Gisella Maestranzi

Macular dysfunction is common in both type 1 and type 2 diabetic patients without macular edema

Purpose: To study retinal function in asymptomatic Type 1 and Type 2 diabetic patients with nonproliferative diabetic retinopathy (NPDR) and no clinical signs of diabetic macular edema. Methods: Thirty-six consecutive Type 1 and Type 2 diabetic patients with nonproliferative diabetic retinopathy and no diabetic macular edema and 28 healthy controls underwent a complete ophthalmologic examination, including spectral domain optical coherence tomography and microperimetry. Results: Seventy-one eyes (17 patients with Type 1 and 19 with Type 2 diabetes) were tested, and data from 36 (17 Type 1 and 19 Type 2) eyes were analyzed. Mean best-corrected visual acuity was 0.00 ± 0.01 logMAR and 0.00 ± 0.02 logMAR for Type 1 and Type 2 diabetic patients, respectively (P = 0.075). Mean central foveal thickness was 234.5 ± 13.7 &mgr;m and 256.3 ± 12.7 &mgr;m for Type 1 and Type 2 diabetic patients, respectively (P = 0.04); the central foveal thickness was statistically different compared with the control groups (P = 0.04 and P = 0.01, respectively). Mean retinal sensitivity was 18.9 ± 0.5 dB and 17.7 ± 0.4 dB for Type 1 and Type 2 diabetic patients, respectively; it was statistically different compared with control groups (P < 0.0001 and P < 0.0001, respectively). Conclusion: We demonstrated a significantly reduced sensitivity in both nonproliferative diabetic retinopathy groups without diabetic macular edema compared with healthy controls; this reduction was greater in Type 2 diabetic patients. Central foveal thickness was increased in all diabetic patients compared with healthy controls, despite the absence of diabetic macular edema.

Macular micropseudocysts in early stages of diabetic retinopathy.

Purpose: To identify by noninvasive means early retinal abnormalities that may predict diabetic macular edema. Methods: The authors analyzed retrospectively data from consecutive patients with Type 1 (n = 16) or Type 2 (n = 23) diabetes who presented for routine follow-up of early retinopathy, had no clinical signs or symptoms of diabetic macular edema, and were evaluated with spectral-domain optical coherence tomography. Age- and gender-matched nondiabetic subjects provided normative data. Results: Spectral-domain optical coherence tomography revealed in the macular region of diabetic patients small hyporeflective areas (median diameter, 55 μm) contained within discrete retinal layers that we named micropseudocysts (MPCs). Micropseudocysts are associated with vascular leakage. The patients showing MPCs had more frequently systemic hypertension and increased central foveal thickness than those without MPCs. The association with increased central foveal thickness was only in the patients with Type 2 diabetes. Conclusion: Macular MPCs in patients with mild diabetic retinopathy appear to reflect leakage and can precede macular thickening. The association of MPCs with increased central foveal thickness in patients with Type 2 diabetes, but not in patients with Type 1 diabetes, points to a greater tendency to retinal fluid accumulation in patients with Type 2 diabetes. Studies in larger cohorts will determine the usefulness of MPCs in strategies to abort diabetic macular edema.

Vitreomacular traction syndrome: a comparison of treatment with intravitreal plasmin enzyme vs spontaneous vitreous separation without treatment

PurposeTo evaluate the effects of intravitreal autologous plasmin enzyme (APE) in patients with focal vitreomacular traction (VMT).MethodsAPE was obtained by incubation of patient-derived purified plasminogen with streptokinase, and intravitreally injected 5–12 days later. Twenty-four hours after injection, in case of incomplete VMT release, a pars plana vitrectomy was performed. The hyaloid internal limiting membrane adherence and removal of the posterior hyaloid were intraoperatively evaluated.ResultsThirteen patients were recruited. During preparation of APE, five patients had spontaneous release of VMT. Eight patients received APE injection (2 IU). In five patients, spontaneous resolution of VMT occurred before APE administration. Twenty-four hours after injection, persistence of VMT was detected in all the eight treated patients. Best-corrected visual acuity was 0.51±0.37 LogMAR at baseline, improving to 0.23±0.14 LogMAR at 6 months (P=0.002). Foveal thickness was 464±180 μm at baseline, reducing to 246±59 μm at 6 months (P<0.001). Hyaloid was intraoperatively judged ‘partially detached’ in seven cases and ‘totally detached’ in one case. Hyaloid peeling was evaluated ‘easy’ in six eyes and ‘very easy’ in two eyes.ConclusionsIn the current study, there was a large percentage of spontaneous resolution of VMT before an APE administration. A single intravitreal APE injection seems insufficient to induce a complete posterior vitreous detachment in these patients.

