A Multilayer Perceptron-Based Spherical Visual Compass Using Global Features

This paper presents a visual compass method utilizing global features, specifically spherical moments. One of the primary challenges faced by photometric methods employing global features is the variation in the image caused by the appearance and disappearance of regions within the camera's field of view as it moves. Additionally, modeling the impact of translational motion on the values of global features poses a significant challenge, as it is dependent on scene depths, particularly for non-planar scenes. To address these issues, this paper combines the utilization of image masks to mitigate abrupt changes in global feature values and the application of neural networks to tackle the modeling challenge posed by translational motion. By employing masks at various locations within the image, multiple estimations of rotation corresponding to the motion of each selected region can be obtained. Our contribution lies in offering a rapid method for implementing numerous masks on the image with real-time inference speed, rendering it suitable for embedded robot applications. Extensive experiments have been conducted on both real-world and synthetic datasets generated using Blender. The results obtained validate the accuracy, robustness, and real-time performance of the proposed method compared to a state-of-the-art method.

Modified perfluorocarbon liquid/internal limiting membrane interface staining in myopic macular hole retinal detachment

PURPOSE

To demonstrate a modified technique of perfluorocarbon liquid (PFCL)/internal limiting membrane (ILM) interface staining in patients affected by macular hole retinal detachment (MHRD) in the setting of high myopia.

METHODS

Two-surgeon retrospective case series and review of surgical videos with step-by-step technique analysis.

RESULTS

Our modified technique was proficiently employed to treat 9 highly myopic patients affected by MHRD. Successful staining and peeling of the ILM with the creation of an inverted flap was achieved in all cases. A limited number of dye injections required to stain the ILM was noted. No subretinal dye migration or other intra- and postoperative complications were recorded.

CONCLUSION

Modified PFCL/ILM interface staining is a surgically efficient technique potentially reducing the risk of iatrogenic damage, including the toxicity of vital dyes to the retinal pigment epithelium (RPE) in myopic MHRD.

Reflectance evaluation of eye fundus structures with a visible and near-infrared multispectral camera

We examined the spectral reflectance of fundus structures in the visible and near-infrared (400-1300 nm) range for contributing to the medical diagnosis of fundus diseases. Spectral images of healthy eye fundus and other ocular diseases were acquired using a novel multispectral fundus camera. Reflectance metrics were computed based on contrast to analyze the spectral features. Significant differences were observed among the structures in healthy and diseased eye fundus. Specifically, near-infrared analysis allows imaging of deeper layers, such as the choroid, which, to date, has not been retrieved using traditional color fundus cameras. Pathological structures, which were hardly observable in color fundus images owing to metamerism, were also revealed by the developed multispectral fundus camera.

Fast visible and extended near-infrared multispectral fundus camera

We present a multispectral fundus camera that performs fast imaging of the ocular posterior pole in the visible and near-infrared (400 to 1300 nm) wavelengths through 15 spectral bands, using a flashlight source made of light-emitting diodes, and CMOS and InGaAs cameras. We investigate the potential of this system for visualizing occult and overlapping structures of the retina in the unexplored wavelength range beyond 900 nm, in which radiation can penetrate deeper into the tissue. Reflectance values at each pixel are also retrieved from the acquired images in the analyzed spectral range. The available spectroscopic information and the visualization of retinal structures, specifically the choroidal vasculature and drusen-induced retinal pigment epithelium degeneration, which are hardly visible in conventional color fundus images, underline the clinical potential of this system as a new tool for ophthalmic diagnosis.

Comparative study of penetrating keratoplasty and vitreoretinal surgery with Eckardt temporary keratoprosthesis in ocular trauma versus non-trauma patients

PURPOSE

To evaluate the effectiveness of temporary keratoprosthesis combined with vitreoretinal surgery and penetrating keratoplasty in patients with or without trauma.

METHODS

This retrospective study included 49 eyes in 49 non-trauma patients and 51 eyes in 48 ocular trauma patients who underwent penetrating keratoplasty and vitreoretinal surgery with Eckardt temporary keratoprosthesis between 2009 and 2016, with a follow-up of at least 12 months. Study variables included previous corneal, glaucoma, or retinal surgeries; various intraoperative surgical maneuvers; lens status; vitreoretinal and corneal pathology; functional outcomes; anatomical retinal reattachment; graft clarity; and need for glaucoma surgery or treatment.

