Clinical efficacy and acceptability of panretinal photocoagulation combined with conbercept for patients with proliferative diabetic retinopathy: A protocol for systematic review and meta-analysis

BACKGROUND

Although conbercept has been used for other diseases associated with new vascular formation, the effect of single-dose conbercept in combination with proliferative diabetic retinopathy (PDR) have not been established. We thus conducted this protocol for systematic review and meta-analysis to compare the efficacy and acceptability of panretinal photocoagulation (PRP) associated with intravitreal conbercept injections versus PRP alone in the treatment of patients with PDR.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols reporting guidelines and the recommendations of the Cochrane Collaboration were followed to conduct this study. Reviewers will search the PubMed, Cochrane Library, Web of Science, and EMBASE online databases using the key phrases "panretinal photocoagulation," "conbercept," and "proliferative diabetic retinopathy" for all cohort studies published up to May 2021. The studies on cohort study focusing on PRP + conbercept and PRP alone for PDR patients will be included in our meta-analysis. At least one of the following outcomes should have been measured: PRP completion rate, proportion of eyes with visual gain/loss, central macular thickness, and incidence of complication. Review Manager software (v 5.4; Cochrane Collaboration) is used for the meta-analysis.

RESULTS

It was hypothesized that intravitreal conbercept plus PRP was more effective than PRP alone.

OSF REGISTRATION NUMBER

10.17605/OSF.IO/HCQ2S.

Clinical efficacy of anti-vascular endothelial growth factor versus panretinal photocoagulation for patients with proliferative diabetic retinopathy: A protocol for systematic review and meta-analysis

BACKGROUND

The argument on the optimal treatment for patients with proliferative diabetic retinopathy (PDR) remains to be resolved. Therefore, the primary objective of the present study was to evaluate the clinical efficacy of anti-vascular endothelial growth factor (anti-VEGF) therapy versus panretinal photocoagulation (PRP) for patients with PDR.

METHODS

Two independent investigators followed The Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines and the recommendations of the Cochrane Collaboration to conduct this meta-analysis. The electronic databases of EMBASE, PubMed, Cochrane Library, and Web of Science were searched from the inception to April 2021 using the following key terms: "proliferative diabetic retinopathy," "anti-vascular endothelial growth factor," and "panretinal photocoagulation," for all relevant studies. We identified literature that met the following inclusion criteria: patients with PDR; studies focusing on assessing anti-VEGF therapy and PRP; the following outcome measures must be shown: anatomical outcomes, including complete regression and recurrence of neovascularization, mean change in best corrected vision acuity from baseline to the end of follow-up period. The Cochrane risk of bias tool was used to evaluate the risk of bias of included randomized clinical trials by 2 independent reviewers.

RESULTS

This protocol will provide a reliable theoretical basis for the following research.

TRIAL REGISTRATION NUMBER

10.17605/OSF.IO/UHYDR.

Clinical efficacy of intravitreal aflibercept injection versus vitrectomy with panretinal photocoagulation for patients with proliferative diabetic retinopathy: A protocol for systematic review and meta-analysis

BACKGROUND

In the current literature, it is still controversial whether intravitreal aflibercept injection can provide better vision restoration compared with vitrectomy with panretinal photocoagulation (PRP) for proliferative diabetic retinopathy (PDR) patients. Given that there is no high-quality meta-analysis or review to incorporate existing evidence, the purpose of this study is to systematically review the level I evidence in the literature to ascertain whether intravitreal aflibercept injection can provide better vision restoration compared with vitrectomy with PRP for PDR patients.

METHODS

The systematic literature review is structured to adhere to PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses), which include requirements deemed essential for the transparent reporting of results. A systematic search will be performed in Web of Science, Embase, Scopus, Science Direct, Cochrane Library up to and inclusive of March 19, 2021. The method of data extraction will follow the approach outlined by the Cochrane Handbook for Systematic Reviews of Interventions. The primary outcome is change in best-corrected visual acuity. The secondary outcomes are change in area of neovascularization and change in area of retinal nonperfusion. Where disagreement occurs, this will be resolved through discussion. All outcomes are pooled on random-effect model. A P value of < .05 is considered to be statistically significant.

RESULTS

The results of our review will be reported strictly following the PRISMA criteria.

CONCLUSIONS

The hypothesis of the study was that visual acuity recovery would be faster with vitrectomy because the blood is mechanically cleared during surgery.

REGISTRATION NUMBER

10.17605/OSF.IO/NCAXW.

