Rapid Onset Neovascular Glaucoma due to COVID-19-related Retinopathy

Aim

Background

Case description

Conclusion

Clinical significance

How to cite this article

Innovator Versus Biosimilar Ranibizumab in Polypoidal Choroidal Vasculopathy: Real-World Evidence

Introduction

To analyze the efficacy and safety profile of the intravitreal ranibizumab biosimilar molecule, Razumab^® (Intas Pharmaceuticals, Ahmedabad, India; BRm; Razumab^®) and the innovator ranibizumab drug (IRm; LUCENTIS^®) in Indian patients with polypoidal choroidal vasculopathy (PCV) under real-world conditions.

Methods

This was a retrospective study of treatment-naïve and previously treated PCV eyes undergoing intravitreal therapy with either BRm or IRm from January 2019 to September 2020 as three loading doses followed by a pro-re-nata (PRN) regimen. Changes in the best-corrected visual acuity (BCVA), subretinal fluid (SRF), intraretinal fluid (IRF), SRF height, and subfoveal choroidal thickness (SFCT) and the safety profiles were assessed at weeks 12, 24, and 52, respectively.

Results

A total of 22 eyes received IRm and 19 eyes underwent BRm therapy, respectively. Both the groups were comparable in age (P = 0.41) and gender distribution, although the BRm arm had significantly more eyes that were previously treated (P < 0.00001) with a greater median number of injections (P < 0.0001). At week 52, both groups had similar gains in visual acuity (P = 0.19), SRF resolution (P = 0.8), IRF resolution (P = 0.47), and SRF height (P = 0.71). The IRm eyes exhibited a significant improvement in BCVA (P = 0.001) at all visits with a greater mean number of injections (IRm: 5.41 ± 0.94; BRm: 4 ± 1.45; P = 0.0004), while the BRm eyes showed a similar increase in BCVA but did not reach statistical significance until week 52. The SFCT decreased significantly in the BRm arm at week 52 (P = 0.045). One eye (5.26%) in the BRm arm experienced mild anterior uveitis, which was treated with topical corticosteroids. In either arm, no other ocular or systemic adverse effects were observed.

Conclusions

Our real-world data demonstrated the ranibizumab biosimilar Razumab to have comparable visual acuity outcomes to the innovator ranibizumab molecule with an adequate safety profile in the management of PCV. Although these encouraging results support its use as a viable alternative to the innovator molecule, further prospective studies in a diverse patient population are needed to validate our findings.

Idiopathic lenticular surface neovascularization: An unusual presentation

Purpose

To present a case of posterior lenticular surface neovascularization in the absence of any ocular or systemic pathology.

Observations

A 29-year-old asymptomatic male was detected with the right eye (OD) posterior lenticular surface neovascularization extending for six-clock hours in the temporal portion along with the presence of mild posterior capsular haze. His best-corrected visual acuity was 20/25 in OD and 20/20 in the left eye (OS). No additional abnormality was identified in the remainder of the OD anterior segment and the fundus respectively. OS evaluation was unremarkable. OD imaging including B-scan ultrasonography and ultrasound biomicroscopy (UBM) were essentially normal. The anterior segment optical coherence tomography (AS-OCT) thickened lens capsule with a dense hyperreflective layer adhered to its posterior surface and separating from the capsule in the periphery. Few hyperreflective dots were visible posterior to the ciliary body although no CB thickening was noted. No systemic abnormality was detected. The patient is being managed conservatively and has shown no signs of progression of the neovascularization over six months.

Conclusions and importance

This is the first reported case of an isolated idiopathic posterior lenticular surface neovascularization occurring in an otherwise healthy patient. Although an unspecified breach in the posterior capsule or undetermined cyclitis can trigger such neovascularization, further histopathological studies of the capsular biopsy and ciliary body can provide better insight into its etiopathogenesis. Additionally, considering the asymptomatic nature of the condition, these patients can be observed and closely monitored.

Intraretinal Cysts in Macular Hole: A Structure-Function Correlation Based on En Face Imaging

Purpose

To characterize retinal micromorphic changes on en face optical coherence tomography (OCT) and to determine their role in pathogenesis and visual outcomes in macular hole (MH) surgery.

Patients and Methods

This is a retrospective, interventional, consecutive case series of 28 eyes undergoing successful MH surgery. Pre- and post-operative en face OCT were manually segmented, and the correlation between parameters such as MH basal diameter and minimal inlet area, area of cyst in inner plexiform layer (IPL) and outer plexiform layer (OPL), percentage of cyst in IPL and OPL, and amount of ellipsoid zone (EZ) defect and external limiting membrane (ELM) defect was performed. Their relationship with visual acuity (VA) outcomes (Group 1: ≥20/60; 14 eyes; Group 2: <20/60; 14 eyes) was also evaluated.

Results

A significant positive correlation was noted between the cyst area in OPL and IPL (r=0.768; p<0.001), which in turn were positively correlated with the basal diameter of the MH in all eyes. The cyst area was significantly more in IPL as compared to OPL in all eyes (p=0.049) and in group 2 (p=0.03) but not in group 1 (p=0.62). As compared to group 2, eyes in group 1 had significantly better pre- and post-operative VA, and significantly smaller basal diameter, minimal inlet area, area of cyst in IPL and OPL, and amount of defect in the ELM (postoperative) and EZ (pre- and post-operative), respectively.

Conclusion

An increase in the basal diameter of the MH is associated with a simultaneous congruous enlargement of the area of cyst in IPL and OPL. Based on these imaging findings, we propose that the possible rationale for the origin of these intraretinal cysts could be a breakdown in the physiological retinal pigment epithelium (RPE) pump due to the anatomical separation of the neurosensory retina from the underlying RPE, ie, "RPE contact loss" theory.

