Optical Coherence Tomography in a Morning Glory Disc Anomaly with a Peripapillary Choroidal Neovascular Membrane.

The purpose of this case report is to describe the optical coherence tomography (OCT) features of a peripapillary choroidal neovascular membrane (PPCNVM) in an eye with morning glory disc anomaly (MGDA). A PPCNVM appears as a hyper-reflective mass in the peripapillary area. It should be distinguished from peripapillary hyper-reflective ovoid mass-like structures, which are markers of axoplasmic flow stasis. This case report describes the distinguishing features between the two. The presence of intraretinal cystic spaces are indicative of an active PPCNVM. In conclusion, MGDA can be associated with PPCNVM and OCT can be used in its detection.

Fractal analysis of the macular region in healthy eyes using swept-source optical coherence tomography angiography.

PURPOSE: This cross-sectional observational study evaluated the relationship between retinal vascular fractal dimension (FD) and age, as well as other vascular parameters in healthy eyes using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: The study cohort consisted of 222 eyes of 116 healthy participants with no ocular or systemic disease. SS-OCTA images were captured and analyzed using the Plex Elite 9000 and software tools available in the advanced retinal imaging (ARI) network hub. The retinal vascular layers were defined by the instrument's automatic retinal layer segmentation. The fractal analysis was performed on the superficial capillary plexus (SCP), deep capillary plexus (DCP), and the whole retina. Grayscale OCTA images were standardized and binarized using ImageJ and fractal box-counting analyses were performed using Fractalyse software. Pearson's correlation was used to analyze the correlation between FD and retinal vascular parameters. RESULTS: The results showed that FD values were significantly higher in the 6 mm ring and the whole 6 × 6 scan region when compared to the 1 mm ETDRS central subfield. The correlation between age and FD was weak with a significant positive correlation between age and FD of the SCP in the 6 mm ring and between age and FD of the DCP in the 1 mm ring. Overall, differences in FD values in these healthy eyes were extremely small regardless of age or macular location. CONCLUSION: FD values in normal eyes show little variation with age and are relatively stable across the macula. This suggests that FD values may not need adjustment for age or location when evaluated in the context of retinal disease.

Relationship between the distribution of intra-retinal hyper-reflective foci and the progression of intermediate age-related macular degeneration.

PURPOSE: To assess the relationship between the distribution of intra-retinal hyper-reflective foci (IHRF) on optical coherence tomography (OCT) and progression of intermediate age-related macular degeneration (iAMD) over 2 years. METHODS: Cirrus OCT volumes of the macula of subjects enrolled in the Amish Eye Study with 2 years of follow-up were evaluated for the presence of iAMD and IHRF at baseline. The IHRF were counted in a series of 5 sequential en face slabs from outer to inner retina. The number of IHRF in each slab at baseline and the change in IHRF from baseline to year 2 were correlated with progression to late AMD at 2 years. RESULTS: Among 120 eyes from 71 patients with iAMD, 52 eyes (43.3%) of 42 patients had evidence of both iAMD and IHRF at baseline. Twenty-three eyes (19.0%) showed progression to late AMD after 2 years. The total IHRF count increased from 243 at baseline to 604 at 2 years, with a significant increase in the IHRF number in each slab, except for the innermost slab 5 which had no IHRF at baseline or follow-up. The IHRF count increased from 121 to 340 in eyes that showed progression to late AMD. The presence of IHRF in the outermost retinal slabs 1 and 2 was independently associated with a significant risk of progression to late AMD. A greater increase in IHRF count over 2 years in these same slabs 1 and 2 was also associated with a higher risk of conversion to late AMD. CONCLUSIONS: The risk of progression to late AMD appears to be significantly associated with the distribution and extent of IHRF in the outermost retinal layers. This observation may point to significant pathophysiologic differences of IHRF in inner versus outer layers of the retina.

