Advances in targeted retinal photocoagulation in the treatment of diabetic retinopathy

AIM

Targeted retinal photocoagulation (TRP) is an emerging laser technology for retinal targeted therapy. TRP can specifically act on unperfused retinal capillaries and retinal intermediate ischemic areas, reduce damage to tissue perfusion areas and panretinal photocoagulation (PRP) complications or adverse events. In this regard, this review discusses the treatment options, efficacy, and latest progress of TRP for diabetic retinopathy (DR) based on randomized controlled trial (RCT), meta-analysis, case review, and other existing studies.

METHODS

In-depth research was conducted on articles about the proposal and development of TRP, its simple application in DR, and combined therapy. In order to review the new progress, application methods, effects, and prospects of TRP in the treatment of DR, the articles related to TRP in the databases of PubMed and Web Of Science since this century were comprehensively analyzed.

RESULTS

TRP is effective in treating DR and may become a substitute for PRP in the future. In addition, the treatment regimen of TRP combined with intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) drugs can also be used as a new therapeutic approach to expand the treatment regimen for the treatment of DR, and this combination therapy also has effects on other retinal vascular diseases.

CONCLUSIONS

With the advancement of technology, TRP has been continuously applied in clinical practice, and its potential benefits have opened up broad prospects for the treatment of DR. The combination therapy of TRP and anti-VEGF is expected to become a new option for patients with DR an retinal diseases.

[Intraoperative optical coherence tomography in vitreoretinal surgery]

This article reviews literature on the use of intraoperative optical coherence tomography (iOCT) in vitreoretinal surgery, describes the historical aspects of the development of this technology from portable devices to optical coherence tomographs integrated into the surgical microscope, considers the advantages, limitations and disadvantages of this technology, which are now becoming obvious due to the accumulated experience. The review also explores the prospects for the development of iOCT and possible ways to solve its problems. In addition, the review presents and systematizes clinical findings that can be revealed with iOCT in such diseases as rhegmatogenous retinal detachment, complications of proliferative diabetic retinopathy, macular pathology, etc.

Systematic review of the efficacy and safety of stage I or II IOL implantation in patients with diabetic retinopathy

BACKGROUND

Intraocular lens (IOL) implantation is required after vitrectomy combined with cataract surgery in diabetic retinopathy patients. However, the question of whether an IOL should be implanted in stage I after vitrectomy or stage II during silicone oil filling has been controversial, and there has been no systematic review of this clinical issue.

METHODS

WanFang, SinoMed CNKI, VIP, PubMed, Embase, and Cochrane Library databases were systematically searched for relevant studies. The deadline was May 8, 2021. All studies of stage I or II IOL implantation in patients with diabetes who underwent vitrectomy were included. Revman 5.3 software was used for the meta-analysis.

RESULTS

Four studies, involving 253 eyes, were included. This study analyzed the literature with a common outcome index by meta-analysis and systematically evaluated the literature without a common outcome index. Four studies compared the efficacy and safety of the 2 sequential surgical methods in patients with diabetic retinopathy. The results of the meta-analysis showed that there was no significant difference in the efficacy and safety of stage II IOL implantation when compared with stage I IOL implantation (P > .05). One study showed that stage II cataract surgery with oil extraction resulted in better postoperative visual acuity and fewer complications than stage I cataract surgery with vitrectomy. One study showed that stage II IOL implantation during oil extraction had better postoperative visual acuity than stage I IOL implantation during vitrectomy without increasing surgical complications.

CONCLUSION

Vitrectomy combined with stage II IOL implantation is safer and more effective than stage I in patients with diabetic retinopathy; however, more clinical studies are needed to verify this.

Ocular findings, surgery details and outcomes in proliferative diabetic retinopathy patients with chronic kidney disease

Purpose

We investigated the influence of impaired renal function on fundus characteristics, pars-plana vitrectomy (PPV) details, and outcomes in patients with proliferative diabetic retinopathy (PDR).

Design

A retrospective cohort study

Methods

We investigated a consecutive series of PDR patients who underwent PPV. The diabetic complications, previous photocoagulation, intravitreal injections before PPV, ocular findings during PPV, surgical details, short-term visual outcome and post-PPV complications were recorded and compared between patients with and without impaired renal function.

Results

149 patients had normal renal function (67.7%), and 71 (32.3%) patients had impaired renal function; 85.4% of patients were identified with chronic kidney disease (CKD) during the preoperative assessment. Impaired renal function was related to hypertension (3.40[1.58–7.29], p = 0.002), incomplete pan-retinal photocoagulation (PRP) (3.18[1.50–6.72], p = 0.002), severe fibrovascular membrane (8.19[3.43–19.54], p<0.001), and extensive retinal vascular closure (3.40[1.54–7.52], p = 0.002). There was a more frequent occurrence of severe intraoperative bleeding (56.3%, 32.2%, p = 0.001) and a higher percentage of intraocular subretinal fluid drainage (45.1%, 22.1%, p = 0.008) in patients with impaired renal function. The percentage of patients whose visual acuity (VA) increased was similar between the two groups (42.3%, 54.4%, p = 0.34).