Short-term Efficacy and Safety of Topical β-Blockers (Timolol Maleate Ophthalmic Solution, 0.5%) in Acute Migraine: A Randomized Crossover Trial

Importance

Oral β-blockers used for the prevention of migraine headache are not effective for the treatment of acute pain. Small case series have suggested that topically applied β-blockers may be useful in the management of acute migraine pain, warranting evaluation with randomized clinical trials.

Objective

To evaluate the short-term efficacy and safety of topically applied timolol maleate ophthalmic solution, 0.5%, compared with topically applied placebo eyedrops in the treatment of acute migraine attacks.

Design, Setting, and Participants

In this randomized, masked placebo-controlled crossover trial conducted from May 27, 2015, to August 28, 2017, 50 patients with migraine were randomized to receive either timolol eyedrops, 0.5%, or a placebo eyedrop (carboxymethyl cellulose, 0.5%). After a 3-month treatment period, patients completed a 1-month washout period and were crossed over to receive the opposite treatment for a final 3 months. Analysis was performed on a modified intent-to-treat basis.

Intervention

After random assignment, patients were instructed to use 1 drop of the assigned medication in each eye at the earliest onset of migraine.

Main Outcomes and Measures

The main outcome measure was reduction in pain score with treatment. The primary end point was reduction of pain score by 4 points, or to zero, 20 minutes after instillation of the eyedrop.

Results

Of the 50 patients, 42 (84%) were females and the mean (SD) age was 27.3 (11.3) years. Of a total of 619 migraine attacks, 284 (46%) were treated with timolol, 271 (44%) were treated with the placebo, and 64 (10%) occurred during the washout period when no study medications were used. Seven patients (14%) withdrew after randomization. A total of 233 of the timolol-treated migraine attacks (82%) were associated with a reduction in pain score by 4 points, or to zero, at 20 minutes compared with 38 of the placebo-treated attacks (14%), with a difference of 68 percentage points (95% CI, 62-74 percentage points). A generalized estimating equation analysis revealed that pain score reduction at 20 minutes was greater in the timolol group compared with the placebo group by a mean (SE) of 4.63 points (0.34) (P < .001).

Conclusions and Relevance

This randomized crossover trial supports consideration of timolol eyedrops in the acute treatment of migraine. Further research is warranted to determine if the improvements observed are sustained for a longer follow-up and with larger groups.

Trial Registration

CTRI/2015/05/005829, UTN: U1111-1167-6439.

External limiting membrane angle as a composite predictive index for post-operative ELM closure in full thickness macular holes

AIM

To evaluate pre-operative qualitative and quantitative parameters of external limiting membranes (ELM) and other associated full thickness macular holes (FTMH) features and their predictive values for post-operative anatomical and functional outcomes.

METHODS

This was a retrospective study of 48 eyes that underwent vitrectomy with internal limiting membrane (ILM) peeling for FTMH and had type 1 closure. All subjects underwent optical coherence tomography (SDOCT, Heidelberg, Spectralis), and the eyes were divided into complete ELM closure (CEC) and incomplete ELM closure (IEC) groups based on the post-operative OCTs within 2 months, and ROC curves were used to estimate which of the pre-operative parameters could best predict eyes falling in the CEC group.

RESULTS

The mean pre-op ELM defect was smaller in CEC group (594 μm vs 1126 μm, p < 0.001) and so was the pre-op EZ defect (770 μm vs 1186 μm, p = 0.001). The mean ELM angle also was smaller in the CEC group (51.6° vs 102.5°, p < 0.001) and so was the mean hole inlet distance (353 μm vs 596 μm, p < 0.001). The post-operative ELM defect showed a significant negative correlation with visual acuity (r = - 0.319; p = 0.027). The ELM angle was most predictive with an AUROC of 0.958, and a cut-off of 68.3° had a sensitivity of 90% and a specificity of 89%.

CONCLUSION

Our study introduces a novel parameter called the ELM angle and proves that it has a high sensitivity and specificity in predicting complete ELM reformation post-surgery in the short term as well as the long term.

Multicolor imaging in macular telangiectasia-a comparison with fundus autofluorescence

PURPOSE

To describe various clinical features of idiopathic juxtafoveal retinal telangiectasis group 2A or idiopathic macular telangiectasia type 2 (MacTel) on multicolor imaging (MCI) and compare imaging findings of MacTel on MCI with fundus autofluorescence (FAF).

METHODS

Patients with a clinical diagnosis of MacTel based on Gass and Blodi's classification were included. FAF and MCI images were graded qualitatively for stage of disease, margins of involvement, hyperautofluorescence on FAF (corresponding retinal atrophy on MCI), and detection of crystals. FAF and MCI were graded quantitatively for the area and number of quadrants involved, hypoautofluorescene on FAF (corresponding intraretinal pigment hyperplasia or retinal pigment epithelium [RPE] atrophy on MCI), and foci of right-angled venules.

RESULTS

Seventy-eight eyes of forty five patients were included with both imaging modalities showing no difference with respect to staging of non-proliferative MacTel. Retinal crystals were recognized on MCI but not on FAF. Neurosensory retinal atrophy and  subretinal neovascular membranes were detected using MCI with 92.3 and 83.3% sensitivity, respectively. Intraretinal pigmented hyperplasia was more accurately detected (70.1 vs 58.4%) compared with RPE atrophy on MCI. MCI showed larger area of involvement, higher number of quadrants involved (p < 0.001), and better delineation of margins (p = 0.002) compared with FAF. A higher mean number of vessel dipping foci was noted on MCI in comparison with FAF (3.34 vs 3.1).

