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BACKGROUND/AIMS: To evaluate the diagnostic accuracy of spectral-domain optical coherence tomography (SD OCT) combined with OCT angiography (OCTA) for myopic myopic macular neovascularisation (MNV) activity. METHODS: Both eyes of patients with myopic MNV diagnosed with fluorescein angiography (FA), SD OCT and OCTA were assessed by unmasked investigators. The images were deidentified and randomised before graded by masked investigators, who determined the presence of active myopic MNV by using SD OCT together with OCTA without FA and by FA alone, respectively. The findings of masked investigators were compared with unmasked investigators. RESULTS: 213 eyes of 110 patients comprising 499 imaging episodes were eligible for grading. For diagnosing new-onset myopic MNV without FA, combined use of SD OCT and OCTA had a sensitivity of 0.94, specificity of 0.84 and area under the curve (AUC) of 0.92. FA had a sensitivity of 0.52 (p<0.01), specificity of 0.80 (p=0.38) and AUC of 0.66 (p<0.01). For recurrent myopic MNV, the combination of SD OCT and OCTA had a sensitivity of 0.98, specificity of 0.78 and AUC of 0.88. FA had a sensitivity of 0.50 (p=0.04), specificity of 0.76 (p=0.85) and AUC of 0.63 (p=0.01). Myopic traction maculopathy was more frequently associated with recurrent myopic MNV (p<0.01). CONCLUSION: SD OCT with dense volumetric scan was highly sensitive for diagnosing myopic MNV. The addition of OCTA improved the diagnostic specificity without FA. Monitoring of the longitudinal changes on SD OCT and judicious use of FA is a reliable surveillance strategy for myopic MNV.
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INTRODUCTION: The objective of this study was to compare the outcome of submacular hemorrhage (SMH) displacement using pneumatic displacement with intravitreal expansile gas versus pars plana vitrectomy (PPV) with subretinal injection of tissue plasminogen activator (tPA), anti-vascular endothelial growth factor (VEGF) agent, and air as primary surgery. METHODS: Retrospective interventional case series of 63 patients who underwent surgical displacement of SMH secondary to neovascular age-related macular degeneration (nAMD) or polypoidal choroidal vasculopathy (PCV) from May 1, 2015, to October 31, 2022. Medical records were reviewed for diagnosis, logMAR visual acuity (VA), central subfield thickness (CST), and postoperative displacement rates and complications up to 12 months after operation. RESULTS: The diagnosis was nAMD in 24 (38.1%) and PCV in 39 (61.9%) eyes. There were 40 (63.5%) eyes in the pneumatic displacement group (38 received C3F8, 2 received SF6) and 23 (36.5%) eyes in the subretinal cocktail injection. Mean baseline VA was 1.46 and 1.62, respectively (p = 0.404). The subretinal injection group had more extensive SMH (p = 0.005), thicker CST (1,006.6 µm vs. 780.2 µm, p = 0.012), and longer interval between symptom and operation (10.65 vs. 5.53 days, p < 0.001). The mean postoperative VA at 6 months was 0.67 and 0.91 (p = 0.180) for pneumatic displacement and subretinal injection groups, respectively, though VA was significantly better in the pneumatic group at 12-month visit (0.64 vs. 1.03, p = 0.040). At least 10 mean change in VA were >10 letters gain in both groups up to 12 months. Postoperative CST reduction was greater (625.1 µm vs. 326.5 µm, p = 0.008) and complete foveal displacement (87.0% vs. 37.5%), p < 0.001, odds ratio [OR] = 11.1) and displacement to arcade or beyond (52.5% vs. 17.5%, p = 0.009, OR = 5.15) were more frequent in the subretinal injection group. Two patients with failed pneumatic displacement were successfully treated with subretinal cocktail injection as a second operation. CONCLUSION: Surgical displacement of SMH leads to clinically meaningful improvement in VA. PPV with subretinal cocktail injection is more effective than pneumatic displacement in displacing SMH with similar safety profile despite longer interval before operation, higher CST, and more extensive SMH at baseline. Retinal surgeons could consider this novel technique in cases with thick and extensive SMH or as a rescue secondary operation in selected cases.