The relationship of diabetic retinopathy severity scales with frequency and surface area of diabetic retinopathy lesions.

PURPOSE: To assess the relationship between qualitative diabetic retinopathy (DR) scales with the precise numbers and surface area of DR lesions within the Early Treatment Diabetic Retinopathy Study (ETDRS) standard seven field (S7F) region on ultrawide-field (UWF) color fundus images. METHODS: In this study, we collected UWF images from adult patients with diabetes. Poor-quality images and eyes with any pathology precluding assessment of DR severity were excluded. The DR lesions were manually segmented. DR severity was graded according to the International Clinical Diabetic Retinopathy (ICDR) and AA protocol by two masked graders within the ETDRS S7F. These lesions' numbers and surface area were computed and correlated against the DR scores using the Kruskal-Wallis H test. Cohen's Kappa was performed to determine the agreement between two graders. RESULTS: One thousand five hundred and twenty eyes of 869 patients (294 females, 756 right eyes) with a mean age of 58.7 years were included. 47.4% were graded as no DR, 2.2% as mild non-proliferative DR (NPDR), 24.0% as moderate NPDR, 6.3% as severe NPDR, and 20.1% as proliferative DR (PDR). The area and number of DR lesions generally increased as the ICDR level increased up to severe NPDR, but decreased from severe NPDR to PDR. There was perfect intergrader agreement on the DR severity. CONCLUSION: A quantitative approach reveals that DR lesions' number and area generally correlate with ICDR-based categorical DR severity levels with an increasing trend in the number and area of DR lesions from mild to severe NPDR and a decrease from severe NPDR to PDR.

Genome-wide analysis reveals allelic variation and chromosome copy number variation in paromomycin-resistant Leishmania donovani.

In the absence of adequate diagnosis and treatment, leishmaniasis remains a major public health concern on a global scale. Drug resistance remains a key obstacle in controlling and eliminating visceral leishmaniasis. The therapeutic gap due to lack of target-specific medicine and vaccine can be minimized by obtaining parasite's genomic information. This study compared whole-genome sequence of paromomycin-resistant parasite (K133PMM) developed through in vitro adaptation and selection with sensitive Leishmania clinical isolate (K133WT). We found a large number of upstream and intergenic gene variations in K133PMM. There were 259 single nucleotide polymorphisms (SNPs), 187 insertion-deletion (InDels), and 546 copy number variations (CNVs) identified. Most of the genomic variations were found in the gene's upstream and non-coding regions. Ploidy estimation revealed chromosome 5 in tetrasomy and 6, 9, and 12 in trisomy, uniquely in K133PMM. These contain the genes for protein degradation, parasite motility, autophagy, cell cycle maintenance, and drug efflux membrane transporters. Furthermore, we also observed reduction in ploidy of chromosomes 15, 20, and 23, in the resistant parasite containing mostly the genes for hypothetical proteins and membrane transporters. We chronicled correlated genomic conversion and aneuploidy in parasites and hypothesize that this led to rapid evolutionary changes in response to drug induced pressure, which causes them to become resistant.

Retino-choroidal evaluation of the macular region in eyes with tubercular serpiginous-like choroiditis using swept-source optical coherence tomography angiography.

AIM: To analyse the alterations in retino-choroidal angioarchitecture in eyes with active tubercular serpiginous-like choroiditis (TB-SLC) using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: This prospective cross-sectional study enrolled 34 eyes diagnosed with TB-SLC and 34 age-matched healthy controls. Data acquisition with SS-OCTA using the PLEX Elite 9000 (Carl Zeiss Meditec Inc., Dublin, CA, USA) with a 6 × 6 mm pattern centered on the foveal center was done. Automated retinal vessel length density (VLD) and perfusion density (PD) and foveal avascular zone architecture were obtained from the ARI hub. Choroidal vascularity index (CVI) and choriocapillaris flow deficits (CCFD) were obtained using Image J. RESULTS: Eyes with TB-SLC showed significantly reduced vessel indices in all retinal layers (P < 0.05), decreased CVI (P = 0.001) and increased CCFD (P = 0.001) as compared to healthy eyes. CCFD was increased significantly in the involved quadrants in eyes with TB-SLC when compared with the uninvolved quadrants and corresponding healthy quadrants in control subjects. CCFD showed a significant negative correlation with visual acuity (r = - 0.46, P = 0.006). CONCLUSION: Eyes with TB-SLC manifest reduced VLD and PD, decreased CVI and increased CCFD. The CCFD alterations are non-uniform in these eyes, mainly located under the regions with disease activity.

