Pharmacological adjuvants for diabetic vitrectomy surgery

Diabetic vitrectomy is a highly intricate surgical procedure performed during the advanced stages of diabetic retinopathy(DR).It is used to treat conditions such as tractional or combined retinal detachment,vitreous hemorrhage,and subhyaloid hemorrhage,which are all severe manifestations of proliferative DR.The results of the surgery are uncertain and variable.Vitreoretinal surgery has made significant progress since the early stages of vitrectomy.In the past ten years,advancements in intravitreal pharmacotherapy have emerged,offering new possibilities to improve the surgical results for our patients.Within the realm of medical terminology,an"adjunct"refers to a pharmaceutical or substance employed to aid or expedite the primary therapeutic intervention for a particular ailment.Their introduction has broadened the range of therapeutic choices that are accessible prior to,during,and following surgical procedures.This review article will specifically analyze the pharmacological adjuncts used in diabetic vitrectomy surgery,with a focus on their role in facilitating or aiding specific steps of the procedure.The implementation of this system of categorization offers benefits to the surgeon by allowing them to foresee potential difficulties that may occur during the surgical procedure and to choose the appropriate pharmacological agent to effectively tackle these challenges,thus enhancing surgical success rates.

Inverted internal limiting membrane flap technique for very large macular hole

AIMTo assess the anatomical and visual outcome of idiopathic macular holes greater than 1000 µm using the inverted internal limiting membrane flap technique.METHODSThis retrospective case series included 5 eyes of 5 patients with idiopathic macular hole with base diameter greater than 1000 µm who underwent inverted internal limiting membrane flap technique along with standard 23G pars plans vitrectomy with posterior hyaloid detachment and fluid gas exchange with 12%-14% perfluoropropane (C3F8). Preoperative and postoperative visual acuity and spectral domain optical coherence tomography images were evaluated. The main outcome measures were visual outcome and macular hole closure.RESULTSMean age was 63.2±8.4y with all 5 subjects being females. Mean duration of symptoms was 11±14mo with a mean postoperative follow up of 13.2±13mo. The mean base diameter of the macular holes was 1420±84.8 µm (1280-1480 µm). Type 1 closure was achieved in four out of five patients, while one patient had type 2 closure using the inverted internal limiting membrane (ILM) flap technique. Median baseline BCVA was 0.79 logMAR (Snellen’s equivalent 20/120) and median final BCVA 0.6 logMAR (Snellen’s equivalent 20/80) with mean visual improvement of approximately three lines improvement. No complications related to surgical procedure were noted.CONCLUSIONThe inverted internal limiting membrane flap technique may be promising for very large macular holes with high rate of macular closure and good visual outcome.

Predictors of visual outcome in eyes with choroidal neovascularization secondary to age related macular degeneration treated with intravitreal bevacizumab monotherapy

AIM:To evaluate the predictors of visual improvement in eyes with naive choroidal neovascularization secondary to age-related macular degeneration (CNV -AMD) treated with intravitreal bevacizumab (IVB) monotherapy. METHODS:Fifty eyes with naive CNV-AMD with pretreatment best-corrected visual acuity (BCVA) better than 20/200 and treated with IVB monotherapy were evaluated. Several variables including age, sex, pre-treatment BCVA, CNV type and lesion size on fluorescein angiogram as well as SD-OCT parameters including pre-treatment central macular thickness (CMT), inner-segment/outer-segment (IS/OS) junction integrity, and external limiting membrane (ELM) integrity were analyzed to predict visual outcome.RESULTS:On univariate regression, pretreatment ELM damage was associated with less visual improvement after treatment (P =0.0145). However, ELM damage predicted only 10% of the visual outcome. On multivariate regression, pretreatment BCVA, IS/OS junction, and ELM integrity on SD-OCT were the significant predictors for the treatment effect and together predicted 37% of visual improvement. CONCLUSION:Pretreatment BCVA, ELM and IS/OS junction integrity on SD-OCT are of significant value inpredicting the visual improvement in naive wet AMD patients treated with IVB monotherapy.

Temporal pattern of resolution/recurrence of choroidal neovascularization during bevacizumab therapy for wet age-related macular degeneration

AIMTo characterize temporal pattern of resolution and recurrence of naive choroidal neovascularization (CNV) secondary to wet age-related macular degeneration (AMD) treated with intravitreal bevacizumab on as needed regimen, and to analyze baseline risk factors for CNV resolution or recurrence.