Subject(s)
Endotamponade , Fluorescein Angiography , Retinal Hemorrhage , Tissue Plasminogen Activator , Tomography, Optical Coherence , Visual Acuity , Vitrectomy , Humans , Retrospective Studies , Retinal Hemorrhage/diagnosis , Retinal Hemorrhage/therapy , Retinal Hemorrhage/etiology , Male , Female , Vitrectomy/methods , Aged , Endotamponade/methods , Tissue Plasminogen Activator/administration & dosage , Tomography, Optical Coherence/methods , Fluorescein Angiography/methods , Intravitreal Injections , Angiogenesis Inhibitors/administration & dosage , Follow-Up Studies , Treatment Outcome , Wet Macular Degeneration/diagnosis , Wet Macular Degeneration/therapy , Wet Macular Degeneration/complications , Fundus Oculi , Fibrinolytic Agents/administration & dosage , Fluorocarbons/administration & dosage , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Aged, 80 and over , Middle Aged , Sulfur Hexafluoride/administration & dosageABSTRACT
PURPOSE: This study aims to compare the performance of the 25+® UltraVit® 5000 cuts per minute (cpm) vitrectomy probe versus the 25+ ® Ultravit 10,000 cpm® beveled tip, dual drive vitrectomy probe. METHOD: In this prospective randomised controlled clinical trial, 52 eyes of 52 consecutive patients were randomized into either the 10,000 cpm (25 patients) or 5000 cpm vitrectomy group (27 patients). Patients were evaluated preoperatively, intraoperatively, and postoperatively on the first day, and at 1 week, 1 month and 3 months. The main outcome measures were vitrectomy time, and secondary endpoints were time to induction of posterior vitreous detachment, intraoperative complications, and number of instruments used. RESULTS: The vitrectomy time was shorter in the 10,000 cpm group (413.7 s) compared to the 5000 cpm group (463.4 s), although there was no significant difference (p = 0.5999). One patient had an iatrogenic retinal break in the 10,000 cpm group while two patients had an iatrogenic retinal break in the 5000 cpm group. The time for posterior vitreous detachment (PVD) induction and the number of instruments used were not significantly different between the two groups. CONCLUSION: The difference in vitrectomy times between the 10,000 cpm vitrectomy probe and the 5000 cpm cutter were not statistically significant. This may suggest that other factors affect efficiency rather than the limitations of equipment.
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Frequent antivascular endothelial growth factor injections in neovascular age-related macular degeneration (nAMD) often lead to poor compliance and suboptimal outcomes. A longer-acting agent has been a pressing unmet need until recently. Brolucizumab, an antivascular endothelial growth factor agent, is a single-chain antibody fragment approved by the US Food and Drug Administration (FDA) on October 8, 2019, for treating nAMD. It delivers more molecules at equivalent volumes of aflibercept, thus achieving a longer-lasting effect. We reviewed literature published in English between January 2016 and October 2022 from MEDLINE, PubMed, Cochrane database, Embase, and Google scholar using the keywords: "Brolucizumab, real-world data, intraocular inflammation (IOI), safety, and efficacy". Brolucizumab showed reduced injection frequency, better anatomic outcomes, and noninferior vision gains compared with aflibercept in HAWK and HARRIER studies. However, post hoc studies on brolucizumab revealed a higher-than-expected incidence of IOI, leading to the early termination of 3 studies: MERLIN, RAPTOR, and RAVEN for nAMD, branch retinal vein occlusion, and central retinal vein occlusion, respectively. Contrastingly real-world data showed encouraging outcomes in terms of fewer IOI cases. The subsequent amendment of the treatment protocol resulted in reduced IOI. Thereafter US FDA approved its use in diabetic macular edema on June 1, 2022. Based on major studies and real-world data, this review shows that brolucizumab is effective for treating naive and refractory nAMD. The risk of IOI is acceptable and manageable, but proper preinjection screening and high-vigilance care of IOI are needed. More studies are warranted to evaluate further the incidence, best prevention, and treatment measures for IOI.
Subject(s)
Diabetic Retinopathy , Macular Edema , Uveitis , Humans , Angiogenesis Inhibitors/therapeutic use , Diabetic Retinopathy/drug therapy , Macular Edema/drug therapy , Endothelial Growth Factors/therapeutic use , Receptors, Vascular Endothelial Growth Factor/therapeutic use , Uveitis/drug therapy , Inflammation , Intravitreal Injections , Recombinant Fusion Proteins/therapeutic useABSTRACT
PURPOSE: To report two cases of bilateral retinal vasculitis in adolescents following COVID-19 vaccination. STUDY DESIGN: Case report. RESULTS: We report the first two cases of retinal vasculitis in adolescents following COVID-19 vaccinations. Both patients received recent second-dose COVID-19 vaccinations (7 weeks and 4 weeks respectively), and presented with bilateral retinal vasculitis and vitritis. Investigations did not reveal other causes of retinal vasculitis. Both patients' retinal vasculitis settled with a short course of oral prednisolone. CONCLUSION: Although rare, the temporal association between vaccination, bilateral eye involvement, and the absence of alternative infective or inflammatory causes, makes this a plausible etiology. mRNA vaccinations may cause an autoimmune reaction via host antigenic mimicry, and systemic vasculitis has previously been described. We believe that a short interval between COVID-19 vaccination doses might be a risk factor for the development of retinal vasculitis in adolescents, and clinicians should be aware to elicit vaccination history.