CONCLUSION

Various parameters were more easily defined using MCI compared with FAF which qualifies MCI as an enface depth-resolved imaging adjunct to conventional multimodal imaging in MacTel. The ability to detect enface as well as cross-sectional imaging features makes MCI a valuable tool in MacTel.

Macular morphometrics in foveal displacement following full thickness macular hole surgery

Purpose

To investigate if the ratio of the preoperative nasal and temporal "arms" of the macular hole (MH) can have a predictive value in the magnitude of foveal displacement postoperatively.

Methods

This is retrospective interventional case series of eyes of 40 patients with full-thickness macular hole (FTMH), which underwent vitrectomy with internal limiting membrane (ILM) peeling and had Type 1 closure.All subjects underwent pre and postoperative optical coherence tomography (OCT, Heidelberg, Spectralis, Germany). Their pre and postoperative foveo-papillary distance (FPD) was measured and the magnitude of shift was calculated. The nasal and temporal arm lengths, their ratio (N/T ratio), and the hole base diameter were measured in the preoperative OCTs.The main outcome measure was the correlation of the N/T ratio with the postoperative foveal displacement.

Results

We observed that in 25% (n = 10) the fovea shifted temporally; in 75% (n = 30) it shifted nasally. The shift did not show a significant correlation with either N/T ratio (r = 0.155, P = 0.34) or with base diameter (r = -0.008, P = 0.961). The odds ratio (OR) was 4.92 (P = 0.04) and the relative risk (RR) was 3.12 (P = 0.039) for a longer temporal segment to predict a temporal shift.

Conclusion

Both nasal and temporal shifts are possible after successful hole closure and temporal shifts can also occur in a significantly high proportion of patients. Temporal shifts are more likely in eyes with a longer temporal segment.

Plume Sign in the Deturgescence of Macular Cysts - A Novel OCT Finding

Aim

To describe a novel OCT finding called “Plume sign” in macular cysts.

Methods

Case records of five cases were retrospectively reviewed. Their case history and imaging findings on spectral domain optical coherence tomography (SD-OCT, Spectralis, Heidelberg, Germany) have been described.

Results

We observed five cases which had a solitary cyst foveal or parafoveal in location, was unique due to the presence of a plume-shaped internal substance, was treated with topical NSAIDs and was associated with good visual outcomes. We observed three cardinal events; firstly, retinal thickening followed by the formation of a foveal or parafoveal solitary cyst. Secondly, a vertical expansion of the solitary cysts in an inverted flask-shaped configuration associated with splitting of the retinal layers suggested by a hyper-reflective line and/or a hyporeflective cleft in the outer nuclear layer. Thirdly and finally, a breach of the outer retina with involvement of the external limiting membrane (ELM) and ellipsoid zone (EZ) with an exit trail of proteinaceous material through the defect in the shape of a plume of smoke hyper-reflective on OCT followed by deturgescence of the cyst.

Conclusion

In conclusion, we describe the “plume” sign – a novel OCT finding is cysts and provide a possible pathogenic hypothesis.

Unilateral isolated superior ophthalmic vein thrombosis

Superior ophthalmic vein (SOV) thrombosis is an uncommon orbital pathology that can present with sudden onset proptosis, conjunctival injection, and visual disturbance. SOV thrombosis is frequently secondary to a cavernous sinus pathology. A 32-year-old female with a known history of autoimmune hemolytic anemia presented with sudden painful proptosis left eye, and on imaging, she was found to have SOV thrombosis without cavernous sinus involvement. She was diagnosed with unilateral isolated SOV thrombosis and was managed conservatively. A careful history and clinical evaluation can help diagnose such rare disorders and initiate appropriate therapy.

Spectral domain optical coherence tomography study of macular microhole morphology and its correlation with vitreomacular interface abnormalities

To describe the demographic, clinical and optical coherence tomography (OCT) characteristics of macular microholes and to determine if the size or character of the microholes has any correlation with vitreomacular interface abnormalities. Case records of 46 eyes of 39 consecutive patients with diagnosed macular microholes were reviewed as a non-interventional retrospective case study. Demographic and clinical features were noted from the detailed case records. Spectral domain OCT images were analysed for microhole and retinal characteristics. SPSS 16.0 was used for statistical analysis. Main outcome measure was the presence of vitreomacular interface abnormalities in large and small macular microholes. Of 39 patients, 21 were male and 18 were female. Most of these patients (56.4 %) presented with visual complaints. Clinically, the commonest feature was a 'red spot' at the fovea on indirect ophthalmoscopy (25 of 44 eyes; 54.3 %). Mean logMAR vision was 0.117 (±SD 0.21). 34 (76.08 %) eyes exhibited a photoreceptor loss, 38 eyes (82.6 %) had lamellar tissue defects involving layers posterior to the outer nuclear layer. The difference between means of the groups with and without vitreomacular interface abnormalities was analysed using the unpaired t test. The presence of vitreomacular interface abnormalities was significantly associated with the size of the microhole, with larger microholes being more likely to have vitreomacular interface abnormalities than smaller ones (p < 0.05). We concluded that there was a positive correlation between the size of the microhole and the presence of vitreomacular interface abnormalities. Visual acuity had no correlation with the size of the microhole; functional vision was generally well preserved in the affected eyes.