Relationship between proximity of choriocapillaris flow deficits and enlargement rate of geographic atrophy.

PURPOSE: To correlate choriocapillaris (CC) flow deficits (FD) in eyes with geographic atrophy (GA) at various distances from the border of the GA lesion with yearly enlargement rate (yER) of GA. METHODS: In this retrospective study, spectral domain optical coherence tomography (SD-OCT) and SD optical coherence tomography angiography (OCTA) images were collected from patients with GA, who were imaged at Doheny Eye Centers between 2016 and 2018, using the Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA). All enrolled patients had one baseline 6 × 6 mm OCTA scan and two 6 × 6 mm SD-OCT cubes, one at baseline and one at a follow-up visit at least 12 months later. The border of the GA was manually outlined on the en face OCT fundus image and the yER was calculated after square root transformation. A grid composed of 100-µm-wide successive concentric rings was created around the GA lesion on the OCTA CC slab using ImageJ and the FD% was calculated from the binarized image. FD% from each ring was correlated with the yER of GA. RESULTS: Thirty eyes of 22 patients were included in the study. The mean yER was 0.2 ± 0.15 mm. The FD% in the first five rings (from 0 to 500 µm from the border of GA) was significantly correlated with the yER. However, there was no statistically significant correlation between the yER and CC FD% beyond 500 µm from the GA lesion. CONCLUSIONS: Only the choriocapillaris FD% in the 500-µm region immediately surrounding GA lesions appears to predict the rate of enlargement of these lesions.

Distribution of peripheral lesions identified by mydriatic ultra-wide field fundus imaging in diabetic retinopathy.

PURPOSE: To analyze the distribution of diabetic retinopathy (DR) lesions in an Indian population using ultra-wide field (UWF) fundus imaging. METHODS: Seven hundred fifteen subjects (1406 eyes) with diabetic retinopathy in India were enrolled in this multicenter, prospective, observational study using UWF pseudocolor imaging with Optos Daytona Plus (Optos plc, Dunfermline, Scotland, UK). Images were transmitted to Doheny Image Reading Center, Los Angeles, CA, for grading. The ETDRS grid was overlaid on stereographic projections of UWF images, and images were graded independently by 2 masked graders. Lesion distribution was graded as predominantly central (PCL) or predominantly peripheral (PPL) according to previous criteria, considering both lesion number and area. An image was graded as PPL if > 50% of the lesion area was seen in at least one peripheral field as compared with the corresponding ETDRS field. Diabetic retinopathy severity was also assessed based on the International Classification of Diabetic Retinopathy (ICDR) grading scale. The main outcome measures were lesion distribution (PPL versus PCL): overall and within specific fields in eyes with various grades of DR. RESULTS: Lesion distribution was rated to be PPL in 37% of eyes and PCL in 63% of eyes (P < 0.003). The frequency of a PPL distribution varied significantly across all ICDR severity levels, with frequencies of mild non-proliferative DR (NPDR) (30.9%), moderate NPDR (40.3%), severe NPDR (38.5%) and PDR (34.9%), P = 0.005. When assessing which individual fields were rated to show a PPL distribution, the frequency was greatest in field 4 and least in field 7. For any grade of DR, temporal fields showed the greatest PPL frequency, followed in order by the superior, inferior, and nasal fields (P < 0.001). Only 3.5% of eyes showed PPL distribution in all five peripheral fields. CONCLUSIONS: One-third of the UWF images showed a PPL distribution in this cohort with the temporal quadrant having the widest distribution of PPL. As the PPL distribution varied significantly between various grades of DR, UWF imaging may prove to be important for screening of referral warranted retinopathy.

