI score, SNP changes seem features of glaucoma therapy-related OSD and negatively affects the patient's quality of life
Fractal dimension as a new tool to analyze optic nerve head vasculature in primary open angle glaucoma
No full textAim: To investigate the features of optic nerve head (ONH) microvasculature in primary open angle glaucoma using fractal geometry analysis. Patients and Method: ONH blood flow was analyzed at the level of the lamina cribrosa by means of confocal scanning laser Heidelberg Doppler flowmetry (HRF) in medically-controlled early and advanced glaucoma. Fractal dimension D of vasculature map was calculated using the Box Counting. Results: Our data demonstrated that, in patients with advanced glaucoma, fractal dimension D was significantly lower than in controls, whereas, in the early stage of disease, its value was similar. Fractal dimension D of microcirculation was significantly and negatively correlated with the cup-disk area ratio in both early and advanced glaucoma groups, whereas linear cup-disk ratio of the disk, cup shape measure and nerve fiber layer thickness, where correlated only in advanced stage of the disease. Conclusion: These findings demonstrate that fractal dimension D of ONH appeared significantly reduced in advanced glaucoma and correlated with the optic disc damage
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