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1.
Retin Cases Brief Rep ; 15(1): 77-80, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-29543621

ABSTRACT

PURPOSE: To report a rare case of peripheral retinal neovascularization in a patient diagnosed with cutis marmorata telangiectatica congenita (CMTC). METHODS: Observational case report. RESULTS: A 16-year-old girl was referred to clinic for retinal evaluation. The patient had a clinical diagnosis of CMTC later confirmed by skin biopsy. Examination revealed temporal peripheral retinal sheathing, as well as lattice degeneration in both eyes. Wide-field fluorescein angiogram showed substantive peripheral retinal nonperfusion with evidence of vascular leakage from areas of presumed retinal neovascularization. The patient subsequently had pan retinal photocoagulation laser treatment to each eye without complication. DISCUSSION: Cutis marmorata telangiectatica congenita is a rare vascular condition known to affect multiple organ systems including the eyes. Although ocular manifestations of CMTC are rare, instances of congenital glaucoma, suprachoroidal hemorrhage, and bilateral total retinal detachments resulting in secondary neovascular glaucoma have been reported. Our patient demonstrates the first reported findings of peripheral nonperfusion and retinal neovascularization related to CMTC in a 16-year-old girl. We propose early retinal examination, wide-field fluorescein angiogram, and early pan retinal photocoagulation laser treatment in patients with peripheral nonperfusion and retinal neovascularization from CMTC.


Subject(s)
Retinal Neovascularization/etiology , Retinal Vessels/pathology , Skin Diseases, Vascular/complications , Telangiectasis/congenital , Adolescent , Female , Fluorescein Angiography/methods , Fundus Oculi , Humans , Laser Coagulation/methods , Livedo Reticularis , Retinal Neovascularization/diagnosis , Retinal Neovascularization/surgery , Retinal Vessels/surgery , Telangiectasis/complications
2.
Jpn J Ophthalmol ; 64(6): 613-620, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32901400

ABSTRACT

PURPOSE: To describe the clinical features and treatment outcomes of severe retinopathy in eyes with incontinentia pigmenti (IP) of infants within a few months of birth. STUDY DESIGN: Retrospective clinical study. METHODS: Six eyes of three patients (6-day-old girl, 5-month-old girl, and 14-day-old boy) with IP were examined and treated under general anesthesia. Ophthalmologic examinations were performed including images from wide-angle fluorescein angiography (FA), swept-source optical coherence tomography (OCT), and OCT angiography (OCTA). RESULTS: Ophthalmoscopy showed prominent vascular tortuosity in five eyes, retinal hemorrhages in four eyes, and incomplete vascular development in two eyes. FA showed extensive avascularity including the posterior pole of the retina in all cases except one eye. Prompt and intensive laser photocoagulation stabilized the pre-proliferative severe retinopathy in five eyes; however, foveal structure and vessel anomalies were detected in three of six eyes by OCT and two of five eyes by OCTA. CONCLUSION: Severe retinopathy in the neonatal period and infancy was present not only in the periphery but also in the posterior pole including the fovea, which might be related to retinal vascular maldevelopment. It is, therefore, recommended that wide-angle fundus FA examination be performed in the early postnatal period to detect early signs of severe retinopathy in infants with IP.


Subject(s)
Diabetic Retinopathy , Incontinentia Pigmenti , Female , Fluorescein Angiography , Humans , Incontinentia Pigmenti/complications , Incontinentia Pigmenti/diagnosis , Incontinentia Pigmenti/surgery , Infant , Infant, Newborn , Laser Coagulation , Lasers , Male , Retinal Vessels/diagnostic imaging , Retinal Vessels/surgery , Retrospective Studies , Tomography, Optical Coherence
3.
Ophthalmic Surg Lasers Imaging Retina ; 50(5): 318-321, 2019 05 01.
Article in English | MEDLINE | ID: mdl-31100164

ABSTRACT

Coats' disease is nonhereditary retinal vascular disorder characterized by telangiectatic retinal vessels with prominent aneurysmal changes and exudation. A conclusive etiology has not yet been determined. In this retrospective case report and literature review, a 64-year-old male with Dubin-Johnson syndrome presented with unilateral retinal vascular changes and exudation consistent with a diagnosis of adult Coats' disease. The authors conclude that patients with Dubin-Johnson syndrome carry mutations in a multidrug resistance associated protein (MRP). MRPs are also expressed in the retina, retinal pigment epithelium, and vascular endothelium, where they export toxins and metabolites, and may serve as a therapeutic target. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:318-321.].