Subject(s)
COVID-19 Vaccines , COVID-19 , Endophthalmitis , Retinal Vasculitis , Adolescent , Humans , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Retinal Vasculitis/diagnosis , Retinal Vasculitis/etiology , Vaccination/adverse effectsABSTRACT
PURPOSE: To describe the clinical and optical coherence tomography (OCT) features of two cases with bilateral diffuse retinal infiltrates as the only presenting feature of chronic myeloid leukemia (CML) on initial diagnosis and upon relapse. METHODS: We reported two patients with CML, one at initial diagnosis and one in remission who presented with bilateral subacute visual impairment. Fundal examination revealed bilateral symmetrical leukostatic appearance with increased vascular tortuosity, diffuse retinal infiltrates with size up to 6 disk diameters, retinal hemorrhages, and Roth's spots. OCT showed multiple intra-retinal hyper-reflective foci corresponding to intra-retinal hemorrhages, and outer retinal hyper-reflective foci in area corresponding to retinal infiltrate. The different retinal layers were relatively preserved and distinguishable. RESULTS: White cell count (WCC) were elevated in both patients ranging from 544 to 810 × 109/L. Bone marrow biopsy confirmed the diagnosis of CML in the patient without prior diagnosis and relapse of CML in another patient. Cytogenetic test detected Abelson murine leukemia (ABL) - breakpoint cluster region (BCR) fusion transcript in both cases. Both patients were started on oral imatinib, subsequently WCC returned to within normal values in both cases. Vision and OCT abnormalities improved and reduction in retinal hemorrhages and infiltrates were observed in follow up. CONCLUSION: This report highlights the important role of ophthalmologists and detailed fundus examination in making a prompt diagnosis of leukemia in patients with visual complaints. Appropriate systemic investigation and hematologist referrals for prompt treatment of CML may improve survival rate and preserve vision.
Subject(s)
Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Retinal Diseases , Humans , Animals , Mice , Retinal Hemorrhage/diagnosis , Retinal Hemorrhage/etiology , Retinal Hemorrhage/drug therapy , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Imatinib Mesylate/therapeutic use , Retina/pathology , Chronic Disease , Retinal Diseases/diagnosis , Retinal Diseases/drug therapy , Retinal Diseases/etiology , Vision Disorders/drug therapyABSTRACT
PURPOSE: To report a novel technique for refixation of the dislocated CZ70BD intraocular lens. METHODS: Posterior vitrectomy is performed with a 23-gauge or 25-gauge pars plana vitrectomy system with chandelier illumination. One needle of a double-arm 9-0 prolene needle is passed through the sclera 1.5 mm postlimbus. The needle is retrieved through the corneal paracentesis using a 27-G needle, and the suture is then cut. The suture end is passed through the eyelet of the dislocated CZ70BD intraocular lens inside the vitreous cavity. This is aided with a pair of 27-G MaxGrip forceps, which is inserted through a 27-G sclerostomy site at the intended scleral outlet. After passing the suture through the eyelet, the suture is pulled out at the 27-G sclerostomy site and a knot is tied and rotated. Similar procedure is performed for the second haptic if necessary. RESULTS: Seven eyes were successfully operated on using this technique with a mean follow-up of 12.4 months. There was significant improvement in the best-corrected visual acuity after the operation ( P = 0.016). Postoperative intraocular lens centration and alignment were satisfactory. One patient developed macula-on retinal detachment 1 month after the operation, which was successfully repaired without loss in the best-corrected visual acuity. CONCLUSION: The described novel technique is effective for refixation of dislocated CZ70BD intraocular lens.