RESULTS

The mean age was 56 years in the non-trauma group and 42 years in the ocular trauma group. A total of 45% of the non-trauma cases and 24% of the ocular trauma cases had a single functional eye. Pseudophakic and aphakic keratopathy was diagnosed in 41% of the non-trauma group and corneal laceration in 65% of the ocular trauma group. In the ocular trauma group, injuries were open globe injury in 78%, closed globe injury in 12%, and intraocular foreign body in 10%. Retinal detachment with proliferative vitreoretinopathy was present in 39% of patients in the non-trauma group and in 35% of the ocular trauma group. Improvement or stability of visual acuity was higher among ocular trauma patients (86%) than in non-trauma patients (78%). The rate of clear corneal grafts was 49% in both groups. Retinal attachment was achieved in 90% and 78% of patients in the non-trauma and ocular trauma groups, respectively. The use of retinotomy had a positive influence on the final attached retina (p = 0.016). The placement of a scleral buckle significantly increased the risk of glaucoma (p = 0.004). Poor functional outcome was related to persistent retinal detachment (10% versus 16% in the non-trauma and ocular trauma groups, respectively), phthisis (25% versus 12%), hypotony (33% versus 18%), corneal graft end failure (51% in both groups), and secondary glaucoma (18% versus 24%).

CONCLUSION

In patients with both vitreoretinal and corneal pathology, the use of Eckardt temporary keratoprosthesis combined with vitreoretinal surgery and penetrating keratoplasty resulted in improvement of visual acuity, particularly in the groups of ocular trauma and monocular patients. The high rate of retinal reattachment and the low rate of graft rejection was probably related to the use of new vitreoretinal techniques, including retinotomy in selected patients.

Effectiveness of an intervention in multicomponent exercise in primary care to improve frailty parameters in patients over 70 years of age (MEFAP-project), a randomised clinical trial: rationale and study design

Background

Physical activity may reverse frailty in the elderly, but we encounter barriers to the implementation of exercise programs in this population. Our main aim is to evaluate the effect of a multicomponent physical activity program, versus regular medical practice, on reverting pre-frailty status among the elderly, 12 months post-intervention.

Methods

Randomized parallel group multicenter clinical trial located in primary care setting, among non-dependent and pre-frail patients > 70 years old, including 190 patients (95 intervention, 95 control group). Intervention: Multicomponent physical activity program (MEFAP, for its acronym in Spanish) with twelve 1.5 h-weekly sessions comprised of: 1. Informative session; 2. Exercises for improving aerobic resistance, muscle strength, propioception-balance and flexibility; and 3. Handing out of at-home exercise chart (twice/week). Main variable: pre-frailty according to the Fried phenotype. Secondary variables: sociodemographic, clinical and functional variables; exercise program adherence, patient satisfaction with the program and quality of life. We will perform an intention-to-treat analysis by comparing the retrogression from pre-frailty (1 or 2 Fried criteria) to robust status (0 Fried criteria) by the end of the intervention, 6 months and 12 months post-intervention. The accumulated incidence in each group will be calculated, as well as the relative risk (RR) and the number needed to treat (NNT) with their corresponding 95% confidence intervals. Protocol was approved by the Ethics Committee Hospital la Paz.

Discussion

Within the context of regular clinical practice, our results will provide evidence regarding the effects of exercise interventions on frailty among pre-frail older adults, a key population given their significant potential for functional, physical, and mental health improvement.

Trial registration

NCT03568084. Registered 26 June 2018. Date of enrollment of the first participant to the trial: July 2nd 2018.

Macular buckle technique in myopic traction maculopathy: a 16-year review of the literature and a comparison with vitreous surgery

PURPOSE

The aim of this study is to review anatomical and functional outcomes following macular buckling (MB) in high myopia and to compare such results with those obtained by pars plana vitrectomy (PPV).

METHODS

PubMed articles on MB in high myopia (2000-2016) were reviewed. Main outcomes included retinal reattachment and macular hole (MH) closure rates, resolution of myopic foveoschisis (MFS), and postoperative visual acuity.

RESULTS

Thirty-one articles included 16 in patients with retinal detachment due to MH (MHRD group), 11 in MFS with or without foveal detachment (MFS group), and 4 in MH patients with MFS (MH-MFS group). Surgical techniques mainly differed in the type of buckle, rectus muscles involvement, and concurrent PPV. In eyes with persistent MH, prognosis in the MHRD and MH-MFS groups differed between eyes receiving MB compared to PPV: functional outcome was markedly poorer and there was a higher risk of retinal redetachment associated with PPV. In the MSF group, secondary MHs were more likely to develop in eyes treated with PPV and internal limiting membrane peeling than those undergoing MB alone or combined with PPV. Retinal pigment epithelium changes, malpositioning, perforation, and choroidal detachment were the main complications.

CONCLUSIONS

Although different approaches are used, complete resolution of foveoschisis, retinal reattachment, and MH closure seem to be achieved more frequently with MB than PPV.

INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE FOR MACULAR HOLES IN HIGH MYOPIA WITH AXIAL LENGTH ≥30 mm

PURPOSE

To evaluate the closure rate of macular holes in highly myopic eyes treated with the inverted internal limiting membrane flap technique.

METHODS

Retrospective study in 33 consecutive patients (33 eyes) with a myopic macular hole (axial length ≥30 mm) and no associated macular retinoschisis, undergoing 23-gauge pars plana vitrectomy combined with the inverted internal limiting membrane flap technique.