Diode-side-pumped, intracavity Nd:YLF/KGW/LBO Raman laser at 573 nm for retinal photocoagulation

Wavelengths in the yellow-orange range are of significant interest for retinal photocoagulation and are especially important in the case of diabetic retinopathy, which can cause blindness and affects 3.3% of all working-age adults. This work presents a highly-efficient, compact, and cost-efficient side-pumped, intracavity Raman configuration to achieve this objective. A side-pumped Nd:YLF/KGW/LBO frequency-doubled Raman laser producing 11.7 W of output power at 1147 nm with 21% of slope efficiency and 6 W of output power at 573.5 nm with 12% slope efficiency is demonstrated.

Anti-VEGF Therapy and Retinal Photocoagulation to Prevent Recurrence of Central Retinal Vein Occlusion: Two Case Reports of Young Patients

Case 1: An 18-year-old man. On initial examination, he was diagnosed with central retinal vein occlusion (CRVO) due to optic papillitis. He had no previous systemic and ocular medical history. His best corrected visual acuity was 20/20 for the right eye, but macular edema accompanied by serous retinal detachment was observed about 2 months after the initial examination. Intravitreal anti-VEGF injection was performed, and the symptoms improved. Then, additional photocoagulation was applied to the retinal nonperfusion area, to maintain its normal state. Case 2: A 36-year-old man. He was diagnosed with neovascular glaucoma associated with CRVO in the right eye by his previous physician. Panretinal photocoagulation and intravitreal anti-VEGF injection were performed under maximum-tolerated medical therapy for the right eye. He had diabetes. On initial examination, his visual acuity was 20/100 and his intraocular pressure was 19mmHg. Macular edema and iris neovascularization recurred half a year later, so intravitreal anti-VEGF injection and additional photocoagulation were applied to nonperfusion area. After that, both macular edema and iris neovascularization have settled down. Conclusions: Intravitreal anti-VEGF injection is effective in young patients with CRVO. Also, photocoagulation to nonperfusion area in addition to the continuous treatment with intravitreal anti-VEGF injection seems effective for preventing recurrence.

A systematic review and meta-analysis to compare the efficacy of conbercept with ranibizumab in patients with macular edema secondary to retinal vein occlusion

BACKGROUND

The objective of this review and meta-analysis is to investigate the efficacy of conbercept and ranibizumab, combined with or without laser photocoagulation, in patients with macular edema secondary to retinal vein occlusion (RVO-ME).

METHODS

Several databases have been used to identify relevant publications. After screening, a meta-analysis was conducted to compare conbercept and ranibizumab with the support of RevMan 5.3 (Cochrane Library Software, Oxford, UK).

RESULTS

In this study, 9 randomized controlled trials and 6 retrospective trials were included with a total of 1180 patients. No significant difference was found in best corrected visual acuity (BCVA) or central macular thickness (CMT) in the baseline parameters [BCVA (weighted mean difference (WMD): -0.01; 95% confidence interval CI: -0.03 to 0.01; P = .17), CMT (WMD: 20.14; 95% CI: -26.70 to 66.97; P = .40). No significant differences were found in the improvements of BCVA and adverse events (AEs) between the 2 groups after injection of loading dosage [the 1st month BCVA (WMD: -0.01; 95% CI: -0.04 to 0.02; P = .54),the 3rd month BCVA (WMD: -0.02; 95% CI: --0.05 to 0.01; P = .23), the 6th month BCVA (WMD: -0.02; 95% CI: -0.05 to 0.01; P = .27), AEs (odds ratio: 0.84; 95% CI: 0.38 to 1.84; P = .66)]. However, there were significant differences between conbercept and ranibizumab treatment in terms of CMT [1st month CMT (WMD: -11.70; 95% CI: -19.71 to -3.68; P < .01), 3rd month CMT (WMD: -10.08; 95% CI: -15.62 to -4.53; P < .01), 6th month CMT (WMD: -15.83; 95% CI: -22.88 to -8.78; P < .01)] and the number of injections (WMD, -0.36; 95% CI: -0.68 to -0.04; P = .03).

CONCLUSION

The current pooled evidence suggested that both therapies of intravitreal conbercept and intravitreal ranibizumab with or without laser photocoagulation are effective in vision function in RVO-ME patients, and confirmed that conbercept has advantages over ranibizumab in terms of CMT and the number of injections for treating RVO-ME. In addition, conbercept has the statistically same visual gains and safety as ranibizumab in RVO-ME patients. Longer-term follow-up surveys on the safety and effectiveness of these 2 treatment regimens are required.

Laser photocoagulation therapy for thyroid nodules: long-term outcome and predictors of efficacy

PURPOSE

The aim of the present study was to retrospectively evaluate the efficacy of interstitial laser photocoagulation (ILP) ablation of thyroid nodules during a 6-year follow-up period and to identify possible predictors of the final outcome.