Conclusions

In PDR patients, screening for CKD was required before PPV. PDR patients with impaired renal function tended to have more severe ischemic retinal conditions. Comparable PPV outcomes could be obtained in patients with and without impaired renal damage.

Effect of pan-retinal laser photocoagulation on intravitreal vascular endothelial growth factor concentration in proliferative diabetic retinopathy

Objective: This study aimed to determine the intravitreal concentration of VEGF in eyes with PDR and to evaluate the effects of previous PRP on its level.

Methods: It was a cross-sectional study performed at the Clinical Centre University. It included 90 eyes surgically treated with PPV, divided into three groups, group A - patients with PDR with previous PRP, group B - patients with PDR without previous PRP, and group C - PPV performed due to the indication unrelated to diabetes. A vitreous sample was obtained during PPV, and the VEGF concentration was determined using an Enzyme-linked immunosorbent assay test (ELISA). Shapiro-Wilk, nonparametric tests Kruskal-Wallis, Mann-Whithney U test, ANOVA and Spearman’s correlation test were used.

Results: The highest vitreous VEGF concentration was in group B - 972.96 (743.33-1149.13) and was higher than in group A - 69.22 (37.33-225.15) and in group C - 19.93 (1.15-32.17) (p<0.001). There was a positive correlation between VEGF vitreous concentration and glucose level in group A patients (Rho=0.410; p=0.027).

Conclusion: As a treatment before PPV surgery, PRP showed to be effective in the reduction of VEGF levels, which also highlighted a decrease in complications during and postoperatively.

Abbreviations: DRS = Diabetic Retinopathy Study, PDR = proliferative diabetic retinopathy, VEGF = vascular endothelial growth factor, PRP = pan-retinal photocoagulation, PPV = pars plana vitrectomy, HbA1c = glycosylated hemoglobin, ETDRS = Early treatment diabetic retinopathy study, ESR = erythrocyte sedimentation rate, BCVA = best corrected visual acuity, OCT = optical coherent tomography, ILM = internal limiting membrane, PHACO = phacoemulsification, IOL = intraocular lens, ELISA = Enzyme-linked immunosorbent assay test, AUC = area under the curve, DME = diabetic macular oedema, TDR = tractional retinal detachment, VMT = vitreomacular traction

Transition from Laser to Intravitreal Injections for Diabetic Retinopathy: Hospital Utilization and Costs from an Extended Healthcare Perspective

PURPOSE

To describe the trends in hospital utilization and economic outcomes associated with the transition from laser to intravitreal injection (IVI) therapy for diabetic retinopathy (DR) at Oslo University Hospital (OUH), which provides the largest retina service in Norway.

METHODS

This descriptive study analyzed hospital administrative data and determined the average utilization and treatment proportions of laser therapy, IVIs and vitrectomy for each patient per year. The Chi-square test was used to compare resource use between treatment groups. From an extended healthcare perspective, the annual cost per patient was calculated using Norwegian tariff data from 2020 and the National Medication Price Registry for patients seen between 2010 and 2018. Bootstrapping was performed to generate 95% confidence intervals for the cost per patient per year.

RESULTS

Among the 1838 (41% female) patients treated for DR between 2005 and 2018, OUH provided on average 1.09 laser treatments per DR patient and 0.54 vitrectomies per DR patient in 2005, whose utilization declined to 0.54 and 0.05 treatments per DR patient, respectively, by 2018. Laser treatments declined from 64% to 10%, while vitrectomies declined from 32% to 1%. In contrast, IVI treatments increased from 4.5% to 89% of the total share, representing an average increase, from 0.08 injections per patient in 2005 to 4.73 injections per patient in 2018. Both the increasing number of DR patients and the shift in the type of treatment increased the economic costs of treating DR from a total of EUR 0.605 million (EUR 2935 per patient) in 2010 to EUR 2.240 million (EUR 3665 per patient) in 2018, with IVIs contributing considerably to these costs.

CONCLUSIONS

Despite the decline in the use of vitrectomies, the transition from laser to IVI therapy for DR increased the healthcare resource utilization and economic costs of its treatment over the observed time. A main cost driver was the need for long-term IVIs, in addition to the drug cost itself. Trade-offs can be achieved through effective alternative IVI delivery or appropriate drug choice that balances patient needs with the economic burden of treating DR.

