Quantification of forward scattering based on the analysis of double-pass images in the frequency domain.

PURPOSE: To assess forward intraocular scattering by means of a new parameter (Frequency Scatter Index, FSI3 ) based on the analysing double-pass retinal images in the frequency domain, which minimizes the impact of aberrations on the results. METHODS: A prospective observational study was carried out in the Department of Ophthalmology, Hospital Universitari Mútua de Terrassa (Spain) on a group of 19 patients diagnosed with nuclear cataracts of various LOCSIII grades and a control group (CG) with nine healthy eyes. We recorded double-pass retinal images with a custom set-up based on a high-sensitivity digital camera. The FSI3 was then computed using spatial frequencies below three cycles per degree. A preliminary validation of the FSI3 was performed on an artificial eye and two eyes of volunteers with and without commercial diffusers, and under defocus. RESULTS: The FSI3 was hardly affected by defocus values up to 2.50 D. The mean (and standard deviation) FSI3 values were as follows: for the CG, 1.19 (0.21); and for LOCSIII grades nuclear opacity 1, 2 and 3, 1.30 (0.12), 1.62 (0.21) and 1.85 (0.21), respectively. Eyes with cataracts showed FSI3 values significantly different than healthy eyes (p = 0.001). A good correlation (ρ = 0.861, p < 0.001) was found between the FSI3 and objective scatter index provided by a commercial instrument. CONCLUSION: Since aberrations have little impact on the FSI3 , the light scatter assessment becomes less dependent on the patient's refractive error compensation and the presence of higher-order aberrations. The FSI3 can further the clinical and scientific understanding of forward intraocular scattering.

Scanning Electron Microscope Analysis of Stromal Surface Regularity in DSAEK Using Manual or Automated Microkeratomes or DMEK.

PURPOSE: To analyze differences in the stromal bed according to the method used to obtain the disc for endothelial transplant with 1) an automated microkeratome for Descemet stripping automated endothelial keratoplasty (DSAEK), 2) homogeneous dissection of Descemet membrane (Descemet membrane endothelial keratoplasty [DMEK]), or 3) a manual microkeratome used for DSAEK. METHODS: We analyzed the stromal bed of 25 consecutive corneas used for endothelial transplantation, divided into 3 groups: 1) 11 samples cut with an automated microkeratome, 2) 5 samples used for DMEK, 3) 9 samples cut with a manual microkeratome. A scanning electron microscope was used to obtain an image of the center of the stromal bed. The irregularity index of the surface complementary to the stromal surface of the disc obtained for grafting was calculated with the Canny algorithm (0: completely smooth; 1: completely irregular). RESULTS: At all thresholds studied (20, 30, 50, and 70), the mean irregularity index for group C (35.2, 24.4, 13.7, and 8.8, respectively) was higher than that of group A (26.2, 14.8, 6.7, and 4.0, respectively), which in turn was higher than that of group B (7.0, 4.2, 2.4, and 1.8, respectively). Differences were statistically significant among all groups and for all thresholds. CONCLUSIONS: Irregularity of the stromal bed after any dissection can be quantified using the Canny method. The use of an automated microkeratome for DSAEK reduces irregularity and helps obtain a surface more similar to that obtained with DMEK than with a manual microkeratome.

Determination of neuronal antibodies in suspected and definite Creutzfeldt-Jakob disease.

