Morphology, Fundus Autofluorescence, and Retinal Sensitivity of Photocoagulated Lesions in Proliferative Diabetic Retinopathy

Purpose

To evaluate the relationships among morphology, fundus autofluorescence (FAF), and retinal sensitivity of photocoagulated lesions more than 1 year after panretinal photocoagulation in patients with proliferative diabetic retinopathy and good vision.

Methods

This retrospective cohort study included patients with proliferative diabetic retinopathy who had undergone panretinal photocoagulation more than 1 year ago. The photocoagulated lesions were classified according to FAF levels: group A, no FAF; group B, diffuse FAF; group C, white-dotted centers with diffuse FAF; group D, white-dotted centers without FAF; and group E, controls. The main outcome measures were FAF, retinal sensitivity, and morphology of the photocoagulated lesions.

Results

The median sensitivity values and number of photocoagulated lesions in groups A (n = 37), B (n = 39), C (n = 4), D (n = 15), and E (n = 39) were 0 dB, 18.0 dB, 13.9 dB, 0.3 dB, and 21.5 dB, respectively. EZ lines were absent in 93.5%, 18.1%, 50%, 93.3%, and 0% of lesions in groups A, B, C, D, and E, respectively. The inner retinal layer was damaged in 45.2%, 3.0%, 50%, 73.3%, and 0% lesions in groups A, B, C, D, and E, respectively. Statistically significant between-group differences were observed in the retinal sensitivities of the photocoagulated lesions, presence of EZ lines, and damage to the inner retinal layer (p < 0.05).

Conclusions

The photoreceptors in most photocoagulated lesions with diffuse FAF retain their morphology and function.

Translational Relevance

Using fundus autofluorescence, the damage to photoreceptors after panretinal photocoagulation in patients with diabetes can be estimated in a noninvasive manner. This process can help in determining the need for additional panretinal photocoagulation.

Anti-Vascular Endothelial Growth Factor Drugs Compared With Panretinal Photocoagulation for the Treatment of Proliferative Diabetic Retinopathy: A Cost-Effectiveness Analysis

OBJECTIVES

This study aimed to evaluate the cost-effectiveness of anti-vascular endothelial growth factor drugs (anti-VEGFs) compared with panretinal photocoagulation (PRP) for treating proliferative diabetic retinopathy (PDR) in the United Kingdom.

METHODS

A discrete event simulation model was developed, informed by individual participant data meta-analysis. The model captures treatment effects on best corrected visual acuity in both eyes, and the occurrence of diabetic macular edema and vitreous hemorrhage. The model also estimates the value of undertaking further research to resolve decision uncertainty.

RESULTS

Anti-VEGFs are unlikely to generate clinically meaningful benefits over PRP. The model predicted anti-VEGFs be more costly and similarly effective as PRP, generating 0.029 fewer quality-adjusted life-years at an additional cost of £3688, with a net health benefit of -0.214 at a £20 000 willingness-to-pay threshold. Scenario analysis results suggest that only under very select conditions may anti-VEGFs offer potential for cost-effective treatment of PDR. The consequences of loss to follow-up were an important driver of model outcomes.

CONCLUSIONS

Anti-VEGFs are unlikely to be a cost-effective treatment for early PDR compared with PRP. Anti-VEGFs are generally associated with higher costs and similar health outcomes across various scenarios. Although anti-VEGFs were associated with lower diabetic macular edema rates, the number of cases avoided is insufficient to offset the additional treatment costs. Key uncertainties relate to the long-term comparative effectiveness of anti-VEGFs, particularly considering the real-world rates and consequences of treatment nonadherence. Further research on long-term visual acuity and rates of vision-threatening complications may be beneficial in resolving uncertainties.

ASSOCIATION OF MACULAR STRUCTURE WITH MICROPERIMETRY SENSITIVITY FOLLOWING VITRECTOMY FOR PROLIFERATE DIABETIC RETINOPATHY

PURPOSE

To evaluate macular sensitivity using microperimetry in patients with proliferate diabetic retinopathy following vitrectomy and to investigate the relationship between the sensitivity and foveal microstructures with optical coherence tomography/angiography.

METHODS

Eighty-four eyes of 84 patients with proliferative diabetic retinopathy, who were indicated for vitrectomy, had no intraocular surgery history 3 months preoperatively, and were able to ensure fundus examination after the vitrectomy, were included. A logMAR best-corrected visual acuity, macular sensitivity of microperimetry, macular retinal thickness, and macular vessel perfusion using optical coherence tomography/angiography were examined at 1 week, 1 month, and 3 months postoperatively.

RESULTS

The logMAR best-corrected visual acuity and mean macular sensitivity of patients with proliferative diabetic retinopathy improved postoperatively (P < 0.05). There was a significant correlation between best-corrected visual acuity and mean sensitivity (P < 0.05). Postoperative mean macular sensitivity was significantly correlated with outer retinal thickness in the 0 to 6 mm macular area (P < 0.05) and also significantly correlated with deep capillary plexus perfusion (P < 0.05). Fixation stability and mean macular sensitivity did not show any correlation with glycated hemoglobin, triglyceride, serum total cholesterol, carbamide, and creatinine and duration of diabetes mellitus (P > 0.05).

