Deranged Metabolic Profile and Identification of Biomarkers in the Vitreous Humour of Patients with Proliferative Diabetic Retinopathy.

BACKGROUND: Systemic biochemical disarray has been implicated in the pathogenesis and progression of diabetes and its complications. However, the modifications in the metabolic state of the retina and its microenvironment in response to the systemic metabolic malfunction has not been documented. OBJECTIVE: The objective of the present study was to document the various biomarkers that may be involved in the pathogenesis and progression of Proliferative Diabetic Retinopathy (PDR). METHOD: The vitreous humour and plasma samples from 38 PDR, 7 Proliferative Vitreo Retinopathy (PVR) and 17 control patients undergoing pars plana vitrectomy were analysed for sixteen different biomarkers. Whole genome Single Nucleotide Polymorphism (SNP) microarray was performed on ten PDR patients' peripheral blood samples. RESULTS: The vitreous humour glucose, creatinine, micro protein, phosphorus and lactate dehydrogenase were found significantly increased in the PDR patients compared to controls. The plasma urea, creatinine and micro protein were also significantly increased. The plasma phosphorus of PDR patients on oral hypoglycemic therapy was found significantly decreased compared with PDR patients on insulin therapy and controls. SNPs previously associated with glucose (5), lactate dehydrogenase (2) and creatinine (2) levels were identified to be polymorphic homozygous (minor allele) in ≥ 60% patients in this study, suggesting enhanced susceptibility. CONCLUSION: The metabolic overactivity of the retinal microenvironment appears to play a vital role in the pathogenesis of PDR. The significantly elevated biomarkers may have diagnostic, prognostic and therapeutic significance. These findings shed light on the biochemical disarray in the vitreous humour of PDR patients that could have significant management implications.

Posterior Chamber Scleral Fixation of Intraocular Lenses in Post-Vitrectomised Aphakic Eyes.

INTRODUCTION: The best method of aphakia correction is in the bag implantation of Posterior Chamber Intraocular Lens (PCIOL). When this ideal procedure is not possible due to lack of integrity of posterior capsule or zonules, the other alternatives are broadly categorized into two: extraocular and intraocular. Whereas, the former includes contact lenses and aphakic glasses, the latter ones are further divided into anterior and posterior chamber methods. Anterior Chamber Intraocular Lenses (ACIOL) can be with or without iris claw. At the posterior chamber, fixation of the lenses can be with glue or sutures. When there is combined Pars Plana Vitrectomy (PPV) and lensectomy or if the indication of PPV is dropped nucleus or intraocular lens, a modality of aphakia correction should be devised. Posterior Chamber Scleral Fixation of Intraocular Lenses (PCSFIOL) with sutures is a preferred method because of its low complication profile. However, data on correction of aphakia after combined PPV and lensectomy is limited. To fill in this gap in knowledge, we evaluated the secondary PCSFIOL in aphakic eyes after previous PPV and lensectomy. AIM: To assess the outcome and complication profile of a large series of patients who underwent secondary PCSFIOL implantation with sutures after combined PPV and lensectomy. MATERIALS AND METHODS: Records of all patients who had undergone secondary PCSFIOL implantation with sutures after combined PPV and lensectomy from 2010 to 2014 were reviewed retrospectively for visual outcomes and complications. Patients' demographic data, indication for PPV, best corrected preoperative and postoperative visual acuities, complications of surgery, and indications of PCSFIOL and length of follow up were collected and analyzed. RESULTS: A total of 148 eyes of 148 patients (127 males and 21 females) were identified. Mean age at surgery was 32.5±8 years (range 2.5-73 years) with a mean follow up 23±14 months (range 3-114 months). A total of 95.27%, 2.70% and 2.02% of patients had improvement, maintenance and worsening of their final postoperative visual acuities respectively. A total of 32 (21.62%) of 148 eyes had postoperative complications from PCSFIOL with Epiretinal Membrane (ERM) formation being the most common. They all required one form of management or the other. Suture breakage leading to PCSFIOL subluxation or dislocation occurred in four eyes (2.70%). CONCLUSION: PCSFIOL with sutures is a preferred method in the management of post-vitrectomised aphakic eyes when the capsular or zonular support is not adequate for in the bag implantation of posterior chamber intraocular lenses.