Tear film stability and its interaction with the corneal surface play an important role in maintaining ocular surface integrity and quality of vision. We present a non-invasive technique to quantify the pre-corneal tear film thickness. A cMOS camera is used to record the interference pattern produced by the reflections from multiple layers of the tear film Principles of spatial autocorrelation are applied to extract the frequency of the periodic patterns in the images. A mathematical model is developed to obtain the thickness of the tear film from the spatial autocorrelation image. The technique is validated using micro-fabricated thin parylene films. We obtained repeatable and precise measurement on a live rabbit model (N = 6). We obtained an average value of 10.2µm and standard deviation of, SD = 0.3 (N = 4). We measured one rabbit infected with HSV-1 virus that had a baseline tear film thickness of 4.7µm.

Purpose

The purpose of this study was to assess the ability of quantitative in vivo confocal microscopy (CM) to detect changes in cystine crystal volume in the cystinosisn (Ctns^−/−)mouse cornea following topical cysteamine therapy.

Methods

Fifteen Ctns^−/− mice were sequentially followed using in vivo CM from 3 to 10 months of age. In a second experiment, five mice receiving topical cysteamine eyedrops (0.55%) for 4 weeks were compared to five untreated mice. The volume of corneal cystine crystals was determined by thresholding and counting high intensity pixels in the in vivo CM scans and dividing by the stromal volume to calculate a crystal volume index (CVI).

Results

Corneal crystals progressively increased in density with age, reaching a peak density at 6–8 months and showing a 70 fold increase in CVI. Eyes treated with cysteamine drops showed significantly less crystal accumulation compared to control eyes (p<0.001) with only a 15% increase in treated eyes (p=ns) compared to 173% increase (p<0.04) for untreated eyes.

Conclusions

Measurement of CVI shows that there is a progressive increase in cystine crystal volume up to 8 months of age and that cysteamine eyedrops significantly inhibits progression in the Ctns^−/− mouse. These findings are similar to those seen clinically in patients with cystinosis, and suggest that measurement of CVI in the Ctns^−/− mouse may be used as a model to develop novel therapeutic strategies for treating corneal cystinosis.

Purpose

The purpose of this study was to assess the ability of quantitative in vivo confocal microscopy to characterize the natural history and detect changes in crystal volume in corneas from a novel animal model of cystinosis, the cystinosin (Ctns^-/-) mouse.

Methods

Two Ctns^−/− mice and one C57Bl/6 mouse were examined at each of the following time points: 2, 3, 5, 7, 10, 12, and 14 months of age. In vivo confocal microscopy scans were performed in 4 different regions of the cornea per eye. After, animals were sacrificed and cornea blocks evaluated for cell morphology using phalloidin and lymphocytic infiltration using CD45 antibodies by ex vivo confocal microscopy. Cystine crystal content in the cornea was measured by calculating the pixel intensity of the crystals divided by the stromal volume using Metamorph Image Processing Software.

Results

Corneal crystals were identified in Ctns^−/− eyes beginning at 3 months of age and increased in density until 7–12 months, at which time animals begin to succumb to the disease and corneas become scarred and neovascularized. Older Ctns^−/− mice (7 months and older) showed the presence of cell infiltrates that stained positively for CD45 associated with progressive keratocyte disruption. Finally, at 12 months of age, decreased cell density and endothelial distortion were detected.

Conclusions

Confocal microscopy identified corneal crystals starting at 3 month old Ctns^−/− eyes. Cystine crystals induce inflammatory and immune response with aging associated with loss of keratocyte and endothelial cells. These findings suggest that the Ctns^−/− mouse can be used as a model for developing and evaluating potential alternative therapies for corneal cystinosis.

Purpose

In this study we aimed to define the prevalence of preoperative and postoperative post-micturition incontinence or post-void dribbling after anterior urethroplasty for urethral stricture disease. We also sought to determine risk factors for its presence.

Materials and methods

We retrospectively reviewed a prospectively maintained, multi-institutional urethral stricture database to evaluate post-micturition incontinence using a single question from a validated questionnaire, "How often have you had a slight wetting of your pants a few minutes after you had finished urinating and had dressed yourself?" Possible answers were never-0 to all the time-3. The presence of post-micturition incontinence was defined as any answer greater than 0. Comparisons were made to stricture type and location, repair type and patient medical comorbidities.

Results

Preoperative and postoperative post-micturition incontinence questionnaires were completed by 614 and 331 patients, respectively. Patients without complete data available were excluded from study. Preoperative post-micturition incontinence was present in 73% of patients, of whom 44% stated that this symptom was present most of the time. Overall postoperative post-micturition incontinence was present in 40% of patients and again it was not predicted by stricture location or urethroplasty type. Of the 331 patients with followup questionnaires 60% reported improvement, 32% reported no change and 8% reported worsening symptoms. The overall rate of de novo post-micturition incontinence was low at 6.3%.

Conclusions

The prevalence of preoperative post-micturition incontinence is high and likely under reported. In most patients post-micturition incontinence improves after urethroplasty and the prevalence of de novo post-micturition incontinence is low. The presence of post-micturition incontinence was not predicted by stricture length or location, or urethroplasty repair type.

Objective

To clinically validate a previously developed adult-acquired buried penis (AABP) classification system that is based on a standardized preoperative physical examination that subtypes patients by their penile skin/escutcheon complex (P), abdominal pannus (A), and scrotal skin (S).

Methods

The Trauma and Urologic Reconstruction Network of Surgeons (TURNS) database was used to create an AABP cohort. Patients were retrospectively classified using the previously described PAS classification system. The frequency of subtypes, surgical methods utilized for AABP repair, and correlations between PAS classification and surgery subtypes were analyzed.

Results

The final cohort consisted of 101 patients from 10 institutions. Interrater reliability between two reviewers was excellent (κ = 0.95). The most common subtypes were P2c (contributory escutcheon+insufficient penile skin; 27%) and P2a (contributory escutcheon+sufficient penile skin; 21%) for penile subtypes, A0 (no pannus; 41%) and A1 (noncontributory pannus; 39%) for abdominal subtypes, and S0 (normal scrotal skin with preserved scrotal sulcus; 71%) for scrotal subtypes. AABP repair procedures included escutcheonectomy (n = 59, 55%), scrotoplasty (n = 51, 48%), split-thickness skin grafting (n = 50, 47%), penile skin excision (n = 47, 44%) and panniculectomy (n = 7, 7%). P, A, and S subtypes were strongly associated with specific AABP surgical techniques.

Conclusion

The PAS classification schema adequately describes AABP heterogeneity, is reproducible among observers, and correlates well with AABP surgery types. Future work will focus on how PAS subtypes affect both surgical and patient-centered outcomes.