Expression of inhibin α by stromal cells of retinal angiomas excised from a patient with von Hippel-Lindau disease

Retinal vasoproliferative tumor regression after intravitreal aflibercept

Retinal vasoproliferative tumors (RVPTs) are rare benign retinal lesions typically located in the inferotemporal peripheral retina. Several treatment options exist for the management of RVPTs, but no consensus has been proposed. There are only a few reports on the use of anti-vascular endothelial growth factor with bevacizumab to treat exudative or neovascular retinal changes secondary to RVPTs. This report describes a 68-year-old female with a history of systemic hypertension that presented with a 2-week history of gradual loss of visual acuity in the right eye. Fundoscopic examination showed a RVPTs with atypical location that had a favorable response to two-intravitreal aflibercept injections 1 month apart, with resulting subretinal fluid absorption and tumor regression.

Rb1/Rbl1/Vhl loss induces mouse subretinal angiomatous proliferation and hemangioblastoma

Von Hippel-Lindau (Vhl) protein inhibits hypoxia-inducible factor (Hif), yet its deletion in murine retina does not cause the extensive angiogenesis expected with Hif induction. The mechanism is unclear. Here we show that retinoblastoma tumor suppressor (Rb1) constrains expression of Hif target genes in the Vhl-/- retina. Deleting Rb1 induced extensive retinal neovascularization and autophagic ablation of photoreceptors in the Vhl-/- retina. RNA-sequencing, ChIP, and reporter assays showed Rb1 recruitment to and repression of certain Hif target genes. Activating Rb1 by deleting cyclin D1 induced a partial defect in the retinal superficial vascular plexus. Unexpectedly, removing Vhl suppressed retinoblastoma formation in murine Rb1/Rbl1-deficient retina but generated subretinal vascular growths resembling retinal angiomatous proliferation (RAP) and retinal capillary hemangioblastoma (RCH). Most stromal cells in the RAP/RCH-like lesions were Sox9+, suggesting a Müller glia origin, and expressed Lgals3, a marker of human brain hemangioblastoma. Thus, the Rb family limit Hif target gene expression in the Vhl-/- retina, and removing this inhibitory signal generates new models for RAP and RCH.

Vitreoretinal Surgery and Panretinal Photocoagulation in a Patient with Multiple Large Retinal Capillary Hemangiomas (von Hippel-Lindau Disease): A Novel Approach

The authors present a novel surgical approach for the treatment of retinal capillary hemangiomas (RCHs) secondary to von Hippel-Lindau (VHL) disease. This is a case report of a 23-year-old male patient with VHL that presented with multiple large RCHs and a thick epiretinal membrane (ERM) in his left eye, with best-corrected visual acuity (BCVA) of 20/80. This condition was surgically addressed with 23-gauge pars plana vitrectomy, ERM and internal limiting membrane peeling, and panretinal photocoagulation. Three monthly intravitreal injections of bevacizumab were administered after surgery. In a 14-month follow-up period, hemangiomas have regressed after laser therapy, macular anatomy has improved, retina remained completely attached, and there has been no development of new tumors or proliferative vitreoretinopathy. The patient achieved a BCVA of 20/40 in the treated eye. Panretinal photocoagulation combined with pars plana vitrectomy may be useful to reduce development of new capillary hemangiomas and reduce overall occurrence of complications in patients with VHL disease. Postoperative intravitreal injections of bevacizumab may have a role in this positive outcome.

Spontaneous Hyaloidal Contraction and Complex Retinal Detachment in a Patient With Von Hippel-Lindau Syndrome

The authors present an interventional case report of a patient with von Hippel-Lindau (VHL) syndrome who developed simultaneous exudative and combined tractional, rhegmatogenous, and exudative retinal detachment (RD) in the right and left eyes, respectively, following uneventful cryotherapy application of retinal capillary hemangioblastoma (RCH). After pars plana vitrectomy combined with encircling scleral buckling with radial element placement and silicone oil injection, complete retinal reattachment was achieved. The exudative RD of the fellow eye was managed initially with intense topical corticosteroid treatment and subsequent placement of a radial scleral buckle due to the presence of clinically apparent traction. Both eyes remained stable after successful surgical interventions, and long-term follow-up revealed no evidence of recurrent disease. The authors conclude that rapid worsening of vitreoretinal traction and exudation are complications that can occur after treatment of RCH in patients with VHL syndrome leading to complex retinal detachments. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:238-241.].