Vitreous Hemorrhage, Aetiology and Visual Outcome of Vitrectomy in a Black African Population

BACKGROUND

Information on the causes and outcome of treatment of vitreous hemorrhage (VH) in sub-Saharan Africa is limited.

OBJECTIVES

To determine the causes and postoperative vision after vitrectomy for VH.

DESIGN

A retrospective review of records from consecutive eyes, with VH greater than one-month duration, who had vitrectomy and adjunctive treatment in a retina unit in Nigeria.

METHODS

We assessed the change between preoperative and postoperative visual acuity, bio data, cause of VH, duration of follow up, and additional treatment. Data was analyzed using SPSS statistical package 17.0 to determine the significance of the change in visual acuity for each cause of VH. A p value <0.05 was considered statistically significant.

RESULTS

Of the 221 eyes of 219 patients, the common causes of VH were trauma 43 eyes, (19.7%), proliferative diabetic retinopathy, 37 eyes (17.0%) and proliferative sickle cell retinopathy, 30 eyes (13.8%). There was no association between cause and the presenting preoperative visual acuity. There was a statistically significant association between cause of VH and postoperative visual outcome. Postoperative visual improvement was significant for branch retinal vein occlusion, central retinal vein occlusion, proliferative diabetic retinopathy with VH only, proliferative sickle cell retinopathy, and trauma with VH only, p value = 0.000, 0.002, 0.001, 0.039, and 0.000 respectively. Postoperative visual change was not significant in age-related macular degeneration and polypoidal choroidal vasculopathy (p value = 0.155, 0.428 respectively).

CONCLUSION

Significant improvements in visual acuity can be achieved with active treatment of VH in the majority of cases in Nigeria. This information is useful for discussions on prognosis and agrees with previous studies.

Spontaneous resolution of subretinal fluid postvitreoretinal surgery for tractional retinal detachment in proliferative diabetic retinopathy

A man in his 60s with proliferative diabetic retinopathy presented with vision loss in both eyes in the past 1 month. On presentation, the best corrected visual acuity was 20/60 and 20/125 for the right and left eyes, respectively. On examination, he had total tractional retinal detachment (TRD) in the left eye and macula threatening TRD in the right eye. In both eyes, the patient had pars plana vitrectomy, membrane peeling, endolaser and silicone oil injection. Though the left eye's postoperative recovery was uneventful, the subretinal fluid (SRF) in the right eye macula persisted. There was no open retinal break noted in the postoperative period, and no surgical intervention was done for the persistent SRF. The fluid was eventually absorbed over 4 months, with the recovery of vision to 20/40.

Study on the effects of ranibizumab as a pretreatment for vitrectomy in proliferative diabetic retinopathy: a retrospective cohort study

OBJECTIVE

The effects of intravitreal ranibizumab (IVR) as a pretreatment for vitrectomy in proliferative diabetic retinopathy (PDR) need further study. The aim of this study is to further analyze this topic.

PATIENTS AND METHODS

The study group (n=26) was treated with IVR, while the control group (n=28) was not. The best corrected visual acuity (BCVA) at different time points within each group was compared. Operation time, intraoperative bleeding, silicone oil usage, iatrogenic retinal rupture and complications were compared between the groups.

RESULTS

BCVA at the 1st month after vitrectomy was significantly improved in the study group (t=2.081, p=0.047) but not in the control group (I=0.164, p=0.871). At the 1st month after vitrectomy, the BCVA of the study group was significantly higher than that of the control group (t=2.1467, p=0.0365). At the 6th month after vitrectomy, the BCVA of the study group was significantly higher than that of the control group (t=2.0424, p=0.0462). The operation time in the study group was significantly shorter than that in the control group (W=2.212, p<0.05). The rates of mild and severe intraoperative bleeding in the study group were significantly lower than those in the control group (p<0.05, respectively). There was no significant difference in complications between the two groups (p>0.05).

CONCLUSIONS

IVR before vitrectomy in patients with PDR can significantly improve BCVA in the early stage, improve BCVA at the 6th month after the operation, reduce the operation time and reduce intraoperative bleeding.

Intravitreal recombinant tPA before vitrectomy for diabetic tractional retinal detachment: A randomized controlled trial

PURPOSE

To investigate the effect of intravitreal recombinant tissue plasminogen activator (rt-PA) injection before vitrectomy on surgical facility and outcome in diabetic tractional retinal detachments (TRD).

METHODS

Prospective, randomized, interventional clinical trial. A total of 38 eyes with diabetic TRD were candidates for vitrectomy. Patients were randomized 1:1 to receive intravitreal rt-PA, five to seven days before vitrectomy or no injection. Intraoperative surgical facility and anatomic success at month 3 after surgery were assessed.

