L. Jay Katz

Analysis of 13 cell types reveals evidence for the expression of numerous novel primate- And tissue-specific microRNAs

Significance MicroRNAs (miRNAs) are small ∼22-nt RNAs that are important regulators of posttranscriptional gene expression. Since their initial discovery, they have been shown to be involved in many cellular processes, and their misexpression is associated with disease etiology. Currently, nearly 2,800 human miRNAs are annotated in public repositories. A key question in miRNA research is how many miRNAs are harbored by the human genome. To answer this question, we examined 1,323 short RNA sequence samples and identified 3,707 novel miRNAs, many of which are human-specific and tissue-specific. Our findings suggest that the human genome expresses a greater number of miRNAs than has previously been appreciated and that many more miRNA molecules may play key roles in disease etiology. Two decades after the discovery of the first animal microRNA (miRNA), the number of miRNAs in animal genomes remains a vexing question. Here, we report findings from analyzing 1,323 short RNA sequencing samples (RNA-seq) from 13 different human tissue types. Using stringent thresholding criteria, we identified 3,707 statistically significant novel mature miRNAs at a false discovery rate of ≤0.05 arising from 3,494 novel precursors; 91.5% of these novel miRNAs were identified independently in 10 or more of the processed samples. Analysis of these novel miRNAs revealed tissue-specific dependencies and a commensurate low Jaccard similarity index in intertissue comparisons. Of these novel miRNAs, 1,657 (45%) were identified in 43 datasets that were generated by cross-linking followed by Argonaute immunoprecipitation and sequencing (Ago CLIP-seq) and represented 3 of the 13 tissues, indicating that these miRNAs are active in the RNA interference pathway. Moreover, experimental investigation through stem-loop PCR of a random collection of newly discovered miRNAs in 12 cell lines representing 5 tissues confirmed their presence and tissue dependence. Among the newly identified miRNAs are many novel miRNA clusters, new members of known miRNA clusters, previously unreported products from uncharacterized arms of miRNA precursors, and previously unrecognized paralogues of functionally important miRNA families (e.g., miR-15/107). Examination of the sequence conservation across vertebrate and invertebrate organisms showed 56.7% of the newly discovered miRNAs to be human-specific whereas the majority (94.4%) are primate lineage-specific. Our findings suggest that the repertoire of human miRNAs is far more extensive than currently represented by public repositories and that there is a significant number of lineage- and/or tissue-specific miRNAs that are uncharacterized.

Randomized Evaluation of the Trabecular Micro-Bypass Stent with Phacoemulsification in Patients with Glaucoma and Cataract

OBJECTIVE To assess the safety and efficacy of the iStent trabecular micro-bypass stent (Glaukos Corporation, Laguna Hills, CA) in combination with cataract surgery in subjects with mild to moderate open-angle glaucoma. DESIGN Prospective, randomized, open-label, controlled, multicenter clinical trial. PARTICIPANTS A total of 240 eyes with mild to moderate open-angle glaucoma with intraocular pressure (IOP) ≤24 mmHg controlled on 1 to 3 medications were randomized to undergo cataract surgery with iStent implantation (treatment group) or cataract surgery only (control). Fifty additional subjects were enrolled to undergo cataract surgery with iStent implantation under protocol expansion. Data in this report are based on the first 240 eyes enrolled. INTERVENTION Implantation of the iStent trabecular micro-bypass stent in conjunction with cataract surgery or cataract surgery only. MAIN OUTCOME MEASURES The primary efficacy measure was unmedicated IOP ≤21 mmHg at 1 year. A secondary measure was unmedicated IOP reduction ≥20% at 1 year. Safety measures included best-corrected visual acuity (BCVA), slit-lamp observations, complications, and adverse events. RESULTS The study met the primary outcome, with 72% of treatment eyes versus 50% of control eyes achieving the criterion (P<0.001). At 1 year, IOP in both treatment groups was statistically significantly lower from baseline values. Sixty-six percent of treatment eyes versus 48% of control eyes achieved ≥20% IOP reduction without medication (P = 0.003). The overall incidence of adverse events was similar between groups with no unanticipated adverse device effects. CONCLUSIONS Pressure reduction on fewer medications was clinically and statistically significantly better 1 year after stent plus cataract surgery versus cataract surgery alone, with an overall safety profile similar to that of cataract surgery alone.

Dysfunctional Filtering Blebs

Guarded filtration surgery, is commonly used to control the intraocular pressure (IOP) in glaucomatous patients. Filtration surgery lowers the IOP by creating a fistula between the inner compartments of the eye and the subconjunctival space (i.e., filtering bleb). There are several options to improve the function of filtering blebs and to prevent their failure. However, improvement of IOP control after guarded filtration procedures is associated with a higher frequency of bleb-related complications. Early (e.g., bleb leak, excessive filtration, flat anterior chamber, filtration failure) and late (e.g., bleb leak, excessive filtration and hypotony, symptomatic blebs, bleb encapsulation, filtration failure, bleb infection) complications associated with filtering procedures should be managed adequately to prevent further problems. Techniques to improve the function of filtering blebs and to treat postoperative complications have progressed over the past decade.