METHODS

Forty-three outpatients (38 women) were assigned to ILP therapy. The study group included euthyroid patients with benign thyroid nodules. Thyroid size, nodule volume and features, and autoimmune test were collected at baseline. Patients underwent US control after the ILP procedure and 1 month, 6 months, 12 months later and then annually.

RESULTS

During the follow-up, two distinct groups of patients emerged: the responders (N = 33) and the non-responder (N = 10) ones to ILP. In the responder group, the nodule volume significantly decreased during the follow-up, but a trend toward a slight increase in nodule volume was recorded up to the end of follow-up. No significant decrease in nodule volume was observed in the non-responder group. Neither baseline clinical nor demographic features were significantly different between responders and non-responders groups. In the whole group of patients, the energy delivered per mL of nodule tissue was significantly correlated with the percent volume decrease at the end of follow-up.

CONCLUSIONS

Interstitial laser photocoagulation is a safe technique able to reduce byabout 50% the volume of benign thyroid nodules in the majority of treated patients. However, due to the great variability of results, an active follow-up is required. The only independent predictor of ILP outcome is the energy delivered per mL of nodule tissue.

Diode laser photocoagulation of sublingual varices in 706 patients on antithrombotic therapy without drug discontinuation

Several conditions such as age, gender, systemic diseases, smoking, consuming vitamin rich foods, denture wearing may play a role in aetiology of sublingual varices. However, few studies investigating these associations. Nevertheless, prevention of potential bleeding of sublingual varices especially in patients in antithrombotic therapy should led clinicians to treat them by diode laser, since it allows a minimally invasive treatment of photocoagulation. We report on a large sample of patients (706) showing single or multiple SVs on antithrombotic therapy, highlighting the possibility to treat lesions without drug discontinuation and without intra- and post -operative complications. KEY WORDS: Antithrombotic therapy, Bleeding, Diode laser photocoagulation, Sublingual varices.

What do Cochrane systematic reviews say about interventions for age-related macular degeneration?

BACKGROUND

Age-related macular degeneration (AMD) is the third largest cause of blindness worldwide, accounting for 8.7% of all cases. A considerable number of preventive or therapeutic interventions have been used for AMD.

OBJECTIVE

This study presents a critical view of the interventions that have been assessed through Cochrane systematic reviews.

DESIGN AND SETTING

Review of systematic reviews, conducted in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP).

METHODS

Review of Cochrane systematic reviews about interventions for AMD.

RESULTS

The 18 systematic reviews included assessed the effects of surgical techniques, laser/photo/radiotherapy, intravitreal injections, systemic drugs and phytotherapy/vitamins/supplements.

CONCLUSION

The Cochrane systematic reviews found evidence that use of bevacizumab, ranibizumab, pegaptanib, laser photocoagulation, photodynamic therapy and multivitamin compounds may present some benefits for treating AMD. There was insufficient evidence for supporting the use of macular translocation, submacular surgery, steroid implantation, radiotherapy, intravitreal aflibercept, interferon alfa, statins or omega-3 fatty acids for treating AMD; or the use of multivitamin antioxidant vitamins or mineral supplementation for preventing AMD. Future randomized controlled trials are imperative to reduce the uncertainty in several clinical questions regarding AMD.

Risk Factors of Neovascular Glaucoma After 25-gauge Vitrectomy for Proliferative Diabetic Retinopathy with Vitreous Hemorrhage: A Retrospective Multicenter Study

Neovascular glaucoma (NVG) is a terminal severe complication in eyes with proliferative diabetic retinopathy (PDR), and PDR eyes with vitreous hemorrhage (VH) which undergo vitrectomy may have higher risk of postoperative NVG. The incidence and the prognostic factor of postoperative NVG after 25-gauge vitrectomy with advanced surgical options remain unclear. We retrospectively reviewed medical records of 268 eyes of 268 consecutive PDR patients with VH who underwent 25-gauge vitrectomy and 12 months follow-up at seven centers. Preoperative ocular factors (visual acuity, tractional retinal detachment, panretinal photocoagulation [PRP]), demographics and clinical factors (sex, age, diabetic duration, HbA1c, hypertension, anticoagulant medication, and kidney function), surgical procedures, and postoperative complications were compared between patients who developed postoperative NVG (9.3%) and those who did not. NVG eyes was significantly younger (P = 0.026), had shorter diabetic duration (P = 0.022), higher HbA1c (P = 0.028), absence of PRP (P = 0.039) and higher frequency of postoperative VH (P = 0.0075) than non-NVG eyes. Logistic regression analysis identified postoperative VH (P = 0.014), shorter diabetic duration (P = 0.029), and no PRP (P = 0.028) as prognostic factors for postoperative NVG. This multicenter study indicates that younger age, uncontrolled diabetes, no PRP, and postoperative VH are risk factors of post-vitrectomy NVG.