RESULTS

Mean patient age was 54.2 ± 9.4 years. There was no statistically significant difference between rt-PA and no injection groups with regard to anatomic success (89% versus 95%, respectively, P = 0.547) and best corrected visual acuity at 3 months (2.0 versus 2.1 logMAR, respectively, P = 0.840). However, surgical facility score was statistically significantly lower in rt-PA injection group compared to no injection group (4.1 ± 1.7, 5.8 ± 2.0, respectively, P = 0.007).

CONCLUSIONS

Vitrectomy for TRD was easier after preoperative rt-PA injection, without affecting the anatomic and visual outcomes.

Outcome of phacoemulsification without anti-vascular endothelial growth factor in patients with treatment naïve diabetic retinopathy

INTRODUCTION

This retrospective, non-randomized, observational study was conducted at ASG Eye Hospital, Kathmandu to evaluate the outcome of phacoemulsification without anti-Vascular Endothelial Growth Factor (VEGF) in patients with treatment naïve diabetic retinopathy.

MATERIALS AND METHODS

Records of all patients who underwent phacoemulsification without Bevacizumab in treatment of naïve patients with any grade of non-proliferative Diabetic Retinopathy (NPDR) were seen. Pre-operative and post-operative visual acuity along with central macular thickness (CMT) was compared.

RESULTS

The study comprised 32 eyes of 20 patients with treatment naïve non-proliferative Diabetic Retinopathy who underwent phacoemulsification. Twelve were men and eight were women with an average age of 69.2 years (range 55 years to 83 years). The average preoperative central macular thickness as measured on optical coherence tomography was 254.63± 20.25 microns and 1-month postoperative central macular thickness was 254.72± 19.96 microns; the study did not find any significant difference (p-value 0.918). The average difference in the central macular thickness between the 1-month postoperative and preoperative values was 0.09 microns.

CONCLUSION

Uneventful phacoemulsification in eyes with treatment naïve diabetic retinopathy does not cause an increase in central macular thickness after surgery and thus anti-Vascular Endothelial Growth Factor as an adjunct is not mandatory.

[Analysis of factors affecting revitrectomy in patients with proliferative diabetic retinopathy]

Objective: To identify prognostic factors for revitrectomy in patients who underwent pars plana vitrectomy (PPV) for complications with proliferative diabetic retinopathy (PDR). Methods: This study was a retrospective case-control study. Clinical data of PDR patients (290 eyes) at Peking University People's Hospital from December 2019 to December 2020 were retrospectively collected.According to the number of operations, patients were divided into two groups: single PPV group (227 eyes) and revitrectomy PPV group (63 eyes). Follow-up will be conducted up to 6 months postoperatively. The BCVA was compared before and after PPV between the two groups, and postoperative complications of revitrectomy PPV group were analyzed. Quantitative data are presented as medians [M (Q₁, Q₃)]. Results: The age of single PPV group patients was 55.0 (47.0, 63.0), and the age of revitrectomy PPV group patients was 49.0 (38.0, 57.0). This difference was statistically significant (P=0.027). The LogMAR visual acuity of two groups were 1.7 (1.0, 2.4) and 2.1 (1.4, 2.4) (P=0.026) preoperative; the visual acuity of single PPV group was 0.75 (0.43, 1.00) (P<0.001), and revitrectomy PPV group was 0.95 (0.60, 1.65) (P<0.001) at 6 months postoperative. The visual acuity improvement of single PPV group was better than revitrectomy PPV group (P=0.021). Age (P=0.043, OR=0.97, 95%CI: 0.95-1.00), preoperative BCVA (P=0.024, OR=1.82, 95%CI: 1.08-3.05), tractional retinal detachment (TRD) (P=0.033, OR=2.16, 95%CI:1.06-4.37), silicone oil tamponade (P=0.028, OR=0.48, 95%CI: 0.25-0.92) were prognostic factors of revitrectomy. Conclusion: Young age, low preoperative BCVA, TRD, and silicon oil tamponade were the potential prognostic factors of revitrectomy for PDR patients.

Epiretinal Membrane in Patients with Diabetic Macular Edema

PURPOSE

To compare anatomical and functional outcomes of pars plana vitrectomy (PPV) with epiretinal membrane (ERM) peeling in diabetes retinopathy (DR) patients with and without diabetic macular edema (DME).

METHODS

A retrospective interventional case series of consecutive patients who underwent PPV with ERM peeling. Patients were divided into two groups: With and without preoperative DME. Visual acuity (VA) and optical coherence tomography (OCT) parameters were evaluated before surgery and during 12 months follow-up.