Cataract surgery with trabecular micro-bypass stent implantation in patients with mild-to-moderate open-angle glaucoma and cataract: Two-year follow-up

PURPOSE: To assess the long‐term safety and efficacy of a single trabecular micro‐bypass stent with concomitant cataract surgery versus cataract surgery alone for mild to moderate open‐angle glaucoma. SETTING: Twenty‐nine investigational sites, United States. DESIGN: Prospective randomized controlled multicenter clinical trial. METHODS: Eyes with mild to moderate glaucoma with an unmedicated intraocular pressure (IOP) of 22 mm Hg or higher and 36 mm Hg or lower were randomly assigned to have cataract surgery with iStent trabecular micro‐bypass stent implantation (stent group) or cataract surgery alone (control group). Patients were followed for 24 months postoperatively. RESULTS: The incidence of adverse events was low in both groups through 24 months of follow‐up. At 24 months, the proportion of patients with an IOP of 21 mm Hg or lower without ocular hypotensive medications was significantly higher in the stent group than in the control group (P=.036). Overall, the mean IOP was stable between 12 months and 24 months (17.0 mm Hg ± 2.8 [SD] and 17.1 ± 2.9 mm Hg, respectively) in the stent group but increased (17.0 ± 3.1 mm Hg to 17.8 ± 3.3 mm Hg, respectively) in the control group. Ocular hypotensive medication was statistically significantly lower in the stent group at 12 months; it was also lower at 24 months, although the difference was no longer statistically significant. CONCLUSIONS: Patients with combined single trabecular micro‐bypass stent and cataract surgery had significantly better IOP control on no medication through 24 months than patients having cataract surgery alone. Both groups had a similar favorable long‐term safety profile. Financial Disclosure: Dr. Craven was an investigator in the clinical trial of the iStent. Dr. Katz is a consultant to Glaukos and was the medical monitor for the clinical trial of the iStent. Dr. Katz is a stockholder in Glaukos. Mr. Wells and Ms. Giamporcaro are employees of Glaukos.

Brimonidine tartrate 0.2% twice daily vs timolol 0.5% twice daily: 1-year results in glaucoma patients

PURPOSE To compare the long-term efficacy and safety of brimonidine 0.2% twice daily with timolol 0.5% twice daily in patients with glaucoma or ocular hypertension. METHODS Of the 926 patients enrolled in the study, 837 met the protocol entry criteria and received either brimonidine 0.2% twice daily (n = 466) or timolol 0.5% (n = 371) twice daily in each eye for 1 year. RESULTS Brimonidine and timolol significantly reduced mean intraocular pressure (P < .001) from baseline levels at every scheduled follow-up visit, both at hour 2 (peak) and hour 12 (trough). At weeks 1 and 2 and months 3 and 12, significantly greater mean decreases in intraocular pressure (P < .040) at peak were observed in patients treated with brimonidine than those treated with timolol. The mean intraocular pressure decrease at trough was significantly greater for timolol than for brimonidine at each follow-up visit (P < .001). With the exception of ocular allergy (in 11.5% of patients using brimonidine and less than 1% using timolol), fewer than 3% of patients in either treatment group withdrew from the study prematurely as a result of a specific adverse event. Patients receiving timolol experienced significant decreases in heart rate (P < .001) from baseline at all follow-up visits. No significant changes in heart rate were seen in patients treated with brimonidine. Neither medication produced clinically significant changes in blood pressure. CONCLUSION Brimonidine is safe and effective in the long-term lowering of intraocular pressure in patients with glaucoma or ocular hypertension, with efficacy comparable to that of timolol but without a notable negative chronotropic effect on the heart.

Reversible Optic Disk Cupping and Visual Field Improvement in Adults With Glaucoma

To assess change over time in the optic disk and the associated change in visual field, we retrospectively reviewed perimetry results and optic disk photographs of adult patients treated for glaucoma. Three glaucoma specialists masked to the clinical course independently reviewed optic disk stereophotographs and visual fields taken before and after treatment. Each member of each pair of stereophotographs or perimetry results, which were presented in a random sequence, were graded as better, worse, or unchanged. Of the 75 eyes, 16 (21%) showed a reversal of optic disk cupping; 20 of the 63 visual fields (31%) were classified as improved. In six of 17 eyes (35%) with a change in the disk (better or worse), a corresponding change was also noted in the visual field. The frequency of improvement in optic disk and visual field appearance was significantly (P less than .05) associated with the degree of intraocular pressure reduction.