Retinal circulation and its role in macular disorders in patients without systemic disease

AIM: To determine whether retinal circulatory changes play a role in the pathogenesis of macular disorders in patients who are otherwise healthy. METHODS: Patients with macular disorders that required angiographic imaging were included in this prospective case series. After a complete ocular exam,fluorescein angiography was performed using a standardized technique on the HRA-II(Heidelberg Engineering, Heidelberg, Germany) with special focus on the posterior pole. Only patients with good quality images were included in the analysis. Circulatory parameters recorded included the arm-choroid time,choroid-retinal artery, and finally the retinal artery-vein time. Zonal asymmetry(between the upper and lower zones divided by a line passing through the centre of the fovea) in transit times, if any was also noted. Appropriate statistical analysis was done. Circulation times were compared with age matched historical controls. Changes in retinal dye transit times relative to historical age matched controls, if any, were noted and compared between various disorders.RESULTS: A total of 156 eyes of 156 patients(120 males)were included in the study. Mean age: 49.14 ±14.93 y.Macular disorders studied were age related degeneration,polypoidal vasculopathy, central serous chorioretinopathy(CSCR) and parafoveal telangiectasia. Delayed circulation time was noted in CSCR patients only.CONCLUSION: CSCR patients appear to have delayed arterial filling, retinal circulatory disturbances do not seem to contribute to the pathogenesis of other macular disorders.

Comparison of choroidal vessel thickness in children and adult eyes by enhanced-depth imaging optical coherence tomography imaging

AIM： To evaluate choroidal thickness, medium choroidal vessel thickness（MCVT） and large choroidal vessel thickness（LCVT） in normal children and adult subjects.METHODS： Manual measurements of subfoveal choroidal thickness（SFCT）, MCVT and LCVT at subfoveal and 750 μm nasal and temporal to fovea locations were completed on enhanced-depth imaging optical coherence tomography（EDI-OCT） scans of normal children and adult subjects.RESULTS： Fifty adult and fifty-seven child subjects were included in the study（including 80 adult and 103 child eyes）. Mean（±SD） SFCT of adult and children eyes in the study was 309.3±95.7 μm and 279.3±50.4 μm respectively. SFCT and subfoveal MCVT in adult eyes were significantly more than children（P=0.01 and P≤0.0001 respectively）.CONCLUSION： There is choroidal thickening with associated thickening of medium choroidal vessels in adults, suggesting that there is alteration in choroidal vasculature with ageing.

Inflammatory choroidal neovascularization after tubercular posterior scleritis

A 45-year-old female presented with typical features of posterior scleritis in her left eye with visual acuity of 20/252. After treatment with oral steroids and immunosuppressive drugs, at 2 months follow-up, posterior scleritis resolved and visual acuity improved to 20/50. Five months later she presented with vision loss(20/160) associated with active choroidal neovascular membrane(CNVM) close to scar. Significant choroidal thinning(subfoveal choroidal thickness =137 microns), compared to fellow eye(subfoveal choroidal thickness =247 microns) was noted. Two doses of intravitreal bevacizumab(IVB) were given at 1 month interval. At 9 months follow-up, her visual acuity was maintained at 20/160 with scarred CNVM. In conclusion, IVB is safe and efficacious in treatment of inflammatory CNVM secondary to posterior scleritis. Choroidal changes after posterior scleritis could be contributory factor for formation of CNVM.

External drainage for exudative retinal detachment secondary to central serous chorioretinopathy

Background: To report the outcomes of external drainage of subretinal fluid(SRF) in exudative retinal detachment secondary to central serous chorioretinopathy(CSCR).Methods: Retrospective observational analysis of six eyes with exudative retinal detachment secondary to CSCR who underwent external drainage of SRF between 2004 and 2014 was performed. Collected data included demographics, steroid usage, surgical details, and visual acuity preoperatively and postoperative visual acuity and clinical examination data were collected. Results: Six eyes of six subjects were included with mean age of 45 years(range, 32 to 61 years). All subjects were male. Mean duration of symptoms was 4.6 months(range, 3 to 8 months). The pre-operative bestcorrected visual acuity(BCVA) ranged from perception of light to 20/60. Four eyes were treated with conventional external drainage and two underwent Chandelier-assisted external drainage. Three cases had laser treatment before drainage and one case underwent photodynamic therapy(PDT) after drainage. The BCVA at last follow-up ranged from 20/2,000(counting fingers at 2 feet) to 20/20. No recurrences were noted in any of the cases till the last follow-up. Mean duration of follow-up was 38 months. Conclusions: Our study demonstrates successful management of exudative retinal detachment secondary to CSCR with external SRF drainage without any complications.