RESULTS

A total of 354 patients underwent PPV with ERM peeling, of which 51 met the inclusion criteria. Twenty-three were diagnosed with DME and were younger (66.3±9.6 vs 73.1±8.2years, p=0.001), had longer diabetes mellitus (DM) duration (18.9±7.1 vs 14.3±10.9 years, p=0.04) and higher HbA1C% (7.6±1.4 vs. 7.1±1.3, p=0.04). VA improved from 20/105 to 20/60 Snellen (p=0.004) and central macular thickness (CMT) decreased from 469.3±64.9μm to 331.1±92.2μm (p<0.001) in the DME group and from 20/87 to 20/44 Snellen (p<0.001) and from 463.1±53.5μm to 341.3±49.5 μm (p=0.01) in the non DME group. Yearly intravitreal injections rate decreased from 5.9±2.5 to 2.9±3.0 (p<0.001) injections in the DME group.

CONCLUSIONS

DME patients with ERM, experience significant improvement in VA, macular thickness and yearly intravitreal injections after PPV with ERM peeling. DME patients are younger, with longer duration of DM and higher HbA1C% levels at presentation in comparison to diabetic ERM patients without DME.

Neovascular glaucoma following Nd:YAG laser capsulotomy: a rare complication in a postvitrectomised patient with diabetes

To describe a case of acute-onset neovascular glaucoma (NVG) after a neodymium:yttrium-aluminium-garnet (Nd:YAG) capsulotomy in a diabetic vitrectomized eye of a patient with severe systemic and ocular comorbidities. A man in his 50s underwent a Nd:YAG capsulotomy for visually significant posterior capsular opacification with a previous history of vitrectomy with silicone oil in situ for diabetic retinopathy. He had systemic and ocular comorbidities implicating an advanced ischaemic status, both systemically and locally. Five days post Nd:YAG capsulotomy, extensive neovascularisation of the iris and angles was noted. Despite maximum antiglaucoma medication, an evisceration ensued due to intractable NVG. This case report highlights the importance of irreversible complications after a seemingly simple capsulotomy in eyes with advanced ocular conditions and systemic comorbidities necessitating extreme caution.

Progression to Vision-Threatening Retinopathy Complications Following Panretinal Laser for Proliferative Diabetic Retinopathy

BACKGROUND AND OBJECTIVE

To report the time in which patients with panretinal photocoagulation (PDR) progress to vision-threatening retinopathy (VTR) complications after receiving PRP, and risk factors in routine clinical practice.

PATIENTS AND METHODS

Records of patients with complete PRP for PDR were retrospectively reviewed for up to 3.5 years after PRP. Two hundred twenty eyes were selected.

RESULTS

Time from PRP to VTR was 1.25 ± 0.82 years. Age, Black race, neovascularization of the disc on examination, diabetic foot disease (DFD), and high-risk PDR characteristics on fluorescein angiography were identified as significant risk factors. Half of patients with DFD on examination developed a VTR within 1.5 years after PRP (P < .001).

CONCLUSION

In clinical practice, providers may consider DFD and Black race as predictors of time to VTR event within 4 years after PRP in patients with PDR. [Ophthalmic Surg Lasers Imaging Retina. 2022;53(4):186-193.].

The relationship between renal function and surgical outcomes of patients with proliferative diabetic retinopathy

OBJECTIVES

The relationship between renal function and diabetic retinopathy has been controversial. This study is to investigate the influence of renal function on the complex and surgical outcomes of proliferative diabetic retinopathy (PDR).

METHODS

This was a post hoc analysis of the CONCEPT clinical trial. A total of 45 eyes with PDR underwent vitrectomy were included. Based on the estimated glomerular filtration rate (eGFR), they were divided into abnormal renal function group (ARF group) and normal renal function group (NRG group). Baseline PDR complex, intraoperative outcomes (Intraoperative bleeding, frequency of endodiathermy, surgical time, iatrogenic hole, and tamponade) and postoperative outcomes (logMAR best-corrected visual acuity, vitreous re-hemorrhage, and macular edema, follow up at postoperative 1 month and 3 months) were estimated. Vitreous, aqueous humor and serum were collected at the vitrectomy day and Vascular endothelia growth factor-A levels were quantified for all included patients using liquid chip method.

RESULTS

There was no significant difference in baseline PDR complex, intraoperative and postoperative outcomes between ARF group and NRG group (all P > 0.05). At the vitrectomy day, there was also no difference of Vascular endothelia growth factor-A levels in vitreous, aqueous humor and serum between the two groups (all P > 0.05).

CONCLUSION

Our results showed that the renal function seems not parallel to the severity of PDR, neither to the surgical outcomes. This might be interpreted by the similar Vascular endothelia growth factor-A levels in vitreous, aqueous humor and serum between the two groups.

Pain Perception of Patients Undergoing Laser Panretinal Photocoagulation: Comparison of Single-Spot Versus Multispot Techniques

BACKGROUND AND OBJECTIVE

To compare pain intensity with single-spot versus multispot technique in laser panretinal photocoagulation, using a 532-nm, solid-state laser system.