Subject(s)
Jaundice, Chronic Idiopathic/diagnosis , Laser Therapy/methods , Retinal Pigment Epithelium/pathology , Retinal Telangiectasis/diagnosis , Retinal Vessels/diagnostic imaging , Fluorescein Angiography , Fundus Oculi , Humans , Jaundice, Chronic Idiopathic/therapy , Male , Middle Aged , Retinal Telangiectasis/surgery , Retinal Vessels/surgery , Tomography, Optical Coherence
4.
Clin Interv Aging ; 14: 505-514, 2019.
Article in English | MEDLINE | ID: mdl-30880931

ABSTRACT

PURPOSE: To present optical coherence tomography (OCT) angiography features in patients with idiopathic full-thickness macular hole before and after vitrectomy. STUDY DESIGN: Prospective case series study. MATERIALS AND METHODS: Patients presenting with an idiopathic full-thickness macular hole (IMH) who underwent posterior vitrectomy with internal limiting membrane peeling and gas tamponade were included in the study. En face OCT and OCT angiography (OCTA) was performed pre- and postoperatively using 3×3 mm scans (Optovue, XR Avanti). Foveal avascular zone (FAZ) area, macular hole size (MHS), central retinal thickness (CRT), macular parafoveal choriocapillary flow area (MCFA), and fovea vessel density (FVDS) were measured and assessed using OCTA. Best-corrected visual acuity (BCVA) was examined before and 3 months after surgery. RESULTS: Twenty-eight eyes of 28 patients were included in the study. The mean age of patient group was 68.28 years. The hole was closed in all eyes after the initial surgery. OCTA showed enlargement of FAZ and increased CRT in foveal area. Mean preoperative FAZ area was 0.39±0.07 mm2. En face images of the middle retina showed a range of preoperative cystic patterns surrounding the hole. BCVA was improved from 0.1±0.11 preoperatively to 0.42±0.17 postoperatively. Mean FAZ area was reduced to 0.24±0.07 mm2 postoperatively with resolution of macular hole and adjacent cystic areas. Mean CRT was reduced from 396±62.6 µm pre-operatively to 272±30.7 µm postoperatively. After vitrectomy, the parafoveal choriocapillary flow area and FVDS of IMH eyes increased compared with the preoperative measurements. CONCLUSION: Quantitative evaluation of vascular and morphological changes following IMH surgery using OCTA shows the potential for recovery due to vascular and neuronal plasticity. OCTA showing vascular changes and their quantitative characteristics might be a useful tool for the assessment of macular holes before and after surgical treatment.


Subject(s)
Fovea Centralis/blood supply , Retinal Perforations/pathology , Retinal Vessels/pathology , Retinal Vessels/surgery , Vitrectomy/methods , Aged , Female , Fluorescein Angiography/methods , Humans , Male , Postoperative Period , Prospective Studies , Regional Blood Flow/physiology , Retinal Perforations/surgery , Tomography, Optical Coherence/methods , Visual Acuity
5.
Int J Comput Assist Radiol Surg ; 14(5): 819-828, 2019 May.
Article in English | MEDLINE | ID: mdl-30790173

ABSTRACT

PURPOSE: Robot-assisted intraocular microsurgery can improve performance by aiding the surgeon in operating on delicate micron-scale anatomical structures of the eye. In order to account for the eyeball motion that is typical in intraocular surgery, there is a need for fast and accurate algorithms that map the retinal vasculature and localize the retina with respect to the microscope. METHODS: This work extends our previous work by a graph-based SLAM formulation using a sparse incremental smoothing and mapping (iSAM) algorithm. RESULTS: The resulting technique, "EyeSAM," performs SLAM for intraoperative vitreoretinal surgical use while avoiding spurious duplication of structures as with the previous simpler technique. The technique also yields reduction in average pixel error in the camera motion estimation. CONCLUSIONS: This work provides techniques to improve intraoperative tracking of retinal vasculature by handling loop closures and achieving increased robustness to quick shaky motions and drift due to uncertainties in the motion estimation.


