Prevalence of obstructive sleep apnea after treatment for advanced T-stage head and neck cancer

PURPOSE

Treatment of head and neck cancer (HNC) may lead to obstructive sleep apnea (OSA), but conclusive results on the prevalence of OSA are lacking. The objective of this study is to investigate the prevalence of OSA in a cohort of patients treated for advanced T-stage HNC.

METHODS

A cross-sectional study was conducted in two tertiary cancer care centers including patients at least 1 year after treatment with curative intent with surgery and/or (chemo)radiotherapy ((C)RT) for advanced T-staged (T3-4) cancer of the oral cavity, oropharynx, hypopharynx, or larynx. A polysomnography (PSG) was performed in all participants. OSA was defined as an apnea-hypopnea index (AHI) of 15 events/h or higher or an AHI of 5 events/h and higher with OSA related symptoms, such as sleeping problems, daytime dysfunction and/or cardiac/metabolic comorbidities collected through file review and questionnaires.

RESULTS

Of the 67 participants, 48 (72%, 95% CI 59-82%) were diagnosed with OSA. Possible risk factors are male gender, higher BMI, greater neck circumference, more nicotine pack years, cardiometabolic comorbidities, use of medication with sleepiness as side effect, present tonsils, lower T-stage (T3 vs. T4 stage), higher AJCC stage and a HPV-negative tumor.

CONCLUSION

In this population of advanced T-stage HNC patients, the prevalence of OSA was 72%, which is considerably higher than in the general population (2-50%). Given the high prevalence, screening of this entire subgroup for OSA may be indicated. Future studies to identify high risk factors and develop an OSA screening protocol are needed.

Effects of Autologous Serum and Platelet-Rich Plasma on Human Corneal Endothelial Cell Regeneration: A Comparative Study

OBJECTIVES

To investigate the effects of autologous serum (AS) and platelet-rich plasma (PRP) on human corneal endothelial cell (HCEC) proliferation and apoptosis in comparison to Y-27632 as the commonly studied Rho-associated kinase (ROCK) inhibitor.

METHODS

The human corneal endothelial primary cell line was used for this study. As the treatment groups, HCECs were incubated with AS, PRP, and Y-27632, whereas the control group received no treatment. Cell proliferation (measured by 5-bromo-2'-deoxyuridine [BrdU] incorporation) and apoptosis (based on the caspase-3 level) were compared between the control, Y-27632, AS, and PRP groups.

RESULTS

In the Y-27632, AS, and PRP groups, the ratios of BrdU-incorporated cells were significantly higher (115±0.2%, 125±0.2%, 122±0.4% at 24 hr, and 138±2.4%, 160±0.2%, 142±0.2% at 48 hr, respectively) than in the control group (100±18.4% at 24 hr, 100±1.1% at 48 hr) ( P <0.05 for all). Furthermore, AS provided a higher HCEC proliferation ratio compared with the Y-27632 group at 24 and 48 hr ( P <0.05 for all). Caspase-3 was significantly lower in the AS group (60.3±3.3%) than in the control (100±2.3%), Y-27632 (101.9±5.2%), and PRP (101±6.8%) groups ( P <0.05 for all).

CONCLUSIONS

The results of this study demonstrated for the first time that AS and PRP promoted HCEC proliferation and AS significantly decreased apoptosis in HCECs. A superior effect on HCEC proliferation was also observed with AS compared with Y-27632. Future "autologous" regenerative therapeutic options for corneal endothelial failure may involve the utilization of AS and PRP owing to their accessibility, simplicity in preparation, immunologic compatibility, and donor-free nature.

The prevalence of keratoconus in northern Poland: A cross-sectional study of patients from a primary healthcare practice

INTRODUCTION

Keratoconus is defined as central and/or paracentral corneal thinning and steepening with consequent irregular astigmatism. To date, no prospective study has reported its prevalence in Central Europe. This study aimed to evaluate the prevalence of keratoconus assessed with Scheimpflug imaging in a profile of general medicine practice in Poland.

METHODS

This cross-sectional study collected data by inviting all patients aged 10-80 years subscribed to a single general practitioner in the Elbląg area, Poland. Corneal measurements were performed using a rotating Scheimpflug corneal tomography system. Three masked examiners established the diagnosis of keratoconus in the right or left eye. Fleiss' kappa coefficient (κ) was used to qualitatively analyze the interexaminer agreement.

