Ocriplasmin: who is the best candidate?

Identification of key genes in colorectal cancer diagnosis by co-expression analysis weighted gene co-expression network analysis

BACKGROUND

The purpose of this study was using bioinformatics tools to identify biomarkers and molecular factors involved in the diagnosis of colorectal cancer, which are effective for the diagnosis and treatment of the disease.

METHODS

We determined differentially expressed genes (DEGs) related to colorectal cancer (CRC) using the data series retrieved from GEO database. Then the weighted gene co-expression network analysis (WGCNA) was conducted to explore co-expression modules related to CRC diagnosis. Next, the relationship between the integrated modules with clinical features such as the stage of CRC was evaluated. Other downstream analyses were performed on selected module genes.

RESULTS

In this study, after performing the WGCNA method, a module named blue module which was more significantly associated with the CRC stage was selected for further evaluation. Afterward, the Protein-protein interaction network through sting software for 154 genes of the blue module was constructed and eight hub genes were identified through the evaluation of constructed network with Cytoscape. Among these eight hub genes, upregulation of MMP9, SERPINH1, COL1A2, COL5A2, COL1A1, SPARC, and COL5A1 in CRC was validated in other microarray and TCGA data. Based on the results of the mRNA-miRNA interaction network, SERPINH1 was found as a target gene of miR-940. Finally, results of the DGIDB database indicated that Andecaliximab, Carboxylated glucosamine, Marimastat, Tozuleristide, S-3304, Incyclinide, Curcumin, Prinomastat, Demethylwedelolactone, and Bevacizumab, could be used as a therapeutic agent for targeting the MMP9. Furthermore, Ocriplasmin and Collagenase clostridium histolyticum could target COL1A1, COL1A2, COL5A1, and COL5A2.

CONCLUSION

Taken together, the results of the current study indicated that seven hub genes including COL1A2, COL5A1, COL5A2, SERPINH1, MMP9, SPARC, and COL1A1 which were upregulated in CRC could be used as a diagnostic and progression biomarker of CRC. On the other hand, miR-940 which targets SERPINH1 could be used as a potential biomarker of CRC. More ever, Andecaliximab, Carboxylated glucosamine, Marimastat, Tozuleristide, S-3304, Incyclinide, Curcumin, Prinomastat, Demethylwedelolactone, Bevacizumab, Ocriplasmin , and Collagenase clostridium histolyticum were introduced as therapeutic agents for CRC which their therapeutic potential should be evaluated experimentally.

Internal limiting membrane peeling in macular hole surgery

Since the era when macular hole was considered untreatable, macular hole surgery has come a long way to being one of the most successful surgeries. Internal limiting membrane (ILM) peeling has been an essential step of macular hole surgery since the establishment of the role of ILM in the aetiopathogenesis and progression of macular hole. However, the novel technique was not all virtuous. It had some vices which were not evident immediately. With the advent of spectral domain optical coherence tomography, short- and long-term effects of ILM peeling on macular structures were known; and with microperimetry, its effect on the function of macula could be evaluated. The technique has evolved with time from total peeling to inverted flap to just temporal peeling and temporal flap in an attempt to mitigate its adverse effects and to improve its surgical outcome. ILM abrasion technique and Ocriplasmin may eliminate the need of ILM peeling in selected cases, but they have their own limitations. We here discuss the role of ILM in the pathogenesis of macular hole, the benefits and adverse effects of ILM peeling, and the various modifications of the procedure, to then explore the alternatives.

REVISED PREDICTIVE BIOMARKER FOR OCRIPLASMIN THERAPY IN VITREOMACULAR TRACTION DISORDERS

PURPOSE

To determine a statistically optimal limit of adhesion size in vitreomacular traction (VMT) syndrome for ocriplasmin treatment.

METHODS

In this retrospective, consecutive, interventional study, we included 106 patients treated with ocriplasmin injection because of VMT between July 2013 and January 2018. A univariate and multivariate risk analysis was performed with grouped factors and continuous factors. We used a receiver operating characteristic curve to measure the prognostic relevance of each continuous factor for therapy success and determined the statistically optimal cutoff value at which specificity and sensitivity are simultaneously maximized.