Subject(s)
Algorithms , Microsurgery/instrumentation , Ophthalmologic Surgical Procedures/instrumentation , Phantoms, Imaging , Retina/surgery , Retinal Diseases/surgery , Retinal Vessels/diagnostic imaging , Equipment Design , Humans , Retinal Diseases/diagnosis , Retinal Vessels/surgery
8.
Int J Comput Assist Radiol Surg ; 14(2): 311-320, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30141126

ABSTRACT

PURPOSE: Nowadays, millions of people suffer from retinal vein occlusion, a blind-making eye disease. No curative treatment currently exists for this vascular disorder. However, a promising treatment consists in injecting a thrombolytic drug directly inside the affected retinal vessel. Successfully puncturing miniature vessels with diameters between 50 and 400 [Formula: see text] remains a real challenge, amongst others due to human hand tremor, poor visualisation and depth perception. As a consequence, there is a significant risk of double-puncturing the targeted vessel. Sub-surfacic injection of thrombolytic agent could potentially lead to severe retinal damage. METHODS: A new bio-impedance sensor has been developed to visually display the instant of vessel puncture. The physical working principle of the sensor has been analysed, and a representative electrical model has been derived. Based on this model, the main design parameters were derived to maximise the sensor sensitivity. A detailed characterisation and experimental validation of this concept were conducted. RESULTS: Stable, repeatable and robust impedance measurements were obtained. In an experimental campaign, 35 puncture attempts on ex vivo pig eyes vessels were conducted. A confusion matrix shows a detection accuracy of 80% if there is a puncture, a double puncture or no puncture. The 20% of inaccuracy most probably comes from the limitations of the employed eye model and the experimental conditions. CONCLUSIONS: The developed bio-impedance sensor has shown great promise to help in avoiding double punctures when cannulating retinal veins. Compared to other puncture detection methods, the proposed sensor is simple and therefore potentially more affordable. Future research will include validation in an in vivo situation involving vitreoretinal surgeons.


Subject(s)
Catheterization/methods , Electric Impedance/therapeutic use , Microsurgery/methods , Retinal Vein Occlusion/surgery , Retinal Vessels/surgery , Animals , Catheterization/instrumentation , Disease Models, Animal , Humans , Swine
9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 2736-2739, 2018 Jul.
Article in English | MEDLINE | ID: mdl-30440967

ABSTRACT

Automatic segmentation of vascular network is a critical step in quantitatively characterizing vessel remodeling in retinal images and other tissues. We proposed a deep learning architecture consists of 14 layers to extract blood vessels in fundoscopy images for the popular standard datasets DRIVE and STARE. Experimental results show that our CNN characterized by superior identifying for the foreground vessel regions. It produces results with sensitivity higher by 10% than other methods when trained by the same data set and more than 1% with cross training (trained on DRIVE, tested with STARE and vice versa). Further, our results have better accuracy $> 0 .95$% compared to state of the art algorithms.


Subject(s)
Algorithms , Deep Learning , Neural Networks, Computer , Retinal Vessels/diagnostic imaging , Humans , Retinal Vessels/surgery
10.
JAMA Ophthalmol ; 136(12): 1391-1397, 2018 12 01.
Article in English | MEDLINE | ID: mdl-30347030