RESULTS

Of 1,705 patients invited to the study, 771 agreed to participate (45.2%). The mean age of the 728 patients (60.6% female and 39.4% male) with gradable images in at least one eye was 53.6 ± 16.5 years. All of the examiners classified the same four cases as keratoconus (0.549%, 549 per 100,000, 95% confidence interval 150 to 1,400 per 100,000), of which two were bilateral. Fleiss' kappa showed almost perfect agreement among the three examiners regarding the diagnostic decision (κ = 0.784, 95% confidence interval 0.750 to 0.817, p < 0.001). The keratoconus cases were all women (p = 0.106), aged 48, 69, 70, and 71 years old.

CONCLUSION

The prevalence of keratoconus in this area was higher than that previously demonstrated in many European countries. Underestimation of the prevalence has been postulated but never demonstrated.

A three-dimensional morpho-volumetric similarity study of Down syndrome keratopathy vs. keratoconus

BACKGROUND

To compare and contrast morpho-volumetric features between Down syndrome (DS) cornea and non-DS keratoconic cornea by three-dimensional (3D) modelling.

METHODS

Forty-three subjects (43 eyes) with DS and 99 patients matching their age and sex (99 eyes) with keratoconus (KC) were included in this single-center cross-sectional study. Main outcome measures were high-order aberrations (HOA), central corneal thickness (CCT), spherical equivalent refraction, and morpho-volumetric parameters established using a 3D corneal model, such as deviation of anterior and posterior corneal apices (D_apexant/D_apexpost) and minimum thickness points (D_mctant/D_mctpost) from corneal vertex, areas of the anterior and posterior surfaces (A_ant/A_post), sagittal area passing through the anterior and posterior corneal apices (A_apexant/A_apexpost) and minimum thickness point (A_mctpost) and corneal volume of the complete cornea (V_total).

RESULTS

Age, gender, spherical equivalent refraction, CCT and V_total were similar between the net on-DS KC and DS groups (P > 0.05), while non-DS KC group had higher HOA than the DS group (P < 0.05). D_apexant, A_ant, A_post and A_apexant showed higher values in the DS group than in the non-DS KC group, whereas D_apexpost showed a reduction in the DS group when compared with the non-DS KC group (P < 0.05).

CONCLUSIONS

This study demonstrated that anterior and posterior corneal apex dynamics were specifically different in DS subjects, as the anterior apex tends to displace more prominently when compared to that from the non-DS KC group, while the posterior apex appears to be more stable than that in non-DS KC, which also support the theory that DS patients suffer from a specific keratopathy, distinctively different to KC but strongly related to it, and probably showing a diversity of corneal phenotypes in all cases of DS.

To what extent is pregnancy-induced keratoconus progression reversible? A case-report and literature review

PURPOSE

This report aims to present a case with pregnancy-induced keratoconus (KC) progression and recovery in topographical parameters after a period from delivery/breastfeeding.

METHODS

A 29-year-old woman with bilateral KC experienced progression in maximum keratometry (Kmax; from 47.6 to 48.2 D in the OD and from 53.7 to 55.2 D in the OS) and several Pentacam indices in both eyes.

RESULTS

The Belin ABCD progression score remained unchanged in the right eye (A0B2C0D0) but increased in the left eye (from A2B3C1D1 to A2B4C1D1) (Pentacam HR, Oculus Optikgeräte GmbH, Wetzlar, Germany) during pregnancy/breastfeeding. About 6-months after cessation of breastfeeding, Kmax improved to baseline values in both eyes. Although there were improvements in "A" and "B" scores, final ABCD stage remained higher than the baseline value in the left eye.

CONCLUSIONS

The current report shows asymmetrically bilateral progression of KC during pregnancy and early post-delivery period, which was followed by a partial recovery in Pentacam parameters after discontinuation of breastfeeding. These findings seem to confirm the postulated link between pregnancy and KC progression. On the other hand, in patients with KC, pregnancy-induced corneal alterations might recover after delivery/breastfeeding and clinician should wait for stabilization of corneal parameters to determine treatment strategy.

Enhanced Ectasia Screening in Patients with Uveitis and Isolated Systemic Inflammatory Disease

PURPOSE

To investigate corneal topographic alterations in patients with uveitis and isolated systemic inflammatory disease (SID).

METHODS

This retrospective cross-sectional study included 44 patients with uveitis with anterior chamber inflammation (uveitis group), 39 subjects with isolated SID, and 91 healthy controls (control group). Topographic images were classified as "normal," "keratoconus (KC) suspect" and "KC" based on maps of axial curvature, corneal thickness, front and back elevation in combination with Belin/Ambrósio Enhanced Ectasia Display (BAD).