RESULTS

Mean initial logarithm of the minimum angle of resolution best-corrected visual acuity was 0.59 (range, 0.22-1.8) (Snellen fraction, 20/80). At the 1-month postoperative control visit, the macular hole was closed in all patients. Reopening of the hole occurred in 2 patients. Visual acuity improved in 13 patients (39.4%): final mean ETDRS (Early Treatment Diabetic Retinopathy Study) improvement was +80 letters, and logarithm of the minimum angle of resolution was 0.4 (20/50). Staphyloma with macular involvement was present in all patients. Dissociated optic nerve fiber layer was observed in 25 patients (75.7%) and was absent in 2 (6.1%); in the remaining 6 patients, the layer could not be assessed. Gliosis was found in 14 patients (42.4%).

CONCLUSION

Vitrectomy plus the inverted internal limiting membrane flap technique was effective for treating macular holes in eyes with axial length ≥30 mm and no associated retinoschisis.

Radio-over-fiber linearization with optimized genetic algorithm CPWL model

This article proposes an optimized version of a canonical piece-wise-linear (CPWL) digital predistorter in order to enhance the linearity of a radio-over-fiber (RoF) LTE mobile fronthaul. In this work, we propose a threshold allocation optimization process carried out by a genetic algorithm (GA) in order to optimize the CPWL model (GA-CPWL). Firstly, experiments show how the CPWL model outperforms the classical memory polynomial DPD in an intensity modulation/direct detection (IM/DD) RoF link. Then, the GA-CPWL predistorter is compared with the CPWL model in several scenarios, in order to verify that the proposed DPD offers better performance in different optical transmission conditions. Experimental results reveal that with a proper threshold allocation, the GA-CPWL predistorter offers very promising outcomes.

MACULAR BUCKLING WITH ANDO PLOMBE MAY INCREASE CHOROIDAL THICKNESS AND MIMIC SEROUS RETINAL DETACHMENT SEEN IN THE TILTED DISK SYNDROME

PURPOSE

Serous subfoveal detachment has been described in the literature as a complication that appears at the border of the staphyloma. Macular buckling induces a postoperative inward bulge that resembles the ridge of a staphyloma. We describe three patients who developed a serous subfoveal detachment after uneventful macular buckling. To our knowledge, this complication, that shares similarities with the staphyloma ridge detachment, has not been previously reported.

METHODS

The clinical records of all cases that underwent macular buckling at our clinic were reviewed.

RESULTS

Three patients developed a serous subfoveal detachment that could not be explained by choroidal neovascularization or polypoidal vascular choroidopathy. Along with the development of the subfoveal detachment, we observed an increase of the choroidal thickness beneath the fovea. This thickening, that tended to progress during the follow-up, resolved spontaneously after explantation of the buckle. The decrease in foveal thickness did also lead to resolution of the subfoveal detachment.

CONCLUSION

The development of the subfoveal detachment in our patients was closely associated with a focal increase of the choroidal thickness after the macular buckling. After the buckle was removed, the choroidal thickness went back to the normal prebuckling values and the detachment resolved in all three patients. This leads us to think that there is a close association between choroidal thickness and the serous subfoveal detachment.

Effect of intravitreal injection of dexamethasone 0.7 mg (Ozurdex®) on intraocular pressure in patients with macular edema

BACKGROUND

To evaluate the effect of Ozurdex® on intraocular pressure in patients with macular edema alone (group 1) or associated with glaucoma or ocular hypertension (group 2).

METHODS

A clinical, retrospective, observational, comparative study included 92 eyes with macular edema treated with a single injection of Ozurdex®; 27 eyes were previously diagnosed with glaucoma or ocular hypertension.

RESULTS

The mean intraocular pressure (group 1 vs. group 2) after injection was 12.1 versus 19.9 mm Hg, (p < 0.05; day 1); 17.5 versus 19.7 mm Hg (p < 0.05; month 1); 18.4 versus 20.9 mm Hg (p < 0.05; month 2); 15 versus 17.4 mm Hg (p < 0.05; month 3); 13.9 versus 16.7 mm Hg (p > 0.05; month 6); 13.8 versus 15.1 mm Hg (p > 0.05; month 9) and 13.1 versus 16.4 mm Hg (p > 0.05; month 12). Thirty eyes (32.6%) showed ocular hypertension (intraocular pressure >21 mm Hg) after the injection: 21.5% of group 1 and 59.3% of group 2. In group 2, 27 eyes (100%) needed medical treatment to reduce intraocular pressure in comparison to 8 patients (12.3%) in group 1 (p < 0.001).

CONCLUSIONS

Intravitreal injection of Ozurdex® was associated with ocular hypertension in 32.6% of the eyes. Previous glaucoma or ocular hypertension are risk factors for this increase.

Optical coherence tomography findings in alport syndrome

PURPOSE

To describe the optical coherence tomography (OCT) findings of the macular area in patients with Alport syndrome (AS), a disease caused by mutations in genes coding for type IV collagen (Col4), which is the main component of the internal limiting membrane (ILM).