ABSTRACT

Importance: Adding a laser-induced chorioretinal anastomosis (L-CRA) to current treatments for central retinal vein occlusion (CRVO) may improve outcomes and lessen therapy burdens. Objective: To determine the 2-year efficacy of intravitreal ranibizumab with an L-CRA vs ranibizumab alone for patients with macular edema caused by CRVO. Design, Setting, and Participants: In this randomized clinical trial conducted at a single university clinic from March 2012 to June 2015, 58 participants with macular edema caused by CRVO were randomized 1:1 to either an L-CRA or sham procedure at baseline. All participants received monthly intravitreal injections of ranibizumab, 0.5 mg. Data were analyzed from April 2017 to September 2017. Interventions: Random assignment to L-CRA plus monthly injections of intravitreal ranibizumab, 0.5 mg, (combination group; n = 29) or to a sham L-CRA procedure plus monthly injections of intravitreal ranibizumab, 0.5 mg, (ranibizumab alone group; n = 29) for 6 months. From month 7 to month 24, participants were evaluated monthly and received an injection of ranibizumab if a loss of 5 or more letters of best-corrected visual acuity (BCVA) on ETDRS chart from previous highest score occurred or if there was evidence of residual macular edema on optical coherence tomography. Main Outcomes and Measures: Mean number of injections from month 7 to month 24, change in BCVA, and change in central subfield thickness (CST). Results: Of the 58 included participants, 38 (66%) were men, and the mean (SD) age was 68.6 (11.8) years; participants had a mean (SD) BCVA of 57.09 (11.87) ETDRS letters (Snellen equivalent, 20/73) and a mean (SD) CST of 738.36 (175.54) µm. A successful L-CRA was created in 24 of 29 participants (83%) in the combination group. The mean number of injections from month 7 to month 24 was 3.2 (95% CI, 2.5-3.8) in the combination group and 7.1 (95% CI, 6.0-8.0) in the ranibizumab alone group. The ratio of the number of injections in the combination group compared with the ranibizumab alone group was 0.46 (95% CI, 0.36-0.61; P < .001). Mixed-effects regression modeling showed a difference in mean BCVA at 2 years between the combination and ranibizumab alone groups (combination, 70.3 letters [Snellen equivalent, 20/40]; ranibizumab alone, 61.6 letters [Snellen equivalent, 20/60]; difference, 8.8 letters; 95% CI, 0.2-17.3; P = .05). There was also a difference in CST at 2 years between the combination and ranibizumab alone groups (mean CST: combination, 303.6 µm; ranibizumab alone, 394.5 µm; difference, 90.9 µm; 95% CI, 24.3-157.5; P = .01). Four participants (14%) in the combination group required a vitrectomy for early macular traction or vitreous hemorrhage. Conclusions and Relevance: For macular edema caused by CRVO, an L-CRA significantly reduced the number of ranibizumab injections required. Trial Registration: anzctr.org.au Identifier: ACTRN12612000004864.


Subject(s)
Choroid/surgery , Laser Therapy/methods , Ranibizumab/administration & dosage , Retinal Vein Occlusion/therapy , Retinal Vessels/surgery , Visual Acuity , Aged , Anastomosis, Surgical/methods , Angiogenesis Inhibitors/administration & dosage , Female , Fluorescein Angiography , Follow-Up Studies , Fundus Oculi , Humans , Intravitreal Injections , Male , Prospective Studies , Retinal Vein Occlusion/diagnosis , Time Factors , Tomography, Optical Coherence , Treatment Outcome , Vascular Endothelial Growth Factor A/antagonists & inhibitors
11.
Indian J Ophthalmol ; 66(7): 1031-1033, 2018 07.
Article in English | MEDLINE | ID: mdl-29941765

ABSTRACT

A 54-year-old male sustained ocular trauma with a projectile. Examination of the right eye revealed an intraocular foreign body (IOFB) adjacent to the optic nerve head, vitritis, vitreous hemorrhage, and translucent perivascular sheathing of the retinal vessels in all quadrants suggesting frosted branch angiitis (FBA). The patient underwent vitrectomy with removal of the IOFB and silicone oil tamponade under steroid cover. With continued use of systemic and topical steroids after surgery, complete resolution of FBA and improvement in vision were noted in a week. Prompt resolution of FBA after IOFB removal points toward a strong association between the presence of IOFB and FBA.


Subject(s)
Eye Foreign Bodies/surgery , Eye Injuries, Penetrating/surgery , Retinal Vasculitis/etiology , Retinal Vessels/injuries , Visual Acuity , Vitrectomy/methods , Eye Foreign Bodies/diagnosis , Eye Injuries, Penetrating/diagnosis , Humans , Male , Middle Aged , Retinal Vasculitis/diagnosis , Retinal Vasculitis/surgery , Retinal Vessels/pathology , Retinal Vessels/surgery
12.
Indian J Ophthalmol ; 66(5): 706-708, 2018 05.
Article in English | MEDLINE | ID: mdl-29676325

ABSTRACT

Spontaneous vitreous hemorrhage is a rare entity, present in 7 out of 100,000 inhabitants. It is associated with different pathologies; however, it is rarely reported to be caused by retinal vessel avulsion syndrome. In the present manuscript, we report a case of avulsion of retinal vessels associated with recurrent vitreous hemorrhage managed, at first, by photocoagulation, but due to the several recurrence of bleeding, the patient went into surgical management.


