To determine the incidence, risk factors, and outcomes of delayed suprachoroidal hemorrhage after... more To determine the incidence, risk factors, and outcomes of delayed suprachoroidal hemorrhage after vitrectomy. Retrospective multicenter cohort study. All consecutive patients who underwent primary vitrectomy, from January 2009 to December 2014, at four tertiary vitreoretinal centers in Italy, were enrolled. Patient demographics and systemic, ophthalmic, operative, and postoperative data from all centers were extracted from the electronic record system using standardized data collection forms. All eyes that developed delayed suprachoroidal hemorrhage within 48 hours of the end of the vitrectomy were identified as the delayed suprachoroidal hemorrhage group; all other eyes that underwent vitrectomy in the same period, without delayed suprachoroidal hemorrhage, were considered the control group. From a total of 4852 vitrectomy procedures, 39 (0.8%) cases of delayed suprachoroidal hemorrhage were identified. Multivariable logistic regression showed that significant risk factors for deve...
Two kinds of forces are active in vitreoretinal traction diseases: tangential and anterior-poster... more Two kinds of forces are active in vitreoretinal traction diseases: tangential and anterior-posterior forces. However, tangential forces are less characterized and classified in literature compared to the anterior-posterior ones. Tangential epiretinal forces are mainly due to anomalous posterior vitreous detachment (PVD), vitreoschisis, vitreopapillary adhesion (VPA), and epiretinal membranes (ERMs). Anomalous PVD plays a key role in the formation of the tangential vectorial forces on the retinal surface as consequence of gel liquefaction (synchysis) without sufficient and fast vitreous dehiscence at the vitreoretinal interface. The anomalous and persistent adherence of the posterior hyaloid to the retina can lead to vitreomacular/vitreopapillary adhesion or to a formation of avascular fibrocellular tissue (ERM) resulting from the proliferation and transdifferentiation of hyalocytes resident in the cortical vitreous remnants after vitreoschisis. The right interpretation of the forces involved in the epiretinal tangential tractions helps in a better definition of diagnosis, progression, prognosis, and surgical outcomes of vitreomacular interfaces.
We discuss some aspects of the fluid dynamics of vitreous substitutes in the vitreous chamber, fo... more We discuss some aspects of the fluid dynamics of vitreous substitutes in the vitreous chamber, focussing on the flow induced by rotations of the eye bulb. We use simple, yet not trivial, theoretical models to highlight mechanical concepts that are relevant to understand the dynamics of vitreous substitutes and also to identify ideal properties for vitreous replacement fluids. We first recall results by previous authors, showing that the maximum shear stress on the retina grows with increasing viscosity of the fluid up to a saturation value. We then investigate how the wall shear stress changes if a thin layer of aqueous humour is present in the vitreous chamber, separating the retina from the vitreous replacement fluid. The theoretical predictions show that the existence of a thin layer of aqueous is sufficient to substantially decrease the shear stress on the retina. We finally discuss a theoretical model that predicts the stability conditions of the interface between the aqueous a...
Journal of refractive surgery (Thorofare, N.J. : 1995), 2014
To evaluate a new curvature gradient topography map to predict postoperative corneal remodeling. ... more To evaluate a new curvature gradient topography map to predict postoperative corneal remodeling. In this retrospective study, 32 eyes of 16 patients with myopia underwent excimer ablation surgery with a postoperative high curvature gradient. The new curvature gradient map (acquired immediately postoperatively) shows the difference between the curvatures of two points over the distance between them; it was compared to the tangential curvature difference map between 1 and 12 months postoperatively to determine their relationship. Corneas were divided into 12 regions for analysis: four 90°-wide sectors centered on 0°, 90°, 180°, and 270°. There were three subdivisions in each sector: central (radius: 0 to 2.75 mm), paracentral (radius: 2.75 to 3.25 mm), and peripheral (radius: 3.25 to 4.5 mm). Linear regression analysis was performed by region. The following regions had significant relationships between the initial curvature gradient and curvature difference between 1 and 12 months pos...
