Bobeck S. Modjtahedi

Quantification of stratum corneum removal by adhesive tape stripping by total protein assay in 96-well microplates.

Background/aims: Examination of stratum corneum (SC) content with tape stripping and a colorimetric method is increasingly used. We examined the possible use of microplates in tandem with a colorimetric method to examine SC removed with tape stripping. As a corollary to this examination, the homogeneity of tape strips was examined.

Lipids and Age-related Macular Degeneration

Given the considerable public health burden imposed by age-related macular degeneration (AMD), much effort has been directed towards elucidating principles of pathogenesis in order to identify risk factors and develop preventive measures and treatments. Together with epidemiological evidence linking cardiovascular risk factors with AMD risk and basic science work examining the role of lipid metabolism in AMD, numerous human studies have assayed a potential relationship between dietary lipids and the development of AMD. We examine the evidence for a role for lipid metabolism in AMD, highlighting key basic biochemical principles, work in animal models, and relevant human studies. The topics of lipoprotein modulation and omega-3 fatty acid intake receive special attention from both a basic science and clinical study standpoint. The evidence suggests that consumption of omega-3 fatty acids, perhaps in concert with antioxidants, may constitute a rational preventative strategy against AMD development, though, absent an appropriately developed double-blind, randomized control trial, insufficient data exist to recommend implementation in the clinical setting at this time.

The sex of the individual as a factor in allergic contact dermatitis

Exogenous and endogenous factors have been implicated in allergic contact dermatitis (ACD); this review explores the sex of the individual as a possible endogenous factor. While there is a clinical impression that women are more skin‐reactive than men, upon review this hypothesis appears oversimplified. This review explores sex differences in controlled testing of adult ACD, occupational ACD and juvenile ACD. Further, geographical location and socioeconomic and cultural factors in relation to sex differences in allergic contact dermatitis are discussed. We conclude that female sex could be a factor predisposing to allergic contact dermatitis not so much because of possible differences in intrinsic skin characteristics between the sexes, but more because of different exposure patterns. This conclusion has practical consequences regarding product labelling requirements, occupational risk assessment and legislation.

In vivo percutaneous absorption of benzene in man: forearm and palm.

The exact role topical exposure to benzene plays in its hazard profile remains incompletely defined. This investigation explores the amount of benzene absorbed through human skin in vivo following one direct topical application to the forearm or palm. Absorption values were found to be nominal with forearm exposure showing an average total absorption of 0.07+/-0.04% and palmar exposure an average total absorption of 0.13+/-0.04% of the applied dose. Differences in excretion and absorption between the surfaces were not found to be within statistical significance. This is in contrast to previous studies that found greater absorption through the forearm than palm. Although total absorption values were small, these findings were gathered in an idealized environment where benzene was present in pure solution and applied only once to non-damaged skin. Therefore, these findings could underestimate benzene flux as many exposure conditions occur and many skin variables exist. Generalization of the data must be taken with caution.

Radiation Therapy for Neovascular Age-related Macular Degeneration

In the enormity of the public health burden imposed by age-related macular degeneration (ARMD), much effort has been directed toward identifying effective and efficient treatments. Currently, anti-vascular endothelial growth factor (VEGF) injections have demonstrated considerably efficacy in treating neovascular ARMD, but patients require frequent treatment to fully benefit. Here, we review the rationale and evidence for radiation therapy of ARMD. The results of early photon external beam radiation therapy are included to provide a framework for the sequential discussion of evidence for the usage of stereotactic radiation therapy, proton therapy, and brachytherapy. The evidence suggests that these 3 modern modalities can provide a dose-dependent benefit in the treatment of ARMD. Most importantly, preliminary data suggest that all 3 can be used in conjunction with anti-VEGF therapeutics, thereby reducing the frequency of anti-VEGF injections required to maintain visual acuity.

Multifocal bilateral choroidal neovascularization in a patient on ipilimumab for metastatic melanoma

Abstract Choroidal neovascularization membrane (CNVM) is a significant cause of ocular morbidity. Immunologic mechanisms have been proposed in the development of these lesions in exudative age related macular degeneration. Here, we describe the case of an 81-year-old man receiving ipilimumab, an immune modulating drug that enhances T cell response, for metastatic melanoma who developed three simultaneous CNVM bilaterally. This is the first case of ipilimumab-associated CNVM as well as the first case of an immune modulating drug possibly causing CNVM to our knowledge.