Subject(s)
Lenses, Intraocular , Sclerostomy , Humans , Sclera/surgery , Lens Implantation, Intraocular/methods , Vitrectomy/methods , Surgical Instruments , Suture Techniques , Retrospective StudiesABSTRACT
PURPOSE: To assess the diagnostic accuracy of optical coherence tomography angiography (OCTA) compared with multimodal imaging for choroidal neovascularization (CNV) in central serous chorioretinopathy (CSC) eyes and to determine the features that predicted CNV. DESIGN: Prospective cross-sectional study. METHODS: Consecutive CSC patients were recruited from retina clinic. The reference standard for CNV was determined by interpretation of multimodal imaging with OCTA, structural OCT line scan, fluorescein angiography (FA), indocyanine green angiography (ICGA), ultra-widefield fundus photography and fundus autofluorescence (FAF). Two independent masked graders examined OCTA without FA and ICGA to diagnose CNV. Univariate and multivariate analyses were performed to evaluate factors associated with CNV. RESULTS: CNV was detected in 69 eyes in 64 out of 277 CSC patients according to reference standard. The two masked graders who examined OCTA had sensitivity of 81.2% (95% Confidence Interval [CI], 71.9%-90.4%) and 78.3% (95% CI, 68.5%-88.0%), specificity of 97.3% (95% CI, 95.9%-98.8%) and 96.2% (95% CI, 94.5%-98.0%), positive predictive values of 82.4% (95% CI, 73.3%-91.4%) and 76.1% (95% CI, 66.1%-86.0%), and negative predictive values of 97.1% (95% CI, 95.6%-98.7%) and 96.7% (95% CI, 95.0%-98.3%). Their mean area under the receiver operating characteristic curve (AUC) was 0.88 with good agreement (Kappa coefficient 0.80 [95% CI, 0.72-0.89]). Flat irregular pigment epithelial detachment on structural OCT, neovascular network on OCTA and ill-defined late leakage on FA significantly correlated with CNV in CSC from multiple regression (P < 0.001, P < 0.001 and Pâ¯=â¯0.005, respectively). CONCLUSIONS: There is discordance between OCTA and multimodal imaging in diagnosing CNV in CSC. This study demonstrated the caveats in OCTA interpretation, such as small extrafoveal lesions and retinal pigment epithelial alterations. Comprehensive interpretation of OCTA with dye angiography and structural OCT is recommended.
Subject(s)
Central Serous Chorioretinopathy , Choroidal Neovascularization , Central Serous Chorioretinopathy/diagnosis , Choroid/diagnostic imaging , Choroidal Neovascularization/diagnostic imaging , Cross-Sectional Studies , Fluorescein Angiography , Humans , Indocyanine Green , Multimodal Imaging , Prospective Studies , Retrospective Studies , Tomography, Optical CoherenceABSTRACT
AIM: To review international guidelines and to share our infection control experience during the coronavirus disease 2019 (COVID-19) pandemic at a tertiary eye centre in Hong Kong. METHODS: Infection control guidelines and recommendations from international ophthalmological bodies are reviewed and discussed. The measures at our hospital were drawn up as per international and local health authorities' guidelines and implemented with the collaboration of doctors, nurses and administrative staff. RESULTS: The aims of our infection control measures are to 1) minimize cross-infection within the hospital; 2) protect and support hospital staff; 3) ensure environmental control. To minimize the risk of cross-infection, outpatient attendance and elective surgery have been reduced by 40%, and general anesthesia procedures were reduced by 90%. Patients entering the hospital are screened for fever, travel history, contact and cluster history, and COVID-19 related symptoms. To protect and support hospital staff, we ensure provision of adequate personal protective equipment (PPE) and provide clear guidelines on the level of PPE needed, depending on the clinical situation. Other protective measures include provision of work uniforms, easy access to alcohol-based hand rub, opening new lunch areas, implementation of self-monitoring and self-reporting systems, and communication via online education and updates. Finally, environmental control is achieved by ensuring regular disinfection of the hospital premise, enhancing ventilation, and usage of disposable ophthalmic instruments. CONCLUSION: Our multi-pronged approach to infection control is, so far, successful in minimizing infection risks, while allowing the maintenance of essential ophthalmic services.
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Purpose. To summarise the surgical advances and evolution of small gauge vitrectomy and discuss its principles and application in modern vitreoretinal surgery. The advent of microincisional vitrectomy systems (MIVS) has created a paradigm shift away from twenty-gauge vitrectomy systems, which have been the gold standard in the surgical management of vitreoretinal diseases for over thirty years. Advances in biomedical engineering and surgical techniques have overcome the technical hurdles of shifting to smaller gauge instrumentation and sutureless surgery, improving surgical capabilities and expanding the indications for MIVS.