METHODS

We reviewed the files for six eyes of three patients with AS. All patients were evaluated by OCT throughout the macula.

RESULTS

One patient had a giant macular hole surrounded by areas of loss of inner retinal tissue that had grown over time. The other two patients had focal zones of inner retinal thinning.

CONCLUSIONS

We postulate that the structural abnormalities of the ILM due to altered Col4 play a more important role in macular hole formation than hemodynamic alterations characteristic of AS. Several hypotheses could be expounded. Future OCT macular studies involving asymptomatic patients with AS would be useful in detecting and monitoring macular alterations. They would also contribute to a greater knowledge of this disease.

Dexamethasone intravitreal implant in vitrectomized versus nonvitrectomized eyes for treatment of patients with persistent diabetic macular edema

PURPOSE

To compare the 6-month anatomic and best-corrected visual acuity (BCVA) response after sustained-release dexamethasone (DEX) intravitreal implant between nonvitrectomized and vitrectomized eyes with persistent diabetic macular edema (DME).

METHODS

Retrospective, comparative, and consecutive review of the medical records of 58 patients with decreased visual acuity, due to refractory DME, who underwent a single injection of Ozurdex between November 2010 and January 2012, at the Instituto de Microcirurgia Ocular, Barcelona, Spain. Then, we divided patients into 2 groups: 24 eyes who had undergone standard pars plana vitrectomy (vitrectomized group), and 34 eyes that were not operated on (nonvitrectomized group). Outcomes measured were BCVA and foveal thickness (FT) at baseline and at months 1, 3, and 6.

RESULTS

Twenty-four of 58 eyes had prior vitrectomy (41%). Statistically significant improvement in BCVA also was seen at 1 month after treatment with a DEX implant and at each subsequent follow-up visit, in either groups (P<0.05). All of the FT reduction outcomes were statistically significant in both groups, with respect to baseline data (P<0.05). There were no statistically significant differences in BCVA and FT between nonvitrectomized and vitrectomized eyes at any time point (P<0.05).

CONCLUSION

In this study, the clinical findings were similar between nonvitrectomized and vitrectomized eyes. Intravitreal treatment with a DEX implant safely reduced DME and improved visual acuity in both groups. No statistically significant differences were found between the 2 groups regarding FT and BCVA.

Myopic traction maculopathy

Myopic traction maculopathy is a high myopia-related complication caused by several mechanisms with traction as a common pathway. Macular hole-related retinal detachment is considered to be the final stage of progressive foveoschisis. In this setting, release of all vitreous and epiretinal tractions is essential in order to achieve surgical success. Pars plana vitrectomy has proven useful in the treatment of myopic foveoschisis, with both good visual and anatomical results. However, the surgical technique for the treatment of macular hole-related retinal detachment is still a controversial issue: reoperations are common and the final visual prognosis is limited, especially in those cases with a pronounced posterior staphyloma. We must also bear in mind that a highly myopic eye has some characteristic traits that may complicate vitreoretinal surgery. In these cases, microincision vitrectomy surgery may offer some advantages compared to conventional vitrectomy.

3D Visual Sensing of the Human Hand for the Remote Operation of a Robotic Hand

New low cost sensors and open free libraries for 3D image processing are making important advances in robot vision applications possible, such as three-dimensional object recognition, semantic mapping, navigation and localization of robots, human detection and/or gesture recognition for human-machine interaction. In this paper, a novel method for recognizing and tracking the fingers of a human hand is presented. This method is based on point clouds from range images captured by a RGBD sensor. It works in real time and it does not require visual marks, camera calibration or previous knowledge of the environment. Moreover, it works successfully even when multiple objects appear in the scene or when the ambient light is changed. Furthermore, this method was designed to develop a human interface to control domestic or industrial devices, remotely. In this paper, the method was tested by operating a robotic hand. Firstly, the human hand was recognized and the fingers were detected. Secondly, the movement of the fingers was analysed and mapped to be imitated by a robotic hand.

Dexamethasone intravitreal implant for treatment of patients with persistent diabetic macular edema

PURPOSE

To report the 6-month anatomical and best-corrected visual acuity (BCVA) response after primary intravitreal dexamethasone implantation (Ozurdex®) in patients with refractory diabetic macular edema (DME).

METHODS

Retrospective review of the medical records of 58 patients with decreased visual acuity, due to refractory DME, who underwent a single injection of Ozurdex between November 2010 and January 2012, at the Instituto de Microcirurgia Ocular, Barcelona, Spain.

RESULTS

At baseline, the mean foveal thickness (FT) was 543.24 ± 156.51 μm. Mean (±SD) values of FT did decrease to 346.82 ± 123.74 μm at month 1 and 341.12 ± 129.64 μm at month 3. Data on the 6-month follow-up showed a mild increase to 420.16 ± 152.15 μm. All of the FT reduction outcomes were statistically significant, with respect to baseline data (p = 0.0001). The baseline BCVA data was 0.66 ± 0.36 logarithm of the minimum angle of resolution (logMAR). The mean BCVA improved to 0.52 ± 0.32 logMAR (p = 0.0001) and 0.44 ± 0.27 logMAR (p = 0.0001) after 1 and 3 months, respectively. At the last visit (6-month follow-up), the mean BCVA increased to 0.51 ± 0.31 logMAR (p = 0.0001).