IMPORTANCE: Creutzfeldt-Jakob disease (CJD) and autoimmune encephalitis with antibodies against neuronal surface antigens (NSA-abs) may present with similar clinical features. Establishing the correct diagnosis has practical implications in the management of care for these patients. OBJECTIVE: To determine the frequency of NSA-abs in the cerebrospinal fluid of patients with suspected CJD and in patients with pathologically confirmed (ie, definite) CJD. DESIGN, SETTING, AND PARTICIPANTS: A mixed prospective (suspected) and retrospective (definite) CJD cohort study was conducted in a reference center for detection of NSA-abs. The population included 346 patients with suspected CJD and 49 patients with definite CJD. MAIN OUTCOMES AND MEASURES: Analysis of NSA-abs in cerebrospinal fluid with brain immunohistochemistry optimized for cell-surface antigens was performed. Positive cases in the suspected CJD group were further studied for antigen specificity using cell-based assays. All definite CJD cases were comprehensively tested for NSA-abs, with cell-based assays used for leucine-rich glioma-inactivated 1 (LGI1), contactin-associated protein-like 2 (CASPR2), N-methyl-d-aspartate (NMDA), and glycine (GlY) receptors. RESULTS: Neuronal surface antigens were detected in 6 of 346 patients (1.7%) with rapid neurologic deterioration suggestive of CJD. None of these 6 patients fulfilled the diagnostic criteria for probable or possible CJD. The target antigens included CASPR2, LGI1, NMDAR, aquaporin 4, Tr (DNER [δ/notch-like epidermal growth factor-related receptor]), and an unknown protein. Four of the patients developed rapidly progressive dementia, and the other 2 patients had cerebellar ataxia or seizures that were initially considered to be myoclonus without cognitive decline. The patient with Tr-abs had a positive 14-3-3 test result. Small cell lung carcinoma was diagnosed in the patient with antibodies against an unknown antigen. All patients improved or stabilized after appropriate treatment. None of the 49 patients with definite CJD had NSA-abs. CONCLUSIONS AND RELEVANCE: A low, but clinically relevant, number of patients with suspected CJD had potentially treatable disorders associated with NSA-abs. In contrast, none of 49 patients with definite CJD had NSA-abs, including NMDAR-abs, GlyR-abs, LGI1-abs, or CASPR2-abs. These findings suggest that cerebrospinal fluid NSA-abs analysis should be included in the diagnostic workup of patients with rapidly progressive central nervous system syndromes, particularly when they do not fulfill the diagnostic criteria of probable or possible CJD.

MAASH Technique for Total Hip Arthroplasty: A Capsular Work.

BACKGROUND: Dislocation and leg length discrepancy are major complications following total hip arthroplasty (THA). Many surgical approaches for THA have been described, but none suggest a capsular incision that assures good exposure while maintaining adequate capsule integrity in closure. PURPOSES: Modified anterolateral approach for stable hip (MAASH) is a modification of the classical Hardinge approach, but specifically preserves the anterior iliofemoral lateral ligament and pubofemoral ligament excising the "weak area" of the capsule, in the so called "internervous safe zone" and introducing the "box concept" for the anterior approach to the hip. This is the main difference of the MAASH approach. This technique can be used as a standard for all THA standard models, but we introduce new devices to make it easier. METHODS: From November 2007 to May 2012, data were collected for this observational retrospective consecutive case study. We report the results of 100 THA cases corresponding to the development curve of this new concept in THA technique. RESULTS: MAASH technique offers to hip surgeons, a reliable and reproducible THA anterolateral technique assuring accurate reconstruction of leg length and a low rate of dislocation. Only one dislocation and six major complications are reported, but most of them occurred at the early stages of technique development. CONCLUSION: MAASH technique proposes a novel concept on working with the anterior capsule of the hip for the anterolateral approach in total hip arthroplasty, as well as for hemiarthroplasty in the elderly population with high dislocation risk factors. MAASH offers maximal stability and the ability to restore leg length accurately.

Grading nuclear, cortical and posterior subcapsular cataracts using an objective scatter index measured with a double-pass system.

PURPOSE: To evaluate objectively intraocular scattering in eyes with nuclear, cortical and posterior subcapsular cataracts by means of an objective scatter index (OSI) obtained from double-pass images. To compare the results with those obtained using clinical conventional procedures. METHODS: In this prospective, observational, cross-sectional, non-consecutive case series study, 188 eyes with cataracts of 136 patients were analysed (123 eyes had nuclear, 41 eyes had cortical and 24 eyes had posterior subcapsular cataracts). The control group consisted of 117 eyes of 68 healthy patients. Patient examination included subjective refraction, best spectacle-corrected visual acuity (BSCVA), cataract grade using the lens opacities classification system III (LOCS III) and OSI. RESULTS: We found a decrease in the BSCVA and an increase in the OSI with increasing cataract grade. Statistically significant differences were observed when the OSI of eyes without cataracts and those with different LOCS III were compared. The comparison between the OSI and LOCS III reported good percentages of agreement regarding the number of eyes classified in equivalent levels: 72.4% (nuclear cataracts), 86.6% (cortical cataracts) and 84.3% (posterior subcapsular cataracts). A non-linear regression model was applied between OSI and BSCVA, which resulted in the following multiple correlation coefficients: r=0.878 (nuclear), r=0.843 (cortical) and r=0.844 (posterior subcapsular). CONCLUSIONS: The results of the study showed that OSI is a useful parameter for evaluating large amounts of intraocular scattering that can be used, in combination with other conventional procedures, as a valuable tool in clinical practice to grade cataracts objectively.