The Effect of Supplementary Staple Fixation on Biomechanical Properties of Soft Tissue Graft Tibial Fixation in Anterior Cruciate Ligament Reconstruction.

This study aimed to test and compare the biomechanical properties of three tibial fixation methods of anterior cruciate ligament (ACL) tendon grafts under cyclic load and load-to-failure testing in the bovine proximal tibiae, comprising (1) staple fixation alone, (2) interference screw fixation alone, and (3) interference screw fixation with a supplementary staple. Twenty-four bovine tibiae used in the study were divided into three groups (eight proximal tibiae in each group) based on tibial fixation methods of ACL tendon grafts: group A (a spiked ligament staple alone), group B (a cannulated interference screw alone), and group C (a cannulated interference screw with a supplementary staple). Each graft fixation was exposed to cyclic loading conditions. Significant differences were determined in failure load among the three groups (p = 0.008). The mean failure load was significantly higher in group B (717.04 ± 218.51 N) than in group A (308.03 ± 17.22 N) (p = 0.006). No significant differences were observed among the groups regarding axial stiffness (p = 0.442). Cyclic displacement differed significantly among the three groups (p = 0.005). In pairwise comparisons, the mean cyclic displacement was significantly higher in group A (8.22 ± 3.24 mm) compared with group C (1.49 ± 0.41 mm) (p = 0.005). Failure displacement varied considerably among the groups (p = 0.037). Although group B (15.53 ± 6.43 mm) exhibited a greater mean failure displacement than both group A (4.9 ± 0.75 mm) and group C (8.84 ± 4.65 mm), these differences did not reach statistical significance (p = 0.602 and p = 0.329, respectively). Interference screw fixation alone and supplementary staple fixation have biomechanically similar characteristics in terms of initial strength and stiffness of tibial ACL soft tissue graft fixation. Regardless of staple use, an interference screw with the same diameter as the tibial tunnel can ensure sufficient tensile strength in tibial ACL graft fixation.

Biomechanical Comparison of Uniplanar versus Biplanar Lateral Opening-wedge Distal Femoral Osteotomy Techniques in Terms of Risk for Medial Hinge Fracture.

The effect of osteotomy type on the initial stiffness of the bone-implant construct in lateral opening-wedge distal femoral osteotomy (LOWDFO) using a uniplanar compared with a biplanar technique has been investigated. However, no study has explored the biomechanical risk factors for medial hinge fracture. This study aimed to compare the biomechanical strength of uniplanar versus biplanar LOWDFO regarding the risk for medial hinge fracture during gap opening. Twelve composite femora were divided into two groups (six in each group) based on the distal femoral osteotomy technique: uniplanar versus biplanar LOWDFO. All LOWDFO models were subjected to incremental static loading. The gap distance was expanded by 1 mm, and displacement values were recorded as anterior and posterior gap distances (mm). The average force values of all samples at certain gap distances were recorded, and the head distance was measured. The uniplanar group had higher load values than the biplanar group at all anterior gap distances. These differences were only significant at 2- and 3-mm gap distances (p = 0.025 and 0.037). At all posterior gap distances, the uniplanar group had higher load values than the biplanar group, but these differences only reached statistical significance at 2 mm (p = 0.037). Both groups had similar anterior, posterior, and average gap distances (p = 0.75, 0.522, 0.873). The uniplanar group had a higher head insertion distance (15.3 ± 5.7) than the biplanar group (14.7 ± 2.9), but it was not significant (p = 0.87). The uniplanar group had a lower average load before medial hinge fracture (46.41 ± 13.91 N) than the biplanar group (54.92 ± 31.94, p = 0.81). The biplanar group had an average maximum load value of 64.18 ± 25.6 N, while the uniplanar group had 57.90 ± 12.21 N (p = 0.81). This study revealed that the biplanar osteotomy technique allows a wider opening wedge gap with less risk of a medial hinge fracture than uniplanar LOWDFO.Level of evidence was level 3, case-control series.

Tibial Press-Fit Fixation Technique in Anterior Cruciate Ligament Reconstruction Surgery.