Morphological patterns of indirect choroidal rupture on spectral domain optical coherence tomography

PURPOSE

To evaluate the morphological types of indirect choroidal rupture (ICR) using spectral domain optical coherence tomography (SD-OCT).

METHODS

This was a prospective interventional study of 18 eyes of 18 patients who presented with a history of blunt ocular trauma resulting in choroidal rupture. All patients underwent detailed ophthalmic evaluation and SD-OCT examination.

RESULTS

Mean age of the patients was 32±9.6 years. Morphologically, two types of choroidal rupture were seen on SD-OCT. The first type seen (Type 1 ICR) was a forward protrusion of the retinal pigment epithelium-choriocapillaris (RPE-CC) layer with an acutely angled pyramid or dome shape. This was associated with either a small loss of continuity of the retinal pigment epithelium layer or elevated RPE-CC projection accompanied by a significant quantity of subretinal hemorrhage. The second type observed (Type 2 ICR) was a larger area of disruption of the RPE-CC layer, photoreceptor inner segment/outer segment junction, and external limiting membrane, with a posteriorly directed concave contour depression at that area and downward sliding of tissues into the defect. At presentation, ten eyes were observed to have Type 1 ICR and eight to have Type 2 ICR. Of the 18 eyes, one with Type 1 ICR and two with Type 2 ICR developed choroidal neovascularization (16.6%).

CONCLUSION

Two distinct tomographic patterns of choroidal ruptures were identified on SD-OCT, which may allow ruptures to be classified into two morphological types. There are morphometric and clinical differences between the two types, which may help to prognosticate visual outcome and anticipate complications following choroidal ruptures.

Association of systemic comorbidity in diabetic serous macular detachment and comparison of various combination therapies in its management

BACKGROUND

The purpose of this research was to study the association between systemic comorbidity in diabetic serous macular detachment (DSMD) and the effect of different forms of combination therapies in its management.

METHODS

In this prospective analysis, 34 eyes from 34 patients with DSMD were investigated for the presence of systemic comorbidity including anemia, dyslipidemia, nephropathy, and cardiac disease, and treated with combination therapy of either intravitreal bevacizumab + laser (group 1, n = 14) or intravitreal triamcinolone + laser (group 2, n = 20). Sequential macular laser was done 2 weeks after intravitreal pharmacotherapy in both groups. Outcome measures included visual acuity and central foveal thickness at 1 and 3 months.

RESULTS

The mean age of the patients was 55.6 ± 7.6 years. The commonest systemic association was nephropathy (82.3%). In group 1, mean visual acuity improved marginally from 6/17 at baseline to 6/16 at 1 month (P = 0.0001) and was maintained at 3 months (P = 0.008); and mean central foveal thickness decreased from 488.7 μm to 318.7 μm at 1 month (P = 0.0001) but increased to 414.4 μm at 3 months (P = 0.049). In group 2, mean visual acuity improved from 6/22 at baseline to 6/19 at 1 month (P = 0.0001) and 6/12 at 3 months (P = 0.0001); and mean central foveal thickness decreased from 428.8 μm to 323.8 μm at 1 month (P = 0.0001) to 269.2 μm at 3 months (P = 0.0001).

CONCLUSION

Nephropathy should be ruled out in patients with DSMD. Although at 1 month both intravitreal triamcinolone and bevacizumab improved vision and decreased central foveal thickness in eyes with DSMD when administered along with focal laser treatment, the former had a more long-lasting effect in maintaining this gain at 3 months.

Effect of panretinal photocoagulation on macular morphology and thickness in eyes with proliferative diabetic retinopathy without clinically significant macular edema

Background

The purpose of this study was to investigate the effect of panretinal photocoagulation (PRP) on macular morphology and thickness in eyes with proliferative diabetic retinopathy (PDR) and without clinically significant macular edema.

Methods

This was a prospective study of 76 eyes from 68 patients diagnosed to have PDR without clinically significant macular edema. Baseline and post PRP visual acuity, morphological changes on optical coherence tomography (OCT), and central foveal thickness were evaluated at one week, one month, and 3 months.

Results

The mean patient age was 56.47 ± 6.55 years. Sixty-two eyes (81.58%) had stable or improved vision, while 14 eyes (18.42%) had worsened visual acuity at 3 months. Compared with baseline, mean visual acuity dropped as early as one week but was regained by 3 months. Mean preoperative central foveal thickness was 222.05 ± 59.11 μm, which increased significantly to 266.84 ± 84.67 μm at one week (P = 0.001), and remained higher at 264.05 ± 102.56 μm by one month (P = 0.01) and 256 ± 101.38 μm by 3 months (P = 0.04). Thirty-four percent of eyes with a normal macula showed morphological changes following PRP. The most common morphological change on OCT after PRP was spongy edema, seen in 48 eyes (31.6%), followed by cystoid macular edema in 36 eyes (23.7%), vitreomacular traction in 28 eyes (18.4%), epiretinal membrane in 24 eyes (15.8%), and subfoveal serous detachment in 16 eyes (10.5%).

Conclusion

PRP may cause a temporary drop in vision in the early post laser phase, and causes macular morphology/thickness changes in eyes with PDR and without clinically significant macular edema. In this study, the change in central foveal thickness did not correlate with a change in visual acuity, and the type of diabetic macular edema on OCT appeared more relevant and correlated better with the visual outcome.

Correlation of spectral domain optical coherence tomography findings in acute central serous chorioretinopathy with visual acuity

Purpose

To evaluate the structural changes in the acute phase of central serous chorioretinopathy and after its resolution, using spectral domain optical coherence tomography, to correlate these tomographic changes with visual acuity (VA).

