Evaluation of Macular and Peripapillary Choroidal Thickness using Enhanched Depth Imaging Optical Coherence Tomography in Patients with Essential Hypertension

PURPOSE: To measure the macular and peripapillary choroidal thickness using Enhanced Depth Imaging (EDI) Spectral Domain optical coherence tomography in patients with essential hypertension. MATERIALS AND METHODS: This was a case–control, cross-sectional prospective study. A total of 25 patients with systemic hypertension, and 25 healthy controls over 30 years of age, were included. Macular and peripapapillary choroidal thickness (SFCT) was measured using a Heidelberg SD-OCT platform operating in the enhanced depth imaging mode. All study participants had best corrected visual acuities of 20/25 or more, a refractive error in the range +3.0 to –3.0 diopters and intraocular pressure (IOP) lower than 21 mmHg. Those with systemic or ocular disease (glaucoma, uveitis, high myopia, age-related macular degeneration, diabetes mellitus, etc.) or a history of ophthalmic surgery that may have affected the choroidal vascular network were excluded. RESULTS: The subfoveal choroidal thickness was significantly thicker in the hypertension group compared to the normal participants (P<0.015). The macular choroidal thickness was significantly thicker in the superior, inferior and temporal quadrants among the hypertensive patients (Superior- P <0.08, inferior P<0.014, temporal P < 0.0003). Though the choroid thickness in the nasal quadrant was also thicker in nasal quadrant in the hypertensive patients the difference was not statistically significant (P<0.067). The peripapillary choroidal thickness in superior, inferior and temporal quadrants was significantly thicker in the hypertensive group (Superior-P<0.023, inferior-P<0.033, nasal-P<0.447, temporal-P<0.008). CONCLUSION: The choroidal thickness was significantly thicker in the hypertensive patients in our study. However further larger population-based studies are required to better understand the effect of systemic hypertension on choroidal thickness

Study of ABCB1 polymorphism (C3435T) in HIV-1-infected individuals from South India

Studies on P-glycoprotein expression and function have revealed that a single nucleotide polymorphism (SNP) in the human ABCB1 gene at 3435 (C > T) results in altered expression and function of P-glycoprotein [1, 2].There have been reports of lower nelfinavir and efavirenz (EFV) concentrations associated with TT genotypes (mutant) of ABCB1 C3435T polymorphism [3, 4].Frequency distribution of this polymorphism is known to vary across populations [3, 5, 6]. We report the genotype distribution of ABCB1 C3435T in 179 individuals (126 HIV-infected and 53 healthy) from South India. The polymorphism was correlated with plasma 12 h EFV and 2 h nevirapine (NVP) concentrations in 55 and 71 patients, respectively. Plasma EFV and NVP were estimated by HPLC [7, 8]. Genotyping was carried out by PCR-RFLP [9]

Repurposing Anti-Inflammasome NRTIs for Improving Insulin Sensitivity and Reducing Type 2 Diabetes Development

Innate immune signaling through the NLRP3 inflammasome is activated by multiple diabetes-related stressors, but whether targeting the inflammasome is beneficial for diabetes is still unclear. Nucleoside reverse-transcriptase inhibitors (NRTI), drugs approved to treat HIV-1 and hepatitis B infections, also block inflammasome activation. Here, we show, by analyzing five health insurance databases, that the adjusted risk of incident diabetes is 33% lower in patients with NRTI exposure among 128,861 patients with HIV-1 or hepatitis B (adjusted hazard ratio for NRTI exposure, 0.673; 95% confidence interval, 0.638 to 0.710; P \u3c 0.0001; 95% prediction interval, 0.618 to 0.734). Meanwhile, an NRTI, lamivudine, improves insulin sensitivity and reduces inflammasome activation in diabetic and insulin resistance-induced human cells, as well as in mice fed with high-fat chow; mechanistically, inflammasome-activating short interspersed nuclear element (SINE) transcripts are elevated, whereas SINE-catabolizing DICER1 is reduced, in diabetic cells and mice. These data suggest the possibility of repurposing an approved class of drugs for prevention of diabetes

Comparison of choroidal thickness using swept-source and spectral-domain optical coherence tomography in normal Indian eyes

BACKGROUND/AIMS: Choroidal thickness measurements are reported to differ between spectral-domain optical coherence tomography (SD-OCT) and swept-source OCT (SS-OCT). The aim of this study was to assess the comparability of choroidal thickness measurements using SS-OCT and SD-OCT devices among normal participants. MATERIALS AND METHODS: This was a prospective study of 31 (62 eyes) normal participants. Choroidal imaging was performed sequentially with the Spectralis OCT (SD-OCT) and the deep range imaging OCT (DRI OCT-1) (SS-OCT) using standardized imaging protocols. The subfoveal choroidal thickness (SFChT) was measured manually by two masked retinal specialists. Paired t-tests and intraclass correlation coefficients (ICCs) were used to compare the measurements. RESULTS: The mean SFChT was 319.5 μm and 325.3 μm for DRI OCT-1 and Spectralis OCT, respectively (P = 0.001), with a mean difference of 5.9 with ICC of 0.97. The mean difference in choroidal thickness between the OCT devices was larger among eyes with choroidal thickness > 350 μm compared with eyes with thinner choroids (8.0 μm vs. 4.7 μm). CONCLUSIONS: SFChT measurements are comparable between DRI OCT-1 and Spectralis OCT. The variability between the devices increases in thicker choroids