QUANTITATIVE ASSESSMENT OF CHORIOCAPILLARIS FLOW DEFICITS SURROUNDING CHOROIDAL NEOVASCULAR MEMBRANES.

PURPOSE: To quantify the regional variation in choriocapillaris (CC) flow deficits percentage (FD%) surrounding treatment-naïve Type 1 choroidal neovascularization (CNV) associated with age-related macular degeneration. METHODS: Patients were imaged with swept-source optical coherence tomography angiography system (Carl Zeiss PLEX Elite 9000; Carl Zeiss Meditec AG, Jena, Germany). Two 6 × 6-mm volume scans were acquired. Boundary-specific segmentation was used to isolate the Type 1 CNV. For CC assessment, both structural and optical coherence tomography angiography CC slabs (10-µm thick, starting 21 µm below the retinal pigment epithelium fit reference) were exported for signal compensation and averaging using ImageJ. The resultant CC image was binarized to calculate the FD%, for para-CNV and peri-CNV rings (each 500-µm wide). In a subgroup of 20 eyes, the FD% was compared with similar regions of age-matched controls. The FD% was also analyzed in small 500 × 500-µm squares equidistant from the fovea to compensate for regional variation of CC FD% as a potential confounding factor. RESULTS: Thirty-two eyes from 27 subjects were enrolled in this study. The CC FD% in the para-CNV ring was 26.58 ± 7.36, which was significantly higher than the peri-CNV ring (21.94 ± 6.31); P < 0.001. The FD% in para-CNV and peri-CNV rings was significantly greater than that of healthy controls (15.82 ± 1.29% and 15.53 ± 1.32%, respectively); P < 0.001. The FD% computed in the 500-µm squares equidistant from the fovea was also greater in the para-CNV ring (26.14 ± 7.11) than that in the peri-CNV ring (22.31 ± 6.21); P < 0.001. CONCLUSION: Choriocapillaris FD% is the highest in the region immediately surrounding the CNV.

Artemisinin-resistant Leishmania parasite modulates host cell defense mechanism and exhibits altered expression of unfolded protein response genes.

Artemisinin, extracted from a medicinal herb Artemisia annua, is widely used to treat malaria and has shown potent anticancer activity. Artemisinin has been found to be effective against experimental visceral and cutaneous leishmaniasis. Despite extensive research to understand the complex mechanism of resistance to artemisinin, several questions remain unanswered. The artesunate (ART)-resistant line of Leishmania donovani was selected and cellular mechanisms associated with resistance to artemisinin were investigated. ART-resistant (AS-R) parasites showed reduced susceptibility towards ART both at promastigote and amastigote stage compared with ART sensitive (WT) parasites. WT and AS-R parasites were both more susceptible to ART at the early log phase of growth compared with late log phase. AS-R parasites were more infective to the host macrophages (p < 0.05). Evaluation of parasites' tolerance towards host microbicidal mechanisms revealed that AS-R parasites were more tolerant to complement-mediated lysis and nitrosative stress. ROS levels were modulated in presence of ART in AS-R parasites infected macrophages. Interestingly, infection of macrophages by AS-R parasites led to modulated levels of host interleukins, IL-2 and IL-10, in addition to nitric oxide. Additionally, AS-R parasites showed upregulated expression of genes of unfolded protein response pathway including methyltransferase domain-containing protein (HSP40) and flagellar attachment zone protein (prefoldin), that are reported to be associated with ART resistance in Plasmodium falciparum malaria. This study presents in vitro model of artemisinin-resistant Leishmania parasite and cellular mechanisms associated with ART resistance in Leishmania.