To evaluate the recurrence of vitreous hemorrhage (VH) in patients treated with intravitreal beva... more To evaluate the recurrence of vitreous hemorrhage (VH) in patients treated with intravitreal bevacizumab (IVB) injection (2.5 mg/0.1 mL) intraoperatively at the end of vitrectomy for treatment of diabetic nonclearing VH. A prospective pilot study of 30 eyes of 28 consecutive diabetic patients who underwent pars plana vitrectomy and IVB injection intraoperatively at the end of vitrectomy was performed. The amount of VH was graded with slit lamp biomicroscopy by three masked retinal specialists from grade 0 to grade 3. Main outcome measures were rate of recurrence of the VH, improvement in visual acuity, incidence of cataract formation, and postoperative complications through a follow-up of 6 months. The percentage of severe recurrent VH with no fundus details (grade 3) was 7%, 13%, 27%, and 30%, respectively, at 7 days and 1-, 3-, and 6-month follow-up. At 6-month followup, the best-corrected visual acuity improved from 1.00 to 0.4 logMAR (p=0.01) in 21 out of 30 eyes (70%). Nine out...
To compare the anatomic and functional effects of three different approaches to nontractional dia... more To compare the anatomic and functional effects of three different approaches to nontractional diabetic macular edema. Retrospective comparative study. Sixty eyes of 60 patients diagnosed with cystoid diabetic macular edema and treated with 1.25 mg/mL intravitreal bevacizumab (Group A), laser photocoagulation (Group B), or vitrectomy with inner limiting membrane peeling (Group C) were included in the study. Changes in number of Early Treatment Diabetic Retinopathy Study letters, central macular thickness, largest diameter of the intraretinal cysts (IC), and choroidal thickness were investigated. Analyses were performed during follow-up visits at Months 1, 3, 6, 9, and 12. Visual acuity only significantly improved in Group A at the last follow-up (P = 0.004). Central macular thickness significantly decreased in every group throughout the follow-up period. Differences in central macular thickness between Groups A and B (P < 0.01), A and C (P < 0.01), and B and C (P < 0.01) were significant. Intraretinal cysts also significantly decreased in each group throughout the follow-up period. Differences in IC size between Groups A and B (P = 0.8), A and C (P = 0.1), and B and C (P = 0.1) were not significant. Choroidal thickness did not undergo any significant change in any group throughout the follow-up period. A significant correlation was also found in Group A between best-corrected visual acuity at month 12 and baseline central macular thickness (R = 0.3; P = 0.006), and in Group B between postoperative best-corrected visual acuity at month 12 and baseline IC size (R = 0.8; P < 0.01, negatively correlated at 92.4%). According to our retrospective data, diabetic macular edema with intraretinal cysts larger than 390 μm should not be treated with vitrectomy with ILM peeling, because this may induce subfoveal atrophy, defined as the "Floor…
ABSTRACT Eye is the official journal of the Royal College of Ophthalmologists. It aims to provide... more ABSTRACT Eye is the official journal of the Royal College of Ophthalmologists. It aims to provide the practising ophthalmologist with information on the latest clinical and laboratory-based research.
To evaluate the role of erythropoietin and vascular endothelial growth factor (VEGF) in a patient... more To evaluate the role of erythropoietin and vascular endothelial growth factor (VEGF) in a patient with retinal neovascularization from a rhegmatogenous retinal detachment of long duration. Fundus photography, fluorescein angiography, and vitreous analysis were performed. The vitreous concentrations of erythropoietin and VEGF were measured by enzyme-linked immunosorbent assays and compared with control levels. An adolescent with a history of mild retinopathy of prematurity presented with a retinal detachment found by routine examination. The patient had a rhegmatogenous retinal detachment with signs of chronicity and extensive retinal neovascularization. The patient's erythropoietin level was higher than those of patients with proliferative diabetic retinopathy. The patient's VEGF level was not as high as those of patients with proliferative diabetic retinopathy but was elevated compared with those of patients without neovascularization. Vitreous concentrations of erythropoietin and VEGF can be elevated in patients with neovascularization secondary to a rhegmatogenous retinal detachment of long duration.