Method

This was a prospective study of 100 consecutive patients with acute central serous chorioretinopathy. It was based on presenting the best-corrected VA, divided into three groups (Group 1, n = 36, VA 6/6; Group 2, n = 49, VA 6/9–6/18; Group 3, n = 15, VA > 6/18). All patients underwent fundus evaluation followed by fluorescein angiography and spectral domain optical coherence tomography.

Results

The mean age of the patients was 40 ± 7.17 years. The mean log MAR VA was 0.176 ± 0.0185. Single pigment epithelial detachment (PED), and multiple discrete and multiple confluent PEDs were seen in 21%, 17%, and 32% of the eyes, respectively. The location of the PED was subfoveal in 35% of the eyes. The presence of subretinal fibrin and a rough undersurface of the neurosensory retina were noted in 61% and 64% of the eyes, respectively. On en-face scanning, a break in the walls of the PED and overlying fibrin were seen in 32.8% and 45% of the eyes, respectively. The mean subretinal fluid height at the fovea was 279.11 ± 148.78 μ. The mean outer nuclear layer thickness during the active stage was 95.10 μ and during the resolved stage, it was 77.69 μ (P = 0.012). The average photoreceptor lengths were 73.1 μ, 84.6 μ, and 94.9 μ in groups 1, 2, and 3, respectively, in the acute phase; and 69.5 μ, 70.8 μ, and 61.6 μ, respectively, after resolution (P = 0.013, P = 0.010, and P = 0.011).

Conclusion

In the acute phase of the disease, poorer VA showed statistically significant association with greater dimensions of subretinal fluid – particularly, greater subretinal fluid height and thinning of the outer nuclear layer at the fovea. The presence of fibrin, subretinal precipitates, subfoveal location, or type of PED did not have any association with poor VA. In resolved central serous chorioretinopathy, poorer VA was associated with a persistently thinner outer nuclear layer, shorter photoreceptor lengths, and inner and outer segment junction atrophy.

Prevention and treatment of DNA vaccine encoding cockroach allergen Bla g 1 in a mouse model of allergic airway inflammation

BACKGROUND

One-fourth of the US population is sensitized to the German cockroach. Primary German cockroach allergen Bla g 1 is detected in 63% of homes and 52% of childcare facilities in the United States. No effective treatment or vaccination strategies are yet available.

OBJECTIVES

We evaluated the prophylactic and therapeutic efficacy of a plasmid DNA-mediated vaccination using the Bla g 1 gene in a mouse model of allergic inflammatory airway disease.

METHODS

A plasmid DNA vector coding for the Bla g 1 allergen controlled by cytomegalovirus promoter was constructed. To estimate the protective efficacy, BALB/c mice were given three injections of plasmid DNA-Bla g 1 prior to sensitization with two priming doses of recombinant Bla g 1 (rBla g 1) antigens, followed by nebulized rBla g 1 challenge. In the therapeutic approach, sensitization was followed by administering Bla g 1 DNA vaccine.

RESULTS

Bla g 1 vaccination significantly reduced allergen-induced airway inflammation, even after mice were presensitized and a Th2-dominant response was established. The Bla g 1 vaccination significantly reduced total inflammatory cell infiltrate, eosinophilia, secretion of Th2 cytokines IL-4 and IL-5 in bronchoalveolar lavage fluid, allergen-induced inflammatory infiltrates in the lungs, and Bla g 1-specific IgE in serum upon challenge with rBla g 1. Importantly, Bla g 1 DNA vaccination was able to induce IL-10-secreting regulatory T cells that could suppress the allergen-specific Th2 cells.

CONCLUSION

DNA vaccination showed protective and therapeutic efficacy against a clinically relevant allergen Bla g 1.

Presentation and management of keloid scarring following median sternotomy: a case study

Introduction

Keloid scars following median sternotomy are rare and occur more frequently in pigmented skin. Different management strategies have been described with variable success. We present a case of keloid scar formation following cardiac surgery including our management and the final aesthetic result.

Case description

A 64 year old female of fair complexion underwent mitral valve replacement. The procedure and postoperative recovery were uncomplicated, however, during the following year, thick keloid scars formed over the incision sites. Initial non surgical measures failed to relieve pain and did not offer any tangible aesthetic benefit. Eventually surgical excision was attempted. She presented to our clinic for nine months follow up with significant improvement in pain and aesthetic result.

Discussion and Evaluation

Several theories have attempted to explore the pathophysiology of keloid scar formation. A number of predisposing factors have been documented however none existed in this case. A variety of invasive and non invasive approaches have been described but significant differences in success rates and methodology of investigations still precludes a standardized management protocol.

Conclusions

In this case study a rare presentation of keloid scar has been presented. The variety of methods used to improve pain and aesthetic result demonstrates the propensity of keloid scars to recur and the therapeutic challenges that surgeons have to face in their quest for a satisfactory patient outcome.

Calcium channel antagonist (nifedipine) attenuates Plasmodium berghei-specific T cell immune responses in Balb/C mice

Nifedipine and verapamil (Martin et al. Science 1987;235:899-901) are a class of calcium channel blockers involved in the reversal of chloroquine (CQ) drug resistance in CQ-sensitive Plasmodium spp. Nifedipine alters calcium-dependent functions of macrophages and neutrophils during Plasmodium berghei malaria. However, knowledge of nifedipine-induced immunomodulation of T cell functions during P. berghei malaria is still limited. We investigated the effect of nifedipine on the immune status of splenic T cells during P. berghei malaria. The intracellular calcium levels were determined in the FURA-2A/M loaded T cells by spectrofluorometry. Splenic T cell proliferation, phosphatidylserine (PS) externalization, Fas expression and Bcl2/Bax expression were determined by flow cytometry. We report a significant increase in mean percent parasitemia in nifedipine-treated and P. berghei-infected mice. Although nifedipine treatment alone did not affect the resting state free calcium levels in splenic T cells, the rise in intracellular calcium levels of T cells following P. berghei infection was significantly less in nifedipine-treated mice compared to untreated groups at various parasitemia levels. Antigen-specific splenic T cell proliferation and apoptosis was ablated in nifedipine-treated and untreated groups at various parasitemia levels. The study unequivocally reflects the suppression of P. berghei-specific T cell immune responses by nifedipine.