Purtscher-like retinopathy: A rare complication of peribulbar anesthesia

Purtscher and Purtscher-like retinopathy is a distinctive retinal syndrome characterized by ischemic retinal whitening in a peripapillary pattern. We report a case of Purtscher-like retinopathy in a healthy 64-year-old man after a routine peribulbar anesthetic injection for cataract surgery. Although peribulbar anesthesia is considered to be a safer alternative to retrobulbar anesthesia, it has been associated with unusual but grave complications including central retinal artery occlusion

Iatrogenic subretinal injection of Ozurdex® implant and its effect on macular edema

PURPOSE: The purpose of this study was to report a rare case of subretinal lodgement of Ozurdex® implant (Allergan Inc., Irvine, CA, USA) and its effect on macular edema in a case of central retinal vein occlusion (RVO). METHODS: A rare complication of subretinal lodgement of Ozurdex® implant without retinal perforation was encountered in a case of RVO with intractable macular edema. As associated retinal perforation was not noted, no intervention was done. The patient was regularly followed up at 1 month, and the effect on macular edema and intraocular pressure was analyzed. RESULTS: The corticosteroid pellets got disintegrated and totally absorbed with a subtle chorioretinal scar by the 3rd follow-up month without any intervention. Even though subretinal, it was capable of reducing macular edema by 181 microns at 1 month postinjection, and its effect started wearing off by 2 months. DISCUSSION: Subretinal lodgement of Ozurdex® implant is rare and preventable, yet a potential complication of intravitreal implants which is now in vogue. We speculate a too acute angle of injection or incomplete insertion of the drug delivery system applicator (DDS) away from the limbus or perhaps less refined previous DDS applicator to be a cause for subretinal delivery of the implant. The early disintegration of implant occurred due to breach in structural integrity that caused loss of controlled drug release and rapid absorption. It reduced macular edema up to 2 months without elevating intraocular pressure. CONCLUSION: A more widespread application of any technology always portends a more significant risk for complications, and an ophthalmologist should be aware of this potential risk. Though subretinal, corticosteroid implant was capable of reducing macular edema by 181 microns by 1 month and its effect wore off by 2 months

Cytoplasmic synthesis of endogenous Alu complementary DNA via reverse transcription and implications in age-related macular degeneration

Alu retroelements propagate via retrotransposition by hijacking long interspersed nuclear element-1 (L1) reverse transcriptase (RT) and endonuclease activities. Reverse transcription of Alu RNA into complementary DNA (cDNA) is presumed to occur exclusively in the nucleus at the genomic integration site. Whether Alu cDNA is synthesized independently of genomic integration is unknown. Alu RNA promotes retinal pigmented epithelium (RPE) death in geographic atrophy, an untreatable type of age-related macular degeneration. We report that Alu RNA-induced RPE degeneration is mediated via cytoplasmic L1-reverse-transcribed Alu cDNA independently of retrotransposition. Alu RNA did not induce cDNA production or RPE degeneration in L1-inhibited animals or human cells. Alu reverse transcription can be initiated in the cytoplasm via self-priming of Alu RNA. In four health insurance databases, use of nucleoside RT inhibitors was associated with reduced risk of developing atrophic macular degeneration (pooled adjusted hazard ratio, 0.616; 95% confidence interval, 0.493-0.770), thus identifying inhibitors of this Alu replication cycle shunt as potential therapies for a major cause of blindness

Anti‐HIV drugs reduce risk of prediabetes and progression to type 2 diabetes in HIV‐infected patients

Abstract The aim of this study was to investigate whether the use of nucleoside reverse transcriptase inhibitors (NRTIs) impacts the incidence of prediabetes or type 2 diabetes mellitus (T2DM) or the progression from prediabetes to T2DM in people living with HIV (PLWH). We conducted a retrospective cohort study using the US Veterans Health Administration database among adult patients with an HIV diagnosis from the year 2000 until 2021 to determine the incidence of prediabetes and further progression to T2DM among NRTI exposed and unexposed patients. A multistate model was used to evaluate progression from normoglycemia to prediabetes and then to T2DM, and covariate adjustment with the Cox proportional hazards model was used to estimate the hazard ratios (HRs). Among 32,240 veterans diagnosed with HIV, prediabetes and T2DM were observed among 20.2% and 20.7% of patients, respectively. Among those diagnosed with prediabetes, 31.8% progressed to T2DM. Patients exposed to NRTIs at any time (86.6%), had a reduced risk of prediabetes [HR: 0.50 (95% confidence interval, CI: 0.47–0.53)] and among prediabetics, a lower risk of progression to T2DM [HR: 0.73 (95% CI: 0.63–0.85)] when compared to patients who never used NRTIs. In summary, NRTIs may reduce the risk of developing prediabetes and the progression from prediabetes to T2DM in PLWH

Study of ABCB1 polymorphism (C3435T) in HIV-1-infected individuals from South India

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