RESULTS

The uveitis and SID groups had higher incidence of KC (6.8% and 10.2%, respectively) and KC suspect (45.5% and 33.3%, respectively), whereas 2.2% of the control subjects had KC and 26.4% represented KC suspect (p < .05).

CONCLUSIONS

Patients with uveitis with or without SID, and isolated SID without intraocular inflammation seem to be more likely to have KC and KC suspect, which might be due to systemic and/or local inflammatory background triggering pathophysiological mechanisms underlying KC.

Increased epithelial backscatter: A novel finding in subclinical and clinical keratoconus

BACKGROUND

To assess alterations in backscatter from the corneal epithelium, anterior stroma and lens surface in eyes with subclinical, mild and moderate keratoconus (KC).

METHODS

In this single-centre, cross-sectional study involving 24 eyes with subclinical KC, 107 eyes with manifest KC (mild = 40 and moderate = 67 eyes) and 90 controls, line densitometry was performed with Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) to obtain simultaneous backscatter values for the corneal epithelium, anterior stroma and anterior lens surface. Backscatter values and Pentacam parameters were used in subsequent statistical analyses.

RESULTS

Eyes with subclinical, mild and moderate KC had similar epithelial and stromal backscatter (P > 0.05) that was significantly increased compared with the controls (P < 0.05). Although anterior lens surface backscatter did not differ between the control and KC groups (P > 0.05), it was significantly higher in the mild and moderate KC groups than in the subclinical KC group (P < 0.05). In the KC group (n = 131) epithelial backscatter was strongly correlated with stromal backscatter (r = 0.911, P < 0.0001).

CONCLUSIONS

Increased epithelial backscatter and a strong correlation with anterior stromal backscatter in the KC groups were consistent with the epithelium-stroma interaction involved in KC pathogenesis. Single-point backscatter analysis can be used with point clouds to construct epithelial and stromal backscatter maps in Pentacam to aid the detection of KC as a novel feature.

Severe Intraocular Inflammation following Hydrophilic Acrylic Phakic Intraocular Lens Implantation in A Case with Concealed History of COVID-19: A Case Report and Literature Review

Purpose: To firstly present management of toxic anterior segment syndrome (TASS) and possible postoperative endophthalmitis (POE) after implantation of a new hydrophilic-acrylic posterior chamber (PC) phakic intraocular lens (pIOL) in a case with undeclared history of COVID-19.Methods: A 21-year-old male without known disease represented severe anterior chamber inflammation (hypopyon), poor vision and corneal edema without vitreous involvement (TASS) at 24-hours after PC-pIOL implantation for unilateral high myopia (amblyopic).Results: Preoperative best-corrected visual acuity (BCVA) was 0.2 OS (-13 diopters). At 56-hours, vitreous was involved with visual loss indicating POE. The patient confessed that he had COVID-19 1-month ago. COVID-19 immunoglobulin M/G tests were positive, while other markers were negative. Intracameral/intravitreal antibiotics were applied. BCVA was 0.15 without hypopyon at 24-hours. Cultures were negative. Final BCVA was 0.6 with normal examination.Conclusion: TASS/POE etiology could not be demonstrated in this case, whereas COVID-19-related proinflammatory systemic background could have effect on triggering/aggravating this scenario.].

Three-Dimensional Morphogeometric and Volumetric Characterization of Cornea in Pediatric Patients With Early Keratoconus

PURPOSE

To present morphogeometric and volumetric characteristics of the cornea and its diagnostic value in pediatric patients with keratoconus (KC) using 3-dimensional (3-D) corneal modeling.

DESIGN

Cross-sectional study.

METHODS

This single-center (VISSUM Innovation, Alicante, Spain) study comprised 49 eyes of 49 pediatric patients (age ≤16 years) with KC and 31 eyes of 31 healthy pediatric controls. Eyes were graded as early (n = 21) and mild KC (n = 28) based on the RETICS (Thematic Network for Co-Operative Research in Health) classification system. The 3-D corneal model was generated using raw topographic data. Deviation of anterior (D_apexant) and posterior (D_apexpost) apex and minimum thickness points (D_mctant, D_mctpost), D_apexant-D_apexpost difference, total corneal volume (V_total), volumetric distribution (VOL_AAP, VOL_PAP, and VOL_MCT), and percentage of relative volume increase (VOL_AAPrel, VOL_PAPrel, and VOL_MCTrel) between 2 consecutive radii centered to anterior/posterior apex and thinnest point were evaluated.