Risk factor awareness and secondary prevention of coronary artery disease: are we doing enough?

We prospectively assessed the patient awareness of risk factors of coronary artery disease (CAD) in this study by performing a voluntary questionnaire survey of 235 patients undergoing first time coronary artery bypass grafting (CABG) between May and December 2003. We assessed patient awareness of smoking, hypertension (HT), hypercholesterolaemia (HC), obesity, family history (FM) and diabetes (DM) and role of medication in secondary prevention. One hundred and eighty-seven ex- or current smokers (79.6%), 175 hypercholesterolaemic (74.5%), 116 had a family history (49.4%), 88 were hypertensive (37.4%), 62 obese (26.4%) and 45 diabetic (19.1%). More patients identified smoking (53.6%) and hypercholesterolaemia (55.3%) as risk factors as compared to hypertension (43%), family history (42.5%), diabetes (14.5%) or obesity (13.6%). A majority of the patients identified their own risk factors correctly. More than 95% of the patients were taking aspirin/clopidogrel and/or a statin. The main sources of information for these patients were hospitals, general practitioners, and booklets. Risk factor awareness in patients undergoing CABG is unsatisfactory. Nearly 95% of patients are taking aspirin/clopidogrel and/or statins, however, just over half realise their role in secondary prevention. For secondary prevention to be effective, more needs to be done to provide patients with necessary information.

The coronary baroreflex in humans

Previous studies have identified the presence of coronary baroreceptors in animal models. We set up a study to explore the presence of coronary baroreceptors in humans, which was performed with isolated, graded aortic root perfusion in patients during cardiopulmonary bypass. With ethical approval 12 patients with normal coronary arteries, aged 58-75 (mean 69) years undergoing mitral valve surgery were recruited to the study with informed consent. Those with aortic valve incompetence, coronary, or peripheral artery disease and diabetes mellitus were excluded. They were randomized to have their coronary perfusion pressure set low at 50 mmHg for 90 seconds and then adjusted high to 80 mmHg for 90 seconds (group L-H) or the reverse sequence (group H-L). Average arterial pressure and approximately constant systemic flow over 30-second periods were used to calculate vascular resistance (SVR). The first six experiments followed initiation of cardiopulmonary bypass and aortic clamping but before the delivery of cold blood cardioplegia; the blood temperature for these experiments was kept at 32 degrees C. The remaining six were conducted prior to removal of the aortic cross clamp at 37 degrees C. Coronary sinus blood samples were analyzed to exclude myocardial ischemia. Coronary sinus blood samples showed insignificant variation in oxygen saturation, lactate, and troponin T. Three patients were excluded because of unstable blood pressure. In the (L-H) group SVR reduced in 4 of 4 remaining patients (mean -9.4%, range -3.9 to -19.6%). In the (H-L) group SVR increased in three patients (mean +2.0%, range 1.1 to 3.7%) but decreased in two (-8.9% and -15.8%). These preliminary results, although not statistically different, suggest the presence of coronary baroreceptors in humans. The reflex vascular responses are similar to those previously reported in animal models.

Post operative sensorineural hearing loss after middle ear surgery

Mild Sensorineural hearing loss subsequent to middle ear surgery has till today been an important complication to middle ear surgery inspite of advances in surgical techniques, operative instruments, monitoring devices and better treatment options. Lack of proper knowledge about this problem is because of under reporting of exact magnitude of hearing loss on account of difficulty in measuring hearing threshold of patients in immediate postoperative period as it may lead to post operative infection and discomfort to the patient.In our study of 80 cases carried out at ENT department, Baroda Medical College and S.S.G Hospital, Baroda, we have utilized weber's lateralisation principle and measured bone conduction thresholds of patients undergoing middle ear surgery for evaluation of postoperative Sensorineural loss as a result of middle ear surgery. Probable causes of post operative hearing loss in a patient undergoing middle ear surgery are, noise due to drills, continuous suction irrigation, vibrations, inner ear injury, manipulation of ossicles and a few unknown reasons.

Metabolic polymorphisms as susceptibility markers for lung and oral cavity cancer

Lung and oral cavity cancers are causally associated with tobacco use. Alcohol is an independent risk factor for oral cavity cancer. Major classes of carcinogens present in tobacco and tobacco smoke are converted into DNA-reactive metabolites by cytochrome P450 (CYP)-related enzymes, several of which display genetic polymorphism. Individual susceptibility to cancer is likely to be modified by the genotype for enzymes involved in the activation or detoxification of carcinogens in tobacco and repair of DNA damage. Molecular epidemiological studies to assess the risk associated with metabolic polymorphisms for cancers of the lung and head and neck have shown that the overall effect of common polymorphisms is moderate in terms of penetrance and relative risk. However, some gene combinations like mutated CYP1A1/GSTM1-null genotype seem to predispose the lung and oral cavity of smokers to an even higher risk for cancer or DNA damage, although these results require confirmation in larger well defined studies that take into account the existence of ethnic variations even within the commonly defined groups. Retinoids, isothiocyanates and tea polyphenols have been identified as possible chemopreventive agents for cancers of the lung and oral cavity. While a number of trials have been conducted with retinoids or beta-carotene, the results were ambiguous and the causes are still being debated. The possible interaction of chemopreventive agents with metabolic polymorphisms as biomarkers in chemoprevention trials is discussed.