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PURPOSE: To evaluate quantitatively the choroidal vascularity in polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (AMD) patients compared to healthy controls. METHODS: All eyes underwent swept source optical coherence tomography (OCT), and choroidal images were binarized into blood vessels lumen and stroma. The choroidal vascular index (CVI) was defined as the ratio of luminal area (LA) over total choroidal area of the subfoveal region with a width of 1500 µm. RESULTS: The study included 73 patients with neovascular AMD or PCV with mean ± standard deviation (SD) age of 71.8 ± 9.3 years, which was older than the mean age of 65.1 ± 10.8 years of 72 healthy eyes from control group (p < 0.01). The 44 PCV eyes had significantly higher mean SFCT of 214.23 ± 95.21 µm than neovascular AMD eyes (172.74 ± 96.48 µm, p = 0.03) and greater luminal area (0.23 ± 0.09 mm2 vs. 0.19 ± 0.08 mm2, p = 0.05). After adjusting for age, axial length, and gender in multivariate regression analysis, the SFCT of PCV and neovascular AMD eyes were not significantly different from healthy eyes (195.55 ± 93.11 µm), but the CVI of both PCV (64.94 ± 5.43%, p = 0.01) and neovascular AMD (62.54 ± 5.57%, p = <0.01) were significantly lower than control (68.53 ± 5.91%). CONCLUSION: Despite physiological changes of choroidal vasculature due to aging, the choroidal morphology is different in PCV, neovascular AMD and healthy eyes, which has implication on disease pathogenesis.
Subject(s)
Choroidal Neovascularization/diagnosis , Macula Lutea/pathology , Polyps/diagnosis , Retinal Vessels/diagnostic imaging , Tomography, Optical Coherence/methods , Wet Macular Degeneration/diagnosis , Aged , Aged, 80 and over , Choroid/blood supply , Cross-Sectional Studies , Female , Fluorescein Angiography , Follow-Up Studies , Fundus Oculi , Humans , Male , Middle Aged , Retrospective Studies , Visual AcuityABSTRACT
Purpose: The purpose of this study was to classify exudative maculopathy by the presence of pachyvessels on en face swept-source optical coherence tomography (SSOCT). Methods: Consecutive patients with signs of exudative maculopathy underwent SSOCT, fluorescein and indocyanine green angiography (ICGA), ultra-widefield fundus color photography, and autofluorescence examinations. Images were analyzed in a masked fashion by two sets of four examiners in different sessions: (1) the presence of pachyvessels in en face OCT and (2) features of exudative maculopathy in conventional imaging modalities. Quantitative data obtained were subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI), which was the ratio of choroidal vessels lumen area to a specified choroidal area from binarized cross-sectional OCT scans. Results: Pachyvessels was observed in 38 (52.1%) of 73 eyes. The pachyvessels group was associated with younger age (69.1 ± 9.4 years, odds ratio [OR] = 0.95, 95% confidence interval [95% CI] = 0.90-0.97, P = 0.04), presence of polypoidal lesions (OR = 3.27, 95% CI = 1.24-8.62, P = 0.01), increased SFCT (OR = 1.08, 95% CI = 1.02-1.14, P < 0.01), and increased CVI (65.4 ± 5.3, OR = 1.12, 95% CI = 1.02-1.23, P = 0.01). In multivariate regression, CVI significantly correlated with pachyvessels (OR = 1.24, 95% CI = 1.03-1.55, P = 0.04). Conclusions: Exudative maculopathy could be classified based on differences in choroidal vasculature morphology. Current results implied that choroidal hemodynamics may be relevant to variable natural history and treatment response in neovascular AMD and polypoidal choroidal vasculopathy.