To report the 4-year outcomes of corneal cross-linking (CXL) for progressive keratoconus in a pop... more To report the 4-year outcomes of corneal cross-linking (CXL) for progressive keratoconus in a population of different age groups. Retrospective, single-center, nonrandomized clinical study. Four hundred consecutive eyes treated with corneal CXL for progressive keratoconus from April 2006 through April 2010. After removal of the epithelium, the cornea was irrigated for 30 minutes with a solution of 0.1% riboflavin and 20% dextran, followed by irradiation with an ultraviolet A light of 3 mW/cm(2) for 30 minutes. Best-corrected visual acuity (BCVA), sphere and cylinder refraction, corneal topography, Scheimpflug tomography, and aberrometry were assessed at baseline and at 1, 6, 12, 24, 36, and 48 months after corneal CXL treatment. The compiled data were stratified according to age (group A, younger than 18 years; group B, 18-29 years; group C, 30-39 years; and group D, older than 40 years). Comparative analysis included 400 eyes of 301 patients. Functional results showed a significant increase in BCVA in group A by a mean reduction of -0.11 logarithm of the minimum angle of resolution (logMAR) after 12 months, in group B by a mean reduction of -0.31 logMAR after 36 months, in group C by a mean reduction of -0.33 logMAR after 36 months, and in group D by a mean reduction of -0.26 logMAR after 36 months. Morphologic results showed an analogous regularization of corneal shape with a significant reduction of opposite sector index by a mean value of -0.53 at 12 months in group A, -1.14 at 36 months in group B, -1.10 at 36 months in group C, and -0.55 at 12 months for group D. Optical quality improvement was demonstrated by a mean significant reduction of coma -1.52 μm after 12 months in group A, -1.58 μm after 24 months in group B, -2.57 μm after 36 months for group C, and -0.25 μm after 36 months in group D. Outcomes stratified by age indicate the efficacy of corneal CXL in stabilizing the progression of ectatic disease in all age groups and improving the functional and morphologic parameters in select groups. Results indicated better functional and morphologic results in the population between 18 and 39 years of age. Proprietary or commercial disclosure may be found after the references.
To determine the incidence, risk factors, and outcomes of delayed suprachoroidal hemorrhage after... more To determine the incidence, risk factors, and outcomes of delayed suprachoroidal hemorrhage after vitrectomy. Retrospective multicenter cohort study. All consecutive patients who underwent primary vitrectomy, from January 2009 to December 2014, at four tertiary vitreoretinal centers in Italy, were enrolled. Patient demographics and systemic, ophthalmic, operative, and postoperative data from all centers were extracted from the electronic record system using standardized data collection forms. All eyes that developed delayed suprachoroidal hemorrhage within 48 hours of the end of the vitrectomy were identified as the delayed suprachoroidal hemorrhage group; all other eyes that underwent vitrectomy in the same period, without delayed suprachoroidal hemorrhage, were considered the control group. From a total of 4852 vitrectomy procedures, 39 (0.8%) cases of delayed suprachoroidal hemorrhage were identified. Multivariable logistic regression showed that significant risk factors for deve...
Two kinds of forces are active in vitreoretinal traction diseases: tangential and anterior-poster... more Two kinds of forces are active in vitreoretinal traction diseases: tangential and anterior-posterior forces. However, tangential forces are less characterized and classified in literature compared to the anterior-posterior ones. Tangential epiretinal forces are mainly due to anomalous posterior vitreous detachment (PVD), vitreoschisis, vitreopapillary adhesion (VPA), and epiretinal membranes (ERMs). Anomalous PVD plays a key role in the formation of the tangential vectorial forces on the retinal surface as consequence of gel liquefaction (synchysis) without sufficient and fast vitreous dehiscence at the vitreoretinal interface. The anomalous and persistent adherence of the posterior hyaloid to the retina can lead to vitreomacular/vitreopapillary adhesion or to a formation of avascular fibrocellular tissue (ERM) resulting from the proliferation and transdifferentiation of hyalocytes resident in the cortical vitreous remnants after vitreoschisis. The right interpretation of the forces involved in the epiretinal tangential tractions helps in a better definition of diagnosis, progression, prognosis, and surgical outcomes of vitreomacular interfaces.