CONCLUSIONS

In this study, intravitreal treatment with a dexamethasone implant safely reduced DME and improved visual acuity in a difficult-to-treat patient population with long-standing refractory DME.

Scleral fixation of dexamethasone intravitreal implant (OZURDEX®) in a case of angle-supported lens implantation

OZURDEX(®) is a biodegradable drug delivery system which has been reported to be an effective treatment in cases of macular edema. However, migration of the implant into the anterior chamber with elevation of intraocular pressure and corneal decompensation might occur in some cases. We report a case of an 80-year-old male who underwent intravitreal scleral fixation of OZURDEX(®) due to postoperative macular edema secondary to complicated cataract surgery. He had a previous angle-supported lens implantation with superior Nd:YAG laser iridotomy. During surgery, the dexamethasone implant was introduced into the vitreous cavity and sutured to the sclera using a 10-0 non-absorbable polypropylene suture to prevent the risk of anterior complications in case of migration into the anterior chamber. After 6 months of follow-up, the macular edema had disappeared completely, the drug delivery system was not observed in the posterior segment and best-corrected visual acuity improved from 20/125 to 20/40 (Snellen equivalent). Neither anterior nor posterior segment complications were reported during the follow-up period. Intravitreal scleral fixation of the OZURDEX(®) to the pars plana could be recommended as an alternative technique to avoid anterior migration of the device in a patient with an anterior chamber intraocular lens, which may lead to corneal decompensation and increased intraocular pressure.

Assessment of OCT measurements as prognostic factors in myopic macular hole surgery without foveoschisis

BACKGROUND

To assess the role of Spectral Domain Optical Coherence Tomography (SD-OCT) measurements as prognostic factors in myopic macular hole (MMH) surgery.

METHODS

In a retrospective cohort study, we evaluated 42 eyes of 42 patients (Spherical equivalent > -6.00 D) who underwent pars plana vitrectomy with internal limiting membrane peeling for MMH without foveoschisis. Statistical analysis was performed to correlate postoperative best corrected visual acuity (BCVA) with preoperative BCVA, age, degree of myopia and seven preoperative OCT measurements: macular hole (MH) base, MH minimum diameter, MH height, Hole Form Factor (HFF), Macular Hole Index (MHI), Diameter Hole Index (DHI) and Tractional Hole Index (THI).

RESULTS

Primary and final anatomical success rate were 83.3% (35/42) and 90.5% (38/42), respectively. Four patients deferred reoperation and three underwent a second surgical approach to achieve MH closure. A posterior staphyloma was observed in 27 of 42 patients, and in three of them the MH was located in the apex of the staphyloma. Two of these three cases showed an open MH after the first surgery. Postoperative visual acuity improved in 22/42 (52.4%) patients, worsened in 7/42 (16.7%) and remained unchanged in 13/42 (30.9%). Only MH minimum diameter (P = 0.03) and HFF (P = 0.02) correlated significantly with postoperative BCVA.

CONCLUSIONS

Minimum diameter and HFF are strongly correlated with postoperative visual outcomes in cases of MMH. Since analyzing MH configuration seems to improve the anatomical success rate after vitreous surgery in highly myopic patients, these parameters should be preoperatively evaluated by SD-OCT.

En face optical coherence tomography of inner retinal defects after internal limiting membrane peeling for idiopathic macular hole

PURPOSE

To describe the appearance of inner retinal defects using en face spectral domain optical coherence tomography (SD-OCT) after idiopathic full-thickness macular hole (FTMH) surgery, referred to as concentric macular dark spots (CMDS).

METHODS

In a retrospective cohort study, the authors evaluated 36 eyes of 36 patients with large idiopathic MH (>400 μm) who underwent standard three-port pars plana vitrectomy with internal limiting membrane (ILM) peeling. All patients were analyzed using B-scan and C-scan en face SD-OCT before and after surgery to determinate the OCT pattern of the retinal surface.

RESULTS

Mean follow-up was 10 months (±8.45 SD; range, 3-30 months). Three months after surgery 36 of 36 eyes (100%) showed a CMDS appearance on en face SD-OCT images. Anatomic success rate was 100% (36/36 eyes) after a single surgical procedure. Once they were evident, these dark spots observed on the retinal surface were not progressive and remained stable over time.

CONCLUSIONS

Inner retinal defects frequently occurred after idiopathic MH surgery when ILM was peeled. To the authors' knowledge, this feature has not been previously reported using an en face SD-OCT imaging, and it consisted of numerous CMDS in the same direction of the optic nerve fibers. All patients in the study showed this typical OCT pattern 3 months after surgery. Thus, the authors suggest that this is a helpful, noninvasive technique to assess complete ILM removal in FTMH surgery if CMDS appearance on the retinal surface is reported.