Detection of Mycobacterium tuberculosis with nested polymerase chain reaction analysis in enucleated eye ball in Eales' disease.

Nested polymerase chain reaction (nPCR) was performed on enucleated eyeball for detection of Mycobacterium tuberculosis (M. tb) genome in a patient with Eales' disease. PCR analysis in all previous studies has been done mainly using aqueous, vitreous and epiretinal membranes from these patients. Paraffin wax embedded tissue section of the enucleated eyeball was analyzed by histopathology and nPCR targeting MPB64 gene and IS6110 region of M. tb genome. Lymphocytic infiltration was seen in the vitreous, iris and the retinal tissue. Ziehl Neelsen stain was negative for acid fast bacilli. Caseation necrosis was not seen in any section. Agarose gel electrophoretogram showed positive results with 200 bp specific amplified product targeting MPB64 gene, whereas nPCR targeting IS6110 region was negative. Since biopsy proven M. tb is extremely difficult in ocular tissues due to extensive necrosis, the nPCR technique aided in the diagnosis.

Solar photocatalytic degradation of ciprofloxacin using biochar supported zinc oxide- tungsten oxide photocatalyst.

Ciprofloxacin (CIP) is an antibiotic used to treat bacterial infections. It is not completely broken down during conventional wastewater treatment processes and can persist in the environment, leading to the development of antibiotic-resistant bacteria. This study focuses on the solar photocatalytic degradation CIP using biochar-supported photocatalysts. The photocatalysts developed by combining ZnO and WO3 in different ratios (1:2, 1:1, 2:1) were supported on hemp herd biochar. The photocatalyst made with a ratio of 2:1:1 of ZnO:WO3:biochar (Z2W1H) reported the highest CIP degradation efficiency of 87.3% and TOC removal efficiency of 43.1% at a catalyst dosage of 2 g/L, initial CIP concentration of 3 mg/L, and treatment time of 150 min. Subsequently, the effects of operating parameters on CIP degradation were investigated using central composite design (CCD). About 85.4% degradation efficiency of CIP was obtained at optimum conditions (pH ∼8.4, initial CIP concentration ∼4.4 mg/L, catalytic dosage ∼3.4 g/L) within 90 min. A quadradic model was developed to interpret the linear and interactive effect of operating parameters on the CIP degradation efficiency with 2.24-4.59% error. The adsorption-desorption study showed around 42.21% of adsorbed CIP was desorbed from Z2W1H. Scavenger studies demonstrated that the CIP breakdown was notably done by the superoxide radical (O2•-). The mechanism of CIP degradation was adsorption on biochar and subsequent degradation by photocatalyst. The prevalent degradation reactions such as C-N bond cleavage, decarboxylation, decarbonylation, defluorination, and ring opening lead to formation of various intermediates. The Z2W1H reusability test showed ~ 4.2% decrease in CIP removal efficiency after three cycles.

Antimony susceptible Leishmania donovani: evidence from in vitro drug susceptibility of parasites isolated from patients of post-kala-azar dermal leishmaniasis in pre- and post-miltefosine era.