Implant-free press-fit tibial fixation technique has recently gained popularity in anterior cruciate ligament reconstruction because it does not cause tunnel widening, does not cause complications associated with additional fixation materials, allows bone-to-bone healing, and does not cause defects in revision surgery. Bone-patellar tendon autograft offers the advantage of direct bone-to-bone integration of the graft, and anterior knee pain is less expected than bone-patellar tendon-bone autograft. This technical report includes details of arthroscopic ACL reconstruction of patellar tendon-tibial tubercle bone autograft distal press-fit fixation technique. We call this the Kocabey distal press-fit technique.

Biomechanical comparison of three different surgical methods in the surgical treatment of distal tibial metaphyseal fractures. An animal model study.

BACKGROUND: The aim of this study is to investigate mechanical properties of minimally invasive plate osteosynthesis (MIPO), supracutaneousplating (SP), and unilateral external fixators (UEF) which can be performed for open tibial fractures. METHODS: An unstable diaphysial tibia fracture was created in 60 fresh sheep tibia specimens by performing an osteotomy at the middle of bones. Specimens were divided into 3 groups. Specimens underwent fracture fixation with a standard MIPO technique, im-planting the plate 15 mm from the bone for SP group. Unilateral uniplanar external fixators were achieved for UEF group. First, thirty specimens (10 specimen for each group) were loaded vertically along the tibial axis to 1800 N. Second, other 30 preperated bones were used for cyclical loading to avoid metal fatigue. For dynamic tests, a 350 N force was applied for 10,000 cycles. RESULTS: In compression testing (vertical loading up to 1800 N) of the three fixation instruments; construct stiffness was highest in MIPO group when compared with SP and UEF groups. While the stiffness of the MIPO group was similar to SP group, it was statistically higher than UEF group (P=0.08 and P=0.002, respectively). SP group was significantly stiffer than UEF group (P=0.0021). The mean peak load was highest in SP group and lowest in UEF group. The peak load in SP group was similar to the MIPO group, it was statistically higher than the UEF group (P=0.743 and P=0.002, respectively). CONCLUSION: Based on the biomechanical properties from this in vitro animal model study, SP technique was biomechanically stronger than UEF and has similar biomechanical properties with MIPO in terms of axial loading.

Tibial Press-Fit Fixation Technique in Anterior Cruciate Ligament Reconstruction.

Implant-free press-fit tibial fixation technique has gained popularity recently due to the problems in bone tunnel expansion, defect, and revision surgery due to the tibial fixation material preferred in anterior cruciate ligament surgery. Patellar tendon-tibial bone autograft offers several advantages in anterior cruciate ligament reconstruction. We describe a tibial tunnel preparation method and the use of patellar tendon-bone graft in the implant-free tibial press-fit technique. We call this the Kocabey press-fit technique.

Internal tibial torsion is associated with medial meniscus posterior horn tears.

PURPOSE: Risk factors for meniscal tears play a decisive role in deciding on treatment and rehabilitation. The purpose of this study was to investigate the effect of tibial rotation on medial meniscus posterior horn tears (MMPHTs). METHODS: This study is a retrospective case-control study. Fifty patients with meniscal tears and 57 knees with intact meniscus were compared. Tibial rotation, femoral version, tibial slope and knee varus were measured in each participant. Knee osteoarthritis was classified according to the Kellgren-Lawrence classification. Demographic characteristics were noted. RESULTS: There were significant differences in the mean tibial torsion angles and mean mechanical axes between the groups. The mean tibial rotation and mean mechanical axis were 26.3° ± 6.7 and 3.7° ± 2.7 in the MMPHT group and 30.3° ± 8.4 and 2.05° ± 2.7 in the control group, respectively (p = 0.008, p = 0.002). CONCLUSION: The current retrospective study has shown that tibial rotation is markedly reduced in patients with MMPHTs. Although the actual mechanism is not clear, the internal torsion of the tibia causes a decrease in the foot progression angle and increases the knee adduction moment, which in turn increases the medial tibial contact pressure. Internal torsion of the tibia, such as knee varus, may play a role in the aetiology of MMPHTs by this way. Whilst there was a significant difference in the mean varus and tibial torsion between the groups, there was no significant difference in the mean femoral version or tibial slope. LEVEL OF EVIDENCE: III.