RESULTS

D_apexpost and D_apexant-D_apexpost difference were higher in the early and mild KC groups compared to the control group (P < .05). Eyes with early and mild KC had decreased V_total compared with the control group (P < .05). D_apexpost, D_apexant-D_apexpost difference, and VOL_MCTrel between 1.0 and 1.4 mm diameters had area under receiver operating characteristics curve (AUROC) values over 0.93 in discrimination of early KC from normal.

CONCLUSIONS

This is the first study presenting morphogeometric and volumetric characterization of cornea in pediatric patients with early and mild KC using a 3-D corneal model. Integration of the morphogeometric and volumetric parameters to topography software can add value in early detection of KC in pediatric patients.

Evidence of a Down Syndrome Keratopathy: A Three-Dimensional (3-D) Morphogeometric and Volumetric Analysis

The aim of this study was to investigate whether a different and abnormal corneal profile is present in Down syndrome (DS) by personalized three-dimensional (3D) modelling. This single-centre cross-sectional study included 43 patients with DS (43 eyes) and 58 age-sex-matched control subjects (58 eyes) with normal karyotype and topography. Refraction, central corneal thickness (CCT), aberrations (high-order, coma and spherical), asphericity and morphogeometric/volumetric parameters based on a 3D corneal model that was generated from raw topographical data were evaluated. Deviation of anterior/posterior apex (D_apexant/D_apexpost) and thinnest point (D_mctant/D_mctpost) from corneal vertex, anterior/posterior surface area (A_ant/A_post), sagittal area passing through the anterior/posterior apex (A_apexant/A_apexpost) and thinnest point (A_mctpost), total corneal volume (V_total) and volumetric progression for each 0.05 mm step of the radius value centred to the thinnest point (VOL_MCT) and anterior/posterior apex (VOL_AAP/VOL_PAP) comprised the morphogeometric/volumetric parameters. In the DS group, 58.1% of the eyes presented abnormal topography. High-order and coma aberrations, asphericity, D_apexant, A_ant, A_post and A_apexant were significantly higher, whereas CCT, A_apexpost, A_mctpost, V_total, VOL_AAP, VOL_PAP and VOL_MCT were lower in the DS group than in the control group (p < 0.05). D_apexpost did not differ between the groups (p > 0.05). This study demonstrates that corneas of the subjects with DS are different and more aberrated than those of normal age- and sex-matched non-DS controls. Anterior corneal apex appears to be displaced in DS even with normal topography, while posterior apex seems stable although topography is abnormal. These findings may help to modify our approach in the diagnosis of keratopathy in subjects with DS.

Subclinical keratoconus detection with three-dimensional (3-D) morphogeometric and volumetric analysis

PURPOSE

To assess the efficacy of morphogeometric and volumetric characterization of the cornea based on three-dimensional (3-D) modelling in diagnosis of subclinical keratoconus (KC).

METHODS

Cross-sectional study. Ninety-three eyes with subclinical KC with a best spectacle-corrected distance visual acuity ≥20/20 (grade zero KC according to the RETICS classification) and 109 control eyes were included. Computer-based 3-D corneal morphogeometric model was generated using raw topographic data. Distance-, area- and volume-based parameters were used for statistical analysis. Distance parameters included deviation of anterior (D_apexant )/posterior (D_apexpost ) apices and minimum thickness points (D_mctant , D_mctpost ) from corneal vertex, and D_apexant -D_apexpost difference. Areal variables were derived from anterior (A_ant ) and posterior (A_post ) corneal surfaces, sagittal plane passing through corneal apices (A_apexant , A_apexpost ) and thinnest point (A_mctant , A_mctpost ). Total corneal volume (V_total ) and volumetric distribution (with 0.1mm steps) centred to thinnest corneal point (VOL_mct ) and anterior (VOL_aap )/posterior (VOL_pap ) apices comprised the volume-based parameters.

RESULTS

In the subclinical KC group, all D values, D_apexant -D_apexpost difference, A_ant , A_post and A_apexant values were higher (p < 0.001), while A_apexpost , A_mctpost , V_total , VOL_mct , VOL_aap and VOL_pap values were lower when compared to the control group (p < 0.001). Regression analysis-based formula correctly classified 96.8% of the eyes with subclinical KC and 94.5% of the normal ones (p < 0.0001).

CONCLUSIONS

Eyes with subclinical KC seem to represent asymmetrically displaced anterior and posterior corneal apex, corneal thinning and volume loss. 3-D morphogeometric and volumetric parameters and differentiation formula can be incorporated into topography software to detect subclinical KC with high sensitivity and specificity in clinical practice.