Subject(s)
Fluorescein Angiography/methods , Retinal Pigment Epithelium/pathology , Retinal Vessels/pathology , Tomography, Optical Coherence/methods , Wet Macular Degeneration/classification , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Follow-Up Studies , Fundus Oculi , Humans , Male , Middle Aged , Reproducibility of Results , Retrospective Studies , Visual Acuity , Wet Macular Degeneration/diagnosisABSTRACT
PURPOSE: To investigate long-term efficacy and prognostic factors of half-dose photodynamic therapy (PDT) in chronic central serous chorioretinopathy (CSCR). DESIGN: Retrospective multicenter interventional case series. METHODS: Patients with chronic CSCR undergoing half-dose PDT between 2005 and 2011 were reviewed. Main outcome measures included resolution of serous retinal detachment (SRD) with single PDT, change in best-corrected visual acuities (BCVAs), and recurrence rate of CSCR at 36 months after PDT. Prognostic factors of visual outcome and recurrence of CSCR after PDT were identified with multivariate regression analysis. RESULTS: A total of 136 eyes of 123 patients were followed up for 57.7 ± 16.2 months. At 36 months after PDT, 132 eyes (97.1%) achieved complete resolution of SRD with single PDT and 4 eyes (2.9%) had CSCR recurrence. The mean logMAR BCVA improved from 0.36 ± 0.29 (Snellen equivalent 20/46; range: 0.1-1.2) at baseline to 0.15 ± 0.23 at 36 months (Snellen equivalent 20/28; range: 0.1-1.5; P < .001) and 0.16 ± 0.24 (Snellen equivalent: 20/29; range: 0.1-1.5; P < .001) at final follow-up. Forty-four eyes (32.4%) had ≥3 lines of BCVA gain while 5 eyes (3.7%) had ≥3 lines of BCVA loss at 36 months after PDT. Nine eyes (6.6%) developed CSCR recurrence at final follow-up. Baseline BCVA was significantly associated with the BCVA (P = .009) and the improvement in BCVA (P < .001) at final follow-up. History of bilateral CSCR was significantly associated with CSCR recurrence at final follow-up (P = .036; odds ratio = 15.84, 95% confidence interval = 1.20-208.32). Eight eyes (5.9%) had complications related to PDT. CONCLUSIONS: Chronic CSCR patients treated with half-dose PDT can achieve long-term stable visual acuity and resolution of SRD. Patients with chronic CSCR are recommended to undergo half-dose PDT before they have significant visual deterioration. Patients with bilateral CSCR are more likely to develop CSCR recurrence after half-dose PDT.
Subject(s)
Central Serous Chorioretinopathy/drug therapy , Photochemotherapy , Photosensitizing Agents/administration & dosage , Porphyrins/administration & dosage , Adult , Aged , Aged, 80 and over , Central Serous Chorioretinopathy/metabolism , Central Serous Chorioretinopathy/physiopathology , Chronic Disease , Coloring Agents/administration & dosage , Female , Fluorescein Angiography , Follow-Up Studies , Humans , Indocyanine Green/administration & dosage , Male , Middle Aged , Prognosis , Recurrence , Retrospective Studies , Tomography, Optical Coherence , Verteporfin , Visual Acuity/physiologyABSTRACT
The anticancer activity of disulfiram (DS) is copper(ii) (Cu)-dependent. This study investigated the anticancer mechanisms of DS/Cu using in vitro cytotoxicity and metabolic kinetic analysis. Our study indicates that DS/Cu targets cancer cells by the combination of two types of actions: (1) instant killing executed by DS/Cu reaction generated reactive oxygen species; (2) delayed cytotoxicity introduced by the end product, DDC-Cu. Nanoencapsulation of DS might shed light on repositioning of DS into cancer treatment.
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In the present work we develop a real-time electrochemical mediator assay to enable the assessment of cell numbers and chemical toxicity. This allowed us to monitor metabolism down to a single cell in a low cost easy to use rapid assay which is not possible with current technology. The developed assay was based on the determination of oxygen. This was made possible via the use of electrochemical mediator ferrocene carboxylic acid (FcA). The FcA showed distinctive catalytic properties in interacting with reactive oxygen species generated from oxygen when compared to ferrocene methanol (FcMeOH). A deeper insight into the chemistry controlling this behaviour is provided. The behaviour is then taken advantage of to develop a cellular aerobic respiration assay. We describe the properties of the FcA system to detect, in real-time, the oxygen consumption of Escherichia coli DH5-α (E. coli). We demonstrated that the FcA-based oxygen assay is highly sensitive, and using a population of cells, oxygen consumption rates could be calculated down to a single cell level. More importantly, the results can be accomplished in minutes, considerably outperforming current commercially available biooxygen demand assays. The developed assay is expected to have a significant impact in diverse fields and industries, ranging from environmental toxicology through to pharmaceutical and agrochemical industries.
