A New and Easier Approach to Preserflo MicroShunt Implantation

PRESERFLO™ MicroShunt is a new minimally invasive glaucoma surgical (MIGS) device, implanted with an ab externo approach, which drains the aqueous humor to the subconjunctival space. It has been designed as a safer and less invasive approach for treating medically uncontrolled primary open-angle glaucoma (POAG) patients. The classic way of MicroShunt implantation involves different key steps, which includes creating a small scleral pocket with a 1mm blade; passing a 25-gauge (25G) needle through the scleral pocket into the anterior chamber (AC); and subsequently flushing the stent with a 23-gauge (23G) thin-wall cannula. However, sliding the needle into the scleral pocket can create false passages, thus making the device’s threading more difficult. The purpose of the current paper is to propose a simplified implantation approach. Our method proposes to make the scleral tunnel by using directly the 25G needle and, at the limbus, this 25G needle is used to slightly depress the sclera and enter into the AC. The MicroShunt is subsequently assembled on a 23G cannula mounted on a 1mL syringe. The syringe can then be used to flush the device. Outflow can thus be confirmed immediately by seeing drops of aqueous humor leaking from the external opening of the stent. This new approach may have different potential advantages, such as better control of the site of entry, avoids wrong passages, reduces or eliminates the risk of aqueous humor sideway flow, facilitates a parallel path to the iris plane, and it is faster.

Primary angle closure glaucoma is characterized by altered extracellular matrix homeostasis in the iris

PURPOSE

To characterize the proteome of the iris in primary angle closure glaucoma (PACG).

EXPERIMENTAL DESIGN

In this cross-sectional study, iris samples were obtained from surgical iridectomy of 48 adults with PACG and five normal controls. Peptides from iris were analysed using liquid chromatography-tandem mass spectrometry on an Orbitrap Q Exactive Plus mass spectrometer. Verification of proteins of interest was conducted using selected reaction monitoring on a triple quadrupole mass spectrometer. The main outcome was proteins with a log₂ two-fold difference in expression in iris between PACG and controls.

RESULTS

There were 3,446 non-redundant proteins identified in human iris, of which 416 proteins were upregulated and 251 proteins were downregulated in PACG compared with controls. Thirty-two upregulated proteins were either components of the extracellular matrix (ECM) (fibrillar collagens, EMILIN-2, fibrinogen, fibronectin, matrilin-2), matricellular proteins (thrombospondin-1), proteins involved in cell-matrix interactions (integrins, laminin, histidine-rich glycoprotein, paxillin), or protease inhibitors known to modulate ECM turnover (α-2 macroglobulin, tissue factor pathway inhibitor 2, papilin). Two giant proteins, titin and obscurin, were up- and down-regulated, respectively, in the iris in PACG compared with controls.

CONCLUSIONS AND CLINICAL RELEVANCE

This proteomic study shows that ECM composition and homeostasis are altered in the iris in PACG.

Malpractice Litigation in Glaucoma

PURPOSE

To analyze and report the causes and outcomes of malpractice litigation for patients with a diagnosis of glaucoma.

DESIGN

Retrospective case series.

PARTICIPANTS

Malpractice litigation cases.

METHODS

The WestLaw database was reviewed for all malpractice litigation with ophthalmologist defendants in the United States between 1930 and 2014. All litigation involving glaucoma was included in this analysis and was compared with litigation in ophthalmology as a whole.

MAIN OUTCOME MEASURES

The primary outcomes were the number of cases, jury award amounts, whether the case resolved in favor of the defendant, and the type of glaucomatous disease or procedure with the highest amount of litigation.

RESULTS

Sixty-nine glaucoma malpractice cases were included. Overall, 62.3% of cases were resolved in favor of defendants. Twenty-nine cases were resolved via jury trial, 8 of which were associated with plaintiff verdicts with a mean adjusted jury award of $994 260. Ten cases resulted in settlements with mean adjusted indemnity of $1 210 414. Commonly litigated allegations included mismanagement of glaucoma (20.3%), failure to diagnose glaucoma (17.4%), failure to diagnose or mismanagement of angle-closure glaucoma (18.5%), adverse drug effects (14.5%), and trabeculectomy complications (8.7%). Overall, the median plaintiff award for all of glaucoma litigation was $977 476; the median award across all ophthalmic subspecialties was $568 302 (P = 0.25). For jury verdicts alone, the median award in glaucoma was $977 474, compared with $604 352 for all ophthalmology (P = 0.05). For settlements alone, the median indemnity payment in glaucoma was $955 988, compared with $827 051 for all ophthalmology (P = 0.24).