Post-kala-azar dermal leishmaniasis (PKDL) patients are a key source of Leishmania donovani parasites, hindering the goal of eliminating visceral leishmaniasis (VL). Monitoring treatment response and parasite susceptibility is essential due to increasing drug resistance. We assessed the drug susceptibility of PKDL isolates (n = 18) from pre-miltefosine (MIL) era (1997-2004) with isolates (n = 16) from the post-miltefosine era (2010-2019) and post-miltefosine treatment relapse isolates (n = 5) towards miltefosine and amphotericin B (AmB) at promastigote stage and towards sodium antimony gluconate (SAG) at amastigote stage. PKDL isolates were examined for mutation in gene-encoding AQP1 transporter, C26882T mutation on chromosome 24, and miltefosine-transporter (MT). PKDL isolates from the post-miltefosine era were significantly more susceptible to SAG than SAG-resistant isolates from the pre-miltefosine era (P = 0.0002). There was no significant difference in the susceptibility of parasites to miltefosine between pre- and post-miltefosine era isolates. The susceptibility of PKDL isolates towards AmB remained unchanged between the pre- and post-miltefosine era. However, the post-miltefosine era isolates had a higher IC50 value towards AmB compared with PKDL relapse isolates. We did not find any association between AQP1 gene sequence variation and susceptibility to SAG, or between miltefosine susceptibility and single nucleotide polymorphisms (SNPs in the MT gene. This study demonstrates that recent isolates of Leishmania have resumed susceptibility to antimonials in vitro. The study also offers significant insights into the intrinsic drug susceptibility of Leishmania parasites over the past two decades, covering the period before the introduction of miltefosine and after its extensive use. IMPORTANCE: Post-kala-azar dermal leishmaniasis (PKDL) patients, a key source of Leishmania donovani parasites, hinder eliminating visceral-leishmaniasis. Assessment of the susceptibility of PKDL isolates to antimony, miltefosine (MIL), and amphotericin-B indicated that recent isolates remain susceptible to antimony, enabling its use with other drugs for treating PKDL.

Impact of slab selection on the relationship between choriocapillaris flow deficits and enlargement rate of geographic atrophy.

OBJECTIVE: To evaluate the effect of changing slab position on the correlation between choriocapillaris (CC) flow deficits (FD) in eyes with geographic atrophy (GA) and yearly enlargement rate (yER) of GA. METHODS: OCT and OCTA images obtained on Cirrus HD-OCT device were collected from patients with GA. Each patient underwent OCTA scan at baseline and two OCT scans, one at baseline and one after at least 12 months. GA was delineated on en-face fundus image to calculate yER. OCTA images were generated from three 10 µm thick slabs 11, 21 and 31 µm posterior to RPE-fit line. 100 µm-wide concentric rings were generated around GA to calculate FD% in each ring which was correlated with yER. RESULTS: For the 11-21 µm slab, FD% was not significantly correlated with yER for any of the rings (p > 0.05). For the 21-31 and 31-41 µm slab, FD% of rings located in the 600 µm region around GA was significantly correlated with yER (p < 0.05). However, in all slab locations, there was no significant correlation between yER and CC FD% of rings located beyond the 600 µm region (p > 0.05). CONCLUSIONS: Slab selection for quantification of CC FD% may have a significant impact on quantitative results in eyes with GA.

Retinal Imaging Findings in Inherited Retinal Diseases.

Inherited retinal diseases (IRDs) represent one of the major causes of progressive and irreversible vision loss in the working-age population. Over the last few decades, advances in retinal imaging have allowed for an improvement in the phenotypic characterization of this group of diseases and have facilitated phenotype-to-genotype correlation studies. As a result, the number of clinical trials targeting IRDs has steadily increased, and commensurate to this, the need for novel reproducible outcome measures and endpoints has grown. This review aims to summarize and describe the clinical presentation, characteristic imaging findings, and imaging endpoint measures that are being used in clinical research on IRDs. For the purpose of this review, IRDs have been divided into four categories: (1) panretinal pigmentary retinopathies affecting rods or cones; (2) macular dystrophies; (3) stationary conditions; (4) hereditary vitreoretinopathies.

Subretinal hyperreflective material in regions of atrophy and fibrosis in eyes with neovascular age-related macular degeneration.