Corneal transplantation outcomes after the extrusion of an intrastromal keratoprosthesis: a pilot study

This short report includes 5 eyes of 5 patients (mean age 63.2 ± 12 years) who underwent a tectonic keratoplasty [deep anterior lamellar keratoplasty (DALK) or penetrating keratoplasty (PK)] in order to rehabilitate the eye after the extrusion of the non-perforating keratoprosthesis (Kpro) KeraKlear (KeraMed, USA). The non-perforating Kpro was extruded after a mean period of 21.4 ± 21.8 months due to melting. In two cases, the keratoplasty was performed the same day of the non-perforating Kpro removal due to a severe melting, while in the other three cases it was performed one to 3 months later. Two eyes received a DALK, but in 3 eyes a macroscopic Descemet membrane perforation forced the conversion into a PK. The mean follow-up period after the keratoplasty was 16.8 ± 6.6 months. No cases of rejection were recorded. All the 5 eyes achieved “anatomical success” (transparent graft, with no signs of infection or inflammation). Two eyes showed limited “functional success” because the achievement of the best visual potential was prevented by the development of glaucomatous optic atrophy during the follow-up period. In conclusion, this short report presents an unexpected success of a keratoplasty performed with a tectonic purpose after the extrusion of the non-perforating Kpro because the corneal graft remained transparent, without neovascularization or scarring during the follow-up period. This initial evidence shows some encouraging results regarding graft survival rate and the achievement of a useful visual rehabilitation with keratoplasty after a non-perforating Kpro failure instead of repeating the Kpro implantation.

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.

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, HbA_1c , 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 HbA_1c > 7 per cent (53 mmol/mol) had lower hexagonality value (p = 0.039) than in the subjects with a HbA_1c ≤ 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 HbA_1c > 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.

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.].

Increased erythrocyte aggregation in patients with primary open angle glaucoma

BACKGROUND

The rationale of this study is to determine alterations in blood rheology (erythrocyte aggregation and deformability) and relationship between structural measurements obtained from optical coherence tomography (OCT) in different stages of primary open angle glaucoma (POAG).

METHODS

This prospective controlled study comprised 23 POAG patients (glaucoma group) and 23 age- and sex-matched healthy subjects (control group). Elongation index (EI), which is the indicator of erythrocyte deformability and erythrocyte aggregation was measured using an ektacytometer. Optic nerve head (ONH) morphology and peripapillary retinal nerve fibre layer (RNFL) thickness were evaluated using a spectral domain (SD) OCT.

RESULTS

There were no significant differences between the groups regarding the elongation index values (p > 0.05). On the other hand, erythrocyte aggregation amplitude (AMP) and mean corpuscular haemoglobin concentration (MCHC) were significantly higher in the glaucoma group than in the control group (p = 0.015, p = 0.003 respectively). A significant correlation was also found between the elongation index and retinal nerve fibre layer (average and superior) thickness (p < 0.05) in patients with late glaucoma.

CONCLUSIONS

In patients with POAG, erythrocyte aggregation appears to be higher. It can be speculated that higher erythrocyte aggregation and deformability may be involved in the pathogenesis of glaucoma by affecting microperfusion of the optic nerve head and retina. Modification of rheological parameters in patients with glaucoma may be considered as an adjuvant future therapy in glaucoma management, whereas further studies in larger groups are needed.

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.

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.

Decreased photoreceptor inner segment/outer segment junction reflectivity in patients with idiopathic epimacular membrane

PURPOSE

To assess the effects of idiopathic epimacular membrane (IEMM) on retinal pigment epithelium (RPE), photoreceptor inner segment/outer segment (IS/OS) junction, and external limiting membrane (ELM) reflectivities to determine functional alterations in these layers using optical coherence tomography (OCT) image analysis.

METHODS

Fifty eyes of 50 patients with untreated IEMM and 41 eyes of 41 age- and sex-matched healthy controls with normal OCT scans were retrospectively reviewed. A single masked physician analyzed OCT images randomly. Reflectivity values of RPE, IS/OS junction, and ELM were obtained using 'plot profile' mode of a medical image processing computer software.

RESULTS

The study comprised 50 patients with untreated IEMM and age- and sex-matched 41 control subjects (P > 0.05). Image analysis demonstrated that IS/OS junction and ELM had significantly lower reflectivity in patients with IEMM compared with those of the control eyes (P = 0.008, P = 0.009, respectively). However, RPE reflectivity did not differ between two groups (P = 0.100). Correlation analyses showed no significant associations between reflectivity values and corrected visual acuity (P > 0.05).

CONCLUSION

In patients with IEMM, photoreceptor IS/OS junction and ELM seem to have lower reflectivity, which might indicate impaired functionality even though these layers are not apparently damaged on OCT imaging.