PHOTOCOAGULATION VERSUS RANIBIZUMAB FOR PROLIFERATIVE DIABETIC RETINOPATHY: Should Baseline Characteristics Affect Choice of Treatment?

PURPOSE

Among eyes with proliferative diabetic retinopathy, identify whether baseline characteristics impact the benefit of ranibizumab over panretinal photocoagulation (PRP) in DRCR.net Protocol S.

METHODS

Participants had proliferative diabetic retinopathy, visual acuity of 20/320 or better, and no previous PRP. Eyes were randomized to PRP or intravitreous 0.5-mg ranibizumab.

RESULTS

Ranibizumab was superior to PRP for change in visual acuity and development of vision-impairing central-involved diabetic macular edema over 2 years (P < 0.001). Among 25 characteristics, there were none in which participants assigned to PRP had superior outcomes relative to ranibizumab-assigned participants. The relative benefit of ranibizumab over PRP for change in visual acuity seemed greater in participants with higher mean arterial pressure (P = 0.03), without previous focal/grid laser (P = 0.03), with neovascularization of the disk and elsewhere on clinical examination (P = 0.04), and with more advanced proliferative diabetic retinopathy on photographs (P = 0.02). For development of vision-impairing central-involved diabetic macular edema, the relative benefit of ranibizumab over PRP seemed greater among nonwhite participants (P = 0.01) and those with higher mean arterial pressure (P = 0.01).

CONCLUSION

There were no characteristics identified in which outcomes were superior with PRP compared with ranibizumab. These exploratory analyses provide additional support that ranibizumab may be a reasonable alternative to PRP for proliferative diabetic retinopathy over a 2-year period.

Intravitreal Ranibizumab With Panretinal Photocoagulation Followed by Trabeculectomy Versus Visco-Trabeculotomy in Management of Neovascular Glaucoma

PURPOSE

The aim of the current study was to compare visco-trabeculotomy (VT) with standard trabeculectomy with mitomycin C (Trab-MMC) in the treatment of quiescent neovascular glaucoma (NVG).

METHODS

The study was conducted on 51 eyes of 51 patients presenting with NVG and treated at an Ophthalmic Center in Egypt between March 2014 and April 2017. All study eyes were subjected to a standard protocol of intravitreal injection of ranibizumab followed by panretinal photocoagulation. Eyes were then randomized to either VT or Trab-MMC. Study eyes were followed up for at least 18 months. Success was defined as an intraocular pressure of ≤21 mm Hg and without vision-threatening complications. Complications were noted.

RESULTS

The mean ± SD (range, median) age of the study patients was 54.1 ± 6.4 (40-67, 54.5) and 52.4 ± 8.8 (38-66, 53) years in the VT (26 eyes) and Trab-MMC (25 eyes) groups, respectively (P = 0.45). The mean ± SD (range, median) intraocular pressure (IOP) of the study eyes was 45.19 ± 2.97 (39-52, 45.5) and 45.64 ± 3.56 (3-53, 45) mm Hg on maximal medical therapy in the VT and Trab-MMC groups, respectively (P = 0.61). At 18 months' follow-up, the mean ± SD (range, median) IOP of the study eyes was 18.19 ± 2.0 (16-23, 17) and 19.92 ± 2.6 (18-26, 19) mm Hg in the VT and Trab-MMC groups, respectively (P = 0.004). There was no difference in postoperative antiglaucoma medication between the 2 groups (P = 0.62). Complications included hyphema and Descemet split in the VT group and an IOP spike in the Trab-MMC group. Success rates were 84.6% and 80% in the VT and Trab-MMC groups, respectively (P = 0.726).

CONCLUSIONS

Both VT and Trab-MMC groups are effective in reducing the IOP in cases of NVG after control of neovascularization with anti-vascular endothelial growth factor and pan retinal photocoagulation.

PASCAL laser platform produces less pain responses compared to conventional laser system during the panretinal photocoagulation: a randomized clinical trial

Background

Most of patients experience pain during the panretinal photocoagulation(PRP). Laser photocoagulation delivery has advanced with the introduction of pattern-scanning laser systems (PASCAL). Shorter pulse duration and less choroidal penetration believed to reduce pain during the laser treatment.

Objectives

To compare the severity of expressed pain scores in patients with PDR who underwent PRP either with PASCAL laser or conventional laser.

Methods

A total of 28 patients with a diagnosis of PDR who were scheduled for bilateral PRP therapy were enrolled into the prospective study. Both eyes were treated within the same session and while one eye was treated with PASCAL the other was treated with conventional laser randomly. Pulse duration was adjusted to 100-ms in conventional laser and 30 ms in PASCAL. The severity of pain was graded using a verbal scale and a visual analog scale (VAS).