We discuss some aspects of the fluid dynamics of vitreous substitutes in the vitreous chamber, fo... more We discuss some aspects of the fluid dynamics of vitreous substitutes in the vitreous chamber, focussing on the flow induced by rotations of the eye bulb. We use simple, yet not trivial, theoretical models to highlight mechanical concepts that are relevant to understand the dynamics of vitreous substitutes and also to identify ideal properties for vitreous replacement fluids. We first recall results by previous authors, showing that the maximum shear stress on the retina grows with increasing viscosity of the fluid up to a saturation value. We then investigate how the wall shear stress changes if a thin layer of aqueous humour is present in the vitreous chamber, separating the retina from the vitreous replacement fluid. The theoretical predictions show that the existence of a thin layer of aqueous is sufficient to substantially decrease the shear stress on the retina. We finally discuss a theoretical model that predicts the stability conditions of the interface between the aqueous a...
Journal of refractive surgery (Thorofare, N.J. : 1995), 2014
To evaluate a new curvature gradient topography map to predict postoperative corneal remodeling. ... more To evaluate a new curvature gradient topography map to predict postoperative corneal remodeling. In this retrospective study, 32 eyes of 16 patients with myopia underwent excimer ablation surgery with a postoperative high curvature gradient. The new curvature gradient map (acquired immediately postoperatively) shows the difference between the curvatures of two points over the distance between them; it was compared to the tangential curvature difference map between 1 and 12 months postoperatively to determine their relationship. Corneas were divided into 12 regions for analysis: four 90°-wide sectors centered on 0°, 90°, 180°, and 270°. There were three subdivisions in each sector: central (radius: 0 to 2.75 mm), paracentral (radius: 2.75 to 3.25 mm), and peripheral (radius: 3.25 to 4.5 mm). Linear regression analysis was performed by region. The following regions had significant relationships between the initial curvature gradient and curvature difference between 1 and 12 months pos...
To evaluate the recurrence of vitreous hemorrhage (VH) in patients treated with intravitreal beva... more To evaluate the recurrence of vitreous hemorrhage (VH) in patients treated with intravitreal bevacizumab (IVB) injection (2.5 mg/0.1 mL) intraoperatively at the end of vitrectomy for treatment of diabetic nonclearing VH. A prospective pilot study of 30 eyes of 28 consecutive diabetic patients who underwent pars plana vitrectomy and IVB injection intraoperatively at the end of vitrectomy was performed. The amount of VH was graded with slit lamp biomicroscopy by three masked retinal specialists from grade 0 to grade 3. Main outcome measures were rate of recurrence of the VH, improvement in visual acuity, incidence of cataract formation, and postoperative complications through a follow-up of 6 months. The percentage of severe recurrent VH with no fundus details (grade 3) was 7%, 13%, 27%, and 30%, respectively, at 7 days and 1-, 3-, and 6-month follow-up. At 6-month followup, the best-corrected visual acuity improved from 1.00 to 0.4 logMAR (p=0.01) in 21 out of 30 eyes (70%). Nine out...
To compare the anatomic and functional effects of three different approaches to nontractional dia... more To compare the anatomic and functional effects of three different approaches to nontractional diabetic macular edema. Retrospective comparative study. Sixty eyes of 60 patients diagnosed with cystoid diabetic macular edema and treated with 1.25 mg/mL intravitreal bevacizumab (Group A), laser photocoagulation (Group B), or vitrectomy with inner limiting membrane peeling (Group C) were included in the study. Changes in number of Early Treatment Diabetic Retinopathy Study letters, central macular thickness, largest diameter of the intraretinal cysts (IC), and choroidal thickness were investigated. Analyses were performed during follow-up visits at Months 1, 3, 6, 9, and 12. Visual acuity only significantly improved in Group A at the last follow-up (P = 0.004). Central macular thickness significantly decreased in every group throughout the follow-up period. Differences in central macular thickness between Groups A and B (P < 0.01), A and C (P < 0.01), and B and C (P < 0.01) were significant. Intraretinal cysts also significantly decreased in each group throughout the follow-up period. Differences in IC size between Groups A and B (P = 0.8), A and C (P = 0.1), and B and C (P = 0.1) were not significant. Choroidal thickness did not undergo any significant change in any group throughout the follow-up period. A significant correlation was also found in Group A between best-corrected visual acuity at month 12 and baseline central macular thickness (R = 0.3; P = 0.006), and in Group B between postoperative best-corrected visual acuity at month 12 and baseline IC size (R = 0.8; P < 0.01, negatively correlated at 92.4%). According to our retrospective data, diabetic macular edema with intraretinal cysts larger than 390 μm should not be treated with vitrectomy with ILM peeling, because this may induce subfoveal atrophy, defined as the "Floor…
ABSTRACT Eye is the official journal of the Royal College of Ophthalmologists. It aims to provide... more ABSTRACT Eye is the official journal of the Royal College of Ophthalmologists. It aims to provide the practising ophthalmologist with information on the latest clinical and laboratory-based research.
