Faculty Bibliography

Corneal dystrophies are a heterogeneous group of bilateral, inherited, rare diseases characterized by slowly progressive corneal opacities, that lead to visual impairment. Most of them have an autosomal dominant pattern of inheritance with variable expressivity, but new mutations have been described. Many corneal dystrophies have been genetically characterized and the specific gene mutations identified, such as for the epithelial-stromal TGFBI dystrophies. Current classification systems identified four main groups of corneal dystrophies based on clinical, histologic, and genetic information. Diagnosis is performed during a routine ophthalmic examination that shows typical cellular abnormalities of the corneal epithelium, stroma, or endothelium. Disease progression should be carefully monitored to decide the proper clinical management. The treatment of corneal dystrophies is variable, depending on symptoms, clinical course, severity, and type of dystrophy. Management aimed to reduce symptoms and to improve vision, includes different surgical approaches. Novel cellular and genetic therapeutic approaches are under evaluation. J. Cell. Physiol. 231: 261-269, 2016. © 2015 Wiley Periodicals, Inc.

IMPORTANCE/OBJECTIVE:Knowledge about the variability of measurements using the TearLab Osmolarity System is necessary when evaluating the clinical utility of readings. OBJECTIVE:To examine the variability of tear osmolarity measured by the TearLab Osmolarity System in patients with Sjögren syndrome (SS), patients with blepharitis, and control participants. DESIGN, SETTING, AND PARTICIPANTS/METHODS:Cross-sectional study at a tertiary care academic center from June 13, 2012, to March 21, 2013. Participants included 74 eyes of 37 patients from a volunteer sample (18 patients with SS, 11 patients with blepharitis, and 8 control participants) who were evaluated using the TearLab Osmolarity System, with 3 consecutive osmolarity measurements taken at 1-minute intervals in a session; 15 of these patients had the same measurements taken by the same examiner in 2 additional sessions on the same day (9 AM-10 AM, 12 PM-1 PM, or 3 PM-4 PM). Most patients with SS and patients with blepharitis were taking systemic or topical dry eye medications at the time of enrollment. MAIN OUTCOMES AND MEASURES/METHODS:Mean osmolarity and its variability calculated from a linear mixed model for each disease group that accounts for the variations attributable to different patients, eyes, and sessions and measurement error specific to each disease group. RESULTS:Mean tear osmolarity was 307 mOsm/L, 304 mOsm/L, and 301 mOsm/L in the SS, blepharitis, and control groups, respectively (P = .46). The error associated with repeated measurements within a session in the patients without dry eye (10.5 mOsm/L [95% CI, 9.0-12.4]) was significantly lower than in the patients with blepharitis (14.6 mOsm/L [95% CI, 12.5-17.5]; P = .006) and patients with SS (15.8 mOsm/L [95% CI, 14.2-17.8]; P < .001) but a difference in the error of repeated measurements between patients with blepharitis and patients with SS was not identified (P = .46). CONCLUSIONS AND RELEVANCE/CONCLUSIONS:There was increased variability attributable to error in repeated measurements in patients with SS and patients with blepharitis compared with control participants. The high variability of TearLab osmolarity readings in all groups makes the clinical interpretation of measurements unclear.

PURPOSE/OBJECTIVE:To determine the intra-observer and inter-observer reliability of a novel ocular staining score among trained ophthalmologists. DESIGN/METHODS:Reliability analysis within a prospective, observational, multicenter cohort study. METHODS:Those enrolled in the National Institutes of Health-funded Sjögren's International Collaborative Clinical Alliance (SICCA) who presented for follow-up at the University of California San Francisco, Aravind Eye Hospital, Johns Hopkins University, and the University of Pennsylvania were included. Study participants were graded using the ocular staining score by at least 2 masked SICCA-trained ophthalmologists. The primary outcome for this study was the intraclass correlation coefficient (ICC) for the total ocular staining score. ICCs were also calculated for tear break-up time (TBUT) and conjunctival and corneal staining. RESULTS:Total ocular staining score had an ICC of 0.91 for the right eye (95% confidence interval [CI] 0.85-0.96) and 0.90 for the left eye (95% CI 0.83-0.97). Corneal staining (right eye 0.86, 95% CI 0.76-0.93, left eye 0.90, 95% CI 0.81-0.95) and conjunctival staining (right eye 0.87, 95% CI 0.80-0.93, left eye 0.85, 95% CI 0.75-0.93) demonstrated excellent agreement. The ICC for TBUT was slightly lower (right eye 0.77, 95% CI 0.64-0.89; left eye 0.81, 95% CI 0.68-0.90). CONCLUSIONS:Previous studies have shown that the ocular staining score is correlated with other diagnostic components of Sjögren syndrome. In this study, we demonstrate high reliability in grading among trained ophthalmologists, completing the validation of this test.