Reversal of optic disc cupping after glaucoma surgery analyzed with a scanning laser tomograph

Abstract Objective To detect and quantitate changes in optic nerve morphology after glaucoma surgery using the Heidelberg Retina Tomograph (HRT, Heidelberg Instruments, Heidelberg, Germany). Design Nonconsecutive observational case series. Participants and intervention The authors prospectively enrolled 21 adult patients undergoing incisional glaucoma surgery for progressive glaucoma damage. Quantitative analysis of the optic nerve head by scanning laser tomography and automated perimetry were performed before and after glaucoma surgery. Main outcome measures Changes in optic nerve parameters were subjected to linear regression analysis with respect to percent of postoperative reduction of intraocular pressure (IOP), as well as with respect to age, refraction, preoperative cup:disc ratio, and change in visual field parameters. Results Seventeen patients had pre- and postoperative images suitable for analysis. Mean IOP at the time of image acquisition before surgery was 30.5 ± 12 mmHg, and after surgery 11.8 ± 5.2 mmHg (mean follow-up, 26 ± 7 weeks). Eleven of 13 (85%) patients having IOP reduction of greater than 40% showed improvement in optic disc parameters. All four patients with less than 25% reduction in IOP showed worsening of most parameters. Changes in optic disc parameters were highly correlated with percent IOP reduction and with age. The parameters in which change most strongly correlated with percent change of IOP were cup area, rim area, cup:disc ratio, and mean cup depth (each, P P P = 0.025). Conclusion Most patients showing a 40% lowering of IOP after glaucoma surgery show improved optic nerve morphology as measured by the HRT. The amount of improvement correlated highly with the percent reduction of IOP.

Conjunctival Impression Cytology in Patients With Glaucoma Using Long-term Topical Medication

Increasing evidence indicates that long-term use of topically administered medications can induce changes in the conjunctiva and ocular surface. We used the technique of conjunctival impression cytology to evaluate the conjunctival changes that develop with long-term use of topically administered antiglaucoma medications. Patients with glaucoma who were on a stable regimen of one, two, or three topically administered medications were recruited for study; glaucoma suspects who were not using topically administered medications served as controls. Eyes with clinical or historical evidence of external eye disease or conjunctival surgery were excluded. Impression cytology specimens, collected from the bulbar and palpebral conjunctiva, were coded and subsequently graded by a masked observer. We examined specimens from 72 eyes by using this technique. Aggregate scores for the bulbar conjunctiva were compiled, using a previously described grading system with a range of 0 (normal) to 3 (diffuse, severe metaplasia). The results show statistically significant degrees of conjunctival metaplasia associated with the number of glaucoma medications used. These results suggest that the long-term use of antiglaucoma medications induces changes in the conjunctival surface. These changes may be related to the medications themselves, the preservatives in the commercial preparations, or the duration of topical treatment. The clinical relevance of these changes remains unknown.

Clinical agreement among glaucoma experts in the detection of glaucomatous changes of the optic disk using simultaneous stereoscopic photographs.

PURPOSE To evaluate the clinical agreement in the detection of optic disk changes in patients with glaucoma using simultaneous stereophotographs. DESIGN Masked-observer variability study. METHODS Ten glaucoma specialists examined pairs of simultaneous stereophotographs of glaucomatous and control optic disks to determine whether there were changes compatible with progression of glaucomatous damage. RESULTS Intraobserver agreement had a kappa value ranging from 0.55 to 0.78. Interobserver agreement among the glaucoma specialists had a kappa value ranging from 0.34 to 0.68. CONCLUSIONS Clinical examination of stereophotographs to detect optic disk changes in glaucoma patients has limitations associated with suboptimal reproducibility.

Trabeculectomy Is Associated with Retrobulbar Hemodynamic Changes: A Color Doppler Analysis

PURPOSE To determine whether color Doppler hemodynamic changes occur in the retrobulbar circulation after trabeculectomy. METHODS The authors prospectively enrolled 20 patients undergoing trabeculectomy and performed color Doppler imaging of both eyes before surgery and then at approximately 2-, 5-, and 14-week intervals after surgery. The systolic maximum velocity, mean velocity, end-diastolic velocity, and vascular resistance (resistance index) of the central retinal artery, nasal and temporal short posterior ciliary arteries, and ophthalmic arteries were determined. Statistical comparison of the preoperative and postoperative measures were performed on both the operative and nonoperative eye using the paired Students t test. RESULTS A statistically significant increase was observed in the mean and end-diastolic velocity and a significant decrease in the vascular resistance of the central retinal artery and both short posterior ciliary arteries at nearly all postoperative intervals (25 of 27 preoperative and postoperative comparisons; P < 0.05) The ophthalmic artery, while showing an increased velocity at all intervals, only attained a statistically significant increase in one of three postoperative intervals for mean velocity and two of three intervals for end-diastolic velocity (P < 0.05). There were no notable changes in resistance. The nonoperative eye did not show a statistically significant change in velocity or in resistance in the central retinal artery or either nasal or temporal short posterior ciliary artery at any interval (0 of 27 preoperative and postoperative comparisons for mean velocity, end-diastolic velocity, and resistance index.) CONCLUSION Sustained increases in mean velocity and end-diastolic velocity and decreases in resistance index were observed in the central retinal artery and the short posterior arteries with clinically attainable reductions in intraocular pressure after trabeculectomy in patients with chronic glaucoma. These findings are consistent with, but not diagnostic of, increased blood flow through these vessels.