Subject(s)
Biological Oxygen Demand Analysis/methods , Biosensing Techniques/methods , Electrochemical Techniques/methods , Escherichia coli/metabolism , Ferrous Compounds/metabolism , Oxygen/metabolism , Escherichia coli/isolation & purification , Ferrous Compounds/chemistry , Metallocenes , Oxygen/analysisABSTRACT
PURPOSE: To describe the results of primary 23-gauge transconjunctival sutureless vitrectomy for rhegmatogenous retinal detachment (RRD). METHODS: In a prospective case series, 24 eyes of 24 consecutive patients with RRD underwent primary 23-gauge transconjunctival pars plana vitrectomy with intraocular gas tamponade. Postoperative follow-up ranged from 6 months to 16 months. RESULTS: Fifteen eyes (62.5%) had multiple breaks. Seven eyes (29.2%) had inferior breaks. Other complications included giant tear in one eye, peripheral choroidal detachment in one eye, and concomitant macular holes in two eyes. The primary anatomical success rate was 91.7%. The mean postoperative visual acuity at postoperative month 3 improved from 20/41 to 20/25 (P = 0.111) and from 20/735 to 20/56 (P < 0.0001) in macula-on and macula-off cases, respectively. One patient (4.2%) had hypotony on postoperative day 1. No patients developed choroidal detachments. No sutures were used in any of the sclerotomy sites. Of the patients, 87.5% reported no or mild foreign body sensation, whereas 79.1% reported no or mild pain on the first postoperative day. CONCLUSIONS: Twenty-three-gauge transconjunctival sutureless vitrectomy appears to be a feasible option in treating RRD in selected cases, with the potential benefit of reducing postoperative ocular irritation.
Subject(s)
Conjunctiva/surgery , Retinal Detachment/surgery , Retinal Perforations/surgery , Vitrectomy/methods , Adult , Aged , Choroid Diseases/complications , Eye Foreign Bodies/physiopathology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Ocular Hypotension/etiology , Pain, Postoperative/etiology , Postoperative Period , Prospective Studies , Retinal Detachment/complications , Retinal Perforations/complications , Sensation , Treatment Outcome , Visual Acuity , Vitrectomy/adverse effectsABSTRACT
PURPOSE: To investigate the penetration of ofloxacin and moxifloxacin into the aqueous and vitreous after topical administration one hour before vitrectomy surgery. DESIGN: Prospective, randomized, double-blind case series study. METHODS: Twenty-seven patients undergoing vitrectomy were randomized to receive either topical ofloxacin 0.3% or moxifloxacin 0.5% every 10 minutes for one hour before surgery. Aqueous and vitreous samples were obtained and analyzed using high-performance liquidation chromatography. RESULTS: The moxifloxacin aqueous (1.576 +/- 0.745 microg/ml) and vitreous (0.225 +/- 0.013 microg/ml) levels were significantly higher than the ofloxacin aqueous (0.816 +/- 0.504 microg/ml) (P = .0009) and vitreous (0.225 +/- 0.013 microg/ml) [P = .0054] levels, respectively. The mean moxifloxacin aqueous and vitreous levels exceeded the minimum inhibitory concentration for 90% of isolates (MIC(90)) for a wide variety of bacteria implicated in endophthalmitis. In contrast, the aqueous level of ofloxacin exceeded the MIC(90) of only a few organisms. CONCLUSIONS: Moxifloxacin applied every 10 minutes during the hour before vitrectomy penetrated the eye significantly better than ofloxacin.
Subject(s)
Anti-Infective Agents/pharmacokinetics , Aqueous Humor/metabolism , Aza Compounds/pharmacokinetics , Ofloxacin/pharmacokinetics , Quinolines/pharmacokinetics , Vitrectomy , Vitreous Body/metabolism , Adult , Aged , Anti-Infective Agents/administration & dosage , Aza Compounds/administration & dosage , Biological Availability , Chromatography, High Pressure Liquid , Double-Blind Method , Female , Fluoroquinolones , Follow-Up Studies , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Moxifloxacin , Ofloxacin/administration & dosage , Prospective Studies , Quinolines/administration & dosage , Retinal Diseases/surgeryABSTRACT
BACKGROUND: To evaluate the use of high-density silicone oil (HDSO) as a tamponade agent for retinal detachment secondary to myopic macular hole. METHODS: 12 eyes of 12 patients with macular hole retinal detachment underwent pars plana vitrectomy, internal limiting membrane peeling and HDSO tamponade. No posturing was required postoperatively and HDSO was removed 3-4 months later. Outcome measures included macular hole closure and retinal attachment rates, best-corrected visual acuity (BCVA), and intraoperative and postoperative complications. RESULTS: The mean age of the patients was 67.8 years and the mean spherical equivalent refractive error was -13.4 diopters. After the removal of HDSO, 10 (83%) eyes had macular hole closure with retinal reattachment without any tamponade. One eye had retinal reattachment after re-operation and the other refused further surgery. At the last follow-up, the median BCVA improved from 20/800 to 20/600 (p = 0.046). A transient increase in intraocular pressure was observed in 5 (42%) eyes and one eye each developed mild oil emulsification and transient peripheral choroidal detachment. None of the eyes was found to have severe intraocular inflammation postoperatively. CONCLUSIONS: HDSO seemed to be an effective tamponade agent for myopic macular hole retinal detachment. Further prospective controlled studies seem warranted.