Biomechanical comparison of four different fixation methods in the management of Pauwels type III femoral neck fractures: Is there a clear winner?

BACKGROUND: Cannulated screws augmented with the medial buttress plate could confer greater biomechanical stability and higher union rates than the screw fixation alone for treating young patients with Pauwels type III femoral neck fractures (FNFs). No study has evaluated the effects of distal bicortical screw fixation and biomechanical properties of buttress plate augmentation under simultaneous vertical and rotational forces, physiologically acting on the hip joint. This study aimed to compare the biomechanical properties of four methods of three cannulated screw fixation under the combined axial and torsional loading in a synthetic femur model of type III FNF. METHODS: Twenty-four third-generation composite femora were divided into four groups (6 femora in each group) based on the screw fixation configuration: inverted triangle configuration (Group A),  Pauwels' configuration (Group B), inverted triangle configuration combined with medial buttress plate using distal unicortical (Group C), and distal bicortical screw placement (Group D). A Pauwels type III FNF was simulated on the sawbones. Each model was subjected to the combined axial and torsional cyclic loading and subsequently tested to failure. RESULT: Significant differences were determined in axial stiffness (AS) among the four groups (p = 0.024), whereas there was no significant difference in torsional stiffness (p = 0.147). The mean AS was higher in group D (639.5 ± 86.2 N/mm) than in group A (430.6 ± 94.8 N/mm), group B (426.2 ± 41.9 N/mm), and group C (451.2 ± 156.7 N/mm). Failure forces (FFs) were significantly different among four groups (p = 0.007), while there was no considerable difference in failure moment values (p = 0.555). The mean FF was significantly higher in group D (1307.1 ± 96.4 N) than in group A  (1076.9 ± 371.2 N) and group B (1075.5 ± 348.3 N) (p = 0.014 and p = 0.018, respectively). There was no significant difference in the mean FF between groups D and C. CONCLUSION: Regardless of the medial plate use, multiple cannulated systems could provide similar biomechanical results regarding torsional stiffness and failure moments. Bicortical placement of the most distal screw in medial buttress plate application could improve axial stability but not significantly affect the rotational stability of the inverted triangle screw fixation system in managing type III FNFs.

Association between fracture type and the risk of bleeding in intertrochanteric femur fractures.

Introduction: The current study aimed to determine the association between fracture type and pre-operative hemoglobin level decrease in intertrochanteric fractures. Further, the erythrocyte unit required in replacement therapy until discharge according to fracture type was evaluated. Patients and methods: We retrospectively analyzed 194 patients diagnosed with intertrochanteric femur fracture who received proximal femoral nail implantation. Among them, 122 met the inclusion criteria, and they were divided into group 1 (stable fracture) and group 2 (unstable fracture) according to the Arbeitsgemeinschaft für Osteosynthesefragen classification. Data on age, sex, fracture side, surgical waiting time, pre- and post-operative hemoglobin levels, and total erythrocyte units required were assessed. Then, statistical analysis was performed. Results: The stable and unstable groups were similar in terms of age, sex, fracture side, and surgical waiting time (p > 0.05). The average erythrocyte units required in replacement therapy were 1.62 (total: 96) in group 2 and 0.91 (total: 57) in group 1. Moreover, group 2 was more likely to require eythrocyte replacement than group 1 (p = 0.001). The average hemoglobin level decreases were 1.70 g/dL in group 1 and 1.95 g/dL in group 2. The pre-operative hemoglobin level decrease had a similar distribution in both groups (p = 0.239). Conclusions: The pre-operative blood loss volume was similar between unstable and stable intertrochanteric fractures. Moreover, at unstable group, the need for erythrocyte replacement therapy was high in the whole period until discharge.

Acromion-axillary nerve distance and its relation to the arm length in the prediction of the axillary nerve position: a clinical study.