PURPOSE/OBJECTIVE:To assess the relationship between tear osmolarity and dry eye symptoms in patients with diabetes. PATIENTS AND METHODS/METHODS:Fifty patients with diabetes were enrolled. Demographic information and past medical history were recorded. Symptoms were assessed using the ocular surface disease index (OSDI). Tear osmolarity of each eye was measured with the TearLab® Osmolarity System. RESULTS:The majority of the subjects were female (76%), African American (56%), and/or had a diagnosis of type 2 diabetes (82%). The mean ± standard deviation (SD) for age was 54.6±13.4, and maximum tear osmolarity was 304.6±12.7 mOsm/L. Men had higher osmolarity than women (mean ± standard error (SE) 311.8±4.0 mOsm/L versus 302.3±1.9 mOsm/L, P=0.02). Age, race, use of artificial tears, years of diabetes, and hemoglobin A1c did not have a statistically significant association with tear osmolarity. Longer duration of diabetes was associated with lower (less severe) OSDI scores (r=-0.35, P=0.01). Higher tear osmolarity was associated with lower (less severe) OSDI scores (r=-0.29, P=0.04). CONCLUSION/CONCLUSIONS:Approximately half of the diabetic subjects in our study had elevated tear osmolarity, and half of our population also reported symptoms consistent with dry eye disease. However, the two were slightly inversely related in that those with higher osmolarity reported fewer symptoms. Subjects with a longer duration of diabetes also reported fewer dry eye symptoms. Therefore, health care providers should be aware that patients who are most likely to have ocular surface disease, including those with long-standing diabetes, may not experience symptoms and seek care in a timely manner.

Nerve growth factor (NGF) is an endogenous neurotrophin involved in the development, maintenance and regeneration of mammalian sympathetic and sensory neurons. Additionally, NGF is known to have trophic and differentiating activity on several populations of cholinergic neurons of the central nervous system (CNS), and to act as a differentiation factor in the development of the visual cortex. The paramount functions of NGF in the visual system are also highlighted by the presence of this neurotrophin and both its receptors TrkA and p75 in most intra-ocular tissues, including lens, vitreous, choroid, iris, and trabecular meshwork. In the retina, NGF is produced and utilized specifically by retinal ganglion cells (RGC), bipolar neurons and glial cells, and is thought to have crucial protective effects in several disease states. Studies on the role of NGF on RGCs survival following optic nerve transection, ischemic injury, ocular hypertension and glaucoma are discussed in this review.

PURPOSE/OBJECTIVE:To preserve limbal stem cell (LSC) function in vitro with xenobiotic-free culture conditions. METHODS:Limbal epithelial cells were isolated from 139 donors using 15 variations of three dissociation solutions. All culture conditions were compared to the baseline condition of murine 3T3-J3 feeders with xenobiotic (Xeno) keratinocyte growth medium at 20% O2. Five Xeno and Xeno-free media with increasing concentrations of calcium and epidermal growth factor (EGF) were evaluated at 5%, 14%, and 20% O2. Human MRC-5, dermal (fetal, neonatal, or adult), and limbal stromal fibroblasts were compared. Statistical analysis was performed on the number of maximum serial weekly passages, percentage of aborted colonies, colony-forming efficiency (CFE), p63α(bright) cells, and RT-PCR ratio of p63α/K12. Immunocytochemistry and RT-PCR for p63α, ABCG2, Bmi1, C/EBPδ , K12, and MUC1 were performed to evaluate phenotype. RESULTS:Dispase/TrypLE was the isolation method that consistently showed the best yield, viability, and CFE. On 3T3-J2 feeders, Xeno-free medium with calcium 0.1 mM and EGF 10 ng/mL at 20% O2 supported more passages with equivalent percentage of aborted colonies, p63α(bright) cells, and p63α/K12 RT-PCR ratio compared to baseline Xeno-media. With this Xeno-free medium, MRC-5 feeders showed the best performance, followed by fetal, neonatal, adult HDF, and limbal fibroblasts. MRC-5 feeders supported serial passages with sustained high expression of progenitor cell markers at levels as robust as the baseline condition without significant difference between 20% and 5% O2. CONCLUSIONS:The LSC function can be maintained in vitro under appropriate Xeno-free conditions.

PURPOSE/OBJECTIVE:The aim of this study was to examine the relationship among oral contraceptive pill (OCP) use, contact lens wear, and dry eye signs and symptoms in healthy young women. METHODS:Fifty-two women using OCPs and 45 women not using any form of hormonal contraception were enrolled. Medical, menstrual, and contact lens histories were obtained and dry eye symptoms assessed using the Ocular Surface Disease Index (OSDI) and Symptom Assessment iN Dry Eye (SANDE) questionnaires. Tear osmolarity testing was performed using the TearLab Osmolarity System. RESULTS:The mean age of all subjects was 26.0 ± 3.7 years. There were no significant differences in any of the measurements between the follicular and luteal phases. Although SANDE scores were significantly higher in subjects with OCP and recent contact lens use (P < 0.01), there were no significant differences in OSDI and tear osmolarity among the same subject groups. Subjects who reported both OCP and recent contact lens use had significantly higher OSDI and SANDE scores (P = 0.015 and P < 0.001, respectively). CONCLUSIONS:There were no differences between the phases of the menstrual cycle. Tear osmolarity was not affected by OCP or contact lens use in young women. However, the combination of OCP use and contact lens wear may increase the severity of dry eye symptoms.