Serous macular detachment associated with dome-shaped macula and tilted disc

Introduction: An entirely new type of staphyloma has been recently described as dome-shaped macula (DSM). It is characterized by an abnormal convex macular contour within the concavity of a posterior staphyloma. We found DSM associated with serous macular detachment (SMD) and tilted disc in two consecutive cases. Case Reports: Case 1: A 37-year-old female presented to our department because of sudden onset blurred vision in her right eye (OD). The best-corrected visual acuity (BCVA) was 0.5 in both eyes. Funduscopy evidenced bilateral tilted disc associated with posterior staphyloma. Optical coherence tomography (OCT) demonstrated a DSM with SMD in her OD. After 15 months of follow-up, BCVA of her OD remained stable with chronic SMD. Case 2: A 32-year-old female presented to our department because of blurred vision in her OD. The BCVA was 0.4 in the OD and 1.0 in the left eye (OS). Bilateral tilted disc and posterior staphyloma were evidenced in the funduscopy. OCT demonstrated a bilateral DSM with SMD in her OD. After 45 months of follow-up, two further episodes of transient SMD were observed in her OD and seven in her OS. The final BCVA was 0.63 in the OD and 0.8 in the OS. Discussion: SMD associated with tilted disc constitutes a potential cause of subretinal fluid accumulation in myopic patients. OCT is essential for the detection of both SMD and DSM.

Radiation maculopathy after epimacular brachytherapy for the treatment of subfoveal choroidal neovascularization secondary to age-related macular degeneration

PURPOSE

To describe a case of radiation maculopathy after a 24-Gy single-fraction epimacular brachytherapy delivered concomitantly with ranibizumab for the treatment of age-related macular degeneration.

METHODS

Case report.

RESULTS

An 82-year-old man with neovascular age-related macular degeneration was treated with epiretinal brachytherapy and 2 intraocular injections of ranibizumab with initial good response. Nineteen months after initial treatment, visual acuity decreased and the patient was diagnosed of radiation maculopathy.

CONCLUSION

Radiation-related ocular side effects such as maculopathy may become evident several years after the treatment. Thus, vascular abnormalities that may appear in the follow-up of these patients can easily be misdiagnosed as a complication of the previous choroidal neovascularization.

Preoperative intravitreal bevacizumab use as an adjuvant to diabetic vitrectomy: histopathologic findings and clinical implications

PURPOSE

To evaluate the effects of intervals between preoperative intravitreal injection of bevacizumab (IVB) and surgery on the components of removed diabetic fibrovascular proliferative membranes.

DESIGN

Interventional, consecutive, prospective, comparative case series.

PARTICIPANTS

A total of 52 eyes of 49 patients with active diabetic fibrovascular proliferation with complications necessitating vitrectomy.

METHODS

Participant eyes that had IVB were divided into 8 groups in which vitreoretinal surgery was performed at days 1, 3, 5, 7, 10, 15, 20, and 30 postinjection. A group of eyes with the same diagnosis and surgical intervention without IVB injection was used for comparison. In all eyes, proliferative membrane specimens obtained during vitrectomy were sent for histopathologic examination using hematoxylin-eosin stain, immunohistochemistry (CD34 and smooth muscle actin), and Masson's trichrome stain.

MAIN OUTCOME MEASURES

Comparative analysis of different components of the fibrovascular proliferation (CD34, smooth muscle actin, and collagen) among the study groups.

RESULTS

Pan-endothelial marker CD34 expression levels starting from day 5 postinjection were significantly less than in the control group (P < 0.001), with minimum expression (1+) in all specimens removed at or after day 30 postinjection. Positive staining for smooth muscle actin was barely detected in the control eyes at day 1, and consistently intense at day 15 and beyond (P < 0.001). The expression level of trichrome staining was significantly high at day 10, compared with control eyes (P < 0.001), and continued to increase at subsequent surgical time points.

CONCLUSIONS

A profibrotic switch was observed in diabetic fibrovascular proliferation after IVB, and our results suggest that at approximately 10 days post-IVB the vascular component of proliferation is markedly reduced, whereas the contractile components (smooth muscle actin and collagen) are not yet abundant.

Experimental validation of ultrasonic guided modes in electrical cables by optical interferometry

In this work, the dispersion curves of elastic waves propagating in electrical cables and in bare copper wires are obtained theoretically and validated experimentally. The theoretical model, based on Gazis equations formulated according to the global matrix methodology, is resolved numerically. Viscoelasticity and attenuation are modeled theoretically using the Kelvin-Voigt model. Experimental tests are carried out using interferometry. There is good agreement between the simulations and the experiments despite the peculiarities of electrical cables.

Transmuscular migration and straddling of the cornea by an encircling buckle

Postoperative complications of scleral buckling surgery are various. The anterior migration through the rectus muscles and positioning in the corneoscleral junction is an atypical and undocumented complication. The authors describe a patient with a migration and straddling of the encircling buckle in the corneoscleral junction 2 years after a classic retinal surgery with an encircling solid silicone buckle. Many predisposing factors can lead to this situation.

