Effect of microalbuminuria on corneal endothelium in patients with diabetes without retinopathy.

BACKGROUND: The aim of this study was to investigate the effect of microalbuminuria on corneal endothelium in patients with diabetes without retinopathy. METHODS: This cross-sectional study comprised 100 patients with type 2 diabetes mellitus (DM) without diabetic retinopathy and 92 control subjects without diabetes. Forty-five patients had microalbuminuria and 55 subjects were microalbuminuria negative. Endothelial measurements were obtained using specular microscopy. Endothelial cell density, average area, co-efficient of variation, maximum area, minimum area, hexagonality and corneal thickness were compared between the groups on the basis of microalbuminuria, DM duration and medication, HbA1c , body mass index, serum lipid and protein profiles, hypertension and hyperlipidaemia diagnosis. RESULTS: There were no significant differences in age, gender, endothelial cell density, average area, co-efficients of variation, maximum area, minimum area, hexagonality or corneal thickness among the microalbuminuria positive, microalbuminuria negative and control groups (p > 0.05). However, microalbuminuria positive patients had lower high-density lipoprotein levels than the microalbuminuria negative patients (p = 0.042). DM and control groups showed similar endothelial measurements (p > 0.05). Patients with a HbA1c > 7 per cent (53 mmol/mol) had lower hexagonality value (p = 0.039) than in the subjects with a HbA1c ≤ 7 per cent. No significant differences were found in endothelial parameters when groups were compared based on DM duration, medication and co-morbidities. CONCLUSIONS: Microalbuminuria positive and negative patients with DM without retinopathy seem to have similar corneal endothelial measurements with controls. However, patients with a HbA1c > 7 per cent should be monitored for deterioration in corneal endothelial cell morphology even without diabetic retinopathy, which might be critical prior to anterior segment surgery.

Early retinal neurodegeneration in preclinical diabetic retinopathy: a multifactorial investigation.

BACKGROUND/OBJECTIVES: To investigate effects of microalbuminuria (MA), diabetes duration, glycosylated haemoglobin (HbA1c) level, hypertension (HT) and/or hyperlipidaemia (HL) coexistence on retinal layers in diabetic patients without diabetic retinopathy (DR) using spectral-domain optical coherence tomography (SD-OCT). SUBJECTS/METHODS: This cross-sectional study involved 95 (45 had MA and 50 had no MA) patients with type 2 diabetes mellitus (DM) without DR and 91 age- and gender-matched non-diabetic controls. Macular and peripapillary SD-OCT measurements (Heidelberg Engineering GmbH, Heidelberg, Germany), DM duration, HbA1c levels and presence of HT and/or HL were used for statistical analyses. RESULTS: The MA (+), MA (-) and control groups had similar age and gender distribution (p > 0.05). The differences in SD-OCT measurements among the MA (+), MA (-) and control groups were insignificant (p > 0.05). However, diabetic patients (n = 95) had significantly thinner inferior-temporal peripapillary retinal nerve fibre layer (RNFL) (p = 0.042) than in the controls (n = 91). Superior peripapillary RNFL was significantly thinner in patients with an HbA1c level > 7% (p = 0.049). However, 3 mm-nasal, temporal and superior perifoveal thicknesses were significantly lower in patients with DM duration over 10 years (p < 0.05). HT and/or HL coexistence did not lead a significant difference in SD-OCT parameters among the groups. CONCLUSIONS: In diabetic patients without DR, peripapillary inferior-temporal RNFL thinning might be an early sign of neuroretinal degeneration and it seems to be independent from vascular endothelial damage (MA). Poor metabolic control appears to lead superior peripapillary RNFL thinning, while perifoveal thicknesses tend to decrease with longer DM duration.

"Crack, Reduce, and Implant": A Safe Phaco Technique in a Case with Hard Brown Cataract.

This report describes two maneuvers in different steps of phaco surgery in a case with hard cataract, which provide debulking of the central dense nucleus and prevents posterior capsule rupture (PCR). In the current case, clear corneal incisions were created, and anterior chamber was filled with ophthalmic viscosurgical device (OVD). Anterior capsule was punctured, and capsulorhexis was completed. Nucleus was cracked into two halves following vertical groove formation. Core nucleus was hollowed sideward bilaterally in the capsular bag. Nuclear halves were removed from capsular bag, and each one was pushed to one side on the iris plane. Capsular bag was inflated with OVD, and intraocular lens (IOL) was implanted. Nuclear halves were removed in confidence. The presented maneuvers initially reduce dense nucleus load in the safe zone and allow surgeon to use IOL as a barrier to protect floppy posterior capsule from early steps of the surgery.

Early deterioration in ellipsoid zone in eyes with non-neovascular age-related macular degeneration.