CONCLUSIONS

Overall, the rate of plaintiff verdicts was similar in glaucoma and in ophthalmology as a whole; however, the magnitude of plaintiff awards was higher in glaucoma than in ophthalmology overall. Common scenarios leading to litigation included failure to diagnose or mismanagement of glaucomatous disease, as well as adverse drug effects and surgical complications. Many cases could have been avoided with careful examinations, thorough documentation in the patients' charts, and detailed conversations with patients.

Identification of a gene that causes primary open angle glaucoma

Glaucoma is a major cause of blindness and is characterized by progressive degeneration of the optic nerve and is usually associated with elevated intraocular pressure. Analyses of sequence tagged site (STS) content and haplotype sharing between families affected with chromosome 1q-linked open angle glaucoma (GLC1A) were used to prioritize candidate genes for mutation screening. A gene encoding a trabecular meshwork protein (TIGR) mapped to the narrowest disease interval by STS content and radiation hybrid mapping. Thirteen glaucoma patients were found to have one of three mutations in this gene (3.9 percent of the population studied). One of these mutations was also found in a control individual (0.2 percent). Identification of these mutations will aid in early diagnosis, which is essential for optimal application of existing therapies.

Risk management issues in the new managed care environment

Malpractice cases in which the defense was based on cost-containment are discussed in this article reprinted from Ophthalmic Risk Management Digest. These cases illustrate that the "dollar defense" is no defense.

Risk management issues in glaucoma: diagnosis and treatment

This article is based on the analysis of 194 claims in cases with a diagnosis of glaucoma. Half of these resulted in indemnity payments, and these payments were nearly 20% higher than the average paid for ophthalmology claims. Risk management guidelines are given.

Applanation tonometer tip sterilization for adenovirus type 8

Eighty-nine ophthalmologists in the Dallas-Fort Worth area were surveyed to find the methods used to sterilize applanation tonometer tips. Sixteen different methods were in use, with the most popular being alcohol wipes (26%) and diluted sodium hypochlorite soak (23%). Six of the most frequently used sterilization techniques were evaluated for removal of type 8 adenovirus applied to sterile tonometer tips. Adenovirus was removed or inactivated from applanation tonometer tip surfaces by using one of the following techniques: soaking inoculated tips for 15 minutes in diluted sodium hypochlorite (1:10 household bleach), 3% hydrogen peroxide, or 70% isopropyl alcohol; or wiping with alcohol "prep pads", 1:1000 merthiolate, or dry tissues.

An assessment of the value of the white cell count in the management of suspected acute appendicitis

A prospective study of 100 consecutive patients was carried out to determine if a knowledge of the white cell count was a useful factor in determining the correct management of patients presenting with suspected acute appendicitis. A retrospective study of the differential white cell count and neutrophil morphology was performed to see if these investigations would provide more specific aids to diagnosis. These studies show that such haematological information is only of limited supportive value in the total assessment of these patients. Where the clinical findings are at variance with the white cell count, the clinical findings should take precedence.

Red cell abnormalities associated with sulphasalazine maintenance therapy for ulcerative colitis

Of 52 patients receiving a mean dose of 2.5g sulphasalazine/day as maintenance therapy for ulcerative colitis, 35 were found to have one or more drug-induced red cell abnormalities, which were not found in 50 normal controls or in 10 colitics not receiving sulphasalazine. Twenty-three of the treated patients had contracted red cells, an abnormality that is thought to result in mild haemolysis. Red cell contraction was related to the dose of sulphasalazine (P smaller than 0.01), the serum total sulphapyridine level (P smaller than 0.001), and acetylator status. Eleven of the treated patients had a macrocytosis, 21 had elevated levels of methaemoglobin, and one had Heinz bodies. A dose of 1.5 g sulphasalazine/day was not associated with red cell contraction, and is suggested as a safer maintenance dose for the asymptomatic colitic.