RESULTS

Among the grouped factors, only a phakic lens status showed a highly significant positive influence on the resolution of the VMT. For the continuous factors, only the adhesion diameter before injection was a good predictor of anatomical success. The statistically optimal threshold value for the adhesion size was calculated to be 480 µm. Eyes below this limit had a 6.84-fold better chance of VMT resolution compared with eyes with a larger adhesion diameter.

CONCLUSION

The threshold value of the VMT diameter for ocriplasmin therapy could be statistically defined as 480 µm and may thus be a new quantitative biomarker to predict treatment success.

[Biomarkers in full-thickness and lamellar defects of the macula]

BACKGROUND

Biomarkers are characteristic biological measurable signs and objective parameters to detect the state of health. Besides functional and temporal factors, imaging biomarkers play an increasingly important role. In full-thickness and lamellar defects of the macula numerous imaging parameters have been described. This knowledge resulted in new classifications for both clinical pictures, which are based on important biomarkers of these clinical pictures and characteristic features of described subtypes.

METHODS

Imaging biomarkers for full-thickness and lamellar macular defects are described with respect to the classification and their functional prognostic importance. The importance of these biomarkers is presented.

RESULTS

The current classification of full-thickness and lamellar macular defects is based on structural biomarkers. Biomarkers are important for prognostic and therapeutic evaluation and they have an impact on the surgical strategy. There are various surgical strategies for treatment of full-thickness macular holes depending on the size of the foramen and other biomarkers. The inverted ILM flap technique improves the closure rate of large macular holes. In lamellar macular holes showing signs of progression an early surgical intervention results in a good anatomical and functional prognosis.

CONCLUSION

Multimodal diagnostics provide important preoperative, intraoperative, and postoperative features for macular holes and lamellar macular holes, which are essential biomarkers for the exact classification, the therapeutic strategy and for assessment of the prognosis.

Mutational Analysis of Ocriplasmin to Reduce Proteolytic and Autolytic Activity in Pichia pastoris

BACKGROUND

Ocriplasmin (Jetrea) is using for the treatment of symptomatic vitreomacular adhesion. This enzyme undergoes rapid inactivation and limited activity duration as a result of its autolytic nature after injection within the eye. Moreover, the proteolytic activity can cause photoreceptor damage, which may result in visual impairment in more serious cases.

RESULTS

The present research aimed to reduce the disadvantages of ocriplasmin using site-directed mutagenesis. To reduce the autolytic activity of ocriplasmin in the first variant, lysine 156 changed to glutamic acid and, in the second variant for the proteolytic activity reduction, alanine 59 mutated to threonine. The third variant contained both mutations. Expression of wild type and three mutant variants of ocriplasmin constructs were done in the Pichia pastoris expression system. The mutant variants were analyzed in silico and in vitro and compared to the wild type. The kinetic parameters of ocriplasmin variants showed both variants with K156E substitution were more resistant to autolytic degradation than wild-type. These variants also exhibited reduced Kcat and Vmax values. An increase in their Km values, leading to a decreased catalytic efficiency (the Kcat/Km ratio) of autolytic and mixed variants. Moreover, in the variant with A59T mutation, Kcat and Vmax values have reduced compared to wild type. The mix variants showed the most increase in Km value (almost 2-fold) as well as reduced enzymatic affinity to the substrate. Thus, the results indicated that combined mutations at the ocriplasmin sequence were more effective compared with single mutations.

CONCLUSIONS

The results indicated such variants represent valuable tools for the investigation of therapeutic strategies aiming at the non-surgical resolution of vitreomacular adhesion.

[Microstructural retinal changes after pharmacological vitreolysis with ocriplasmin-an SD-OCT supported analysis]

PURPOSE

Ocriplasmin (Jetrea®) is a therapeutic option for patients with focal vitreomacular traction (VMT) with or without small full thickness macular holes (FTMH) < 400 µm. Retinal alterations after injection with ocriplasmin have been described. The purpose of this essay was to determine Ocriplasmin-associated side-effects and changes in the retinal microstructure.

