The Use of Polarization Filters to Detect the Edge of the Descemet’s Stripping Automated Endothelial Keratoplasty(DSAEK) Graft

To report the technique of combining the two different polarization filters to detect the flap edge of the corneoscleral tissue before trephining the Descemet's stripping automated endothelial keratoplasty (DSAEK) tissue. A human DSAEK donor tissue was prepared with mechanical microkeratome and the tissue on the cutting block was brought under the microscope. The liner, circular, or the combination of these two polarization filters was placed between the tissue and the microscope. The tissue images were taken with digital camera under either of 3 settings. The combination of circular and linear polarization filters enabled us to recognize the edge of the flap more easily than others. This simple system with polarization filters was effective in clear visualization of the flap edge during DSAEK tissue preparation. These features may significantly enhance safety of various surgical procedures, in addition to DSAEK tissue preparation

Subconjunctival Emphysema After Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK)

DSAEK has recently evolved as a preferred method in place of PKP. After DSAEK, we experienced subconjunctival emphysema, decreased air bubble in the AC and low IOP. This could lead to complications, higher rate of dislocation or infection. We should control the wound closure with suture when in doubt

Corneal Microlayer Optical Tomography Review

Anterior segment ultra-high resolution OCT (UHR-OCT) uses a resolution of 1–4 μm to provide non-invasive imaging of the tear film and cornea. This new high definition imaging technology increases our understanding of normal structure and pathological changes in the cornea, and resolution has continued to improve over time. UHR-OCT is useful in the treatment of disease such as dry eye, subclinical keratoconus, keratoconus, and ocular surface pathology. It also aids clinicians in fitting contact lenses and screening tissue for corneal transplantation. In this review, we summarize applications of imaging the normal and pathologic ocular surface and cornea. Novel developments, such as the new-generation micro-OCT, Anterior segment OCT angiography and artificial intelligence have the potential to continue to increase our knowledge

Customized pachymetric guided epithelial debridement for corneal collagen cross linking

<p>Abstract</p> <p>Backround</p> <p>We describe a modified method for deepitheliazation prior to corneal cross linking (CXL). The technique may overcome the current corneal pachymetric limitation parameter (over 400 microns) that is necessary for the safety of the procedure without affecting the overall benefits.</p> <p>Methods</p> <p>In a series of two patients, with inferior topographic steepening and regional thinning (less than 400 microns corresponding to the area of corneal steepening), CXL after customized epithelial removal was performed.</p> <p>Results</p> <p>There were no intra- or postoperative adverse events seen by the nine month follow up examination. Stabilization of the corneal ectasia was observed up to nine months post-costumized pachymetric-guided epithelial removal.</p> <p>Conclusion</p> <p>The technique of customized pachymetric-guided epithelial removal is easy to perform and may overcome the limitations of the preoperative corneal pachymetry expanding the application of the procedure in patients with regional corneal thinning.</p

Combined anterior segment OCT and wavefront-based autorefractor using a shared beam

We have combined an anterior segment (AS) optical coherence tomography (OCT) system and a wavefront-based aberrometer with an approach that senses ocular wavefront aberrations using the OCT beam. Temporal interlacing of the OCT and aberrometer channels allows for OCT images and refractive error measurements to be acquired continuously and in real-time. The system measures refractive error with accuracy and precision comparable to that of clinical autorefractors. The proposed approach provides a compact modular design that is suitable for integrating OCT and wavefront-based autorefraction within the optical head of the ophthalmic surgical microscope for guiding cataract surgery or table-top devices for simultaneous autorefraction and ocular biometry

Clinical Study Long Term Followup of Photorefractive Keratectomy with Adjuvant Use of Mitomycin C

properly cited. Purpose. To study the long term refractive and visual outcomes of photorefractive keratectomy (PRK) with intraoperative application of mitomycin C (MMC). Methods. This study included 37 eyes who received myopic PRK; after photoablation, a sponge soaked in 0.02% MMC solution was applied in all corneas for 2 minutes. Efficacy, safety, predictability, and stability of PRK MMC were evaluated. Endothelial cell density was evaluated at the last postoperative interval. Results. Mean preoperative spherical equivalent (SEQ) was −6.03 ± 1.87 D (diopters) and reduced to −0.09 ± 0.53 D at the last postoperative examination. Mean followup was 44.73 ± 18.24 months. All the eyes were in the ±1.00 D of attempted versus achieved SEQ at the one-year follow-up interval. Furthermore, 95% of the eyes did not lose lines or gained 1 to 2 lines of CDVA, while 5% lost 1 line. At the third postoperative month, 89% of the eyes either were clear or had trace haze, while 4 eyes had mild haze; by the 12-month postoperative interval, none of the eyes demonstrated haze. Mean endothelial cell density (ECD) at the last postoperative interval was 2658 ± 153 cells/mm 2 . Conclusions. PRK, with intraoperative use of MMC, demonstrates stable refractive and visual outcomes up to 44 months after surgery

