Nanobiotechnology in the Management of Glaucoma

As the prevalence of glaucoma continues to rise, clinicians and researchers are confronted with an age-old problem: how to reduce risk factors and preserve vision in glaucoma. Current management options revolve around a validated paradigm—intraocular pressure reduction. Active investigations to improve drug delivery efficacy and surgical outcomes are flourishing. This article aims to provide the interested readers with a review of recent discoveries in nanobiotechnology for the management of glaucoma. Targeted drug-delivery systems using mesoscale vectors demonstrate promising delivery profiles. The utility of nanoparticulate therapies to support retinal ganglion cell survival is being investigated. Studies to modulate tissue regeneration and remodeling and improve post-trabeculectomy outcomes are underway. Though these modalities promise new avenues to manage glaucoma, immediate market availability is not anticipated soon.

A Novel Y-Suture Transfixation Technique to Improve Graft Adherence in High-Risk Descemets Stripping Automated Endothelial Keratoplasty

Purpose: To report a novel Y-suture transfixation technique to improve success rate of high-risk Descemets stripping automated endothelial keratoplasties (DSAEK). Design: Retrospective non-comparative case series. Participants: Twenty five high-risk patients undergoing DSAEK at one tertiary care institution. Methods: A retrospective evaluation of consecutively enrolled high-risk DSAEK cases performed by three surgeons at one institution during a 3-year period (2007-2010). Main outcome measures were graft adherence and suture-related complications. Results: Highrisk factors were defined as followed: prior incisional glaucoma surgery (58%), presence of vitreous in the anterior chamber (15%), anterior chamber intraocular lens (8%), graft dislocation (8%), previous DSAEK (8%), and iris trauma/aphakia (3%). Twenty-five high-risk patients underwent DSAEK with Y-suture transfixation. Postoperative follow-up ranged from 3 to 27 months. One patient had dislocation due to hypotony from prior trabeculectomy (4%), requiring repeat DSAEK. Neither primary graft failure nor suture-related complication was observed. Conclusion: The Y-suture transfixation technique is associated with improved success rate of high-risk DSAEK transplant.

“提壶揭盖”法的自然科学原理探讨

三焦为六腑之一，其主要生理功能是主持诸气和通调水道。上焦为横膈以上部位（心、肺等），中焦为横膈至脐以上部位（脾、胃），下焦为脐以下部位（大肠、小肠、肾、膀胱）。“提壶揭盖”法原指要想使水从壶盖很紧的茶壶中顺利倒出，就须任壶盖上打孔或把壶盖揭开，水才能顺利流出。中医认为，如肺气宣降不利、闭阻，可出现癃闭、水肿、喘证、淋证、便秘等，因此治疗应宣降肺气。

Electron-induced rapid crosslinking in supramolecular metal-peptide assembly and chemically responsive disaggregation for catalytic application

The applications of supramolecular metal-peptide assemblies as catalyst or catalyst precursor have recent attracted increasing attentions.In this work,a fragment of the amyloid β-peptide,NH_(2)-KLVFF-COOH,was assembled into nanofilms with encapsulated Pd,Pt and Au nanoparticles(NPs)via a one-step room temperature electron induction method.The effects of building block,intermolecular interaction,driving force and side-chain on the assembly were investigated.The assembly mechanism was thereby proposed.The crosslinking of peptide monomers results in mainly random and unordered structures.The obtained metal-peptide assemblies are extremely stable in water at neutral pH for long term.However,the metal NPs are able to be responsively released under basic and reductive conditions.The released NPs show a high activity to catalyze the reduction of 4-nitrophenol.The present studies on assembly mechanism and responsive release will be helpful for the design of organic skeletons and also for the future development of peptide stabilized metallic NPs with applications beyond catalysts.

Clinical manifestations and outcomes of ocular sarcoidosis in Saudi Arabia

Dear Sir,We write to report on the clinical manifestations and outcomes of ocular sarcoidosis in patients presenting to uveitis referral centers in the Kingdom of Saudi Arabia.This is the first report focused solely on ocular sarcoidosis from this country.

