Farkas MH, Grant GR, White JA, Sousa ME, Consugar MB, Pierce EA.
Transcriptome analyses of the human retina identify unprecedented transcript diversity and 3.5 Mb of novel transcribed sequence via significant alternative splicing and novel genes. BMC Genomics 2013;14:486.
AbstractBACKGROUND: The retina is a complex tissue comprised of multiple cell types that is affected by a diverse set of diseases that are important causes of vision loss. Characterizing the transcripts, both annotated and novel, that are expressed in a given tissue has become vital for understanding the mechanisms underlying the pathology of disease. RESULTS: We sequenced RNA prepared from three normal human retinas and characterized the retinal transcriptome at an unprecedented level due to the increased depth of sampling provided by the RNA-seq approach. We used a non-redundant reference transcriptome from all of the empirically-determined human reference tracks to identify annotated and novel sequences expressed in the retina. We detected 79,915 novel alternative splicing events, including 29,887 novel exons, 21,757 3' and 5' alternate splice sites, and 28,271 exon skipping events. We also identified 116 potential novel genes. These data represent a significant addition to the annotated human transcriptome. For example, the novel exons detected increase the number of identified exons by 3%. Using a high-throughput RNA capture approach to validate 14,696 of these novel transcriptome features we found that 99% of the putative novel events can be reproducibly detected. Further, 15-36% of the novel splicing events maintain an open reading frame, suggesting they produce novel protein products. CONCLUSIONS: To our knowledge, this is the first application of RNA capture to perform large-scale validation of novel transcriptome features. In total, these analyses provide extensive detail about a previously uncharacterized level of transcript diversity in the human retina.
Fay A, Nallasamy N, Nallassamy N, Pemberton JD, Callahan A, Wladis EJ, Nguyen J, Durand ML, Durand ML.
Prophylactic postoperative antibiotics for enucleation and evisceration. Ophthalmic Plast Reconstr Surg 2013;29(4):281-5.
AbstractPURPOSE: To investigate the necessity and usefulness of prophylactic postoperative antibiotics in patients undergoing enucleation or ocular evisceration. METHODS: A retrospective, multicenter, comparative case series was designed. After obtaining Institutional Review Board authorization, a medical records' review was conducted. Demographics, indication for surgery, surgical technique, postoperative antibiotic dosing, and postoperative course were evaluated. Records were grouped according to antibiotic protocols, and presence or absence of postoperative wound infection (orbital cellulitis) was recorded. Rates of postoperative infection were analyzed statistically. RESULTS: Between 1996 and 2011, 666 evisceration or enucleation surgeries were conducted at 4 institutions. Six hundred forty-eight records were available for analysis, of which 4 were excluded due to insufficient follow-up data. All the remaining 644 patients received a single, perioperative, intravenous dose of antibiotics. Five hundred seventy-eight patients (90%) received an orbital implant, while 66 (10%) did not. Three hundred eighty-one patients (59%) received postoperative antibiotics, and 263 patients (41%) did not. Two cases were identified with signs suggestive of infection, but no culture-positive infections were found, and no patient was admitted to the hospital for management. Of the 2 suspicious cases, 1 was found in the group that received postoperative antibiotics (group 1) and 1 in the group that did not receive postoperative antibiotics (group 2). No statistically significant difference in postoperative infection rate was noted between the 2 groups (p=0.52). While patients with infectious indications for surgery were more likely to receive postoperative antibiotics (p<0.001), there was no statistically significant difference in rates of infection among patients with infectious indications for surgery based on receiving or not receiving postoperative antibiotics (p=0.79), and no patients with infectious indications for surgery not receiving postoperative antibiotics developed a postoperative infection. CONCLUSIONS: This study demonstrates the clinical safety of withholding postoperative prophylactic antibiotics in orbital surgery even when implanting alloplastic material in a sterile field. Furthermore, Centers for Disease Control and Prevention guidelines mandate cessation of postoperative antibiotics within 24 hours of surgery. Surgeons are cautioned not to generalize these results to nonsterile surgery such as sinonasal or nasolacrimal surgery.