Subject(s)
Light Coagulation/methods , Retinal Perforations/complications , Retinal Vessels/diagnostic imaging , Vitreous Hemorrhage/etiology , Female , Humans , Middle Aged , Recurrence , Retinal Perforations/diagnosis , Retinal Perforations/surgery , Retinal Vessels/surgery , Tomography, Optical Coherence , Vitreous Hemorrhage/diagnosis , Vitreous Hemorrhage/surgery
13.
Korean J Ophthalmol ; 32(1): 65-69, 2018 02.
Article in English | MEDLINE | ID: mdl-29376220

ABSTRACT

PURPOSE: We report the detection of peripheral retinal vascular abnormalities in the fellow eye with normal fundus in children with unilateral Coats' disease. METHODS: The clinical records of patients diagnosed with Coats' disease were retrospectively reviewed. We recorded the subjects' characteristics and obtained fundus photography and fluorescein angiography (FA) images. The main outcome measure was peripheral vascular abnormalities in the contralateral eye with normal fundus in children with unilateral Coats' disease, observed with FA. RESULTS: Out of 47 patients with Coats' disease, two (4.3%) were diagnosed with clinically bilateral Coats' disease. Of the 45 patients with presumed unilateral Coats' disease, four (8.9%) had bilateral abnormal peripheral vasculature in FA. The mean age of these four patients was 6.4 ± 5.4 years (range, 1 to 14 years), and three patients were male (75%). All four had peripheral retinal nonperfusion, and two (50%) received laser photocoagulation due to peripheral leakage with telangiectatic vessels. CONCLUSIONS: Coats' disease may more often be a bilateral disease with asymmetry than previously thought. Patients with Coats' disease should undergo careful examination of the fellow eye with FA in order to detect and treat vascular abnormalities that are not visible clinically.


Subject(s)
Fluorescein Angiography , Retinal Telangiectasis/diagnosis , Retinal Vessels/pathology , Adolescent , Child , Child, Preschool , Female , Fundus Oculi , Humans , Infant , Laser Coagulation , Male , Retinal Telangiectasis/surgery , Retinal Vessels/surgery , Retrospective Studies , Visual Acuity/physiology
14.
Acta Ophthalmol ; 96(4): 405-410, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29193789

ABSTRACT

PURPOSE: We aimed to investigate changes in retinal vascular geometry over time after panretinal photocoagulation (PRP) in patients with proliferative diabetic retinopathy (PDR). METHODS: Thirty-seven eyes with PDR were included. Wide-field fluorescein angiography (Optomap, Optos PLC., Dunfermline, Scotland, UK) was used to diagnose PDR at baseline and to assess activity at follow-up month three and six. At each time-point, a trained grader measured retinal vessel geometry on optic disc (OD) centred images using semiautomated software (SIVA, Singapore I Vessel Assessment, National University of Singapore, Singapore) according to a standardized protocol. RESULTS: At baseline, the mean age and duration of diabetes were 52.8 and 22.3 years, and 65% were male. Mean HbA1c was 69.9 mmol/mol, and blood pressure was 155/84 mmHg. Of the 37 eyes with PDR, eight (22%) eyes had progression at month three and 13 (35%) progressed over six months. Baseline characteristics, including age, sex, duration of diabetes, HbA1c, blood pressure, vessel geometric variables and total amount of laser energy delivered did not differ by progression status. However, compared to patients with progression of PDR, patients with favourable treatment outcome had alterations in the retinal arteriolar structures from baseline to month six (calibre, 154.3 µm versus 159.5 µm, p = 0.04, tortuosity 1.12 versus 1.10, p = 0.04) and in venular structures from baseline to month three (fractal dimension 1.490 versus 1.499, p = 0.04, branching coefficient (BC) 1.32 versus 1.37, p = 0.01). CONCLUSION: In patients with PDR, successful PRP leads to alterations in the retinal vascular structure. However, baseline retinal vascular geometry characteristics did not predict treatment outcome.


