Analysis of Neurotrophins in Patients with Diabetic Retinopathy

Abstract

 

Purpose

 

Diabetic retinopathy is the foremost cause of irreversible acquired blindness in the Western World, secondary to both vascular and neural dysfunction. Numerous studies have demonstrated that hyperglycemia-induced pathways result in an inflammatory response with oxidative stress, apoptosis, and the promotion of angiogenesis (Figure 1). Subsequent retinal neurodegeneration results from altered levels of Neurotrophins (NT), such as Brain Derived Neurotrophic Factor (BDNF), Ciliary Neurotrophic Factor (CNTF), Nerve Growth Factor (NGF), Glial Cell Line Derived Neurotrophic Factor (GDNF), Neurotrophin-3 (NT3). Hence, Neurotrophins play an important, but uncharacterized, role in delaying the onset of vascular damage in diabetic retinopathy. In our study, we aspire to assay the human vitreous in an attempt to further investigate the role of Neurotrophins in diabetic retinopathy.

 

Methods

 

Prospective study with 51 patients, whom met study criteria, were enrolled into the study between December 2012 and December 2013. All patients with a history of uveitis (active or inactive at time of surgery), steroid use (intravitreal or systemic), intraocular trauma, intraocular surgery within the past 6 months and/or previous vitreoretinal surgery were excluded from this study. A single surgeon (AT) obtained a 0.8mL specimen of undiluted vitreous that was transferred directly to cryotubes to be stored at −80°C. Quantitative analysis was determined using Cytometric Bead Array (CBA) system (BD, Heidelberg, Germany).

 

Results

 

Fifty-one eyes of 51 patients were enrolled in our prospective study, Twenty-four eyes (47.1%) were of diabetic patients requiring pars plana vitrectomy, and 27 eyes (52.9%) stood as non-diabetic control eyes and required pars plana vitrectomy for non-diabetic causes. The average patient age was 65.4 years (range: 42-90). Our quantitative data (Figure 2) indicates the expression of Neurotrophins in the human vitreous.

 

Conclusions

 

Our study has established the presence of Neurotrophins in the human vitreous. Moving forward, future studies shall increase the sample size and study power. Also, a patient centered approached to therapeutic agents and prognostic assessment shall be sought.

 

 

Figure 1 - Biochemical and molecular mechanisms of diabetic retinopathy

 

 

Table 2 - Relationships between patients and the expression of Intravitreal Neurotrophins.

 

Keywords: 490 cytokines/chemokines • 499 diabetic retinopathy • 763 vitreous