Functional elements of the strong psbAI promoter of Synechococcus elongatus PCC 7942

The psbAI gene of the cyanobacterium Synechococcus elongatus PCC 7942 is one of three psbA genes that encode a critical photosystem II reaction center protein, D1. Regulation of the gene family in response to changes in the light environment is complex, occurs at transcriptional and posttranscriptional levels, and results in an interchange of two different forms of D1 in the membrane. Expression of psbAI is downregulated under high-intensity light (high light) in contrast to induction of the other two family members. We show that, in addition to a known accelerated degradation of the psbAI message, promoter activity decreases upon exposure to high light. Unlike the other psbA genes, additional sequences upstream of the psbAI -35 element are required for expression. Mutagenizing the atypical psbAI -10 element from TCTCCT to TATAAT increased the magnitude of expression from both psbAI::lacZ and psbAI::luxAB fusions but did not affect downregulation under high light. Inactivation of group 2 sigma factor genes rpoD2 and sigC, in both wild-type and -10-element mutagenized backgrounds, resulted in elevated psbAI::luxAB expression but did not alter the response to high light. The results are consistent with redundancy of promoter recognition among cyanobacterial group 2 sigma factors. Electrophoretic mobility shift assays showed that the DNA sequence corresponding to the untranslated leader of the psbAI message binds one or more proteins from an S. elongatus extract. The corresponding region of psbAII efficiently competed for this binding activity, suggesting a shared regulatory factor among these disparately regulated genes.

Genetic polymorphism of CYP genes, alone or in combination, as a risk modifier of tobacco-related cancers

Tobacco use is causally associated with cancers of the lung, larynx, mouth, esophagus, kidneys, urinary tract, and possibly, breast. Major classes of carcinogens present in tobacco and tobacco smoke are converted into DNA-reactive metabolites by cytochrome P450 (CYP)-related enzymes, several of which display genetic polymorphism. Individual susceptibility to cancer is likely to be modified by the genotype for enzymes involved in the activation or detoxification of carcinogens in tobacco and repair of DNA damage. We summarize here the results of case-control studies published since 1990 on the effects of genetic variants of CYP1A1, 1A2, 1B1, 2A6, 2D6, 2E1, 2C9, 2C19, 17, and 19 alone or in combination with detoxifying enzymes as modifiers of the risk for tobacco-related cancers. The results of studies on gene-gene interactions and the dependence of smoking-related DNA adducts on genotype were also analyzed. Some CYP variants were associated with increased risks for cancers of the lung, esophagus, and head and neck. The risk was often increased in individuals who also had GSTM1 deficiency. For breast cancer in women, a few studies suggested an association with CYPs related to metabolism of tobacco carcinogens and steroidal hormones. The overall effects of common CYP polymorphisms were found to be moderate in terms of penetrance and relative risk, with odds ratios ranging from 2 to 10. Some CYP1A1/GSTM1 0/0 genotype combinations seem to predispose the lung, esophagus, and oral cavity of smokers to an even higher risk for cancer or DNA damage, requiring, however, confirmation. Future strategies in molecular cancer epidemiology for identifying such susceptible individuals are discussed with emphasis on well-designed larger studies.

Genetic cancer susceptibility and DNA adducts: studies in smokers, tobacco chewers, and coke oven workers

Preventive strategies require identification of cancer-susceptible individuals resulting from combinations of carcinogen exposure, cancer-predisposing genes, and lack of protective factors. To this aim, related to tobacco smoking and chewing (betel quid), we measured PAH-DNA adducts as exposure and susceptibility markers together with genetic polymorphism in drug-metabolizing enzymes related to CYP1A1, GSTM1, and GSTT1 genes in case-control studies. (+)-anti-Benzo(a)pyrene diol-epoxide (BPDE)-DNA adduct levels were quantitated in white blood cells (WBCs) and lung tissue DNA. CYP1A1 polymorphism and GSTM1 or GSTT1 gene deletion was analyzed in genomic DNA from lung parenchyma, WBCs, or oral biopsies (leukoplakia patients from India) and from oral exfoliated cells (healthy controls). Results from lung cancer patients and PAH-exposed coke oven workers correlated CYP1A1-GSTM1 genotype combinations with BPDE-DNA adduct levels. Smokers with homozygous CYP1A1 variant and GSTM1 null had the highest adduct levels and were, as shown in Japanese smokers, most susceptible to lung cancer. In oral premalignant leukoplakia cases associated with betel quid/tobacco chewing, the prevalence of the GSTM1 null and GSTT1 null genotypes was significantly higher, as compared to healthy controls. The combined GST null genotypes prevailed in 60% of the cases with none detected in controls. Based on this short review we conclude that (i) BPDE-DNA adduct levels resulting from "at risk" genotype combinations may serve as markers to identify most susceptible individuals; (ii) in Indian betel quid/tobacco chewers, the null genotypes of GSTM1 and GSTT1 greatly increased the risk for developing oral leukoplakia.