Subject(s)
Diabetic Retinopathy/surgery , Fluorescein Angiography/methods , Laser Coagulation/methods , Retinal Vessels/diagnostic imaging , Tomography, Optical Coherence/methods , Diabetic Retinopathy/diagnosis , Female , Follow-Up Studies , Fundus Oculi , Humans , Male , Middle Aged , Prospective Studies , Retina/pathology , Retina/surgery , Retinal Vessels/surgery
15.
Int J Med Robot ; 14(1)2018 Feb.
Article in English | MEDLINE | ID: mdl-28719002

ABSTRACT

BACKGROUND: Fast and accurate mapping and localization of the retinal vasculature is critical to increasing the effectiveness and clinical utility of robot-assisted intraocular microsurgery such as laser photocoagulation and retinal vessel cannulation. METHODS: The proposed EyeSLAM algorithm delivers 30 Hz real-time simultaneous localization and mapping of the human retina and vasculature during intraocular surgery, combining fast vessel detection with 2D scan-matching techniques to build and localize a probabilistic map of the vasculature. RESULTS: In the harsh imaging environment of retinal surgery with high magnification, quick shaky motions, textureless retina background, variable lighting and tool occlusion, EyeSLAM can map 75% of the vessels within two seconds of initialization and localize the retina in real time with a root mean squared (RMS) error of under 5.0 pixels (translation) and 1° (rotation). CONCLUSIONS: EyeSLAM robustly provides retinal maps and registration that enable intelligent surgical micromanipulators to aid surgeons in simulated retinal vessel tracing and photocoagulation tasks.


Subject(s)
Microsurgery/instrumentation , Microsurgery/methods , Ophthalmologic Surgical Procedures , Retina/surgery , Retinal Vessels/diagnostic imaging , Retinal Vessels/surgery , Algorithms , Calibration , False Positive Reactions , Humans , Imaging, Three-Dimensional , Light , Light Coagulation , Micromanipulation , Probability , Reproducibility of Results , Retina/diagnostic imaging , Robotics
18.
Int Heart J ; 58(4): 624-628, 2017 Aug 03.
Article in English | MEDLINE | ID: mdl-28690297

ABSTRACT

The most important factor for preventing contrast-induced nephropathy (CIN) during percutaneous coronary intervention (PCI) in patients with severe renal dysfunction is to minimize the contrast volume. Herein, we report a successful case of complete revascularization after 3 separate PCI procedures using a super-low volume of contrast medium in a patient with 3-vessel disease, including two chronic total occlusions (CTOs). A 70-year-old man having exertional angina despite maximal medical therapy was referred to our hospital. He had severe renal dysfunction (estimated glomerular filtration rate 19 mL/minute/1.73 m2). Coronary angiography, in which a total volume of 15 mL (over 3 injections) of contrast medium was used after hydration with normal saline, demonstrated 2 CTOs in the proximal left circumflex artery (LCX) and the proximal right coronary artery (RCA) as well as focal stenosis in the mid left descending artery (LAD). Because the patient refused coronary artery bypass grafting, we opted for revascularization with PCI, divided into 3 procedures. We made full use of microcatheter tip injection and evaluation with intravascular ultrasound and achieved complete revascularization with a total of 31 mL of contrast medium: 9 mL for RCA, 6 mL for LAD, and 16 mL for LCX, without the occurrence of CIN. Additionally, we present tips for performing PCI using super-low contrast medium.


Subject(s)
Contrast Media/administration & dosage , Coronary Angiography/methods , Coronary Occlusion/surgery , Coronary Vessels/diagnostic imaging , Percutaneous Coronary Intervention/methods , Renal Insufficiency/complications , Surgery, Computer-Assisted/methods , Acute Kidney Injury/prevention & control , Aged , Chronic Disease , Coronary Occlusion/complications , Coronary Occlusion/diagnosis , Coronary Vessels/surgery , Humans , Male , Retinal Vessels/diagnostic imaging , Retinal Vessels/surgery
19.
Acta Ophthalmol ; 95(6): e462-e467, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28597519

