Age related macular degeneration and drusen: neuroinflammation in the retina

Inflammation protects from dangerous stimuli, restoring normal tissue homeostasis. Inflammatory response in the nervous system ("neuroinflammation") has distinct features, which are shared in several diseases. The retina is an immune-privileged site, and the tight balance of immune reaction can be disrupted and lead to age-related macular disease (AMD) and to its peculiar sign, the druse. Excessive activation of inflammatory and immunological cascade with subsequent induction of damage, persistent activation of resident immune cells, accumulation of byproducts that exceeds the normal capacity of clearance giving origin to a chronic local inflammation, alterations in the activation of the complement system, infiltration of macrophages, T-lymphocytes and mast-cells from the bloodstream, participate in the mechanisms which originate the drusen. In addition, aging of the retina and AMD involve also para-inflammation, by which immune cells react to persistent stressful stimuli generating low-grade inflammation, aimed at restoring function and maintaining tissue homeostasis by varying the set point in relation to the new altered conditions. This mechanism is also seen in the normal aging retina, but, in the presence of noxious stimuli as in AMD, it can become chronic and have an adverse outcome. Finally, autophagy may provide new insights to understand AMD pathology, due to its contribution in the removal of defective proteins. Therefore, the AMD retina can represent a valuable model to study neuroinflammation, its mechanisms and therapy in a restricted and controllable environment. Targeting these pathways could represent a new way to treat and prevent both exudative and dry forms of AMD.

Recent developments in the management of dry age-related macular degeneration

Dry age-related macular degeneration (AMD), also called geographic atrophy, is characterized by the atrophy of outer retinal layers and retinal pigment epithelium (RPE) cells. Dry AMD accounts for 80% of all intermediate and advanced forms of the disease. Although vision loss is mainly due to the neovascular form (75%), dry AMD remains a challenge for ophthalmologists because of the lack of effective therapies. Actual management consists of lifestyle modification, vitamin supplements, and supportive measures in the advanced stages. The Age-Related Eye Disease Study demonstrated a statistically significant protective effect of dietary supplementation of antioxidants (vitamin C, vitamin E, beta-carotene, zinc, and copper) on dry AMD progression rate. It was also stated that the consumption of omega-3 polyunsaturated fatty acids, such as docosahexaenoic acid and eicosapentaenoic acid, has protective effects. Other antioxidants, vitamins, and minerals (such as crocetin, curcumin, and vitamins B9, B12, and B6) are under evaluation, but the results are still uncertain. New strategies aim to 1) reduce or block drusen formation, 2) reduce or eliminate inflammation, 3) lower the accumulation of toxic by-products from the visual cycle, 4) reduce or eliminate retinal oxidative stress, 5) improve choroidal perfusion, 6) replace/repair or regenerate lost RPE cells and photoreceptors with stem cell therapy, and 7) develop a target gene therapy.

T-shaped macular buckling combined with 25G pars plana vitrectomy for macular hole, macular schisis, and macular detachment in highly myopic eyes

OBJECTIVE

To report our experience using the T-shaped macular buckle (MB) with or without pars plana vitrectomy (PPV) as primary surgery or with a previous failed surgical approach in patients affected by high myopia and macular hole (MH) with or without macular detachment and with or without macular schisis. The primary goal was to evaluate complete closure of the MH and reattachment of the retina.

DESIGN

Retrospective case series of 21 consecutive patients who underwent T-shaped MB implant alone or combined with PPV at the Academic Medical Center in Amsterdam, The Netherlands, between January 2013 and November 2014. The mean axial length was 31.22 mm. The mean follow-up period was 7 months.

RESULTS

Retinal reattachment was achieved in 100% of cases while MH closure was achieved in 90.5%. No major perioperative complications were observed. Best corrected visual acuity improved in 71.4% of patients.

CONCLUSIONS

MB combined with PPV should be considered as the preferred surgical approach both in primary and recurrent retinal detachment secondary to MH in high myopic eyes.