Elastic guided wave propagation in electrical cables

This article analyzes the propagation modes of ultrasound waves inside an electrical cable in order to assess its behavior as an acoustic transmission channel. A theoretical model for propagation of elastic waves in electric power cables is presented. The power cables are represented as viscoelastic-layered cylindrical structures with a copper core and a dielectric cover. The model equations then have been applied and numerically resolved for this and other known structures such as solid and hollow cylinders. The results are compared with available data from other models. Several experimental measures were carried out and were compared with results from the numerical simulations. Experimental and simulated results showed a significant difference between elastic wave attenuation inside standard versus bare, low-voltage power cables.

RETINAL PIGMENT EPITHELIUM TEARS AFTER INTRAVITREAL INJECTION OF BEVACIZUMAB (AVASTIN) FOR NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

BACKGROUND

Intravitreal bevacizumab (Avastin, Genentech, Inc., South San Francisco, CA) treatment of neovascular age-related macular degeneration (AMD) has become an important part of clinical retinal practice. We describe retinal pigment epithelium (RPE) tears that were noted after intravitreal injection of bevacizumab.

METHODS

In this multimember, retrospective case series, data on eyes that developed RPE tears after intravitreal bevacizumab injection were collected and analyzed. Previous treatments, type of lesion, time to tear, and preinjection and final visual acuities were all compared. The total numbers of bevacizumab injections were available from all four institutions and compiled to estimate the incidence rate.

RESULTS

Four retina centers administered a total of 1,455 intravitreal 1.25-mg bevacizumab injections for neovascular AMD during the 9-month study period. Twelve patients presented with RPE tears within 4 days to 8 weeks of injection (mean +/- SD, 24.3 +/- 15.2 days from injection to tear). In each case, the RPE tear was preceded by an RPE detachment, and all had a component of serous sub-RPE fluid. On the basis of our collective data, we estimate an incidence rate of approximately 0.8%.

CONCLUSIONS

RPE tears can occur after intravitreal injection of bevacizumab. The low incidence of this adverse event should not preclude anti-vascular endothelial growth factor therapy counseling for patients with neovascular AMD, but eyes with serous RPE detachments appear to be most vulnerable to this adverse event.

Adsorption Behavior of Bovine Serum Albumin on Lowly Activated Anionic Exchangers Suggests a New Strategy for Solid-Phase Proteomics

Diluted solutions of bovine serum albumin (BSA) (e.g., 0.1 mg /mL) do not form detectable protein large aggregates. Using gel-filtration experiments, we determined that a diluted solution of BSA is 97% monomeric BSA and 3% dimeric. The adsorption of this diluted BSA on highly activated anionic exchangers (e,g., having 40 micromol/wet g) keeps this mainly monomeric form. When supports activated with 2 micromol/wet g are used, only dimers become adsorbed to the support, accounting for 100% of the offered BSA. When the diluted BSA solution is offered to very mildly activated anionic exchangers (even only 0.125 micromol/wet g), an unexpected adsorption of most of the BSA on the support was also observed. These very slightly activated supports are only able to adsorb very large proteins or very large protein-protein complexes, larger than BSA dimers. In fact, a rapid cross-linking of the adsorbed BSA with dextran-aldehyde reveals the formation of very large BSA-BSA complexes with molecular mass higher than 500 000 Da, complexes that may be observed for soluble BSA with very high concentrations but are not detectable at 0.1 mg/mL. Moreover, the size of the aggregates strongly depends on the concentration of the ionized groups on the support: the less activated the supports are, the higher the sizes of the complexes. It seems that the interaction of the BSA molecules on the margins of the BSA aggregate with the groups on the support may stabilize the whole protein aggregate, although some components are not interacting with the support. Aggregates could account for more than 40% of the BSA in the solution after 50 h of incubation. However, only these large BSA aggregates were adsorbed in the support.

Menin molecular interactions: insights into normal functions and tumorigenesis

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disease predisposed by heterozygous germline mutations in the MEN1 tumor suppressor gene. Biallelic loss of MEN1 resulting from small mutation and/or loss of heterozygosity occurs in a large tissue spectrum of MEN1 tumors or non-hereditary tumors. Mouse models of MEN1 underexpression or overexpression have also supported the tumor-suppressor effect of the MEN1 gene. Menin, the 610-amino-acid protein encoded by MEN1, is expressed ubiquitously and found predominantly in the nucleus. Sequence analyses do not reveal motifs of known function other than two nuclear localization sequences. Menin has been found to partner in vitro with a variety of proteins that comprise transcription factors, DNA processing factors, DNA repair proteins, and cytoskeletal proteins. The diverse functions of menin interactors suggest roles for menin in multiple biological pathways. Inactivation of menin switches its JunD partner from a downstream action of growth suppression to growth promotion. This is a plausible mechanism for menin tumorigenesis.