MATERIALS AND METHODS

This was a prospective, interventional, randomized, single-masked comparison trial. Patients received two types of intervention: conventional single-spot technique, with an exposure time of 150 ms, and multispot technique, done with an exposure time of 20 ms, Both techniques used power sufficient to produce visible gray-white burns, and spot size of 20 μm. Participants received both treatments in the same eye, each one in one hemiretina, and were randomized to receive first single- or multispot technique and to the initial site of treatment. We assessed pain intensity using a numerical pain scale immediately after completion of each treatment.

RESULTS

A significantly lower pain scale was observed with the multispot when compared with the single-spot technique (coefficient [Coef]: -1.61; 95% CI, -2.49 to -0.74; P < .001), which was not affected by treatment order, the hemiretina treated, or treatment duration (P > .05). Among demographic characteristics, multiracial patients had a pain scale 1.25 greater than that of White patients (Coef: 1.25; 95% CI, 0.47 to 2.04; P = .002), but there is no effect of age or sex on the pain scale (P > .05). Regarding treatment duration, a shorter procedure was also observed in the multispot technique (Coef: -1.13; 95% CI, -1.43 to -0.82; P < .001), and it was not affected by order of treatment (P = .098), hemiretina (P = .327), pain (P = .141), or demographic data, such as age, sex, and race (P > .05).

CONCLUSION

The use of the multispot technique, with a short pulse duration (20 ms), is significantly less painful and less time-consuming for patients with proliferative retinopathy compared with the conventional single-spot technique using an exposure time of 150 ms. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:40-45.].

A comparison between the therapeutic effects of Conbercept combined with panretinal photocoagulation and panretinal photocoagulation monotherapy for high-risk proliferative diabetic retinopathy

OBJECTIVE

To compare the therapeutic effects of the administration of intravitreal Conbercept (IVC) plus panretinal photocoagulation (PRP) to that of PRP monotherapy in patients with high-risk proliferative diabetic retinopathy (PDR).

METHODS

In this retrospective consecutive case series, we analyzed the data on high-risk PDR patients followed up for 12 months. Patients were divided into two groups: the IVC+PRP group and the PRP monotherapy group. Patients in the IVC+PRP group were initially administered 3 IVC injections and PRP, while patients in the PRP monotherapy group received PRP only. Depending on the grouping criteria, patients in both groups were administered either IVC+PRP or PRP only if the neovascularization (NV) did not regress. From the initiation to month 12 of treatment, we recorded and compared the data on the NV regression rate, improvement in best-corrected visual acuity (BCVA), laser spots, changes in central macular thickness (CMT), complications, and the need for vitrectomy for all patients.

RESULTS

In this study, 79 eyes of 58 patients in the IVC+PRP group and 86 eyes of 60 patients in the PRP monotherapy group were included. During the follow-up of 12 months, the number of eyes with complete regression, partial regression, and no regression or increase in NV were 56 (70.88%), 23 (29.12%), and 0 (0%) in the IVC+PRP group and 13 (15.12%), 50 (58.14%), and 23 (26.74%) in the PRP group (p < 0.001). The BCVA was significantly higher and CMT was lower in the patients of the IVC+PRP group than in the PRP monotherapy group at 3, 6, and 12 months of follow-up (p < 0.05). The mean number of laser spots was lower in the patients of the IVC+PRP group than in the PRP group (1,453 ± 87 spots vs. 2,267 ± 94 spots, p < 0.05). A significantly lower percentage of patients in the IVC+PRP group underwent vitrectomy than that in the PRP group (7 (8.86%) vs. 27 (31.40%), p < 0.001).

CONCLUSION

High-risk PDR patients treated with IVC + PRP showed a higher rate of NV regression, more effective improvement in the BCVA, and lower vitrectomy rate compared to those who were administered PRP monotherapy.

Intravitreal Bevacizumab Alone Versus Intravitreal Bevacizumab In Combination With Focal Macular Photocoagulation In Diabetic Macular Oedema

BACKGROUND

To compare the mean best corrected visual acuity (BCVA) between intravitreal bevacizumab (IVB) and combination treatment bevacizumab and Focal Macular Photocoagulation (FMP) for diabetic macular oedema (DME).

METHODS

It is a randomized control trial conducted at Department of ophthalmology at Institute of Ophthalmology, Liaquat University of medical and health sciences, Jamshoro from 1st November 2019 to 31st October 2020, in which 260 Patients between the ages of 40 to 75 years, with DME were included. While patients with macular oedema secondary to other causes than diabetic retinopathy, presence of vitreomacular traction, aphakic patients, history of glaucoma or who had received pan-retinal photocoagulation, IVB, triamcinolone within 12 months, patients with history of stroke or cardiac disease, patients with media opacities such as corneal opacities were also excluded from the study. Two hundred sixty (260) patients were divided in two groups. Group A has 130 patients and they were treated with IVB alone. Group B also included 130, and they were treated with combination of IVB+FMP. The patients were followed-up monthly for 3 months and BCVA was checked at the end of 3 months.