BACKGROUND: Subretinal hyperreflective material (SHRM) is a significant biomarker for poor visual outcomes in neovascular age-related macular degeneration (nAMD); however, its relationship with fibrosis and atrophy is not well understood. This study aims to evaluate the relationship between SHRM, atrophy, and fibrosis in eyes receiving antivascular endothelial growth factor therapy for nAMD. METHODS: Post-hoc analysis of the 65 patients enrolled in the SEVEN-UP study, a multicenter cross-sectional study of patients originally enrolled in the ANCHOR and MARINA trials of ranibizumab. Color fundus photographs (CFP) were reviewed and manually segmented to define regions of atrophy and fibrosis. SHRM borders on OCT volume scans were manually delineated, and thickness measurements were computed and compared in corresponding regions of atrophy and fibrosis on the CFPs. RESULTS: Of the 65 subjects, 51 eyes showed atrophy and/or fibrosis on CFP and were included in the final analysis. Both atrophy and fibrosis regions exhibited SHRM on OCT. The mean SHRM thickness on OCT was significantly greater in CFP-fibrosis regions (44.19 ± 46.95 µm) compared with CFP-atrophy regions (14.28 ± 13.35 µm; p < 0.001). Additionally, the average maximum height of SHRM in fibrotic regions (268.04 ± 130.05 µm) was significantly thicker than in atrophic regions (121.95 ± 51.17 µm; p < 0.001). CONCLUSIONS: Although atrophy and fibrosis are thought to be different end-stage outcomes in eyes with nAMD, they both demonstrate SHRM on OCT; the main distinction being thickness. Given these similarities, these regions of nAMD-associated atrophy may be better-termed "atrosis" to distinguish these lesions from typical atrophy in the absence of neovascular disease.

Relationship between macular perfusion and lesion distribution in diabetic retinopathy.

BACKGROUND/OBJECTIVES: To assess the relationship between macular vessel density metrics and foveal avascular zone (FAZ) characteristics on optical coherence tomography angiography (OCTA) and lesion distribution in eyes with diabetic retinopathy (DR). SUBJECTS/METHODS: Patients with DR who underwent both Optos ultrawidefield (UWF) pseudocolor imaging and macular OCTA (Cirrus Angioplex, 6 × 6 mm) were included in this cross-sectional observational study. The distribution of DR lesions was assessed by comparing each of the peripheral ETDRS extended fields (3-7) against their corresponding ETDRS field, hence eyes were defined as either having predominantly peripheral lesions (PPL) or predominantly central lesions (PCL). En face OCTA images from the superficial and deep capillary plexuses (SCP and DCP) were then analysed using Image J software. Perfusion density (PD), vessel length density (VLD), and fractal dimensions (FD) were calculated following binarization and skeletonization of the images. RESULTS: Out of 344 eyes, 116 (33.72%) eyes had PPL and 228 (66.28%) eyes had PCL. For all DRSS levels, VLD, PD, and FD were not significantly different between eyes with PPL and PCL. The FAZ in eyes with PPL, however, was found to be more circular in shape compared to eyes with PCL (p = 0.037). CONCLUSION: Although the presence of PPL has been associated with a higher risk for diabetic retinopathy progression, the macular perfusion is similar in eyes with PPL and PCL. The FAZ is more circular in eyes with PPL, but the clinical relevance of this difference remains to be defined.

Longitudinal Evaluation of the Distribution of Intraretinal Hyper-Reflective Foci in Eyes with Intermediate Age-Related Macular Degeneration.