BACKGROUND: Because of the broad anatomic variation in the course of the axillary nerve, several cadaveric studies have investigated the acromion-axillary nerve distance and its association with the humeral length to predict the axillary nerve location. This study aimed to analyze the acromion-axillary nerve distance (AAND) and its relation to the arm length (AL) in patients who underwent internal plate fixation for proximal humerus fractures. METHODS: The present prospective study involved 37 patients (15 female, 22 male; the mean age = 51 years, age range 19-76) with displaced proximal humerus fractures treated by open reduction and internal fixation. After anatomic reduction and fixation were achieved, the following parameters were measured in each patient before wound closure without making an extra incision or dissection: (1) the distance from the anterolateral edge of the acromion to the course of the axillary nerve was recorded as the acromion-axillary nerve distance and (2) the distance from the anterolateral edge of the acromion to the lateral epicondyle of the humerus was recorded as arm length. The ratio of AAND to AL was then calculated and recorded as the axillary nerve index (ANI). RESULTS: The mean AAND was 6 ± 0.36 cm (range 5.5-6.6), and the mean arm length was 32.91 ± 2.9 cm (range 24-38). The mean axillary nerve ratio was 0.18 ± 0.02 (range 0.16 to 0.23). There was a significant moderate positive correlation between AL and AAND (p = 0.006; r = 0.447). The axillary nerve location was predictable in only 18% of the patients. CONCLUSION: During the anterolateral deltoid-splitting approach to the shoulder joint, 5.5 cm from the anterolateral edge of the acromion could be considered a safe zone to prevent possible axillary nerve injury.

The intra- and interobserver reliability of five commonly used intertrochanteric femur fracture classification systems.

OBJECTIVES: This study aims to evaluate the effect of surgical experience on reliability for Boyd-Griffin, Evans/Jensen, Evans, Orthopaedic Trauma Association (main and subgroups), and Tronzo classification systems. PATIENTS AND METHODS: Between January 2013 and December 2014, radiological images of a total of 60 patients (13 males, 47 females; mean age: 78.9±21.9 years; range, 61 to 96 years) with the diagnosis of intertrochanteric femur fracture were analyzed. Radiographs were evaluated and classified by five residents and five orthopedics and traumatology surgeons according to the Evans, Boyd-Griffin, Evans/Jensen, OTA, and Tronzo classification systems. Intra- and interobserver reliability were calculated using the kappa statistics. RESULTS: The worst intraobserver compatibility among the residents was the classification system with OTA subgroups (κ=0.516), while the classification system with the best intraobserver fit was found to be OTA main groups (κ=0.744). The worst agreement among surgeons was in the Evans classification system (κ=0.456). However, the best intraobserver agreement was in the OTA main groups (κ=0.741). The best interobserver agreement was observed regarding the OTA main groups (κ=0.699). CONCLUSION: The classification that has the best harmony both among residents and surgeons, and between residents and surgeons is the OTA main group classification.

An oblique osteotomy is better for subtrochanteric shortening in total hip arthroplasty for high hip dislocation: a mechanical comparison of four techniques.

BACKGROUND: Subtrochanteric femoral shortening is used during total hip arthroplasty for high hip dislocation in developmental dysplasia of hip patients. METHODS: We mechanically tested the stability of various commonly used subtrochanteric osteotomy techniques. As the equivalent of a femoral stem placed in a shortened femur without any stable fixation at the osteotomy line, 2 polyvinylchloride pipes were loosely intertwined. 4 different osteotomies (Z-subtrochanteric osteotomy, oblique-45° osteotomy, double Chevron-90° and 120° subtrochanteric osteotomy) were simulated. Torsional and axial loads were applied, and torsional stiffness was calculated for each test model. RESULTS: Z, double Chevron-90° and 120° subtrochanteric osteotomy models demonstrated lower mean torsional stiffness than oblique-45° osteotomy. With the highest torsional stiffness oblique-45° provides the best stability for treatment of high dislocation hips when a subtrochanteric osteotomy is added. CONCLUSIONS: This matches our previous clinical experience. Oblique osteotomy may also provide higher contact surfaces in the osteotomy lines to promote bone healing.

Comparison of the efficacy of irrigation with epinephrine or tranexamic acid on visual clarity during arthroscopic rotator cuff repair: A double-blind, randomized-controlled study.