CONCLUSION

Postoperative mean macular sensitivity was significantly correlated with outer retinal thickness and deep capillary plexus perfusion for patients with proliferative diabetic retinopathy. The authors found that the visual performance of patients can be evaluated by the outer retinal thickness and deep capillary plexus perfusion, so optical coherence tomography/angiography examination can be an important prognostic factor for visual performance in patients.Clinical Trial Registration: This trial is registered with the Chinese Clinical Trial Registry (http://www.chictr.org.cn; Registration No.: ChiCTR2100043399).

Six-month results of 577 nm subthreshold micropulse laser therapy in non-center involving diabetic macular edema

BACKGROUND

This study aimed to evaluate the efficacy of 577 nm subthreshold micropulse laser (SML) therapy in patients with non-center involving diabetic macular edema (DME).

METHODS

Twenty-two eyes of 18 patients diagnosed with non-center involving DME were included in this prospective, observational study. The patient's baseline best corrected visual acuity (BCVA), maximum retinal thickness (MRT), central macular thickness (CMT), and the area of macular exudates were determined and re-evaluated at 1, 3, and 6 months after laser treatment.

RESULTS

There was no statistically significant change in BCVA at the 1st, 3rd and 6th months compared to the baseline in the follow-up (p = 0.067, p = 0.270, p = 0.027 according to Bonferroni correction p < 0,01). 1st, 3rd, and 6th month MRT was statistically significantly lower than baseline (p = 0,009, p = 0,006, p = 0,007). No statistically significant change was detected in CMT at the 1st, 3rd and 6th months compared to the baseline in the follow-up (p = 0.384, p = 0.794, p = 0.363). No statistically significant change in the area of macular exudates was detected at the 1st, 3rd, and 6th months compared to the baseline (p = 0.904, p = 0.444, p = 0.277).

CONCLUSIONS

This study observed a significant decrease in extrafoveal retinal thickness in patients with DME. There was no progression to central macular involvement, an increase in the area of exudates, and a decrease in BCVA in any patient. SML may be an effective alternative to conventional argon laser in non-center involving DME.

Autonomous screening for laser photocoagulation in fundus images using deep learning

BACKGROUND

Diabetic retinopathy (DR) is a leading cause of blindness in adults worldwide. Artificial intelligence (AI) with autonomous deep learning algorithms has been increasingly used in retinal image analysis, particularly for the screening of referrable DR. An established treatment for proliferative DR is panretinal or focal laser photocoagulation. Training autonomous models to discern laser patterns can be important in disease management and follow-up.

METHODS

A deep learning model was trained for laser treatment detection using the EyePACs dataset. Data was randomly assigned, by participant, into development (n=18 945) and validation (n=2105) sets. Analysis was conducted at the single image, eye, and patient levels. The model was then used to filter input for three independent AI models for retinal indications; changes in model efficacy were measured using area under the receiver operating characteristic curve (AUC) and mean absolute error (MAE).

RESULTS

On the task of laser photocoagulation detection: AUCs of 0.981, 0.95, and 0.979 were achieved at the patient, image, and eye levels, respectively. When analysing independent models, efficacy was shown to improve across the board after filtering. Diabetic macular oedema detection on images with artefacts was AUC 0.932 vs AUC 0.955 on those without. Participant sex detection on images with artefacts was AUC 0.872 vs AUC 0.922 on those without. Participant age detection on images with artefacts was MAE 5.33 vs MAE 3.81 on those without.

CONCLUSION

The proposed model for laser treatment detection achieved high performance on all analysis metrics and has been demonstrated to positively affect the efficacy of different AI models, suggesting that laser detection can generally improve AI-powered applications for fundus images.

Comparison of the cytokines levels in aqueous humor in vitrectomized eyes versus non-vitrectomized eyes with diabetic macular edema

BACKGROUND

This study was conducted to compare concentrations of VEGF family growth factors, inflammation-related factors, and adhesion molecules in the aqueous humor of eyes with diabetic macular edema (DME), with and without prior vitrectomy.

METHODS

A total of 31 eyes were included, 11 with DME that had undergone vitrectomy, 9 with DME but without vitrectomy, and 11 from age-related cataract patients as controls. The concentrations of cytokines including TNF-α, IL-6, IL-8, IP-10, MCP-1, IFN-γ, MIP-1 α, MIP-1 β, PECAM-1, MIF, VCAM-1, ICAM-1, PIGF were quantified using Luminex Human Discovery Assay. Central macular thickness (CMT) values of all eyes were measured using optical coherence tomography (OCT).

RESULTS

(1) Vitrectomized DME eyes exhibited significantly higher levels of IL-6 and IL-8 compared to non-vitrectomized eyes (P < 0.05). (2) In vitrectomized group, after Benjamini-Hochberg correction, there was a significant positive correlation between the levels of VEGF and PlGF (rs = 0.855, P < 0.05), as well as the levels of TNF-α and IFN-γ (rs = 0.858, P < 0.05). In non-vitrectomized group, significant positive correlations were found between VEGF and PlGF levels after correcting for multiple comparisons (rs = 0.9, P < 0.05). (3) In non-vitrectomized group, the concentrations of VEGF and PlGF in aqueous humor were significantly positively correlated with CMT values (rs = 0.95, P < 0.05; rs = 0.9, P < 0.05, respectively).