Eyelash alopecia areata: case series and literature review

OBJECTIVES To characterize the clinical presentations, features, and outcomes of eyelash alopecia areata. DESIGN Retrospective chart review of patients evaluated for eyelash loss and found to have eyelash alopecia areata. A 3-year follow-up was required. PARTICIPANTS The study involved 15 patients. METHODS Patients who presented at a tertiary care eye clinic for evaluation of eyelash loss and were found to have eyelash alopecia areata were reviewed. Demographic considerations were categorized; they included age at presentation, areas of other hair loss, other relevant history, and treatment responses. RESULTS Patients were young (mean age 18 years) and had a large female predominance (female-to-male ratio, 14:1). Concurrent scalp and brow involvement, either in isolation (20% and 13%, respectively) or together (13%), were seen in half of the patients (46%). Upper eyelid involvement was more common and severe than lower eyelid involvement, and 40% of patients experienced complete regrowth of lashes, with a mean time to regrowth of 28 months (range, 6 to 60 months). Of these, 13% experienced partial regrowth. Younger age at presentation was associated with regrowth, whereas presence or absence of other involved sites, personal or family histories of atopy, family history of alopecia, other autoimmune diseases, or the use of topical steroids did not appear to affect prognosis. CONCLUSIONS Eyelash alopecia areata is a unique entity, although it remains potentially underdiagnosed. The key differential diagnosis is trichotillomania, which is commonly associated with obsessive-compulsive disorders. The presence of exclamation-mark hairs in alopecia areata plays an important role in differentiating the 2 diagnoses.

Comparison of macular thickness measurement and segmentation error rate between stratus and fourier-domain optical coherence tomography.

BACKGROUND AND OBJECTIVE To compare macular thickness measurements and segmentation error rates between Stratus optical coherence tomography (OCT) (Carl Zeiss Meditec, Inc., Dublin, CA), and Fourier-domain OCT (RTVue, Optovue, Inc., Fremont, CA). PATIENTS AND METHODS A retrospective study was performed of 93 normal and pathologic eyes from 79 subjects imaged with both OCT instruments on the same day. Both the macular thickness measurement for each Early Treatment Diabetic Retinopathy Study (ETDRS) zone and the incidence of segmentation error in the central macula between the two instruments were compared. RESULTS Macular thickness measurements for all nine ETDRS zones were higher with RTVue compared with Stratus OCT (P < .01). Linear regression analysis showed the highest correlation in the central macula (R(2) = 0.88), with progressively lower correlation peripherally. The overall segmentation error rate was 29% with Stratus OCT versus 32% with RTVue (P > .05). CONCLUSION Macular thickness measurement was greater with RTVue than with Stratus OCT in all ETDRS areas, with the best correlation seen in the central macula. No difference in segmentation error rate was noted between the two instruments.

Role of Physical Chemical Properties in Drug Relay into Skin Compartments

The ability of a drug to reach the interstitial fluid is an important aspect of drug efficacy – as a possible indicator of skin and cell compartment concentration. This overview addresses the relationship of the physical properties of several antibiotics to their ability to enter the interstitial fluid utilizing a cantharidin blister model. By collecting pharmacokinetic data for 12 antibiotics administered orally and 11 intravenously, we compared the fraction of drug that reaches the interstitial fluid (AUCblister/AUCserum) to partition coefficients. Following data analysis, we found no correlation (p = 0.98 and 0.09, respectively) between hydrophobicity and the ability to reach the interstitium. Both orally and intravenously administered antibiotics display a strong linear correlation (p < 0.001 and p = 0.006, respectively) in the total concentration found in the serum and interstitial fluid indicating that serum concentration may be an important factor in dictating interstitial fluid concentration. This correlation may prove useful in clinical application as a means of determining interstitial fluid concentration by measuring only serum levels.

Diseases of Periocular Hair

Diseases of the periocular hair range from localized disease to systemic processes and may present challenging diagnostic questions. We present a comprehensive clinical guide to the evaluation and diagnosis of these disorders. Deficiencies in growth, excess production, changes in pigmentation, aberrant position, or abnormalities in form may affect this regions hair. These range from benign to sight-, and even life-, threatening pathologies.