Repair of Spontaneous Corneal Perforation in Pellucid Marginal Degeneration Using Amniotic Membrane

A 47-year-old woman with a history of pellucid marginal degeneration was referred for management of hydrops and peripheral perforation of the right cornea. The initial management with cyanoacrylate tissue adhesive and bandage contact lens did not preclude aqueous leakage the next day. Amniotic membrane grafting using both a surgical graft and a bandage patch was thus performed in the operating room the following day. There was no aqueous leakage on the first post-operative day. The corneal integrity was restored with resolution of the corneal edema;and the visual acuity improved from 20/400 before surgery to 20/40 three months later. This case illustrates the clinical efficacy of amniotic membrane grafting as an effective alternative in the management of spontaneous corneal perforation resulted from pellucid marginal degeneration.

Wavefront-optimized surface retreatments of refractive error following previous laser refractive surgery: a retrospective study

Background:Retreatments are sometimes necessary to correct residual or induced refractive errors following refractive surgery.Many different combinations of primary treatment methods and retreatment techniques have been studied,however,few studies have investigated wavefront-optimized(WFO)technology for retreatment following primary refractive surgery.This study aimed to report the outcomes of WFO photorefractive keratectomy(PRK)retreatments of refractive error following previous laser refractive surgery with PRK,laser in situ keratomileusis(LASIK),or laser-assisted subepithelial keratectomy(LASEK).Methods:We reviewed records of patients who underwent WFO PRK retreatments using the Allegretto Wave Eye-Q 400 Hz Excimer Laser System(Alcon Surgical)between January 2008 and April 2011 at Walter Reed Army Medical Center and Madigan Army Medical Center.Outcomes were recorded in terms of uncorrected distance visual acuity(UDVA),manifest refraction spherical equivalent(MRSE),corrected distance visual acuity(CDVA),and complications at 1 month(M),3 M,and 6 M post-op.Results:Seventy-eight patients(120 eyes)underwent WFO PRK retreatment during the study period.Primary surgery was surface ablation in 87 eyes(78 PRK,9 LASEK)and LASIK in 33 eyes.The mean spherical equivalent before retreatment was−0.79±0.94 D(−3.00 to 1.88 D).UDVA was≥20/20 in 69 eyes(60.0%)at 1 M,54 eyes(71.1%)at 3 M,and 27 eyes(73.0%)at 6 M follow-up.MRSE was within±0.50 D of emmetropia in 78 eyes(67.8%)at 1 M,59 eyes(77.6%)at 3 M,and 25 eyes(67.6%)at 6 M follow-up.CDVA was maintained within±1 line of pre-op in 113 of 115 eyes(98.3%)at 1 M,74 of 76 eyes(97.4%)at 3 M,and 37 eyes(100%)at 6 M follow-up.Conclusion:Although follow-up was limited beyond 3 M,WFO PRK retreatments in patients with residual refractive error may be a safe and effective procedure.Further studies are necessary to determine the long-term safety and stability of outcomes.

Recent Progress in Exploiting Small Molecule Peptides as Supramolecular Hydrogelators

Small molecule peptides and their derivatives are an emerging class of supramolecular hydrogelators that have attracted rapidly growing interest in the fields of drug delivery and regenerative medicine due to their inherent biodegradability and biocompatibility, as well as versatility in molecular design and ease of synthesis. Built upon the directional, intermolecular interactions such as hydrogen bonding and π-π stacking, peptide-based molecular units can associate in aqueous solution into filamentous assemblies of various sizes and shapes. Under appropriate conditions, these filamentous assemblies can percolate into a 3D network with materials properties tailorable for specific biomedical applications. In this review, we survey the literature published over the past three years in the development of peptide-based hydrogelators for biomedical applications. We highlight several representative examples and center our discussion on the fundamentals of molecular design, assembly, and gelation conditions.