CONCLUSIONS

The concentrations of IL-6 and IL-8 in the aqueous humor were significantly higher in vitrectomized DME eyes compared to nonvitrectomized DME eyes and the levels of VEGF were similar in the two groups, suggesting that inflammation after vitrectomy may be a key factor in the occurrence and development of DME.

The effect of adjuvant Mitomycin C during vitrectomy on functional and anatomical outcomes in patients with severe diabetic tractional retinal detachment

PURPOSE

To evaluate the effect of adjuvant Mitomycin C (MMC) use on the anatomical and functional success of vitreoretinal surgery (VRS) in severe diabetic tractional retinal detachment (dTRD) patients.

METHODS

A retrospective analysis of consecutive patients undergoing VRS due to severe dTRD was conducted. Patients were categorized into those who received 20 µg/0.1 mL MMC via MMC sandwich method (Group 1) and those who did not (Group 2). Demographics, surgical characteristics, visual outcomes, and complications that may related to MMC were analyzed.

RESULTS

A total of 25 eyes were included, 13 in Group 1 and 12 in Group 2. No statistical difference was observed in baseline characteristics between the groups. The mean best-corrected visual acuity was 1.90 ± 0.43 logMAR and 1.93 ± 0.41 logMAR preoperatively and 1.60 ± 0.78 logMAR and 1.56 ± 0.78 logMAR postoperatively in Groups 1 and 2, respectively (p = 0.154). The postoperative mean intraocular pressure was 16.23 ± 2.55 mmHg and 13.08 ± 4.94 mmHg in Groups 1 and 2, respectively (p = 0.225). The rate of re-surgery was significantly lower in Group 1 (0% vs. 41.7% in Group 2, p = 0.015). Retina was attached in all patients at the last visit. No MMC-related complication was recorded.

CONCLUSION

Intraoperative adjuvant MMC application for severe dTRD significantly reduces re-surgery rates with good anatomical and functional outcomes safely.

Comparison of postoperative morphological changes and retinal displacement in diabetic and idiopathic epiretinal membranes

PURPOSE

To compare the postoperative retinal displacement by optical coherence tomography (OCT) in idiopathic epiretinal membranes (iERM) and diabetic epiretinal membranes (dERM).

METHODS

This retrospective study included 36 iERM and 22 dERM cases. In cross-sectional OCT images (B-scan) the presence of foveal pit, subfoveal fluid, cotton ball sign (CBS), intraretinal cystic changes (ICC), disorganization of retinal inner layers (DRILs) and ectopic inner foveal layer (EIFL) were recorded. Central macular thickness (CMT) and EIFL thicknesses were calculated. Retinal displacement was quantified using infrared image of OCT approach consisting of the fovea to disc margin, interarcade distance and perimacular distances.

RESULTS

The presence of subfoveal fluid (p = 0.014) and DRIL (p = 0.02) was significantly higher in the dERM group. CMT decreased significantly in both groups (p˂0.001). The EIFL was significantly thicker in the iERM group compared to the dERM group (p = 0.049), and it decreased significantly in the iERM group postoperatively. In the iERM group, while the fovea-disc margin distance decreased, the interarcade and perimacular distance increased significantly (p˂0.001). In the dERM group, the disc-fovea distance change was not significant (p = 0.082). Significant visual improvement was achieved with vitrectomy in both groups (p˂0.001). In the dERM group, the presence of DRIL was associated with lower pre and post-op visual acuity (VA) (r = 0.596 and p = 0.004 for pre-operative and r = 0.567 and p = 0.007 for post-operative).

CONCLUSION

Significant retinal displacement occurs after vitrectomy in both iERM and dERM. The low VA in the dERM group may be related to the presence of DRILs.

Short Term Effect of Pre-Operative Anti-VEGF on Angiogenic and Fibrotic Profile of Fibrovascular Membranes of Proliferative Diabetic Retinopathy

Purpose

Adjuvant, pre-operative intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections have been used to reduce peri-operative bleeding in eyes undergoing pars-plana vitrectomy for complications of proliferative diabetic retinopathy (PDR). To address the concern over their potential off-target effects of progressive fibrous contraction, we sought to dissect the transcriptional changes in the surgically extracted fibrovascular membranes (FVMs).

Methods

We analyzed surgically extracted FVMs from 10 eyes: 4 eyes pretreated with intravitreal bevacizumab (IVB) and 6 untreated eyes. FVMs were digested into single cells, mRNA was extracted from endothelial cell-enriched (microbead selection with CD31) and non-endothelial cell compartments, followed by RT-qPCR quantification. We then compared the relative expression of genes involved in angiogenesis, endothelial cell integrity, and myofibroblastic processes between treated and untreated FVMs.

