Nagi Assaad

Crystal structure of the soluble form of the redox-regulated chloride ion channel protein CLIC4.

The structure of CLIC4, a member of the CLIC family of putative intracellular chloride ion channel proteins, has been determined at 1.8 Å resolution by X‐ray crystallography. The protein is monomeric and it is structurally similar to CLIC1, belonging to the GST fold class. Differences between the structures of CLIC1 and CLIC4 are localized to helix 2 in the glutaredoxin‐like N‐terminal domain, which has previously been shown to undergo a dramatic structural change in CLIC1 upon oxidation. The structural differences in this region correlate with the sequence differences, where the CLIC1 sequence appears to be atypical of the family. Purified, recombinant, wild‐type CLIC4 is shown to bind to artificial lipid bilayers, induce a chloride efflux current when associated with artificial liposomes and produce an ion channel in artificial bilayers with a conductance of 30 pS. Membrane binding is enhanced by oxidation of CLIC4 while no channels were observed via tip‐dip electrophysiology in the presence of a reducing agent. Thus, recombinant CLIC4 appears to be able to form a redox‐regulated ion channel in the absence of any partner proteins.

Acute haptic-induced pigmentary glaucoma with an AcrySof intraocular lens

A 49-year-old man had uneventful endocapsular phacoemulsification with in-the-bag implantation of an AcrySof SA60AT single-piece intraocular lens (IOL) (Alcon) in the right eye. Twenty-seven days postoperatively, he presented with ocular pain, intraocular pressure of 48 mm Hg, 360 degrees of hyperpigmentation of the trabecular meshwork, and iris pigment epithelial atrophy in the region of the upper temporal haptic, which had dislocated into the sulcus. The patient made an excellent recovery following IOL removal and exchange. Scanning electron microscopy of the explanted IOL demonstrated that the haptic had a rough lateral surface and anterolateral edge. We do not think this IOL should be implanted in the sulcus placement of the heptics. In this article, we report the case of a patient with an AcrySof SA60ATIOL (Alcon) who developed acute pigmentary glaucoma when the inferior haptic slipped out of the bag and came into contact with the pigmented iris and ciliary body.

Infrared reflectance imaging in age‐related macular degeneration

The purpose of this article is to describe the appearance of age‐related macular degeneration (AMD) phenotypes using infrared (IR) reflectance imaging. IR reflectance imaging of the retina has the potential to highlight specific sub‐retinal features and pathology. However, its role in macular disease, specifically AMD, is often underestimated and requires clarification.

Rapid Response of Refractory Ocular Surface Dysplasia to Combination Treatment With Topical All-trans Retinoic Acid and Interferon Alfa-2b

T opical treatments of ocular surface dysplasia are attractivebecause theseconditions tendtorecur. Traditional surgical procedures such as excision and cryotherapy are destructive and can have long-term consequences, particularly with limbal involvement. Interferonalfa-2b is awell-toleratedandgenerally efficacious topical therapy option for ocular surface dysplasia. The combination of interferon with retinoic acid may be a useful alternative for treating interferon-unresponsive lesions.

Fundus Autofluorescence in Age-related Macular Degeneration.

ABSTRACT Fundus autofluorescence (FAF) provides detailed insight into the health of the retinal pigment epithelium (RPE). This is highly valuable in age-related macular degeneration (AMD) as RPE damage is a hallmark of the disease. The purpose of this paper is to critically appraise current clinical descriptions regarding the appearance of AMD using FAF and to integrate these findings into a chair-side reference. A wide variety of FAF patterns have been described in AMD, which is consistent with the clinical heterogeneity of the disease. In particular, FAF imaging in early to intermediate AMD has the capacity to reveal RPE alterations in areas that appear normal on funduscopy, which aids in the stratification of cases and may have visually significant prognostic implications. It can assist in differential diagnoses and also represents a reliable, sensitive method for distinguishing reticular pseudodrusen. FAF is especially valuable in the detection, evaluation, and monitoring of geographic atrophy and has been used as an endpoint in clinical trials. In neovascular AMD, FAF reveals distinct patterns of classic choroidal neovascularization noninvasively and may be especially useful for determining which eyes are likely to benefit from therapeutic intervention. FAF represents a rapid, effective, noninvasive imaging method that has been underutilized, and incorporation into the routine assessment of AMD cases should be considered. However, the practicing clinician should also be aware of the limitations of the modality, such as in the detection of foveal involvement and in the distinction of phenotypes (hypo-autofluorescent drusen from small areas of geographic atrophy).