Results

Mean age was 61.36±9.10 years. Mean verbal and VAS scores were 1.32±0.47 and 2.86±1.21 in the PASCAL laser and 2.39±0.49 and 5.75±1.35 in the conventional laser group, respectively. Differences between expressed pain scores obtained by both two scales were statistically significant (p<0.001).

Conclusion

PASCAL laser significantly alleviates pain levels possibly due to the shorter laser pulse duration and lower intensity.

Subthreshold micropulse laser photocoagulation therapy in a case of bilateral retinal astrocytic hamartomas with tuberous sclerosis complex: A case report

RATIONALE

Report a case of bilateral multiple retinal hamartomas (RAHs) in a patient with tuberous sclerosis complex (TSC) and introduced a new method (subthreshold micropulse laser photocoagulation) for the treatment of RAHs.

PATIENT CONCERNS

A 20-year-old man with TSC complained of decreased vision and metamorphosia in both eyes for 2 months. At presentation, visual acuity (VA) was 20/32 in the right eye and 20/40 in the left eye. Fundus photographs, optical coherence tomography, fundus fluorescein angiography (FFA), and indocyanine green angiography indicated multiple RAHs in both eyes.

DIAGNOSES

Bilateral retinal astrocytic hamartomas.

INTERVENTIONS

In the right eye, 577 nm photocoagulation was adopted to treat the RAHs with obvious fluorescein leakage in FFA. The paramacular RAHs were treated by subthreshold micropulse mode to minimize the damage to macula. Photocoagulation therapy was administrated in the left eye after 1 dose of intravitreal ranibizumab treatment.

OUTCOMES

After photocoagulation therapy (including subthreshold micropulse laser photocoagulation for the paramacular RAHs in both eyes), the VA improved to 20/25 OD and 20/32 OS with no recurrence of exudation.

LESSONS

About 577 nm photocoagulation for the peripheral RAHs in combination with subthreshold micropulse laser photocoagulation for RAHs in the macular zone is a good option for multiple RAHs in patients with TSC.

Idiopathic macular hole with asteroid hyalosis: Two case reports

INTRODUCTION

Asteroid hyalosis (AH) is characterized by mild vitreous-body liquefaction and a reduced likelihood of posterior vitreous detachment (PVD). Here, we report the clinical features of 2 cases of macular hole (MH) in eyes with AH. The extent of retinal vitreous adhesion at the time of vitreous surgery, the presence or absence of iatrogenic retinal breaks, and the postoperative course was examined in regard to the association with AH.

CASE PRESENTATION

Case 1 involved a 67-year-old female with decreased visual acuity in her left eye. Although preoperative optical coherence tomography examination revealed complete PVD with operculum around the fovea central region, vitreoretinal adhesion was quite strong starting at the midperiphery of the fundus, and an iatrogenic retinal break was formed at the inferior site during vitreous surgery. Endophotocoagulation was performed, and no onset of retinal detachment (RD) postsurgery was observed. Case 2 involved a 74-year-old male with metamorphopsia in his right eye. Preoperative perifoveal PVD was observed, yet vitreoretinal adhesion was strong starting at the midperiphery of the fundus and multiple iatrogenic retinal breaks had formed on the inferior, superior, and temporal sites. Moreover, RD occurred during surgery. Endophotocoagulation and gas tamponade was performed; however, postoperative RD requiring multiple reoperations occurred.

CONCLUSION

As with normal MH, MH with AH is thought to be caused by perifoveal PVD, yet as the vitreoretinal adhesion was found to be quite strong starting at the midperiphery of the fundus, we decided to keep the artificial PVD within a range where adhesion was loose.

Effectiveness of multiple therapeutic strategies in neovascular glaucoma patients: A PRISMA-compliant network meta-analysis

PURPOSE

Neovascular glaucoma (NVG) is a severe secondary glaucoma with uncontrolled intraocular pressure that leads to serious eye pain and vision loss. Presently, the therapeutic strategies for NVG are diverse, but the therapeutic effects are still not ideal. We performed a network analysis to assess the effect of multiple therapeutic strategies on the treatment of NVG patients.

METHODS

We searched public electronic databases through April 2017 using the following keywords "neovascular glaucoma," "iris neovascularization," "hemorrhagic glaucoma," and "random" without language restrictions. The outcome considered in the present analysis was treatment success rate. A network meta-analysis and multilevel mixed-effects logistic regression were used to compare regimens.