Subject(s)
Myopia, Degenerative/complications , Retinal Detachment/therapy , Retinal Perforations/therapy , Silicone Oils/therapeutic use , Aged , Aged, 80 and over , Epiretinal Membrane/surgery , Female , Humans , Male , Middle Aged , Pressure , Prospective Studies , Retinal Detachment/etiology , Retinal Perforations/complications , Visual Acuity , Vitrectomy/methodsABSTRACT
OBJECTIVE: To compare the safety and efficacy of different doses of intravitreal triamcinolone (ivTA) in treating clinically significant diabetic macular oedema (CSMO). METHODS: 63 eyes of 63 patients with CSMO and central foveal thickness (CFT) of > or =250 microm on optical coherence tomography were randomised to receive 4 mg (n = 23), 6 mg (n = 20) or 8 mg (n = 20) ivTA. Patients were followed up for 6 months, and changes in best-corrected visual acuity (BCVA), optical coherence tomography CFT, standardised change in macular thickness (SCMT), and side effects such as intraocular pressure and cataractogenesis were compared between the three groups. RESULTS: After ivTA injection, improvements of BCVA and CFT occurred in all groups. The mean BCVA improvement at 6 months was significantly higher for the 8 mg group compared with the 4 mg group, with 9.9 and 3.1 improvement in letters on the Early Treatment of Diabetic Retinopathy Study chart, respectively (p = 0.047). The mean SCMT at 6 months for the 4, 6 and 8 mg groups was 28.7%, 42.3% and 60.5%, respectively (p = 0.06). The proportion of eyes with SCMT > or =75% at 6 months was higher in the 8 mg group, but the difference failed to reach significance (p = 0.06). Ocular hypertensive responses (>21 mm Hg) occurred in 39%, 30% and 55% of eyes in the 4, 6, and 8 mg groups, respectively (p = 0.27). CONCLUSIONS: Higher doses of ivTA may prolong the duration of visual benefit in diabetic CSMO and seemed to result in more sustained reduction in macular oedema. Further studies are warranted to investigate the optimum dose of ivTA in treating diabetic CSMO.
Subject(s)
Anti-Inflammatory Agents/administration & dosage , Diabetic Retinopathy/drug therapy , Glucocorticoids/administration & dosage , Macular Edema/drug therapy , Triamcinolone Acetonide/administration & dosage , Aged , Anti-Inflammatory Agents/adverse effects , Anti-Inflammatory Agents/therapeutic use , Diabetic Retinopathy/pathology , Diabetic Retinopathy/physiopathology , Dose-Response Relationship, Drug , Female , Fovea Centralis/pathology , Glucocorticoids/adverse effects , Glucocorticoids/therapeutic use , Humans , Injections , Macular Edema/pathology , Macular Edema/physiopathology , Male , Middle Aged , Ocular Hypertension/chemically induced , Prospective Studies , Triamcinolone Acetonide/adverse effects , Triamcinolone Acetonide/therapeutic use , Visual Acuity/drug effects , Vitreous BodyABSTRACT
PURPOSE: A prospective observational case series to assess the prevalence of appositional angle closure in darkness among iridotomized Chinese eyes after acute primary angle closure (APAC) with the use of both clinical methods and ultrasound biomicroscopy. METHODS: Sixteen Chinese patients who had history of APAC and subsequent successful treatment with laser peripheral iridotomy were examined. Fourteen additional control subjects were studied. Gonioscopy and ultrasound biomicroscopic examination were performed in the dark. Gonioscopic appearance of the angle was assessed, and quantitative measurements of the angle from the ultrasound biomicroscopic images were taken. RESULTS: Of the APAC eyes 55.6% had appositionally closed angle clinically and in 38.9% only Schwalbe's line was visible on gonioscopy. Ultrasound biomicroscopy confirmed structurally different anterior segments between eyes with APAC and the control eyes. In particular, the trabecular-ciliary-process distances were markedly different between the two groups. CONCLUSION: This study documented a high prevalence of appositional closure in iridotomized eyes after APAC in Chinese patients. The anteriorly positioned ciliary body, as documented in these cases by ultrasound biomicroscopy, is the likely mechanism of the angle crowding in this patient population.