PURPOSE: Intraretinal hyper-reflective foci (IHRF) are optical coherence tomography (OCT) risk factors for progression of age-related macular degeneration (AMD). In this study we assess the change in the number and distribution of IHRF over two years. METHODS: The axial distribution of IHRF were quantified in eyes with intermediate AMD (iAMD) at baseline and 24 months, using a series of 5 sequential equidistant en face OCT retinal slabs generated between the outer border of the internal limiting membrane (ILM) and the inner border of the retinal pigment epithelium (RPE). Following thresholding and binarization, IHRF were quantified in each retinal slab using ImageJ. The change in IHRF number in each slab between baseline and month 24 was calculated. RESULTS: Fifty-two eyes showed evidence of IHRF at baseline, and all continued to show evidence of IHRF at 24 months (M24). The total average IHRF count/eye increased significantly from 4.67 ± 0.63 at baseline to 11.62 ± 13.86 at M24 (p < 0.001) with a mean increase of 6.94 ± 11.12 (range: - 9 to + 60). Overall, at M24, 76.9% eyes showed an increase in IHRF whereas 15.4% of eyes showed a decrease (3 eyes [5.7%] showed no change). There was a greater number of IHRF and a greater increase in IHRF over M24 in the outer slabs. CONCLUSIONS: IHRF are most common in the outer retinal layers and tend to increase in number over time. The impact of the distribution and frequency of these IHRF on the overall progression of AMD requires further study.

Effects of chewing tobacco on corneal endothelium in patients with diabetes mellitus.

OBJECTIVE: To determine the impact of tobacco chewing on corneal endothelial structure in patients with diabetes mellitus (DM). METHODS: Corneal endothelial parameters (endothelial cell count, ECD; coefficient of variation, CV; hexagonality, Hex, and central corneal thickness, CCT) were analysed in 1234 eyes of 1234 patients using non-contact specular microscopy (EM 4000 Tomey Nishi-Ku, Nagoya, Aichi, Japan). The study group (with a present history of tobacco chewing) comprising of 948 subjects, with 473 having DM was compared with age and gender-matched control group comprising of 286 subjects (139 having DM) with no history of tobacco use in any form. RESULTS: Tobacco chewers had a significantly reduced ECD (P = 0.024) and Hex (P = 0.009) as compared with non-chewers. Similar results were noted in ECD (P = 0.004) and Hex (P = 0.005) in patients with DM. Tobacco chewers had a significantly decreased ECD values among males, HbA1C ≤ 7.5% and duration of DM ≤ 20 years, and significantly decreased Hex among those with >50 years of age, females, and duration of DM > 20 years. The CV and CCT values were comparable between the study and the control groups. Tobacco chewers showed a significant association of ECD with age, HbA1C, and duration of DM; CV with HbA1C; Hex with age and duration of DM; and CCT with gender, age, HbA1C and duration of DM. CONCLUSIONS: Tobacco chewing may negatively impact corneal health, especially confounded by additional factors like age and DM. These factors must be accounted for in the pre-operative evaluation of such patients prior to any intra-ocular surgery.

Association of anthropometric parameters as a risk factor for development of diabetic retinopathy in patients with diabetes mellitus.

OBJECTIVE: To study the relationship of body fat distribution in patients with diabetes mellitus (DM), and its long-term complications like diabetic retinopathy (DR), in Indian population. METHODS: This was a prospective, cross-sectional observational study involving 1773 subjects diagnosed with DM and 1778 age and gender-matched individuals. The patients with DM were assessed for the presence and severity of DR. Severe non-proliferative DR and proliferative DR were categorised as sight threatening DR (STDR). Anthropometric parameters, i.e., neck circumference (NC); mid-upper arm circumference (MAC); waist circumference (WC); hip circumference (HC); mid-thigh circumference (MTC) and body mass index (BMI) were measured using standardised technique. RESULTS: The mean age was 59.33 ± 9.32 for DM group, and 66.03 ± 11.04 for non-DM group. DM group showed significantly greater NC, WC, and MTC and significantly reduced MAC and weight. HC and BMI were comparable between the groups. There was a significant positive correlation of MAC and WC (with any level of DR) and MAC, WC, and weight (for STDR); and a significant negative correlation of HC and MTC (with any level of DR) and NC, HC, MTC, and BMI (for STDR). Multiple logistic regression analysis confirmed that WC was the single most important predictor for any level of DR and STDR. CONCLUSIONS: Association of body fat distribution with DM and DR appears multifactorial. However, central obesity signified by waist circumference appears to be the significant risk related to the development of DR and STDR in Indian population.