The purpose of this study was to investigate the early effects of soft drusen on retinal pigment epithelium (RPE), ellipsoid zone (EZ, photoreceptor inner segment/outer segment junction), and external limiting membrane (ELM) reflectivities using optical coherence tomography (OCT) image analysis. This retrospective comparative study comprised 47 patients with non-neovascular AMD (with intact RPE, EZ, and ELM bands on OCT) and 45 age- and sex-matched healthy controls with normal OCT. A single masked physician performed OCT image analysis using a medical image processing software. Reflectivities of RPE, EZ, and ELM; number of drusen; vertical and horizontal diameters of the largest druse; druse reflectivity; foveal involvement by a druse; and presence of ≥1 large druse (n) were evaluated based on the macular OCT scan. Forty-seven right eyes of 47 patients with non-neovascular AMD and 45 right eyes of 45 healthy subjects were recruited. In the non-neovascular AMD group, absolute EZ and RPE reflectivities were significantly lower compared to those of the control eyes (P < 0.001 and P = 0.001, respectively). Comparing relative reflectivity values, only relative EZ reflectivity (EZ/ELM reflectivity) remained to show a significant difference between the groups (P < 0.001). Correlation analyses revealed no significant relation between the reflectivity values and drusen characteristics (P > 0.05). In eyes with non-neovascular AMD, decreased RPE (only absolute) and EZ (both absolute and relative) reflectivities prior to the disruption of these layers on OCT might indicate early photoreceptor damage. However, lower reflectivity values appear to be independent of the drusen characteristics.

Visual, Topographic, and Pachymetric Effects of Pediatric Corneal Collagen Cross-linking.

PURPOSE: To evaluate the effects of pediatric corneal collagen cross-linking (CXL) on corrected distance visual acuity (CDVA), maximum keratometry (Kmax), and other Scheimpflug imaging system parameters during 2 years of follow-up. METHODS: The records of 29 eyes of 29 pediatric patients who underwent unilateral CXL treatment for progressive keratoconus were reviewed. Changes in CDVA, Kmax, anterior chamber depth, anterior chamber volume, anterior chamber angle, pupil-center pachymetry, apical pachymetry, thinnest pachymetry, corneal volume, and topographic indices (index of surface variance [ISV], index of vertical asymmetry [IVA], index of height asymmetry [IHA], keratoconus index [KI], center keratoconus index [CKI], index of height decentration [IHD], and minimum radius of curvature [Rmin]) were analyzed among baseline and 1 and 2 years after the CXL treatment. RESULTS: Mean CDVA and Kmax significantly improved from baseline at 1 year (-0.17 logMAR, P < .0001; -1.18 diopters [D], P = .012, respectively) and 2 years (-0.21 logMAR, P < .0001; -1.40 D, P = .001, respectively) after the CXL treatment. Anterior chamber parameters, corneal thicknesses, and corneal volume remained unchanged during the period following CXL (P > .05). Five of the seven Scheimpflug topographic indices (including ISV, KI, CKI, IHD, and Rmin) showed significant improvement after CXL between baseline and 2 years (P < .05). CONCLUSIONS: In pediatric patients with progressive keratoconus, CXL appears to be effective in improving CDVA, Kmax, and corneal topographic irregularity at 2 years' follow-up. However, long-term effects of CXL should be tested by further studies in pediatric keratoconus. [J Pediatr Ophthalmol Strabismus. 2017;54(2):84-89.].

Diagnostic Consistency and Relation Between Optical Coherence Tomography and Standard Automated Perimetry in Primary Open-Angle Glaucoma.

PURPOSE: To assess diagnostic consistency and relation between spectral-domain optical coherence tomography (SD-OCT) and standard automated perimetry (SAP) in patients with primary open-angle glaucoma (POAG). METHODS: This retrospective study comprised 51 eyes of 51 patients with a confirmed diagnosis of POAG. The qualitative and quantitative SD-OCT parameters (retinal nerve fiber layer thicknesses [RNFL; average, superior, inferior, nasal and temporal], RNFL symmetry, rim area, disc area, average and vertical cup/disc [C/D] ratio and cup volume) were compared with parameters of SAP (mean deviation, pattern standard deviation, visual field index, and glaucoma hemifield test reports). RESULTS: Fifty-one eyes of 51 patients with POAG were recruited. Twenty-nine eyes (56.9%) had consistent RNFL and visual field (VF) damage. However, nine patients (17.6%) showed isolated RNFL damage on SD-OCT and 13 patients (25.5%) had abnormal VF test with normal RNFL. In patients with VF defect, age, average C/D ratio, vertical C/D ratio, and cup volume were significantly higher and rim area was lower when compared to those of the patients with normal VF. In addition to these parameters, worsening in average, superior, inferior, and temporal RNFL thicknesses and RNFL symmetry was significantly associated with consistent SD-OCT and SAP outcomes. CONCLUSIONS: In routine practice, patients with POAG can be manifested with inconsistent reports between SD-OCT and SAP. An older age, higher C/D ratio, larger cup volume, and lower rim area on SD-OCT appears to be associated with detectable VF damage. Moreover, additional worsening in RNFL parameters might reinforce diagnostic consistency between SD-OCT and SAP.

Age-based analysis of choroidal thickness and choroidal vessel diameter in primary open-angle glaucoma.