Results

Endothelial cells from IVB pretreated FVMs showed significant reduction of VEGFA, VEGF receptors (FLT1 and KDR), and angiopoietin 2 expression as well as increased vascular endothelial cadherin and endothelin, suggesting reduced angiogenesis and enhanced vascular integrity. The non-endothelial cell fraction showed decreased expression of VEGFA and fibronectin, without significant difference in the expression of other profibrotic factors.

Conclusions

Our findings confirm that adjuvant pre-operative IVB decreased fibronectin and increase endothelin-1 expression without affecting other profibrotic gene expression, uncovering an important interaction between IVB and endothelin-1 that deserves further study.

Application of optical coherence tomography angiography in the assessment of diabetic macular edema staging and laser photocoagulation efficacy

OBJECTIVE

This study aimed to analyze the effect of optical coherence tomography angiography (OCTA) on diabetic macular edema (DME) staging and assess the efficacy of laser photocoagulation.

METHODS

Eighty-six patients (141 eyes) with suspected DME who visited our hospital from August 2019 to March 2022 were selected and underwent fundus angiography and OCTA. The two examination methods were compared in terms of their efficacy in macular edema staging. Subsequently, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of OCTA in diagnosing DME were assessed using fundus angiography as the gold standard. In patients with clinically significant macular edema (CSME) treated with laser photocoagulation, the central concave non-perfused zone (FAZ), vascular density (VD), central macular retinal thickness (CRT), whole retinal blood flow density (FD-300), superficial capillary plexus (SCP), and deep capillary plexus (DCP) were measured using the OCTA 3 mm × 3 mm mode before treatment, at 3 months after treatment, and at 6 months after treatment. SCP, deep capillary plexus (DCP), blood flow density (VD), best corrected visual acuity (BCVA), and central retinal thickness (CRT) were recorded before treatment, 3 months after treatment, and 6 months after treatment. The correlation between BCVA and pre-treatment OCTA parameters at 6 months after treatment was analyzed using Pearson's correlation.

RESULTS

Fundus angiography was performed in 86 patients (141 eyes) with suspected DME. Of the 141 eyes, 44 had no leakage, 52 had diffuse edema, 40 had focal macular edema, and 5 had eyes ischemia. A total of 97 eyes showed CSME on fundus angiography. Using fundus angiography as the gold standard, OCTA exhibited a sensitivity of 97.94 %, a specificity of 63.64 %, and an accuracy of 87.23 % in diagnosing CSME. The Kappa value between OCTA and fundus angiography was 0.674. The receiver operating characteristic curve revealed that the area under the curve (AUC) of OCTA in diagnosing CSME was 0.808 (95 % confidence interval: 0.717-0.899). The BCVA was higher, while the CRT was lower in CSME patients at 3 and 6 months after treatment (P<0.05). No significant difference was observed in the OCTA parameters in CSME patients at 3 months after treatment compared with that before treatment (P>0.05). Similarly, no significant difference was found in the FD300 of CSME patients at 6 months after treatment compared with that before treatment (P>0.05). However, the FAZ area, DCP-VD (overall, central concave, and paracentral concave), and SCP-VD (overall, central concave, and paracentral concave) were higher in CSME patients at 6 months after treatment compared with that before treatment (P<0.05). Pearson's correlation showed that BCVA was positively correlated with pre-treatment FAZ area, DCP-VD, and SCP-VD (r>0, P<0.05), and negatively associated with CRT (r<0, P<0.05).

CONCLUSION

OCTA exhibited high sensitivity and specificity in diagnosis and staging DME. It adeptly captures the microvascular and visual changes in the central macular recess before and after laser photocoagulation therapy, which can quantitatively guide the follow-up treatment of DME.

Preoperative co-application of bevacizumab and tissue plasminogen activator in vitrectomy for proliferative diabetic retinopathy

PURPOSE

To investigate the clinical benefits of the co-application of bevacizumab and tissue plasminogen activator as adjuncts in the surgical treatment of proliferative diabetic retinopathy.

METHODS

Patients who underwent vitrectomy for proliferative dia-betic retinopathy complications were preoperatively given in-travitreal injection with either bevacizumab and tissue plasminogen activator (Group 1) or bevacizumab alone (Group 2). Primary outcomes were surgery time and number of intraoperative iatrogenic retinal breaks. Secondary outcomes included changes in the best-corrected visual acuity and postoperative complications at 3 months postoperatively.

RESULTS

The mean surgery time in Group 1 (52.95 ± 5.90 min) was significantly shorter than that in Group 2 (79.61 ± 12.63 min) (p<0.001). The mean number of iatrogenic retinal breaks was 0.50 ± 0.59 (0-2) in Group 1 and 2.00 ± 0.83 (0-3) in Group 2 (p<0.001). The best-corrected visual acuity significantly improved in both groups (p<0.001). One eye in each group developed retinal detachment.

CONCLUSION

Preoperative co-application of bevacizumab and tissue plasminogen activator as adjuncts in the surgical treatment of proliferative diabetic retinopathy shortens the surgery time and reduces the number of intraoperative iatrogenic retinal breaks.