The value of visual field testing in the era of advanced imaging: clinical and psychophysical perspectives

White‐on‐white standard automated perimetry (SAP) is widely used in clinical and research settings for assessment of contrast sensitivity using incremental light stimuli across the visual field. It is one of the main functional measures of the effect of disease upon the visual system. SAP has evolved over the last 40 years to become an indispensable tool for comprehensive assessment of visual function. In modern clinical practice, a range of objective measurements of ocular structure, such as optical coherence tomography, have also become invaluable additions to the arsenal of the ophthalmic examination. Although structure‐function correlation is a highly desirable determinant of an unambiguous clinical picture for a patient, in practice, clinicians are often faced with discordance of structural and functional results, which presents them with a challenge. The construction principles behind the development of SAP are used to discuss the interpretation of visual fields, as well as the problem of structure‐function discordance. Through illustrative clinical examples, we provide useful insights to assist clinicians in combining a range of clinical results obtained from SAP and from advanced imaging techniques into a coherent picture that can help direct clinical management.

OCT and Fundus Autofluorescence Enhances Visualization of White Dot Syndromes.

Purpose White dot syndromes (WDS) are a group of inflammatory conditions characterized by white lesions at the retina and choroid level. Detection and monitoring of these syndromes are currently hampered by the subtlety of these lesions, making them difficult to image using traditional clinical techniques. New imaging modalities such as optical coherence tomography (OCT) and fundus autofluorescence (FAF) offer new opportunities for clinicians to noninvasively image WDS. Methods A literature search was performed using a variety of WDS as the search terms. All articles from January 2004 to May 2014 were analyzed for clinical information regarding imaging of the diseases using OCT or FAF. Results Current descriptions of OCT and FAF imaging of WDS are fragmented across case reports and small-scale studies. Assessing clinical presentation of WDS using OCT and FAF, however, is useful as the retinal layers affected in these syndromes are well characterized by these technologies. Furthermore, the new information revealed by OCT and FAF is helpful to elucidate the underlying mechanisms of these diseases in combination with known clinical and angiographic findings. Conclusions This review collates current literature and provides a succinct overview of the clinical presentation of WDS using OCT and FAF.

Conjunctival Autograft Failure in Eyes Previously Exposed to ß-Radiation or Mitomycin

For reasons of efficacy and longterm safety, conjunctival or limbal conjunctival autograft surgery is generally regarded as the procedure of choice for the treatment of primary and recurrent pterygia. Although surgical management of pterygium has traditionally relied on destructive procedures (excision and treatment with -radiation or chemotherapy), reconstructive approaches have come into use more recently. It is generally accepted that recurrence rates are higher for surgery of recurrent as compared with primary pterygium, but it remains uncertain as to why this should be the case. A contributing factor may relate to adjunctive measures used during the initial surgery, particularly if a conjunctival autograft is used in a subsequent procedure. We describe 3 patients for whom graft failure occurred following previous -radiation or mitomycin used as adjunctive therapy in the initial surgical management for pterygium. This complication does not appear to have been previously reported.

Delusional infestation: are you being bugged?

This case report documents a 58-year-old male who presented to the clinic with a 12-month history of a burrowing sensation in his eyelids that he attributed to a parasitic infestation. After being extensively investigated and reviewed by relevant specialties, no evidence of parasitic infestation was found. He was diagnosed with and treated for blepharitis. Psychiatric referral for presumed delusional infestation (DI) was recommended. Despite this, he remained insistent in his belief of infestation, and was inevitably lost to follow-up. DI, previously known as delusional parasitosis, is a rare delusional disorder where affected individuals have a fixed, false belief that they have a parasitic infestation. Diagnosis can be challenging. Practitioners need to evaluate between primary and secondary DI carefully, as management differs depending on the etiology. Despite this, patients diagnosed with primary DI tend to be resistant to psychiatric referral. This report aims to optimize management by giving the reader a guideline for appropriate investigations and advice on patient approach. It is important to recognize hallmark features of DI to minimize self-inflicted trauma and associated psychosocial consequences. Effective treatment for DI is available, and devastating consequences, including blindness, can be avoided.

Use of adjuvant hyperbaric oxygen therapy to support limbal conjunctival graft in the management of recurrent pterygium.

Purpose: To assess the role of hyperbaric oxygen therapy (HBOT) in the management of recurrent pterygium. Methods: Thirty-nine eyes with recurrent pterygium were treated with surgical excision and limbal conjunctival autograft, followed by a course of HBOT. Patients were followed for development of recurrence. Results: Of the 39 eyes, 18 had a known history of exposure to beta radiation or mitomycin C. The mean duration of follow-up in this group was 23.1 months. A single recurrence was noted in this group. For the remaining 21 eyes, the mean duration of follow-up was 19.4 months. No recurrences were recorded in this group. No significant complications from HBOT were recorded. Conclusions: The use of HBOT together with excision and limbal conjunctival autograft for recurrent pterygium is associated with a low recurrence rate. Adjuvant HBOT should be considered in the surgical management of recurrent pterygium.