Two-year results of macular translocation with scleral infolding in myopic choroidal neovascularisation

PURPOSE

To assess the two year outcome following macular translocation (MT) with scleral infolding in the management of myopic subfoveal choroidal neovascularisation (CNV).

DESIGN

Prospective, clinical interventional noncomparative consecutive case series.

PARTICIPANTS

79 eyes of 79 patients with myopic subfoveal CNV and less than 6 months of duration of the symptoms.

INTERVENTION

MT with scleral infolding.

MAIN OUTCOME MEASURES

Visual Acuity (VA), reading ability of 12 point Arial letter sentences at a reading distance without magnifying systems and foveal displacement.

RESULTS

Mean preoperative VA was 20/125, after two years the mean VA was 20/80. Reading ability of 12 point Arial letter sentences at a reading distance (33 cm) was obtained in 59% of the eyes at one year, descending to 43% at two years. Mean foveal displacement after surgery was 942 microns. Intraoperative complications have been: retinal breaks (21.5%) and choroidal haemorrhage not affecting the posterior pole (3.7%). Main postoperative complications have been: Insufficient foveal displacement: 20%; Retinal detachment: 8.8%; Subfoveal recurrence: 28%; macular fold: 2.5% and macular hole: 1.2%.

CONCLUSION

MT with scleral infolding offers the opportunity to recover central vision and reading ability in patients with myopic CNV but it remains unpredictable.

Surgical removal of peripapillary choroidal neovascularization associated with optic nerve drusen

PURPOSE

To assess the anatomical and functional results after surgical removal of peripapillary choroidal neovascularization (CNV) associated with optic nerve head drusen.

METHODS

A retrospective study was carried out on four eyes (four patients) undergoing vitrectomy, retinotomy, and removal of CNV associated with optic disk drusen. CNV was preoperatively demonstrated by fluorescein angiography in all cases. In three cases, the CNV had a subfoveal extension, and a serous-hemorrhagic retinal detachment was the cause of the central vision disturbance in the remaining one. Optic nerve head drusen were bilateral and were confirmed with computed tomography scan.

RESULTS

Visual acuity (VA) improved in all cases after a follow-up ranging from 12 to 42 months. Preoperative VA was 20/200, 20/200, 20/50, and count fingers and final VA was 20/50, 20/25, 20/25, and 20/30, respectively. There was no evidence of CNV recurrence during the follow-up period.

CONCLUSION

The results of surgical removal of peripapillary CNV with macular involvement associated with optic nerve head drusen are very encouraging, especially if we consider the variable outcome of the natural course in these cases.

Surgery for subfoveal choroidal neovascularization in toxoplasmic retinochoroiditis

PURPOSE

To report a case of subfoveal choroidal neovascularization in a patient with toxoplasmic retinochoroiditis who underwent surgical excision.

DESIGN

Interventional case report.

METHODS

A 36-year-old woman with toxoplasmic retinochoroiditis presented with sudden dimness of vision and metamorphopsia in the left eye. The patient was examined with ophthalmoscopy and fluorescein angiography.

RESULTS

Fundus examination and fluorescein angiography of the left eye revealed a subfoveal choroidal neovascularization. Pars plana vitrectomy with submacular surgery was performed, with a postoperative improvement of visual acuity and resolution of the distortion.

CONCLUSIONS

This case report describes a case of subfoveal choroidal neovascularization associated with toxoplasmic retinochoroiditis that responded remarkably well to vitrectomy surgery.

Biotransformations catalyzed by multimeric enzymes: stabilization of tetrameric ampicillin acylase permits the optimization of ampicillin synthesis under dissociation conditions

The importance of the stabilization of the quaternary structure of multimeric enzymes has been illustrated using a model reaction with great industrial relevance: the enzymatic synthesis of ampicillin from 6-amino penicillanic acid (6APA) and phenylglycine methyl ester (PGM) catalyzed by the tetrameric enzyme alpha-amino acid ester hydrolase from Acetobacter turbidans. The stabilization of the multimeric structure of the enzyme was achieved by multi-subunit immobilization of the enzyme followed by its further solid-phase chemical intersubunit cross-linking with polyfunctional macromolecules (dextran-aldehyde). This stabilized derivative has permitted the study of the reaction under conditions where nonstabilized enzyme molecules tended to dissociate (e.g., absence of phosphate ions). Synthetic yields improved from around 65%, under conditions where the nonstabilized derivative was stable, to around 85% in conditions where only the stabilized derivative could be utilized (40% methanol and absence of phosphate ions). When using high concentrations of PGM, a significant worsening of the reaction performance was detected with a significant decrease in the yields (below 55%, using 50 mM 6APA and PGM). This problem has been sorted out by using a fed-batch reaction system. By addition of PGM continuously to the reaction mixture (to maintain the concentration between 0.5 and 3 mM), 95% of 6-APA could be transformed to antibiotic (47.5 mM) by only using a 20% excess of acylating ester.