Results of office-based fluid-air exchange for postvitrectomy hemorrhage in diabetic retinopathy

PURPOSE

This study aimed to evaluate the efficacy and clinical outcomes of a one-way fluid-air exchange procedure for the treatment of postvitrectomy diabetic vitreous hemorrhage in patients with proliferative diabetic retinopathy.

METHODS

This retrospective study included 233 patients with proliferative diabetic retinopathy, who underwent vitrectomy. A one-way fluid-air exchange procedure was performed in 24 eyes of 24 (10.30%) patients with persistent vitreous cavity rebleeding after the operation. Preprocedural and postprocedural best-corrected visual acuity values were achieved. Complications occurring during and after the procedure were analyzed.

RESULTS

Significant visual improvement was observed 1 month after the one-way fluid-air exchange procedure (2.62 ± 0.60 LogMAR at baseline vs. 0.85 ± 0.94 LogMAR at postprocedure, p<0.0001). Moreover, 19 (79.17%) eyes needed the procedure once, and 5 (20.83%) eyed had the procedure more than twice. In 3 (12.50%) eyes, reoperation was eventually required because of persistent rebleeding despite several fluid-air exchanges. No complication was observed during the follow-up.

CONCLUSIONS

The one-way fluid-air exchange procedure can be an excellent alternative to re-vitrectomy for patients with proliferative diabetic retinopathy suffering from postvitrectomy diabetic vitreous hemorrhage by removing the hemorrhagic contents directly and achieving fast recovery of visual function without apparent complications.

Subthreshold Compared with Threshold Macular Photocoagulation for Diabetic Macular Edema: A Systematic Review and Meta-Analysis

TOPIC

To compare the efficacy and safety of subthreshold macular laser to conventional focal laser photocoagulation for the treatment of vision loss secondary to diabetic macular edema (DME).

CLINICAL RELEVANCE

Macular laser remains an important and cost effective treatment option for vision loss secondary to DME. Although anti-VEGF therapy is often first-line, macular laser is of utility in low-resource or remote settings, for patients at risk of loss to follow-up, and for DME not meeting country-specific reimbursement criteria for anti-VEGF therapy. Subthreshold laser is a modality that does not produce clinical or histologic evidence of thermal damage, thereby potentially limiting the common complications of conventional laser.

METHODS

Ovid MEDLINE, EMBASE, and CENTRAL databases were searched for randomized controlled trials (RCTs) from inception to September 28, 2022. Meta-analyses were performed using random-effects modeling. Data were collected at 12 and 24 months for best-corrected visual acuity (BCVA), central retinal thickness, diabetic retinopathy severity scale, rate of adverse events, rate of enrolled patients not completing treatment, rate of patients receiving retreatment, and quality-of-life measures. The risk of bias and certainty of evidence were assessed using Cochrane's Risk-of-Bias version 2 and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) frameworks, respectively. Subgroup analysis was performed between subthreshold laser modalities and evaluated with Instrument to assess the Credibility of Effect Modification Analyses tool.

RESULTS

Fourteen RCTs comprising 514 eyes receiving conventional laser and 574 eyes receiving subthreshold laser were included. Subthreshold laser likely results in no difference to BCVA (moderate GRADE certainty) compared with conventional laser. Conventional laser demonstrated a small, statistically significant improvement in central retinal thickness (low GRADE certainty); however, the magnitude of this improvement is unlikely to be clinically important. There may not be a difference in the rate of adverse events (low GRADE certainty) at 12 months when comparing subthreshold laser to conventional laser for DME.

CONCLUSION

Randomized controlled trial literature to date suggests subthreshold laser to be as effective as conventional laser in the treatment of DME. Increased follow-up duration is needed to observe any long-term safety benefit from reduced retinal damage.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Reperfusion of retinal nonperfusion by neovascular-vascular anastomosis in proliferative diabetic retinopathy

BACKGROUND

Retinal nonperfusion is a significant cause of vision loss in patients with proliferative diabetic retinopathy (PDR). Therefore, reperfusion of a nonperfusion has been a matter of strong interest, but few previous studies have demonstrated the potential benefits of reperfusion.

CASE REPORTS

Here, we report longitudinal optical coherence tomography angiographic analysis of two cases of PDR, in which the retinal neovascularization (RNV) that developed in response to retinal ischemia formed anastomoses with pre-existing physiological retinal vessels, resulting in both superficial and deep capillary reperfusion within the nonperfusion. We named this interesting finding "neovascular-vascular anastomosis." Retinal reperfusion due to neovascular-vascular anastomosis differed from recanalization, defined as reperfusion of once-occluded blood vessels, and has not been reported previously.

CONCLUSION

Our observation highlights the potential of RNV to rescue retinal ischemia by the formation of neovascular-vascular anastomoses.

Topical anesthesia versus topical and subconjunctival anesthesia combined in diabetic retinopathy photocoagulation

PURPOSE

comparison between two anesthetic techniques on the ability to reduce pain during panretinal photocoagulation (PRP) treatment.