RESULTS

Patients in group B showed superior visual outcome, when they were treated with IVB+FMC as compared to patients in group A who received IVB alone.

CONCLUSIONS

Combination treatment OF IVB+FMP is an effective treatment option for diabetic macular oedema as compared to IVB alone with better mean visual outcome.

Recovery of visual field defects following vitrectomy for proliferative diabetic retinopathy: A case report

RATIONALE

Proliferative diabetic retinopathy (PDR) may lead to severe visual impairment, and visual field (VF) loss in such patients has been reported. Vitrectomy is performed in PDR cases complicated with either vitreous hemorrhage or tractional retinal detachment to restore their visual acuity. However, its effect on VF defects is limited in data. Herein, we report the recovery of VF defects following vitrectomy in a patient with PDR.

PATIENT CONCERNS

A 25-year-old female with bilateral PDR and vitreous hemorrhage received 2 monthly intravitreal injections of aflibercept in both eyes. Six months after her last injection, she presented with fibrovascular membrane formation in both eyes and VF defects of -9.02 dB and -20.05 dB in the right and left eye, respectively.

DIAGNOSES

Proliferative diabetic retinopathy in both eyes.

INTERVENTIONS

The patient underwent vitrectomy for her left eye.

OUTCOMES

Although her visual acuity did not improve as expected, results from the Humphrey visual field analyzer showed notably improvement of her left eye (-9.05 dB) after the surgery.

LESSONS

Vitrectomy potentially allows recovery of VF defects in patients with PDR.

Altered oxylipin levels in human vitreous indicate imbalance in pro-/anti-inflammatory homeostasis in proliferative diabetic retinopathy

Proliferative diabetic retinopathy (PDR) is an advanced stage of diabetic retinopathy (DR), characterized by retinal neovascularization. It is a progressive fundus disease and a severe complication of diabetes that causes vision impairment. Hyperglycemia-induced persistent low-grade inflammation is a crucial factor underlying the pathogenesis of DR-associated damage and contributing to the progression of PDR. Highly enriched polyunsaturated fatty acids (PUFAs) in the retina are precursors to oxidized metabolites, namely, oxylipins, which exert pro-inflammatory or anti-inflammatory (resolving) effects under different pathological conditions and have been implicated in diabetes. To evaluate differences in oxylipin levels in the vitreous obtained from PDR and non-diabetic subjects, we performed a targeted assessment of oxylipins. A total of 41 patients with PDR and 22 non-diabetic control subjects were enrolled in this study. Vitreous humor obtained during routinely scheduled vitrectomy underwent a targeted but unbiased screening for oxylipins using mass spectrometry-based lipidomics. We found 21 oxylipins showing statistically significant differences in their levels between PDR and non-diabetic subjects (p < 0.05). Lipoxygenase (LOX)- and cytochrome P450 (CYP)- derived oxylipins were the most affected, while cyclooxygenase (COX) oxylipins were affected to a lesser extent. When categorized by their precursor PUFAs, ±19,20-EpDPE, a CYP product of docosahexaenoic acid (DHA) and 12S-HETE, a LOX product of arachidonic acid (ARA), were increased by the largest magnitude. Moreover, of these 21 oxylipins, 7 were considered as potential biomarkers for discriminating PDR patients from the non-diabetic controls. Our results indicate that altered oxylipin levels in the vitreous implicate an underlying imbalanced inflammation-resolution homeostasis in PDR.

Increasing metabolic variability increases the risk for vitrectomy in proliferative diabetic retinopathy

PURPOSE

Proliferative diabetic retinopathy (PDR) can be treated by retinal photocoagulation, but in some cases, the treatment is initiated too late or is insufficient so that the disease advances to a stage requiring vitrectomy. There is a need to identify risk factors that can predict if patients with PDR will develop complications in need for vitrectomy.

METHODS

Survival analysis with death as competing risk was used to study systemic risk factors for PDR progression to a complication in need for vitrectomy in right eyes of all 1288 diabetic patients from the Aarhus area, Denmark, who had developed proliferative retinopathy in the right eye during the 25 years period from 1 July 1994 until 1 July 2019.