OBJECTIVES: This study aims to investigate whether there was a difference between epinephrine (EPN) and tranexamic acid (TXA) in providing visual clarity during arthroscopic rotator cuff tear repair. PATIENTS AND METHODS: This double-blind, prospective, randomized-controlled clinical study included a total of 90 patients (42 males, 48 females; mean age: 55.6±8.3 years; range, 18 to 69 years) in whom either EPN (EPN group, n=47) or TXA-diluted irrigation solutions (TXA group, n=43) were used during rotator cuff tear arthroscopy between December 2017 and November 2019. Arthroscopy was performed using irrigation fluid containing 0.33 mg of EPN per 1 L of saline in the EPN group and 0.42 mg of TXA per 1 L of saline in the TXA group. All procedures were performed by two specialized shoulder surgeons. Visual clarity (primary endpoint) was rated by the operating surgeon using the Visual Analog Scale (VAS) in the immediate postoperative period. Secondary endpoints included total operating time (TOT), potential thrombotic or thromboembolic side effects, mean arterial pressure (MAP), and total amount of irrigation fluid used. RESULTS: There was no significant difference in the surgeon rated- VAS scores between the groups. The mean VAS score was 7.6±1.62 (range, 4 to 10) in the EPN group and 7.1±1.74 (range, 3 to 10) in the TXA group (p=0.59). No cardiac, thrombotic, or thromboembolic complications were observed in any of the groups. CONCLUSION: Adding TXA to the irrigation fluid during the arthroscopic rotator cuff repair may provide similar visual quality to the EPN, as measured by VAS.

Potential utility of dermoscopy in the examination of ocular pigmentations.

BACKGROUND: Dermoscopy is a fundamental method in the examination of melanocytic neoplasms. Limited data exist about the dermoscopic features of ocular pigmentations (OPs). OBJECTIVES: We aimed to investigate the usefulness of dermoscopy in the examination of OPs. METHODS: Dermoscopic images of OPs of 20 consecutive patients were recorded. Impression cytology (IC) was performed to these lesions. Dermoscopic images were evaluated for specific dermoscopic structures and patterns without knowing the cytological examination results. RESULTS: Fifteen percent (3/20) of the lesions presented with suspicious cytological findings. More of the suspicious lesions had 4 colors compared to benign lesions (66.7% vs 11.8%, p=0.088). This was also determined for blue-gray (66.7% vs 11.8%, p=0.088) and white (66.7% vs 17.7%, p=0.14) colors. At least 3 structures were observed in all suspicious lesions (100%), but were observed in only in 41.2% of benign lesions (p=0.105). Besides, two-thirds of suspicious lesions had more than 4 structures, but none of the benign lesions reported this (p=0.016). Most of the benign lesions showed asymmetry in one axis (93.3%), whereas all suspicious lesions showed asymmetry in 2 axes (p=0.004). CONCLUSIONS: Dermoscopy seems to be a useful method in the evaluation of OPs. The existence of dermoscopic patterns, colors, and dermoscopic structure plurality and asymmetry raise suspicion in OPs, similarly to skin pigmentations. Dermatologists should be aware of the ocular area, and closer collaboration should be developed between dermatologists and ophthalmologists in the management of pigmented lesions.

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.

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.].

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.

Density of the crystalline lens in obese and nonobese children.

PURPOSE: To compare crystalline lens density in obese and nonobese children. METHODS: A total of 40 obese (25 females) and 46 age-sex matched controls (26 females) were included in this prospective study. Children with ocular diseases (except for mild refractive errors), ocular trauma, or surgery and any systemic disorders, including diabetes, were excluded. Lens densitometry (LD), central corneal thickness (CCT), anterior chamber depth (ACD) and corneal volume (CV) were measured by Pentacam HR. RESULTS: Mean participant age was 12.0 ± 1.9 (range, 7.2-18 years) in the obese group and 11.7 ± 2.0 (range, 7.5-16.1 years) in the control group. The BMI was 29.9 ± 4.5 in the obese group and 18.7 ± 2.5 in the control group (P ≤ 0.05). The vertical, horizontal, and areal lens density measurements were higher in obese group than in controls (P ≤ 0.05). There was a positive correlation between BMI and vertical, horizontal, and areal lens density measurements. The difference in CCT, ACD, and CV was not statistically significant between groups (P ≥ 0.05). CONCLUSIONS: There is increased lens density in the obese children compared with controls. Pentacam HR may provide objective data about lens density in children.

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.