METHODS

Observational retrospective single center study. Medical charts of patients who underwent PRP for proliferative diabetic retinopathy were revised. Patients were included if they had the first eye treated with oxybuprocaine hydrochloride drops, and in case of severe pain, the fellow eye received topical anesthesia in combination with 2% subconjunctival lidocaine. The groups were compared for pain perception using an analog visual scale (VAS), number of laser spots, number of interruptions, and laser session duration.

RESULTS

Forty-two eyes of 21 patients (mean age: 58.3 ± 7.6 years) were analyzed. The mean number of laser spots was significantly higher under combined anesthesia (+84.2 ± 155.9 spots, p = 0.01), with a reduced time for laser execution (-2.5 ± 3.12, p = 0.0008). The use of combined anesthesia significantly decreased the number of interruptions (-40.8%, p < 0.0001) into a single session. On the pain grading scale, the pain perception was significantly lower in the combined anesthesia group (p < 0.0001). In eyes receiving topical anesthesia the treatment was stopped for pain in 5 eyes (23.8%), while 5 eyes under combined anesthesia presented subconjunctival hemorrhage (23.8%).

CONCLUSION

Using combined anesthesia in patients subjected to PRP appeared to reduce pain perception limiting the treatment duration and the interruptions for pain without significant complications. Further studies on a larger scale would be desirable to replicate such findings and standardize the analgesic procedures in ophthalmology.

Visual outcome of treating proliferative sickle cell retinopathy in 108 eyes

AIM

To report treatment methods and visual outcome of treating proliferative sickle cell retinopathy (PSCR).

DESIGN

Retrospective interventional.

METHODS

Review of PSCR eyes treated between 2017 to 2022. Patient demographics, fundus findings at presentation, genotype, PSCR stage, treatment used, and visual outcome were assessed.

RESULTS

108 eyes of 88 consecutive patients were studied. Male: Female 48:40. Mean age: 38.91 (SD:12.52) years. Genotype: sickle cell haemoglobin C (SC) 83 eyes (76.9%), sickle cell haemoglobin S (SS) 19 eyes (17.6%), and sickle cell trait (AS) 6 eyes (5.5%). PSCR stages: 3: 15 eyes (11.0%), 4: 74 eyes (67.0%), and 5: 19 eyes (22.0%). Treatment methods: Intravitreal Injection (IVI) of anti-vascular endothelial growth factor (VEGF) only (27 eyes,25%), scatter retinal laser photocoagulation (SRLP) only (7 eyes, 6.5%), Vitrectomy + SRLP (29 eyes, 26.9%), IVI + SRLP (25 eyes, 23.1%), and Vitrectomy + IVI + SRLP (20 eyes, 18.5%). The treatment used correlated with PSCR stage (p = 0.000). IVI only was mostly used to treat stage 4 (81.4%), and SRLP only was used for stages 3 (42.9%) and 5 (57.1%). IVI + SRLP treated eyes had the best pre- and post-treatment vision. Vitrectomy + SRLP treated eyes had the most improved vision. SRLP only had least visual improvement. Fundus findings correlated with visual outcome (p = 0.003); but stage of PSCR, genotype and treatment used had no correlation (P > 0.05).

CONCLUSION

Several options effectively treat PSCR. Visual outcome improved or remained same in 90.7% of treated eyes. Randomized controlled trials will determine the optimum treatment for each distinct presentation of PSCR. Treatment guidelines and a disease classification system of prognostic value are unmet needs.

Aflibercept 5+PRN with retinal laser photocoagulation is more effective than retinal laser photocoagulation alone and aflibercept 3+PRN with retinal laser photocoagulation in patients with high-risk proliferative diabetic retinopathy and diabetic macular edema: a 12-month clinical trial

Objective

This study aimed to investigate and compare the efficacy and safety of retinal laser photocoagulation (PRP) alone, PRP with aflibercept 3+PRN, and PRP with aflibercept 5+PRN in patients with both high-risk proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME).

Methods

Overall, 170 patients with high-risk PDR and DME (170 eyes from 170 patients) who visited our ophthalmology clinic from December 2018 to December 2020 were divided into the PRP (n=58), aflibercept 5+PRN with PRP (n=53), and aflibercept 3+PRN with PRP (n= 59) groups. General information, such as age, sex, and eye category, was obtained. Moreover, best-corrected visual acuity (BCVA), baseline central macular foveal thickness (CFT), microaneurysm (MA), area of neovascularization (NV), area of hard exudate (HE), and cytokine levels in atrial fluid before and after treatment, were assessed. The χ2 test was used for comparison between groups for statistical data. Analysis of variance was used for the statistical description of measurement data, independent samples were analyzed using Student's t-test, and Student-Newman-Keuls test was used for group comparisons. Differences were considered statistically significant at P < 0.05.