METHODS

We included 70 patients with ocriplasmin treatment in our study. On all patients SD-OCT (spectral-domain optical coherence tomography) scans were performed prior to injection with Ocriplasmin. If present, adverse events were registered. The OCT scans were then evaluated taking the following into account: macular hole (MH) size, macular edema, subretinal fluid (SRF), changes in the ellipsoid zone (EZ) and the external limiting membrane (ELM).

RESULTS

Twenty of the 70 examined patients showed a preoperative FTMH. One week after ocriplasmin IVI (intravitreal injection) 8 of the 20 FTMHs were already closed. Overall 12 patients showed a FTMH closure and 4 patients developed a FTMH after ocriplasmin IVI. Twelve of the 24 MH (macular hole) patients still required an operative closure of the FTMH. We noticed a resolution of the VMT on 51 patients. Three patients developed a retinal detachment. Furthermore, after ocriplasmin IVI we detected changes in the EZ and ELM on 8 patients.

CONCLUSIONS

Ocriplasmin is a substantial minimal invasive option in the therapy of VMT with or without small FTMH. Nevertheless, there seem to be some specific ocriplasmin-associated risks, although usually transient. Severe complications like retinal detachment are rare but exist. Therefore, every indication of ocriplasmin should be considered carefully.

Vision Preference Value Scale and Patient Preferences in Choosing Therapy for Symptomatic Vitreomacular Interface Abnormality

Importance

While symptomatic vitreomacular interface abnormalities (VIAs) are common, assessment of vision preference values and treatment preferences of these may guide treatment recommendations by physicians and influence third-party payers.

Objective

To determine preference values that individuals with VIA assign to their visual state and preferences of potential treatments.

Design, Setting, and Participants

In this cross-sectional one-time questionnaire study conducted between December 2015 and January 2017, 213 patients from tertiary care referral centers in Thailand, the United Kingdom, and the United States were studied. Patients with symptomatic VIA diagnosed within 1 year of data collection, visual acuity less than 20/20 OU, and symptoms ascribed to VIAs were included. Data were analyzed from January 2017 to November 2017.

Main Outcomes and Measures

The primary end points were overall mean preference value that individuals with VIA assigned to their visual state and patients' preferences for potential treatments. Preference values were graded on a scale from 0 to 1, with 0 indicating death and 1 indicating perfect health with perfect vision.

Results

Of the 213 included patients, 139 (65.3%) were women, and the mean (SD) age was 65.6 (7.7) years. Diagnoses included epiretinal membrane (n = 100 [46.9%]), macular hole (n = 99 [46.5%]), and vitreomacular traction (n = 14 [6.6%]). The mean (SD) vision preference value was 0.76 (0.15), without differences identified among the 3 VIA types. More participants were enthusiastic about vitrectomy (150 [71.1%]) compared with intravitreal injection (120 [56.9%]) (difference, 14.2%; 95% CI, 5.16-23.3; P = .002). Adjusted analyses showed enthusiasm for vitrectomy was associated with fellow eye visual acuity (odds ratio, 10.99; 95% CI, 2.01-59.97; P = .006) and better-seeing eye visual acuity (odds ratio, 0.03; 95% CI, 0.001-0.66; P = .03). Overall enthusiasm for treatment was associated with fellow eye visual acuity (odds ratio, 7.22; 95% CI, 1.29-40.40; P = .02). Overall, most participants (171 [81.0%]) were enthusiastic about surgery, injection, or both.

Conclusions and Relevance

Study participants reported similar preference values among 3 types of VIAs. The data suggest that most patients with these conditions would be enthusiastic about undergoing vitrectomy or an injection to treat it, likely because of the condition's effect on visual functioning, although there may be a slight preference for vitrectomy at this time.

PNEUMATIC VITREOLYSIS FOR RELIEF OF VITREOMACULAR TRACTION

Pneumatic vitreolysis with C₃F₈ gas is effective in releasing focal vitreomacular traction in a high percentage of eyes with few adverse events, especially with limited vitreomacular traction (within 1 disk area), lack of thick cellophane membranes, no diabetes mellitus, younger age (mean age of 69.1 years vs. 78.1 years), better baseline best spectacle–corrected visual acuity (mean of 20/50 vs. 20/66), small Stage 2 macular hole, and female gender.