RESULTS

We included 27 articles assessing a total of 1884 NVG patients in our analysis. According to the network analysis, interferon and mitomycin plus trabeculectomy (94.9%), glaucoma valve implantation (86.9%), and iris photocoagulation plus trabeculectomy (81.9%) were the most likely to improve treatment success rate in NVG patients. The multilevel logistic regression analysis showed that glaucoma valve, bevacizumab, interferon, cyclophotocoagulation, trabeculectomy, iris photocoagulation, ranibizumab, and mitomycin had advantages in terms of improving treatment success rate in NVG patients. However, the application of retinal photocoagulation and vitrectomy reduced patient treatment success rate.

CONCLUSION

The regimen including mitomycin, interferon, and trabeculectomy was the most likely to improve the treatment success rate in NVG patients. The application of glaucoma valve and bevacizumab were more beneficial for improving patient treatment success rate as a surgery and as an agent, respectively.

Preoperative photocoagulation reduces corneal endothelial cell damage after vitrectomy in patients with proliferative diabetic retinopathy

Proliferative diabetic retinopathy (PDR) is a severe complication of diabetes and is a leading cause of visual decline and irreversible blindness. So we designed this study to investigate retrospectively the effect of preoperative photocoagulation on corneal endothelial cells after vitrectomy in patients with PDR.The study included 52 eyes of 46 patients with PDR complicated with vitreous hemorrhage, who underwent vitrectomy. Patients were apportioned to a photocoagulation group (26 eyes/23 patients) or nonphotocoagulation group (26/23 patients), according to their history of preoperative photocoagulation. A specular microscope was used to assess the corneal endothelial cell density and percentage of hexagonal cells (PHC) before surgery, and at 1 week, 1 month, and 3 months after surgery.The cell density was lower 3 months after surgery in the photocoagulation group, but at 1 month in the nonphotocoagulation group, all cases were significantly different from the preoperative value (P < .05 or P < .01). One week after surgery, the mean cell densities between the photocoagulation and nonphotocoagulation groups were not statistically different (P > .05). However, the mean cell densities at 1 and 3 months after surgery in the photocoagulation group were significantly higher than those in the nonphotocoagulation group (P < .05). The PHC values in the photocoagulation group at 1 week and in the nonphotocoagulation group at 1 week, 1 month, and 3 months were much lower than their respective preoperative values (P < .05 or P < .01). More importantly, at 1 and 3 months, the PHC had recovered to preoperative values in the photocoagulation group, but not in the nonphotocoagulation group. As for cell density and PHC, they were both significantly higher 1 and 3 months after surgery in the photocoagulation group than in the nonphotocoagulation group (P < .05).Photocoagulation before vitrectomy reduces subsequent corneal endothelial cell damage in PDR patients.

A Novel Nanoparticle Mediated Selective Inner Retinal Photocoagulation for Diseases of the Inner Retina

A novel nanoparticle mediated methodology for laser photocoagulation of the inner retina to achieve tissue selective treatment is presented.

METHODS

Transport of 527, 577, and 810 nm laser, heat deposition, and eventual thermal damage in vitreous, retina, RPE, choroid, and sclera were modeled using Bouguer-Beer-Lambert law of absorption and solved numerically using the finite volume method. Nanoparticles were designed using Mie theory of scattering. Performance of the new photocoagulation strategy using gold nanospheres and gold-silica nanoshells was compared with that of conventional methods without nanoparticles. For experimental validation, vitreous cavity of ex vivo porcine eyes was infused with gold nanospheres. After ~6 h of nanoparticle diffusion, the porcine retina was irradiated with a green laser and imaged simultaneously using a spectral domain optical coherence tomography (Spectralis SD-OCT, Heidelberg Engineering).

RESULTS

Our computational model predicted a significant spatial shift in the peak temperature from RPE to the inner retinal region when infused with nanoparticles. Arrhenius thermal damage in the mid-retinal location was achieved in ~14 ms for 527 nm laser thereby reducing the irradiation duration by ~30 ms compared with the treatment without nanoparticles. In ex vivo porcine eyes infused with gold nanospheres, SD-OCT retinal images revealed a lower thermal damage and expansion at RPE due to laser photocoagulation.

CONCLUSION

Nanoparticle infused laser photocoagulation strategy provided a selective inner retinal thermal damage with significant decrease in laser power and laser exposure time.

SIGNIFICANCE

The proposed treatment strategy shows possibilities for an efficient and highly selective inner retinal laser treatment.

Decreased ocular blood flow after photocoagulation therapy in neonatal retinopathy of prematurity

PURPOSE

To evaluate the relationships between optic nerve head blood flow, expressed as mean blur rate (MBR) measured by laser speckle flowgraphy (LSFG), and photocoagulation therapy in neonates with retinopathy of prematurity (ROP).

STUDY DESIGN

Case series study.

