Background: Diabetic cataract extraction can be frequently complicated by macular oedema, progression of retinopathy, or development of iris neovascularisation. The pathogenesis of these complications may be the result of changes in the concentration of angiogenic and anti-angiogenic cytokines in the immediate postoperative period. The study aims to prospectively analyse this. Methods: Uneventful phacoemulsification with intraocular lens implant was performed in seven eyes of six patients with diabetic retinopathy ranging from severe non-proliferative to quiescent proliferative. Patients were reviewed 1 day, 1 week, 1 month, and 3 months after surgery with fundus fluorescein angiography (FFA) and aqueous sampling. Each sample was analysed for VEGF, HGF, Il-1 b (pg/ ml), and PEDF (mg/ml) by sandwich ELISA. Results: Clinically significant macular oedema (CSMO) occurred in one patient although increased macular hyperfluorescence occurred in three patients on FFA at 1 month. VEGF 165 concentration increased 1 day after surgery from a median baseline of 68 pg/ml (range 22-87 pg/ml) to 723 pg/ml (range 336-2071) at day 1. By 1 month it had decreased to 179 (range 66-811 pg/ml). HGF concentrations steadily increased over the month while IL-1 b and PEDF concentrations demonstrated an acute rise on day 1 after surgery and then IL-1b returned to baseline concentrations while PEDF decreased to below baseline. Conclusion: These results confirm altered concentrations of angiogenic and antiangiogenic growth factors after cataract surgery, which may induce subclinical and clinical worsening of diabetic maculopathy.

Aim There are changes in blood flow during the clinical stages of diabetic retinopathy with increasing leukostasis and secondary elaboration of cytokines. This study evaluated the vitreous concentrations of haemodynamicrelated (endothelin-1 (ET-1) and nitric oxide (NO)), inflammatory and anti-inflammatory (interleukin-1 receptor antagonist, IL-1 Ra) cytokines in the diabetic patients (with nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR)), compared them with those of control patients (full thickness macular hole, FTMH) and correlated to macular structural indices. Method Vitreous samples from five FTMH patients representing normal controls were analysed together with the vitreous samples of 15 patients with NPDR and five with PDR. The vitreous concentrations of nitrite (total NO), ET-1, and prostacyclin was determined using ELISA kits (R&D Systems, Minneapolis, MN, USA) according to the manufacturer's instructions. A sandwich luminescent immunoassay technique was used to determine IL-1b and IL-1 Ra concentrations. Results In the different clinical groups, there were no differences in the vitreous NO and prostacyclin concentrations. In NPDR, the median ET-1 concentration (0.7 pg/ml SD 70.8 pg/ml) was significantly reduced (Po0.05), compared to PDR (6.35 pg/ml SD 70.6 pg/ml) and FTMH (3.6 pg/ml SD 70.14 pg/ml). Its concentration also positively correlated with foveal thickness and macular volume (Po0.05) in patients with NPDR and macular oedema. IL-1 b was detected in PDR, and diabetic patients demonstrated a lower concentration of the anti-inflammatory cytokine IL-1 Ra.Conclusion Reduced concentrations of ET-1 in NPDR may reflect the haemodynamic changes of NPDR. The IL-1 Ra concentration suggests a change in the anti-inflammatory environment of the diabetic retina.

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Purpose A prospective study to evaluate the macular structural and functional effects of pars plana vitrectomy (PPV) for persistent diffuse clinically significant macular oedema (CSMO). Method A total of 12 patients with persistent diffuse CSMO were recruited and underwent assessment including best-corrected visual acuity, fundus fluorescein angiography, optical coherence tomography (OCT) and fine matrix mapping (FMM) at baseline and over a period of a year poststandard three-port PPV. Results The median baseline ETDRS letters score for all 12 patients was 52 (range 41-63) while at 12 months it had increased to 65 (range of 27-68), an improvement of two complete ETDRS lines (P ¼ 0.037). Similarly, there was an improvement in the perifoveal cone thresholds (P ¼ 0.02). The foveal thickening for all 12 patients ranged from a median of 183 to 751 lm (normal range 126-180 lm) and the macular volume ranged from a median of 2.13 to 6.42 mm 3 (normal o1.66 mm 3 ). After surgery, both the median foveal thickness (from 334 to 280 lm) and median macular volume (from 3.24 to 2.61 mm 3 ) demonstrated decreases over 12 months (P ¼ 0.01). On baseline OCT, the patients fell into two anatomically distinct groups: Group 1 (n ¼ 4) had a dome-shaped thickened macula with a partial posterior hyaloid separation and a significantly higher foveal thickness and macular volume than Group 2 (n ¼ 8) which had a diffuse lowelevation profile of the thickened macula (P ¼ 0.007).

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