Traumatic Vitreous Hemorrhage in Children-Clinical Features and Outcomes

Purpose: To determine the clinical profile, causes, and outcomes of traumatic vitreous hemorrhage(TVH) in children(<18 years of age).Methods:.Retrospective computer assisted chart review..501 eyes of 464 children(103 females; 361 males) who presented with TVH between 2001 and 2012 were included. All children underwent a complete ocular and systemic examination and investigation. The etiology, visual, and anatomic results of pediatric TVH were the outcome measures.Results: Median age: 12.27±4.51 years. 37 patients had bilateral VH; 43.24% of these were firecracker injuries..Commonest complaint was diminished vision(96.45%)..Mean BCVA(logMAR) at presentation was 2.64±1.11 logMAR. Sticks(43.43%).and cricket balls.(13.24%).were the commonest causes..Treatment included medical therapy(topical and / or systemic; 56 eyes), laser photocoagulation(34 eyes), and /or surgery.(387 eyes)..Mean final BCVA was significantly better(1.01±0.58 logMAR;P=0.011,Z test). Mean follow up in the closed and open globe trauma was 47±12.47 and 36.24±9.72 months, respectively.Conclusion:.TVH has significant implications in children.Firecracker injuries are notorious for bilateral VH.

Neurodegeneration in branch retinal vein occlusion

One of the most common forms of visual impairment and reduction in overall visual acuity is branch retinal vein occlu- sion （BRVO）, second only to diabetic retinopathy （Rogers et al., 2010; Sun et al., 2013）. Unlike central retinal vein occlusion （CRVO） which is a similar macular disease, BRVO is extremely more prevalent and generally only affects a smaller portion of the retina （Osborne et al., 2004） due to the nature of the dis- ease.

Subthreshold laser systems:a narrative review of the current status and advancements for retinal diseases

Background and Objective:Subthreshold laser therapy has emerged as a therapeutic alternative to traditional laser photocoagulation for certain ophthalmic diseases including central serous chorioretinopathy(CSCR),diabetic macular edema(DME),macular edema secondary to branch retinal vein occlusion(BRVO),and age-related macular degeneration(AMD).The objective of this paper is to review and discuss the clinical applications of subthreshold laser and the mechanisms of different subthreshold laser techniques including subthreshold micropulse laser(SMPL),selective retina therapy(SRT),subthreshold nanosecond laser(SNL),endpoint management(EpM),and transpupillary thermotherapy(TTT).Methods:A narrative review of English literature and publicly available information published before November 2021 from literature databases and computerized texts.We discuss the currently available subthreshold laser systems and the advancements made to perform different subthreshold laser techniques for various ophthalmic diseases.We highlight various clinical studies and therapeutic techniques that have been conducted to further understand the effectiveness of subthreshold laser in the clinical setting.We conclude the article by covering emerging subthreshold laser systems that are currently being developed for future clinical use.The PubMed database was utilized for peer-reviewed articles and pertinent information on subthreshold systems was cited from publicly available online websites covering specific systems.Key Content and Findings:Various subthreshold laser systems have been developed to treat certain retinal diseases.Several systems are currently in development for future clinical applications.Conclusions:While conventional laser photocoagulation has been effective in treating various retinal diseases,subthreshold laser systems aim to provide a therapeutic effect without visible signs of damage to the underlying tissue.This technology may be particularly effective in treating macular disorders.Further clinical studies are needed to evaluate their role in the management of retinal diseases.

Current systems and recent developments of subthreshold laser systems in glaucoma:a narrative review

Background and Objective:Subthreshold laser technologies and their applications in ophthalmology have greatly expanded in the past few decades.Initially used for retinal diseases such as central serous chorioretinopathy and diabetic macular edema,subthreshold lasers have recently shown efficacy in the treatment of various types of glaucoma.Our primary objectives are to review the clinical applications of subthreshold laser in the context of glaucoma treatment and discuss the mechanisms of different subthreshold laser techniques,including subthreshold selective laser trabeculoplasty(SSLT),micropulse laser trabeculoplasty(MLT),pattern-scanning laser trabeculoplasty(PSLT),titanium laser trabeculoplasty(TLT),and micropulse transscleral cyclophotocoagulation(MP-TSCPC).Methods:This was a narrative review compiled from literature of PubMed and Google Scholar.The review was performed from March 2021 to October 2021 and included publications in English.We also included information from web pages to cover details of relevant laser systems.We discuss the history of subthreshold laser,recent advancements in subthreshold techniques,and commercially available systems that provide subthreshold capabilities for glaucoma.We highlight basic science and clinical studies that deepen the understanding of treatment mechanisms and treatment effectiveness in the clinical setting respectively.We review commonly used parameters for each technique and provide comparisons to conventional treatments.Key Content and Findings:We found five distinct types of subthreshold laser used in the management of glaucoma.Numerous subthreshold laser systems are commercially available and can provide this treatment.Therefore,understanding the differences between subthreshold techniques and laser systems will be critical in utilizing subthreshold laser in the clinical setting.Conclusions:Traditional laser trabeculoplasty(LT)and cyclophotocoagulation(CPC)have shown effectiveness in the treatment of various types of glaucoma but are associated with visible damage to the underlying tissue and adverse effects.Subthreshold laser systems aim to provide the therapeutic effect found in traditional lasers,while minimizing unwanted treatment related effects.Further clinical studies are needed to evaluate the role of subthreshold lasers in the management of glaucoma.