We aimed to assess choroidal thickness and vessel diameter in patients with primary open-angle glaucoma (POAG) using enhanced depth imaging (EDI) optical coherence tomography (OCT) with age-based analysis. Fifty-four patients with a confirmed diagnosis of POAG and 44 age-sex matched healthy subjects were included into the study. A masked physician performed measurements of largest choroidal vessel diameter and choroidal thicknesses (subfoveal, nasal, and temporal) using EDI OCT. Subgroup analyses were performed to compare choroidal measurements based on age (with a cut point of 70 years). The study cohort comprised 54 patients with POAG (mean age of 63.2 ± 8.8 years) and 44 healthy control subjects (mean age of 62.9 ± 8.5 years) (P = 0.870). We found no significant differences in terms of choroidal measurements (P > 0.05) between the glaucoma and control groups. However, in the glaucoma group, patients with an age ≥70 years had significantly thinner subfoveal and nasal choroid compared to those of the patients with <70 years of age (P = 0.017, 0.002 respectively). In the control group, choroidal thickness and vessel measurements showed no significant difference when the subjects were subgrouped according to the age cut point (P > 0.05). Choroidal thickness and vessel caliber seem not to differ between patients with POAG and healthy controls. However, an age ≥70 years might be associated with thinning in subfoveal and nasal choroid in patients with POAG. Further studies are needed to elucidate whether choroidal thinning is a cause or result in POAG.

Impaired photoreceptor inner segment ellipsoid layer reflectivity in mild diabetic retinopathy.

OBJECTIVE: To determine alterations in retinal pigment epithelium (RPE), photoreceptor inner segment ellipsoid layer (ISel), and external limiting membrane (ELM) reflectivities using optical coherence tomography (OCT) image analysis in patients with mild nonproliferative diabetic retinopathy (NPDR). DESIGN: Retrospective, single-centre, controlled clinical study. PARTICIPANTS: The study cohort included 42 eyes of 42 patients with mild NPDR (NPDR group) and 40 eyes of 40 healthy subjects (control group). Eyes with moderate and severe NPDR, proliferative DR, macular edema, and other macular pathologies were excluded. METHODS: The reflectivities of RPE, ISel, and ELM were calculated using a medical image-processing software based on greyscale OCT images. The differences in the reflectivity values between the NPDR and control groups were analyzed. RESULTS: The NPDR group comprised 22 males and 20 females (with a mean age of 61.3 ± 6.5 years), and the control group consisted of 14 males and 26 females (with a mean age of 63.0 ± 4.1 years) (p > 0.05). The ISel had significantly lower reflectivity (both absolute and relative) in eyes with mild NPDR compared with that of the control eyes (p < 0.001), whereas the reflectivities of RPE and ELM did not differ between the 2 groups (p = 0.126, p = 0.053 respectively). CONCLUSIONS: Although previous ex vivo studies reported photoreceptor degeneration in diabetic retinopathy, this is the first clinical study to investigate retinal layer reflectivities in NPDR using OCT. In eyes with mild NPDR, ISel seems to have lower reflectivity, and this finding might indicate early photoreceptor degeneration in diabetic retinopathy pathogenesis.

A combination of topographic and pachymetric parameters in keratoconus diagnosis.

PURPOSE: To evaluate the utility of topographic and pachymetric parameters of Scheimpflug system in keratoconus diagnosis. METHODS: This study included 183 eyes of 183 patients with keratoconus (keratoconus group) and 131 eyes of 131 age and sex-matched healthy subjects (control group). Mean keratometry (K, front), topographic astigmatism, pupil-center pachymetry, apical pachymetry, thinnest pachymetry (TP), corneal volume and maximum K (Kmax) were obtained from the Scheimpflug imaging system. A receiver operating characteristic (ROC) analysis was performed and area under the curve (AUC) was calculated to determine the diagnostic ability of each parameter in eyes with ≤ stage 3, ≤ stage 2 and stage 1 keratoconus based on the Amsler-Krumeich grading system. RESULTS: The Kmax and TP showed the highest individual performance (with sensitivity-specificity of 92.9-92.4% and 89.6-93.3%, respectively) in diagnosis of keratoconus. The AUCs and sensitivity-specificity values for the Kmax/TP and Kmax(2)/TP were calculated to improve the diagnostic performance. As expected, sensitivity-specificity values significantly increased by using Kmax/TP (97.3-94.7% at the level ≥0.08) and Kmax(2)/TP (99.5-95.7% at the level ≥4.1) in discrimination of keratoconic eyes from normals. Moreover, Kmax(2)/TP had very high sensitivity (>99%) and specificity (>94%) in diagnosis of stage 1 and stage 2 keratoconus. CONCLUSIONS: Although Kmax and TP appear to have high diagnostic ability in keratoconus, the use of either single parameter in isolation might be unsatisfactory in differential diagnosis. Therefore, the Kmax(2)/TP ratio has been introduced, which reflects major characteristics of keratoconus and might be used as an important criterion in keratoconus diagnosis.