To evaluate the role of erythropoietin and vascular endothelial growth factor (VEGF) in a patient... more To evaluate the role of erythropoietin and vascular endothelial growth factor (VEGF) in a patient with retinal neovascularization from a rhegmatogenous retinal detachment of long duration. Fundus photography, fluorescein angiography, and vitreous analysis were performed. The vitreous concentrations of erythropoietin and VEGF were measured by enzyme-linked immunosorbent assays and compared with control levels. An adolescent with a history of mild retinopathy of prematurity presented with a retinal detachment found by routine examination. The patient had a rhegmatogenous retinal detachment with signs of chronicity and extensive retinal neovascularization. The patient's erythropoietin level was higher than those of patients with proliferative diabetic retinopathy. The patient's VEGF level was not as high as those of patients with proliferative diabetic retinopathy but was elevated compared with those of patients without neovascularization. Vitreous concentrations of erythropoietin and VEGF can be elevated in patients with neovascularization secondary to a rhegmatogenous retinal detachment of long duration.
To report the 4-year outcomes of corneal cross-linking (CXL) for progressive keratoconus in a pop... more To report the 4-year outcomes of corneal cross-linking (CXL) for progressive keratoconus in a population of different age groups. Retrospective, single-center, nonrandomized clinical study. Four hundred consecutive eyes treated with corneal CXL for progressive keratoconus from April 2006 through April 2010. After removal of the epithelium, the cornea was irrigated for 30 minutes with a solution of 0.1% riboflavin and 20% dextran, followed by irradiation with an ultraviolet A light of 3 mW/cm(2) for 30 minutes. Best-corrected visual acuity (BCVA), sphere and cylinder refraction, corneal topography, Scheimpflug tomography, and aberrometry were assessed at baseline and at 1, 6, 12, 24, 36, and 48 months after corneal CXL treatment. The compiled data were stratified according to age (group A, younger than 18 years; group B, 18-29 years; group C, 30-39 years; and group D, older than 40 years). Comparative analysis included 400 eyes of 301 patients. Functional results showed a significant increase in BCVA in group A by a mean reduction of -0.11 logarithm of the minimum angle of resolution (logMAR) after 12 months, in group B by a mean reduction of -0.31 logMAR after 36 months, in group C by a mean reduction of -0.33 logMAR after 36 months, and in group D by a mean reduction of -0.26 logMAR after 36 months. Morphologic results showed an analogous regularization of corneal shape with a significant reduction of opposite sector index by a mean value of -0.53 at 12 months in group A, -1.14 at 36 months in group B, -1.10 at 36 months in group C, and -0.55 at 12 months for group D. Optical quality improvement was demonstrated by a mean significant reduction of coma -1.52 μm after 12 months in group A, -1.58 μm after 24 months in group B, -2.57 μm after 36 months for group C, and -0.25 μm after 36 months in group D. Outcomes stratified by age indicate the efficacy of corneal CXL in stabilizing the progression of ectatic disease in all age groups and improving the functional and morphologic parameters in select groups. Results indicated better functional and morphologic results in the population between 18 and 39 years of age. Proprietary or commercial disclosure may be found after the references.
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