RESULTS

The overall cumulative incidence of reaching a vitrectomy end point in the right eye was 24.1% (n = 311). In 9.3% (n = 120) of the patients where vitrectomy had been performed together with the first photocoagulation, the age of onset of diabetes was significantly higher (p < 0.0001), the diabetes duration longer (p < 0.035) and BMI higher (p < 0.01) than in the patients who had been vitrectomized later than the first photocoagulation. The risk for vitrectomy was significantly increased by high variability of HbA1c before the development of PDR (p < 0.0001), but not by other parameters known to increase the risk for developing PDR.

CONCLUSION

Increasing variability of HbA1c before the development of PDR increases the risk for progression to a complication in need of vitrectomy. The need for vitrectomy is unaffected by other risk factors known to increase the risk for developing PDR.

Potential bias of preoperative intravitreal anti-VEGF injection for complications of proliferative diabetic retinopathy

PURPOSE

Intravitreal anti-VEGF injection (IVI) is administered before vitrectomy to assist management of proliferative diabetic retinopathy (PDR)-related complications. In the clinical setting, retinal surgeons determine the use of preoperative IVI based on individual criteria. In this study, we investigated factors related to the potential bias of retinal surgeons in using IVI prior to vitrectomy for PDR-related complications, and evaluated the real-world outcomes of surgeon-determined preoperative IVI.

METHODS

Medical records of 409 eyes of 409 patients who underwent 25-gauge vitrectomy for PDR complications at seven Japanese centers (22 surgeons) were retrospectively reviewed. Ocular factors, demographic and general clinical factors, surgical procedures, and postoperative complications were compared between IVI group (patients who received preoperative IVI; 87 eyes, 21.3%) and non-IVI group (patients who did not receive preoperative IVI; 322 eyes, 78.7%). In addition, baseline HbA1c in IVI group and non-IVI group was compared between eyes with and without postoperative complications.

RESULTS

At baseline, IVI group was younger (P<0.001), had shorter duration of diabetes treatment (P = 0.045), and higher frequencies of neovascular glaucoma [NVG] (P<0.001) and tractional retinal detachment [TRD] (P<0.001) compared to non-IVI group. Although IVI group had higher frequencies of intraoperative retinal break and tamponade procedure, there were no significant differences in postoperative complications and additional treatments between two groups. Baseline HbA1c levels were also not correlated with postoperative complications of VH, NVG, and RD both in IVI group and non-IVI group. Logistic regression analysis identified age (P<0.001, odds ratio [OR] 0.95), presence of NVG (P<0.001, OR 20.2), and presence of TRD (P = 0.0014, OR 2.44) as preoperative factors in favor of IVI.

CONCLUSIONS

In this multicenter real-world clinical study, younger age and presence of NVG and TRD were identified as potential biases in using IVI before vitrectomy for PDR complications. Eyes that received preoperative IVI had more intraoperative retinal breaks requiring tamponade than eyes not receiving IVI, but postoperative outcome was not different between the two groups.

Changes in entropy on polarized-sensitive optical coherence tomography images after therapeutic subthreshold micropulse laser for diabetic macular edema: A pilot study

Purpose

To investigate the dynamics of the healing process after therapeutic subthreshold micropulse laser (SMPL) for diabetic macular edema (DME) using polarization-sensitive optical coherence tomography (PS-OCT).

Methods

Patients with treatment-native or previously-treated DME were prospectively imaged using PS-OCT at baseline, 1, 2, 3, and 6 months. The following outcomes were evaluated: changes in the entropy value per unit area (pixel²) in the retinal pigment epithelium (RPE) on the B-scan image; changes in the entropy value in each stratified layer (retina, RPE, choroid) based on the ETDRS grid circle overlaid with en face entropy mapping, not only the whole ETDRS grid area but also a sector irradiated by the SMPL; and the relationship between edema reduction and entropy changes.

Results

A total of 11 eyes of 11 consecutive DME patients were enrolled. No visible signs of SMPL treatment were detected on PS-OCT images. The entropy value per unit area (pixel²) in the RPE tended to decrease at 3 and 6 months from baseline (35.8 ± 17.0 vs 26.1 ± 9.8, P = 0.14; vs 28.2 ± 18.3, P = 0.14). Based on the en face entropy mapping, the overall entropy value did not change in each layer in the whole ETDRS grid; however, decrease of entropy in the RPE was observed at 2, 3, and 6 months post-treatment within the SMPL-irradiated sectors (P < 0.01, each). There was a positive correlation between the change rate of retinal thickness and that of entropy in the RPE within the SMPL-irradiated sector at 6 months (r² = 0.19, P = 0.039).

Conclusion

Entropy measured using PS-OCT may be a new parameter that facilitates objective monitoring of SMPL-induced functional changes in the RPE that could not previously be assessed directly. This may contribute to a more promising therapeutic evaluation of DME.

Clinical trial

This clinical study was registered in UMIN-CTR (ID: UMIN000042420).