Results

After treatment, no significant improvement in the BCVA (logMAR) of patients in the PRP group was observed. The BCVA (log MAR) decreased from 0.72 ± 0.17 and 0.74 ± 0.17 to 0.50 ± 0.13 and 0.53 ± 0.17 in PRP with aflibercept 5+PRN and PRP with aflibercept 3+PRN groups, respectively, with a statistically significant difference compared to those in the PRP group (P<0.05 in all cases). However, no statistically significant difference was observed between the combined treatment groups (P>0.05). The CFT in the PRP-only group decreased slightly from 361.80 ± 36.70 μm to 353.86 ± 40.88 μm, with no statistically significant difference (P>0.05), whereas the CFT in the aflibercept 5+PRN with PRP and aflibercept 3+PRN with PRP groups decreased from 356.57 ± 37.57 μm and 358.17 ± 44.66 μm to 284.87 ± 31.52 μm and 303.19 ± 37.00 μm, respectively, with statistically significant differences before and after treatment (P<0.05 for both groups). Statistically significant differences were observed in CFT between the three groups after treatment (P<0.05 in all cases). The number of MA (pcs) in the PRP, aflibercept 5+PRN with PRP, and aflibercept 3+PRN with PRP groups decreased from 118.34 ± 27.96, 118.60 ± 33.34, and 116.59 ± 28.95 to 92.95 ± 29.04, 44.60 ± 20.73, and 54.26 ± 25.43, respectively. The two-way comparison of the three groups revealed statistically significant differences in MA (P<0.05 in all cases). In the three groups, NV decreased from 1.00 ± 0.21 mm², 1.01 ± 0.18 mm², and 0.98 ± 0.20 mm² before treatment to 0.49 ± 0.17 mm², 0.31 ± 0.16 mm², and 0.38 ± 0.14 mm², respectively, with statistically significant differences (P<0.05 in all cases). After 12 months of treatment, 13, 18, and 18 patients had reduced HE area in the PRP-only, aflibercept 5+PRN with PRP, and aflibercept 3+PRN with PRP groups, respectively, with statistically significant differences (P<0.05 in all cases). After 12 months of treatment, vascular endothelial growth factor, monocyte chemoattractant protein-1, and glial fibrilliary acidic protein levels (pg/mL) in the aqueous humor decreased in both combined treatment groups compared with that at baseline, with statistically significant differences; however, no significant difference was observed between the two combined treatment groups (P>0.05).

Conclusion

Aflibercept 5+PRN combined with PRP was safe and effective in treating patients with high-risk PDR and DME, and was more effective than PRP-only and aflibercept 3+PRN with PRP in improving CFT and MA.

Subthreshold micropulse diode laser treatment in diabetic macular edema: biological impact, therapeutic effects, and safety

PURPOSE

To introduce the treatment of diabetic macular edema (DME) with subthreshold micropulse diode laser (SMPL), to summarize the biological impact, therapeutic effects, and safety of this treatment, and to discuss the response to DME when SMPL is combined with anti-vascular endothelial growth factor (anti-VEGF) or steroid.

METHODS

The literature search was performed on the PubMed database, with a selection of English-language articles published from 2000 to 2023 with the following combinations of search terms: diabetes macular (o) edema, micropulse laser or subthreshold micropulse laser, anti-vascular endothelial growth factor, and steroid.

RESULTS

SMPL is a popular, invisible retinal laser phototherapy that is inexpensive, safe, and effective in the treatment of DME. It can selectively target the retinal pigment epithelium, reduce the expression of pro-inflammatory factors, promote the absorption of macular edema, and exert a similar and lasting clinical effect to traditional lasers. No significant difference was found in the therapeutic effects of SMPL between different wavelengths. However, HbA1c level and pretreatment central macular thickness (CMT) may affect the therapeutic outcomes of SMPL.

CONCLUSION

SMPL has a slow onset and produces lasting clinical effects similar to conventional photocoagulation. It has been reported that SMPL combined with the intravitreal anti-VEGF injection can significantly reduce the number of injections without influencing the therapeutic effect, which is essential for clinical applications and research. Although 577 nm SMPL is widely used clinically, there are no standardized protocols for SMPL. Additionally, some important problems regarding the treatment of SMPL require further discussion and exploration.

Clinical efficacy of subthreshold micropulse laser combined with anti-VEGF drugs in the treatment of diabetic macular edema: A meta-analysis

BACKGROUND

To systematically evaluate the efficacy and safety of subthreshold micropulse laser (SML) combined with anti-vascular endothelial growth factor (VEGF) drugs for the treatment of diabetic macular edema (DME).

METHODS

The randomized controlled trials on SML combined with anti-VEGF drugs for DME were retrieved from China National Knowledge Infrastructure, Wan Fang Data, VIP Data, Sino Med (China Biomedical Literature Database), PubMed, Web of Science, The Cochrane Library, and Embase by computer from inception to April 19, 2022. The observation group was treated with SML combined with anti-VEGF drugs, while the control group was treated with anti-VEGF agents alone or SML. And the references of the included literature were manually searched. The Meta-analysis was performed using Revman 5.4 and STATA SE 15.