METHODS

We studied 5 ROP neonates either during sleep or under sedation both before and after photocoagulation, and evaluated 8 eyes in which the circulation could be measured three times consecutively. Correlations between the MBR-A (mean of all values), MBR-V (vessel mean) and MBR-T (tissue mean) and postmenstrual age were evaluated using Spearman's rank correlation coefficient. In addition, correlations between the relative MBR (-A, -V, -T) value and number of photocoagulation burns and the NV score were evaluated. Differences between post-treatment MBR in ROP subjects and normal neonates' MBR were estimated using analysis of covariance (ANCoVA), with adjustment for postmenstrual age.

RESULTS

The relative MBR (-A, -V, -T) values after photocoagulation were 69.6 ± 16.0%, 66.7 ± 17.0% and 74.3 ± 14.6%, respectively. Postmenstrual age was significantly correlated with post-treatment MBR-A (r = 0.83, p = 0.0101), MBR-V (r = 0.85, p = 0.007) and MBR-T (r = 0.76, p = 0.0282). The relative MBR-T value was significantly correlated with the number of photocoagulation burns (r = -0.75, p = 0.033) and NV score (r = -0.72, p = 0.0437). The ANCoVA results showed no significant difference between post-treatment MBR and normal neonates' MBR.

CONCLUSIONS

Photocoagulation improved the dilation of veins and tortuosity of arteries and reduced ocular blood flow in ROP subjects. Since the post-treatment MBR was not different from a normal neonate's MBR, it is suggested that the pre-treatment MBR was higher in severe ROP cases.

When Should We Give Up Filtration Surgery: Indications, Techniques and Results of Cyclodestruction

PURPOSE

Cyclodestructive procedures are traditionally used in cases of glaucoma that are refractory to medical and surgical therapy. The goal of this chapter is to describe the indications, contraindications, techniques, and pitfalls of cyclodestructive procedures, including transscleral cyclophotocoagulation (TCP), micropulse TCP (MP-TCP), endoscopic cyclophotocoagulation (ECP), and ultrasound cilioplasty.

METHODS

A literature search for cyclodestructive techniques was performed, and relevant studies were included for evaluation and review.

RESULTS

It is encouraging that TCP seems relatively efficacious even for patients who have been refractory to other treatments, depending on the energy setting, follow-up period, and definition of success. Repeated TCP is often required. TCP was more often used in eyes with limited visual potential caused by severe forms of glaucoma than in eyes with good visual potential. Serious complications were significant vision loss, inflammation, hypotony, and phthisis. ECP came later into clinical use for the treatment of refractory glaucoma. ECP is able to specifically target the ciliary epithelium under direct viewing as compared to TCP, which is an indirect cyclodestructive procedure. In the literature, it has been demonstrated that ECP has overall good success with relatively low complication rates when used for adult forms of glaucoma. A new technology using MP-TCP is a promising alternative to conventional cyclophotocoagulation. Early evidence shows that MP-TCP has clinical utility and a good safety profile. Ultrasound cilioplasty is a possible alternative to laser cyclodestruction that is already being commercialized and is currently under investigation.

CONCLUSIONS

Both TCP and ECP are effective cyclodestructive procedures and alternatives for the treatment of glaucoma refractory to medical and surgical therapy, though potential for serious complications exists. TCP, ECP, and ultrasound cilioplasty are being used increasingly as the primary surgery for various kinds and stages of glaucoma.

Anaesthesia modalities during laser photocoagulation for retinopathy of prematurity: a retrospective, longitudinal study

OBJECTIVES

Laser photocoagulation surgery is a routine treatment for threshold retinopathy of prematurity (ROP). However, little is known about which anaesthesia protocols provide efficient pain control while minimising exposure risk to vulnerable infants. In this study, therefore, we assessed the efficacy and tolerability of multiple anaesthesia techniques used on premature infants during laser therapy.

DESIGN AND MAIN OUTCOME MEASURES

Anaesthesia modalities consisted of topical eye drops anaesthesia, general anaesthesia and intravenous fentanyl sedation with mechanical ventilation. Laser treatment efficacy and detailed operative information were retrospectively and consecutively analysed. Cardiorespiratory stability was assessed and compared. The Neonatal Pain Agitation and Sedation Scale (N-PASS) was used to evaluate tolerability in infants that underwent intravenous fentanyl sedation.

RESULTS

97 cases of prematurity were included in this study. In 94/97 (96.9%) cases, vascular proliferation regressed. In the topical anaesthesia groups, the ophthalmologist needed 12-16 min more to complete the treatment. During the 3 postoperative days, topical anaesthesia demonstrated the greatest instability; 4/31 (12.90%) infants in this group suffered from life threatening events requiring resuscitation. The only instability observed in general anaesthesia and fentanyl sedation was attributed to difficulty in extubating within 24 hours after surgery. During laser therapy, the N-PASS score increased to 1.8 in the fentanyl sedation group.

