Is cataract surgery a risk factor for progression of macular degeneration?

PURPOSE OF REVIEW: There is a suggestion of increased risk or progression of age-related macular degeneration after cataract surgery, which is related to the increased exposure of the retina to short-wavelength light. RECENT FINDINGS: Cell culture and animal work has described retinal and retinal pigment epithelium phototoxicity on acute light exposure. Clinical studies suggest that the use of short-wavelength-blocking intraocular lenses can help but may also affect visual function and circadian rhythm. SUMMARY: Evidence to date fails to prove conclusively that light alone or cataract surgery can induce or cause the progression of age-related macular degeneration. A randomized clinical study of the use of short-wavelength (blue)-blocking lenses to prove or disprove the ability of these intraocular lenses to help in preventing progression of age-related macular degeneration is needed.

Pars plana vitrectomy with and without peeling of the inner limiting membrane for diabetic macular edema.

PURPOSE: A prospective, comparative, nonrandomized study to evaluate the efficacy of pars plana vitrectomy (PPV) with and without inner limiting membrane (ILM) peeling for persistent diffuse clinically significant macular edema. METHODS: Eighteen patients with persistent diffuse clinically significant macular edema despite laser photocoagulation were recruited for the study. Clinical assessment included determination of best-corrected visual acuity, fundus fluorescein angiography, optical coherence tomography, and perifoveal cone function testing. Eight patients underwent PPV with elevation and removal of the posterior hyaloid alone, and 10 patients underwent vitrectomy and ILM peeling. The follow-up was 12 months. RESULTS: Patients with ILM peeling had improvement in foveal thickness (P = 0.07) and significant improvement in the macular volume (P = 0.039) 12 months after surgery but did not have significant improvement in Early Treatment Diabetic Retinopathy Study vision or perifoveal cone function. There was no significant difference in outcome parameters between the no peeling group and the ILM peeling group. CONCLUSIONS: In this prospective, comparative study of PPV with and without ILM peeling for diffuse clinically significant macular edema, structural improvement was seen but with limited visual improvement after ILM peeling.

Vitreous and aqueous concentrations of proangiogenic, antiangiogenic factors and other cytokines in diabetic retinopathy patients with macular edema: Implications for structural differences in macular profiles.

The aim of the study was to determine anatomical and growth factor profiles in patients with clinically significant macular oedema (CSMO) undergoing pars plana vitrectomy (PPV). Twenty patients with moderate nonproliferative diabetic retinopathy (NPDR) with persistent CSMO underwent PPV. Patients had baseline and postoperative clinical assessment including Ocular Coherence Tomography (OCT). Baseline vitreous and aqueous and serial postoperative aqueous samples were analysed for vascular endothelial growth factor-A (VEGF-A), pigment epithelium derived Factor (PEDF) and other factors (pg/ml) including hepatocyte growth factor, MMP 9, soluble flt-1 Receptor, and TGF beta1 by ELISA. Vitreous from patients with full thickness macular holes (8) and proliferative diabetic retinopathy (22) were collected for comparison as controls. Vitreous VEGF-A concentration in the NPDR group was 957 pg/ml compared to 239 pg/ml in the macula hole (FTMH) control (p < 0.0001) and 596 pg/ml compared to PDR (p = 0.006). The median diabetic vitreous PEDF concentration was 1.36 microg/ml (FTMH 2.6 microg/ml p = 0.05). In NPDR, it was higher (1.59 microg/ml) than PDR (1.27 microg/ml) p = 0.02. There were changes to the HGF, soluble flt-1 Receptor and TGF b1 concentrations in the NPDR compared to either PDR or the normal state. In CSMO, two OCT profiles were identified: dome-shaped macular elevation (Group 1) (n = 4) and diffuse-low elevation profile (Group 2) (n = 16) which also showed differences in the postoperative median aqueous VEGF concentrations despite macular volume decreasing for both. The results suggest that there is an up-regulation of VEGF in the vitreous of the diabetic eye with a reciprocal decrease in PEDF. The structural and molecular differences between the two OCT macular profiles may explain the varying response to PPV in patients with diffuse CSMO.