Silencing of ocular transthyretin, a gene responsible for hereditary transthyretin amyloidosis, by intravitreal injection of an siRNA conjugate into rabbit eyes.

The first small interfering RNA (siRNA) therapeutic received approval for hereditary transthyretin (ATTRv) amyloidosis, and the patients' lifespan extension by specific inhibition of hepatic synthesis of transthyretin (TTR) is expected. However, ocular amyloidosis in these patients has been a crucial issue. This study aims to evaluate the efficacy and safety of intravitreal TTR siRNA conjugate injection into rabbit eyes. Rabbit (r) TTR siRNA is a screened TTR siRNA conjugate from 53 candidates. The intraocular pressure (IOP) immediately after injection was high despite the 65.9 % decrease of aqueous humor TTR protein levels in the rTTR siRNA group compared with those in the Control siRNA group 2 weeks after the 50 µL siRNA injection. The IOP spike was milder after the 30 µL siRNA injection, and aqueous humor TTR levels decreased by ∼50 % in the rTTR siRNA group, which is consistent with the mRNA levels in the retina. The parameters of dark-adapted, light-adapted, and light-adapted 30 Hz electroretinogram and the thickness of each retinal layer in histological analysis demonstrated no significant differences between the groups. In conclusion, we developed TTR siRNA conjugates for rabbit eyes, and the results indicate that intravitreal TTR siRNA conjugate injection could be a therapeutic option for ocular amyloidosis caused by ATTRv amyloidosis.

Factors associated with the surgical outcomes of Baerveldt glaucoma implant for open-angle glaucoma, an age-related eye disease.

To identify the factors associated with the surgical outcomes of Baerveldt glaucoma implant (BGI) for open-angle glaucoma (OAG), the medical records of 51 consecutive OAG patients (age, 43-91 years) who underwent BGI were retrospectively reviewed (median follow-up, 21.7 months). Surgical success was defined as the following postoperative intraocular pressures (IOPs, mmHg): (A) 6 ≤ IOP ≤ 21; (B) 6 ≤ IOP ≤ 18; and (C) 6 ≤ IOP ≤ 15 without loss of light perception or additional glaucoma surgery. Univariate analysis showed that age (all criteria), glaucoma type (criterion C), and preoperative IOP (criteria A and B) were the candidate factors (P < 0.20). When the patients were divided into two groups according to median age (72 years), the success probability was higher in the older group for criteria B (P = 0.047) and C (P = 0.02), and the postoperative IOP was lower in the older group 1-year post-surgery (P = 0.002). Furthermore, the multivariate Cox proportional hazards model revealed that older age was independently associated with surgical success for criteria B (relative risk [RR], 0.94; P = 0.02) and C (RR, 0.94; P = 0.01). In conclusion, older age is a factor associated with the surgical success of BGI for OAG.