Central Corneal Thickness in Patients With Neovascular Age-Related Macular Degeneration

Purpose: To compare the central corneal thickness (CCT) measurements of patients with neovascular age-related macular degeneration (AMD) and control subjects. Methods: The CCT value (measured with ultrasound corneal pachymetry) of 130 eyes (130 patients, 1 eye from each patient) with neovascular AMD (AMD group) and 98 eyes (98 patients, 1 eye from each patient) of similar age, sex, and eye&apos;s axial length healthy control subjects (normal group) was compared. Results: The mean age (AMD group: 69.1 years vs. control group: 69.5 years, P = 0.81), sex (AMD group: 77 women, 59% vs. control group: 59 women, 60%, P = 0.77), and eye&apos;s axial length (AMD group: 25.05-mm vs. control group: 24.61-mm, P = 0.38) of patients with neovascular AMD and healthy control subjects were comparable. There were no statistically significant differences in the mean CCT measurements in the neovascular AMD group in comparison with the control group (549.44 vs. 544.35 mm, P = 0.11). Conclusions: CCT measurements do not differ in patients with neovascular AMD compared with healthy control subjects

Relationship of EMAST and Microsatellite Instability Among Patients with Rectal Cancer

Elevated microsatellite instability at selected tetranucleotide repeats (EMAST) is a genetic signature identified in 60% of sporadic colon cancers and may be linked with heterogeneous expression of the DNA mismatch repair (MMR) protein hMSH3. Unlike microsatellite instability-high (MSI-H) in which hypermethylation of hMLH1 occurs followed by multiple susceptible gene mutations, EMAST may be associated with inflammation and subsequent relaxation of MMR function with the biological consequences not known. We evaluated the prevalence of EMAST and MSI in a population-based cohort of rectal cancers, as EMAST has not been previously determined in rectal cancers. We analyzed 147 sporadic cases of rectal cancer using five tetranucleotide microsatellite markers and National-Cancer-Institute-recommended MSI (mononucleotide and dinucleotide) markers. EMAST and MSI determinations were made on analysis of DNA sequences of the polymerase chain reaction products and determined positive if at least two loci were found to have frame-shifted repeats upon comparison between normal and cancer samples from the same patient. We correlated EMAST data with race, gender, and tumor stage and examined the samples for lymphocyte infiltration. Among this cohort of patients with rectal cancer (mean age 62.2 ± 10.3 years, 36% female, 24% African American), 3/147 (2%) showed MSI (three males, two African American) and 49/147 (33%) demonstrated EMAST. Rectal tumors from African Americans were more likely to show EMAST than Caucasians (18/37, 49% vs. 27/104, 26%, p = 0.014) and were associated with advanced stage (18/29, 62% EMAST vs. 18/53, 37%, non-EMAST p = 0.02). There was no association between EMAST and gender. EMAST was more prevalent in rectal tumors that showed peri-tumoral infiltration compared to those without (30/49, 60% EMAST vs. 24/98, 25% non-EMAST, p = 0.0001). EMAST in rectal cancer is common and MSI is rare. EMAST is associated with African-American race and may be more commonly seen with metastatic disease. The etiology and consequences of EMAST are under investigation, but its association with immune cell infiltration suggests that inflammation may play a role for its development

The Comparison between Circadian Oscillators in Mouse Liver and Pituitary Gland Reveals Different Integration of Feeding and Light Schedules

The mammalian circadian system is composed of multiple peripheral clocks that are synchronized by a central pacemaker in the suprachiasmatic nuclei of the hypothalamus. This system keeps track of the external world rhythms through entrainment by various time cues, such as the light-dark cycle and the feeding schedule. Alterations of photoperiod and meal time modulate the phase coupling between central and peripheral oscillators. In this study, we used real-time quantitative PCR to assess circadian clock gene expression in the liver and pituitary gland from mice raised under various photoperiods, or under a temporal restricted feeding protocol. Our results revealed unexpected differences between both organs. Whereas the liver oscillator always tracked meal time, the pituitary circadian clockwork showed an intermediate response, in between entrainment by the light regimen and the feeding-fasting rhythm. The same composite response was also observed in the pituitary gland from adrenalectomized mice under daytime restricted feeding, suggesting that circulating glucocorticoids do not inhibit full entrainment of the pituitary clockwork by meal time. Altogether our results reveal further aspects in the complexity of phase entrainment in the circadian system, and suggest that the pituitary may host oscillators able to integrate multiple time cues