"Low-dose" aprotinin modifies hemostasis but not proinflammatory cytokine release

BACKGROUND

Cytokines are implicated in the pathogenesis of the "whole-body inflammatory response" that may complicate the period after cardiopulmonary bypass (CPB). Low-Dose aprotinin in the pump during CPB has been shown to improve postoperative hemostasis and platelet preservation. We tested the hypothesis that low-dose aprotinin influences the inflammatory reaction (in terms of cytokine release) after CPB.

METHODS

In a prospective, randomized study, 36 patients undergoing elective coronary artery bypass grafting were investigated. Nineteen patients received low-dose aprotinin (2 x 10(6) KIU (280 mg] in the pump), and a control group of 19 did not. Complement activation, cytokine production, leukocyte elastase release. D-dimer level, full blood count, postoperative blood loss, and transfusion requirements were analyzed before, during, and after after CPB.

RESULTS

Interleukin-1 beta was not detected in either group, whereas traces of tumor necrosis factor-alpha were infrequently observed. Plasma elastase, interleukin-6, interleukin-8, and neutrophil count increased (p < 0.001) during and after CPB compared with the baseline levels, reaching a peak at 2 hours after protamine administration in both groups before returning toward baseline at 24 hours. Proinflammatory cytokine markers did not differ significantly (p > 0.1) between the groups throughout the study period. The C5b-9 level increased (p < 0.001) in both groups perioperatively, reaching its peak 15 minutes after protamine. Twenty-four-hour postoperative blood loss was significantly (p < 0.001) reduced in the aprotinin group in association with markedly reduced D-dimer levels (p < 0.001). Patients in the aprotinin group also received significantly less banked blood postoperatively than the control group (p < 0.01).

CONCLUSIONS

Low-dose aprotinin fails to modify proinflammatory cytokine release, yet confers hemostatic improvement through reduced fibrinolysis in patients undergoing routine coronary artery bypass grafting.

Magnesium flux caused by coronary artery bypass operation: three patterns of deficiency

We undertook a study to evaluate the patterns of magnesium deficiency that may develop during and following coronary artery bypass operation without cardioplegia. In 18 patients intraoperative measurements of plasma magnesium and potassium concentrations and measurements of cardiac and skeletal muscle content of these ions were taken. The changes in plasma concentrations and excretion were evaluated postoperatively. Hemodilution at initiation of cardiopulmonary bypass caused a 17.3% decrease in plasma magnesium concentration (p < 0.01), which persisted until the first postoperative day. By the fifth postoperative day the level was 19.5% greater than the preoperative value. Urinary excretion of magnesium reflected changes in plasma magnesium concentration. Cardiac muscle content of magnesium decreased by 13.3%. Plasma potassium concentration was elevated by hemodilution (p < 0.01), and muscle potassium was not depleted. We conclude that three patterns of magnesium depletion occur: hemodilution, intraoperative cellular depletion, and postoperative cellular depletion. The findings support the need for magnesium supplementation during and after cardiac operation.

Effects of antiplatelet therapy with indobufen or aspirin-dipyridamole on graft patency one year after coronary artery bypass grafting

Saphenous vein coronary artery bypass graft patency can be increased by antiplatelet therapy. Aspirin plus dipyridamole are effective but are associated with tolerability problems. Indobufen is a possible alternative antiplatelet agent that may be better tolerated. A prospective, randomized, double-blind, parallel-group study was undertaken to compare the efficacy and safety of indobufen 200 mg twice daily with aspirin 300 mg thrice daily plus dipyridamole 75 mg thrice daily in preventing occlusion of autologous saphenous vein coronary artery bypass grafts. A total of 803 patients were randomized in the study, of whom 552 had a follow-up coronary angiogram approximately 1 year after operation. All anastomoses were patent in 56% of indobufen-treated patients and 59% of aspirin-dipyridamole recipients (p = 0.384). The percentage of all anastomoses patent was 82% in the indobufen group and 83% in the aspirin-dipyridamole group (p = 0.297). Mean postoperative blood loss was significantly less in the indobufen group (p = 0.043). Patients who received indobufen also had significantly fewer adverse events considered to be treatment-related compared with aspirin-dipyridamole recipients (p = 0.02). At the doses tested indobufen was as effective as aspirin plus dipyridamole in preventing occlusion of saphenous vein grafts and was better tolerated. Because indobufen was associated with less postoperative blood loss it may be used before operation in coronary artery bypass grafting.

Evaluation of frequency of micronucleated oral mucosa cells as a marker for genotoxic damage in chewers of betel quid with or without tobacco

The frequency of micronucleated cells (MNC) derived from exfoliated human oral mucosal cells has been measured to assess genotoxic damage in chewers of betel quid with tobacco (BQT) and tobacco with lime (T). Significantly elevated frequencies of MNC were observed in the exposed groups (BQT = 4.83 +/- 0.70; T = 5.20 +/- 0.66 per 1000 cells) compared to the control group (C = 2.59 +/- 0.37) although the levels observed were lower than those reported in the literature. No correlation was seen between age, duration and frequency of habits and the frequency of MNC in the 2 habit groups. Clastogenic agents in betel quid possibly involved in micronucleus formation are discussed.

Surgical treatment of endomyocardial fibrosis with preservation of mitral valve

A 48-year-old Kenyan African, who presented with a history of coronary and cerebral embolism, was found to have endomyocardial fibrosis of the left ventricle. It proved possible to remove all diseased tissue at operation, and at the same time to preserve the mitral valve. It is important to inspect the mitral valve from both the atrial and ventricular aspects so that the valve can be spared, if it is not involved in the disease process. The choice of transatrial of transventricular surgical approach for the removal of pathological tissue may depend on whether or not the mitral valve requires replacement.