ABSTRACT

PURPOSE: To describe a new robot-assisted surgical system for retinal vascular bypass surgery (RVBS) and to compare the success rate with freehand RVBS. METHODS: A robot-assisted system for retinal microsurgery was constructed to include two independent robotic arms. A 23-gauge light probe and an intraocular forceps were affixed to the arm end effectors to perform the intraocular manipulation. Harvested porcine eyes were introduced to be established animal models of closed-sky eyeballs after that pars plana vitrectomy using temporary keratoprosthesis was performed by a skilful surgeon. Retinal vascular bypass surgery (RVBS) was performed by an inexperienced ophthalmologist to test the ease of use. A stainless steel wire (45-µm pipe diameter) was used as an artificial vessel. Before RVBS, the wires were prepositioned at the retinal surface of the eyes. The Control group (n = 20) underwent freehand RVBS, and the Experimental group (n = 20) underwent robot-assisted RVBS. To create the simulated bypass, the distal end of the wire was inserted into the selected vessel and advanced ~4 mm away from the optic disc. If successful, then the proximal wire end was inserted and advanced ~2 mm towards the optic disc. The difference in the success rate for the freehand and robot-assisted procedures was analysed by the chi-square test. RESULTS: The success rate for the freehand RVBS was 5% (1/20 eyes). In contrast, the robot-assisted success rate was 35% (7/20) of eyes (p < 0.05). CONCLUSION: This study demonstrated the feasibility of robot-assisted RVBS in ex vivo porcine eyes. The robotic system increased the accuracy and stability of manipulation by eliminating freehand tremor, leading to a higher surgical success rate.


Subject(s)
Microsurgery/methods , Retinal Diseases/surgery , Retinal Vessels/surgery , Robotics/instrumentation , Vascular Surgical Procedures/methods , Animals , Disease Models, Animal , Feasibility Studies , Humans , Reproducibility of Results , Swine
20.
Jpn J Ophthalmol ; 61(1): 51-60, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27730425

ABSTRACT

PURPOSE: The effect of combination therapy using intravitreal ranibizumab (IVR) injections and short pulse focal/grid laser photocoagulation was evaluated for the treatment of diabetic macular edema (DME). METHODS: The current investigation was a preliminary single-arm, open-label, prospective clinical study conducted on 21 eyes at 4 sites in Japan. Treatment protocol consisted of two phases. The induction IVR phase included two monthly IVRs followed by PRN IVR phase in which additional IVR was administered if the central macular thickness (CMT) exceeded 300 µm. One week after each IVR in both phases, short pulse focal/grid laser was delivered to treat residual leakage outside of the fovea (>500 µm) and reduce edema fluid influx. At the 6-month endpoint, the effects of treatment were examined in terms of best corrected visual acuity (BCVA), CMT, and required number of IVR injections in eyes with or without perifoveal leaking microaneurysms (MAs). RESULTS: In eyes with initial BCVA ≤70 letters, mean BCVA was significantly ameliorated by 7.0 ± 7.4 letters (P = 0.0324) and mean CMT improved significantly by 174.8 ± 105.0 µm (P = 0.0005). Both BCVA improvement (P = 0.8693) and CMT reduction (P = 0.9336) were comparable between MA(-) and MA(+) groups. The MA(-) group required significantly fewer PRN-IVR injections than did the MA(+) group over the 6-month study period (mean 3.4 ± 1.6 vs. 5.3 ± 0.9, median 3.0 vs. 5.5; P = 0.0229). CONCLUSIONS: Short pulse focal/grid laser photocoagulation could reduce the number of IVR injections required to resolve macular edema and increase BCVA in a possible mechanism of reduced influx of edema fluid into the foveal area in eyes without apparent perifoveal microaneurysms.


Subject(s)
Diabetic Retinopathy/complications , Laser Coagulation/methods , Macular Edema/complications , Microaneurysm/etiology , Ranibizumab/administration & dosage , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Visual Acuity , Angiogenesis Inhibitors/administration & dosage , Diabetic Retinopathy/diagnosis , Diabetic Retinopathy/therapy , Female , Follow-Up Studies , Fovea Centralis/diagnostic imaging , Humans , Intravitreal Injections , Macular Edema/diagnosis , Macular Edema/therapy , Male , Microaneurysm/diagnosis , Microaneurysm/therapy , Middle Aged , Prospective Studies , Retinal Vessels/diagnostic imaging , Retinal Vessels/surgery , Tomography, Optical Coherence , Treatment Outcome
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