CONCLUSIONS

Topical anaesthesia was associated with more cardiorespiratory instability during ROP laser treatment. While general anaesthesia and fentanyl sedation had similar postoperative cardiorespiratory results, the latter demonstrated acceptable pain stress control. However, the difficulty of weaning off mechanical ventilation in some cases after surgery needs to be addressed in future studies.

A Computational Model of Peripheral Photocoagulation for the Prevention of Progressive Diabetic Capillary Occlusion

We developed a computational model of the propagation of retinal ischemia in diabetic retinopathy and analyzed the consequences of various patterns and sizes of burns in peripheral retinal photocoagulation. The model addresses retinal ischemia as a phenomenon of adverse local feedback in which once a capillary is occluded there is an elevated probability of occlusion of adjacent capillaries resulting in enlarging areas of retinal ischemia as is commonly seen clinically. Retinal burns of different sizes and patterns, treated as local oxygen sources, are predicted to have different effects on the propagation of retinal ischemia. The patterns of retinal burns are optimized with regard to minimization of the sum of the photocoagulated retina and computer predicted ischemic retina. Our simulations show that certain patterns of retinal burns are effective at preventing the spatial spread of ischemia by creating oxygenated boundaries across which the ischemia does not propagate. This model makes no statement about current PRP treatment of avascular peripheral retina and notes that the usual spot sizes used in PRP will not prevent ischemic propagation in still vascularized retinal areas. The model seems to show that a properly patterned laser treatment of still vascularized peripheral retina may be able to prevent or at least constrain the propagation of diabetic retinal ischemia in those retinal areas with intact capillaries.

Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly. AMD is diagnosed based on characteristic retinal findings in individuals older than 50. Early detection and treatment are critical in increasing the likelihood of retaining good and functional vision.

Panretinal Photocoagulation vs Intravitreous Ranibizumab for Proliferative Diabetic Retinopathy: A Randomized Clinical Trial

IMPORTANCE

Panretinal photocoagulation (PRP) is the standard treatment for reducing severe visual loss from proliferative diabetic retinopathy. However, PRP can damage the retina, resulting in peripheral vision loss or worsening diabetic macular edema (DME).

OBJECTIVE

To evaluate the noninferiority of intravitreous ranibizumab compared with PRP for visual acuity outcomes in patients with proliferative diabetic retinopathy.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial conducted at 55 US sites among 305 adults with proliferative diabetic retinopathy enrolled between February and December 2012 (mean age, 52 years; 44% female; 52% white). Both eyes were enrolled for 89 participants (1 eye to each study group), with a total of 394 study eyes. The final 2-year visit was completed in January 2015.

INTERVENTIONS

Individual eyes were randomly assigned to receive PRP treatment, completed in 1 to 3 visits (n = 203 eyes), or ranibizumab, 0.5 mg, by intravitreous injection at baseline and as frequently as every 4 weeks based on a structured re-treatment protocol (n = 191 eyes). Eyes in both treatment groups could receive ranibizumab for DME.

MAIN OUTCOMES AND MEASURES

The primary outcome was mean visual acuity change at 2 years (5-letter noninferiority margin; intention-to-treat analysis). Secondary outcomes included visual acuity area under the curve, peripheral visual field loss, vitrectomy, DME development, and retinal neovascularization.

RESULTS

Mean visual acuity letter improvement at 2 years was +2.8 in the ranibizumab group vs +0.2 in the PRP group (difference, +2.2; 95% CI, -0.5 to +5.0; P < .001 for noninferiority). The mean treatment group difference in visual acuity area under the curve over 2 years was +4.2 (95% CI, +3.0 to +5.4; P < .001). Mean peripheral visual field sensitivity loss was worse (-23 dB vs -422 dB; difference, 372 dB; 95% CI, 213-531 dB; P < .001), vitrectomy was more frequent (15% vs 4%; difference, 9%; 95% CI, 4%-15%; P < .001), and DME development was more frequent (28% vs 9%; difference, 19%; 95% CI, 10%-28%; P < .001) in the PRP group vs the ranibizumab group, respectively. Eyes without active or regressed neovascularization at 2 years were not significantly different (35% in the ranibizumab group vs 30% in the PRP group; difference, 3%; 95% CI, -7% to 12%; P = .58). One eye in the ranibizumab group developed endophthalmitis. No significant differences between groups in rates of major cardiovascular events were identified.

CONCLUSIONS AND RELEVANCE

Among eyes with proliferative diabetic retinopathy, treatment with ranibizumab resulted in visual acuity that was noninferior to (not worse than) PRP treatment at 2 years. Although longer-term follow-up is needed, ranibizumab may be a reasonable treatment alternative, at least through 2 years, for patients with proliferative diabetic retinopathy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01489189.