Purpose:

To evaluate the outcome of perfluoropropane (C₃F₈) gas injection for symptomatic vitreomacular traction (VMT) with or without Stage 2 macular hole (MH).

Methods:

A retrospective review of eyes with VMT treated with 0.3 mL of C₃F₈ gas was performed. Patients avoided the supine position until gas resolution. Patients with small MH maintained partial face-down positioning.

Results:

Forty-nine consecutive patients (50 eyes) with symptomatic VMT underwent pneumatic vitreolysis between 2010 and 2016. A posterior vitreous detachment developed in 43 eyes (86.0%) after a single gas injection, at a median of 3.0 weeks. Twenty-eight of 35 eyes (80.0%) with VMT only and all 15 eyes (100%) with a small Stage 2 MH developed a posterior vitreous detachment, with MH closure in 10 of 15 eyes (66.7%). Median baseline and last best spectacle–corrected visual acuities were 20/50 and 20/40, respectively (P < 0.001). Mean follow-up time was 11.1 ± 9.9 months. Rate of posterior vitreous detachment was reduced with presence of diabetes mellitus (25%) and with thick cellophane membrane (50%). Univariate analysis showed increased VMT release for eyes with VMT extent within 1 disk area (χ² = 13.1, P = 0.002), eyes with absence of diabetes mellitus (χ² = 8.8, P = 0.007), and eyes with Stage 2 MH (χ² = 5.47, P = 0.019); there was a trend between success and lack of thick cellophane membrane (χ² = 3.32, P = 0.068). Results using logistic regression also showed younger age (P = 0.012), followed by better baseline best spectacle–corrected visual acuity (P = 0.044), lack of diabetes mellitus (P = 0.077), and female gender (P = 0.045) to be predictors of increased VMT release. One VMT-only eye formed a MH and another VMT-only eye developed a retinal detachment. Both eyes responded to vitrectomy.

Conclusion:

Pneumatic vitreolysis with limited face-down position is a viable option for treating VMT with few adverse events. More studies are needed to elucidate its indications, benefits, and risks.

Ocriplasmin retinopathy: Possible cause of macular hole closure failure

CASE REPORT

A 53 year-old woman with a stage 2 macular hole received ocriplasmin injection as a first approach. She subsequently underwent pars plana vitrectomy due to enlargement of the hole post-injection. The visual gain following the surgery was minimal despite closure of the hole. This could be explained by outer retina atrophy as a consequence of potential toxic mechanisms related to ocriplasmin.

DISCUSSION

Further studies may be warranted to fully understand the impact of ocriplasmin on long-term visual function.

From the analysis of pharmacologic vitreolysis to the comprehension of ocriplasmin safety

INTRODUCTION

Pharmacologic vitreolysis is a strategy used to treat anomalous posterior vitreous detachment, by weakening vitreoretinal adhesion with an intravitreal drug. Pharmacologic vitreolysis facilitates surgery, and abnormalities of the vitreoretinal interface including vitreomacular traction (VMT) and early stage macular hole (MH) could be resolved. Ocriplasmin is a recombinant protease, active against fibronectin and laminin, which are important components of the vitreoretinal interface. Ocriplasmin has been approved for symptomatic treatment of VMT and MH with visible traction, and it functions by dissolving the proteins that link the vitreous to the macula, thereby creating a complete posterior vitreous detachment (PVD).

AREAS COVERED

This paper reviews the current knowledge and status of investigations regarding the use of ocriplasmin for pharmacologic vitreolysis and its safety.

EXPERT OPINION

Ocriplasmin is a non-specific enzyme; therefore, it dissolves vitreal proteins as well as possibly proteins associated with visual function in the retina, choroid, and lens. Ocular adverse events (OAEs) of ocriplasmin include transient visual loss, intraocular inflammation, vitreous floaters, lens opacification, zonular instability of the lens, and intraocular hemorrhage. The prevalence of the OAEs is very low; however, on rare occasions, they can result in widespread retinal dysfunction. Research into the acute and long-term safety of ocriplasmin is required.