RESULTS

This study finally included 15 randomized controlled trials involving 891 eyes for Meta-analysis. The results showed that there was no statistically significant difference between the 2 groups in best-corrected visual acuity at 1, 3, 6, 9, and 12 months after treatment. There was no statistical difference between the 2 groups in central macular thickness (CMT) at 1, 3, and 6 months after treatment (P > .05). CMT in the observation group was lower than that in the control group at 9 and 12 months (P < .05). There was no statistical difference between the 2 groups in total macular volume at 3, 6, 9, and 12 months in CMT (P > .05). The number of anti-VEGF drugs injections in the observation was lower than that in the control group (P < .05). The occurrence of complications between the 2 groups was not statistically significant difference (P > .05).

CONCLUSION

SML in combination with anti-VEGF drugs in patients with DME are comparable in reducing the number of anti-VEGF drugs injections and CMT, thereby reducing the financial burden on patients. It does not differ in best-corrected visual acuity and total macular volume.

Vitreous rebleeding rate after vitrectomy or phacovitrectomy in patients with proliferative diabetic retinopathy: A retrospective study

BACKGROUND

The most common complication after vitrectomy is the rebleeding in vitreous cavity. It is important to detect the different factors that can increase the vitreous rebleeding rate in these patients.

OBJECTIVE

To carry out a retrospective review of the rate of vitreous rebleeding after vitrectomy or phacovitrectomy.

METHOD

Retrospective, descriptive and comparative study of patients with a diagnosis of proliferative diabetic retinopathy with phacovitrectomy or vitrectomy procedure. Personal background data, type of surgical intervention and grade of the surgeon who carried out the procedure were obtained.

RESULTS

1227 files of diabetic patients with vitrectomy or phacovitrectomy were reviewed. 65% presented systemic arterial hypertension. The average glomerular filtration rate was 63.50 (±32.36) ml/min/1.73 m2 and glycosylated hemoglobin (HBA1C) of 8% (4.6 to 15%). In the comparison of variables, a significant difference in the rate of vitreous rebleeding was obtained comparing phacovitrectomy with vitrectomy. (p = 0.003), in the relationship between vitrectomy with vitreous rebleeding, an odds ratio of 1.44 was obtained.

CONCLUSION

The results obtained show a lower rate of rebleeding in patients undergoing phacovitrectomy in patients with proliferative diabetic retinopathy.

Subthreshold Photocoagulation, Laser Endpoint Management Based on Optical Coherence Tomography Angiography in Cases of Diabetic Macular Edema Refractory to Anti-VEGF

PURPOSE

This study aimed to determine the changes that occur in the vasculature, as based on optical coherence tomography angiography (OCTA) after non-damaging endpoint management (EpM), using a continuous wave yellow laser. The study was on eyes with diabetic macular edema (DME) that were resistant to anti-vascular endothelial growth factors (anti-VEGFs).

MATERIALS AND METHODS

This was a retrospective analysis of OCTA images of 44 eyes in 44 patients with DME refractory to anti-VEGF. The eyes were treated with a PASCAL Streamline yellow laser (577 nm wavelength, 200 mm spot size). Treatment was administered to the DME area and utilized 10% continuous wave laser energy and 0.50 µm beam diameter spot spacing. Best-corrected visual acuity (BCVA) and enhanced in-depth imaging with optical coherence tomography (EDI-OCT) and fundus autofluorescence (FAF) images were recorded at baseline, and 3 and 6 months posttreatment. Total choroidal area (TCA), luminal area (LA), stromal area (SA), and the choroidal vascularity index (CVI) were calculated using Image J software. The macula was divided into five quadrants in accordance with the mapping system in the Early Treatment Diabetic Retinopathy Study (ETDRS).

RESULTS

All patients (mean age: 58.90 ± 9.55 years) were diagnosed with diabetes mellitus type 2. Mean BCVA at baseline was 0.30 ± 0.11 logarithm of the minimum angle of resolution (logMAR) versus 0.23 ± 0.10 logMAR at 3 months (p = 0.032) and 0.17 ± 0.10 logMAR at 6 months (p = 0.013). The foveal avascular zone area (FAZ) decreased in the deep capillary plexus (DCP) from baseline to 6 months (p = 0.028). Vessel densities (VDs) of the superficial capillary plexus (SCP), DCP, and choriocapillaris decreased significantly in the fovea at 3 and 6 months compared to baseline (p < 0.05 for both follow-up time points). There were significant decreases in SCP and DCP in the superior quadrant at the end of month 6 (p = 0.001 and p = 0.038, respectively). There was a significant decrease in the nasal quadrant of the DCP and choriocapillaris at the end of month 6 (p = 0.024 and p = 0.049, respectively). Although there was a significant decrease in central macular thickness (CMT) (p < 0.001), subfoveal choroidal thickness (SFCT) (p < 0.001), and LA (p = 0.034) at months 3 and 6, there was no significant change in the CVI (p = 0.19). According to the DME recovery rate, 36 eyes (81%) were irradiated once, whereas 8 eyes (19%) were irradiated twice.

CONCLUSIONS

Non-damaging EpM therapy using a continuous wave yellow laser in eyes with DME that are resistant to anti-VEGFs induces significant changes in the SCP, choriocapillaris, and, most commonly, the DCP, which caused a significant decrease in VDs during 6 months of follow-up.