Optical coherence tomography evaluation of patients with macula-off retinal detachment after different postoperative posturing: a randomized pilot study

PURPOSE

To assess the presence of outer and inner retinal folds (RFs) and drop-out of the ellipsoid zone (EZ) occurring after surgical repair of macula-off rhegmatogenous retinal detachment (RRD) with different postoperative posture and preoperative use of adjuvant perfluorocarbon liquid (PFCO).

METHODS

In this prospective study, 56 eyes of 56 consecutive patients affected by RRD were subjected to 23- or 25-gauge pars plana vitrectomy (PPV). The patients were randomized in four groups (14 prone 5 hr without PFCO, 14 supine 5 hr without PFCO, 14 prone 5 hr with PFCO and 14 supine 5 hr with PFCO) and followed up with spectral domain optical coherence tomography (SD-OCT).

RESULTS

Spectral domain optical coherence tomography (SD-OCT) was recorded before surgery, at days 30 and 90 to detect the presence of outer RFs, inner RFs and drop-out of EZ and to follow their variation over time. No statistical significance was found in our groups for outer RFs, inner RFs, drop-out of EZ formation and evolution. The postoperative best-corrected visual acuity (BCVA) improved in all groups (mean preoperative BCVA 1.47 logMar ± 0.19, mean postoperative BCVA 0.27 logMar ± 0.11, p < 0.01), without statistical variations between the four groups in BCVA after surgery.

CONCLUSION

The use of adjuvant and variation in postoperative position did not change the risk of presenting outer RFs, inner RFs and drop-out of EZ after RRD.

Terson syndrome and leukemia: a case report

Background

Terson syndrome is defined as intraocular hemorrhage associated with intracranial bleeding. This syndrome can occur in the event of intracranial hemorrhage or elevated intracranial pressure. To our knowledge, it has never been associated with chronic myeloid leukemia. A 45-year-old woman suffering from chronic myeloid leukemia was referred to our clinic with Terson syndrome after intracranial bleeding. We followed this patient for a year, performing visual acuity assessment, fundus examination, color retinography, and A-scan and B-scan ultrasonography. At presentation, her best-corrected visual acuity on the right was 20/63 and on the left was 20/320. In the right eye, retinoscopy showed blurring of the optic margins surrounded by retinal and preretinal hemorrhages, preretinal fibrosis of the optic disc along the vascular arcades, and perivascular retinal infiltrates. In the left eye, the optic disc was surrounded by retinal and preretinal hemorrhages, and massive fibrosis with hard exudates and severe preretinal hemorrhage were observed at the posterior pole. Roth spots and many circular hemorrhages were noted at the periphery of the retina. A-scan and B-scan ultrasonography did not show intraocular leukemic infiltration. The clinical picture remained stable over the following 12 months. In this patient, we observed the ophthalmoscopic features of chronic myeloid leukemia, but also coexistence of features typical of Terson syndrome. To our knowledge, no similar cases have been reported previously.

Penetrating keratoplasty after radial keratotomy and recurrent immune overreaction

A 32-year-old man suffering from keratoconus was treated with radial keratotomy. Twenty weeks later, he presented visual deterioration, edema and corneal perforation. A penetrating keratoplasty was required. The postoperative course was regular, but after 9 months, the patient presented kerato-uveitis. Subsequent phlogistic relapses occurred approximately every 6 months during the following 5 years. The performed cultures were positive only during the first episode. Radial keratotomy is not indicated in keratoconus. The multiple relapses of kerato-uveitis could not be explained by infection, and we hypothesized that they may be due to a ‘traumatic memory’ of the cornea caused by the several suffered traumatisms, without clinical features of corneal graft rejection. The risks of new penetrating keratoplasty and cataract surgery are high. As the cornea is the tissue with the highest sensitivity in the body, we tried to explain the relapsing kerato-uveitis as a consequence of the disruption of the nervous corneal network.