Reply to Grzybowski and Ascaso

Sir, We thank Drs Grzybowski and Ascaso1 for their interest in and comments on our recent article.2 We agree that in our paper there is a lack of details concerning the statistical tests used (which were omitted for the sake of brevity). In the study, we proved that each variable group was normally distributed using the Kolmogorov-Smirnov normality test. Then we applied the ANOVA for repeated measures test, which best fitted for our analysis. Please note, the Kruskal-Wallis test is valuable only for a two-group comparison. We also agree that the lack of a control group is crucial, and this was acknowledged as a limitation of our study. We also acknowledged the unmasked design of the study as a limitation of our analysis. Regarding the evaluation of posterior hyaloid peeling, our method to describe the intrasurgical findings has been already published by Azzolini et al3 in a study investigating autologous plasmin enzyme for diabetic macular oedema, and, to our knowledge, no other classification systems are available in the literature. In the conclusion section, we stated that a single intravitreal autologous plasmin enzyme injection seemed to be insufficient to induce a complete posterior vitreous detachment in patients affected by focal vitreomacular traction syndrome, as in our case series, we did not obtain any complete posterior vitreous detachment with a single injection. We thank the authors for the opportunity to clarify this important aspect, which we do not find contradictory. As per our ethical committee approved protocol (reported in the Methods section), we were allowed to perform just one single intravitreal injection for each study patient, with a 24-hour waiting time before vitrectomy. Although we could not ascertain if a greater time gap could have influenced the rate of posterior vitreous detachment occurrence, we remarked that the single injection appeared as a useful tool in vitreoretinal surgery by obtaining an easier-to-peel posterior hyaloid. Finally, during the revision process of our paper, we preferred to exclude the comparison of our results with the MIVI-IIT study,4 as the MIVI-IIT study has a very different study design and uses a different drug. Particularly, we believe that our impossibility (per protocol) to re-inject patients preclude any comparison between the two studies.

Surgical Management and Techniques

Technical advancements have substantially extended the indications for surgery in diabetic retinopathy (DR) during the last 40 years, from the traditional indications including non-clearing vitreous hemorrhage, traction retinal detachment (RD), and traction-rhegmatogenous RD, to epiretinal membrane (ERM), vitreomacular traction, diffuse macular edema, neovascular glaucoma, and anterior hyaloid fibrovascular proliferation. The goals of vitreoretinal surgery in DR are multiple: clearing media opacities, release of traction (anteroposterior and/or tangential), segmentation and/or removal of traction bands, peeling of ERMs, hemostasis, laser photocoagulation, and tamponade of retinal breaks with gas or silicone oil. The best management is achieved with integrated care provided by physicians with expertise in medical management of diabetes and surgical care of DR. In this chapter, the indications for surgery, preoperative considerations, surgical techniques, and complications, together with their management, will be discussed.

Sudden Visual Loss after Cardiac Resynchronization Therapy Device Implantation

Purpose To report a case of sudden decrease in visual acuity possibly due to a cardiogenic embolism in a patient who underwent cardiac resynchronization therapy (CRT) device implantation. Methods A 62-year-old man with severe left ventricular systolic dysfunction and a left bundle branch block was referred to our department because of a sudden decrease in visual acuity. Nine days earlier, he had undergone cardiac transapical implantation of a CRT device, which was followed, 2 days later, by an inflammatory reaction. The patient underwent several general and ophthalmologic examinations, including multimodal imaging. Results At presentation, right eye (RE) best-corrected visual acuity (BCVA) was counting fingers and RE pupil was hyporeactive. Fundus examination revealed white-centered hemorrhagic dots suggestive of Roth spots. Fluorescein angiography showed delay in vascular perfusion during early stage, late hyperfluorescence of the macula and optic disk, and peripheral perivascular leakage. The first visual field test showed complete loss of vision RE and a normal left eye. Due to suspected giant cell arteritis, temporal artery biopsy was performed. Thirty minutes after the procedure, an ischemic stroke with right hemisyndrome and aphasia occurred. The RE BCVA worsened to hands motion. Four months later, RE BCVA did not improve, despite improvement in fluorescein angiography inflammatory sign. Conclusions We report a possible cardiogenic embolism secondary to undiagnosed infective endocarditis causing monocular visual loss after CRT device implantation. It remains unclear how the embolus caused severe functional damage without altering the retinal anatomical structure.

Proliferative Diabetic Retinopathy

Proliferative diabetic retinopathy (PDR) is characterized by a fibrovascular proliferation that arises from the disk or from the superficial retinal vasculature, as a response to chronic retinal hypoxia. Panretinal photocoagulation (PRP) is the recommended treatment and a reduction of 50 % of severe visual loss has been described in the high-risk PDR group. Nevertheless, visual field loss, ingravescence of diabetic macular edema, and visual impairment have been reported as possible side effects. The injection of vascular endothelium factor (VEGF) inhibitor has shown some favorable effects in the regression of neovascularization, even if the benefits are limited and a high rate of recurrence has been shown in the short term. Thus, the combination therapy of anti-VEGF injection and PRP has been considered a valuable treatment option to improve the results in some selected cases.

Reply to Matonti et al.

Sir, We thank Dr Matonti et al1 for their interest in and comments on our recent article.2 We agree that in our study we should have been waiting longer to definitely assess the effects of autologous plasmin enzyme (APE) in patients with vitreomacular traction syndrome. In fact, although we could not ascertain if a greater time gap could have influenced the rate of posterior vitreous detachment occurrence, as Dr Matonti et al correctly pointed out, we remarked that the single injection appeared as a useful tool in vitreoretinal surgery because of obtaining an easier-to-peel posterior hyaloid.3 However, as per our ethical committee-approved protocol (reported in the Methods section), and due to medico-legal reasons, we were allowed to perform just one single intravitreal injection for each study patient, with a 24-h waiting time before vitrectomy. This, together with the impossibility (per protocol) to re-inject patients with APE, should be acknowledged as the limitation of our study.