Feke GT, Rhee DJ, Turalba AV, Pasquale LR.
Effects of dorzolamide-timolol and brimonidine-timolol on retinal vascular autoregulation and ocular perfusion pressure in primary open angle glaucoma. J Ocul Pharmacol Ther 2013;29(7):639-45.
AbstractPURPOSE: To assess whether dorzolamide 2%-timolol 0.5% (D/T) and/or brimonidine 0.2%-timolol 0.5% (B/T) alters retinal vascular autoregulation (RVA) and seated ocular perfusion pressure (sOPP) in primary open angle glaucoma (POAG) patients who demonstrate retinal vascular dysregulation (RVD) on timolol 0.5% alone. METHODS: In this prospective, observer-masked, crossover study, 21 POAG patients with untreated intraocular pressure (IOP) >21 mmHg were treated for 6 weeks with timolol 0.5%. Subsequently, we measured inferior temporal retinal artery blood flow in the left eye with subjects seated and then while reclined for 30 min using the Canon Laser Blood Flowmeter. Subjects with a change in retinal blood flow in response to posture change outside of the range previously found in healthy subjects were designated as having RVD and randomized to either D/T or B/T for 6 weeks and re-tested. This was followed by treatment with the opposite medication. RESULTS: Seven of the 21 subjects demonstrated RVD in response to posture change following timolol 0.5%. Multiple linear regression analysis indicated that lower sOPP was the main determinant of RVD (P=0.033). After treatment with D/T, all 7 converted from RVD to normal RVA status (P=0.001). Four of 6 subjects showed a similar return to normal RVA following B/T (P=0.066). Mid-morning sOPP was 41.1±5.5 mmHg post-timolol, 46.3±6.5 mmHg post-D/T, and 38.6±6.0 mmHg post-B/T (D/T vs. B/T, P=0.026). CONCLUSIONS: D/T significantly improved RVA in POAG patients exhibiting RVD while on timolol 0.5% alone. D/T also increased sOPP compared to B/T. There was no significant difference (P=0.37) between D/T and B/T in improving RVA.
Ferrari G, Hajrasouliha AR, Sadrai Z, Ueno H, Chauhan SK, Dana R.
Nerves and neovessels inhibit each other in the cornea. Invest Ophthalmol Vis Sci 2013;54(1):813-20.
AbstractPURPOSE: To evaluate the regulatory cross-talk of the vascular and neural networks in the cornea. METHODS: b-FGF micropellets (80 ng) were implanted in the temporal side of the cornea of healthy C57Bl/6 mice. On day 7, blood vessels (hemangiogenesis) and nerves were observed by immunofluorescence staining of corneal flat mounts. The next group of mice underwent either trigeminal stereotactic electrolysis (TSE), or sham operation, to ablate the ophthalmic branch of the trigeminal nerve. Blood vessel growth was detected by immunohistochemistry for PECAM-1 (CD31) following surgery. In another set of mice following TSE or sham operation, corneas were harvested for ELISA (VEGFR3 and pigment epithelium-derived factor [PEDF]) and for quantitative RT-PCR (VEGFR3, PEDF, and CD45). PEDF, VEGFR3, beta-3 tubulin, CD45, CD11b, and F4/80 expression in the cornea were evaluated using immunostaining. RESULTS: No nerves were detected in the areas subject to corneal neovascularization, whereas they persisted in the areas that were neovessel-free. Conversely, 7 days after denervation, significant angiogenesis was detected in the cornea, and this was associated with a significant decrease in VEGFR3 (57.5% reduction, P = 0.001) and PEDF protein expression (64% reduction, P < 0.001). Immunostaining also showed reduced expression of VEGFR3 in the corneal epithelial layer. Finally, an inflammatory cell infiltrate, including macrophages, was observed. CONCLUSION: Our data suggest that sensory nerves and neovessels inhibit each other in the cornea. When vessel growth is stimulated, nerves disappear and, conversely, denervation induces angiogenesis. This phenomenon, here described in the eye, may have far-reaching implications in understanding angiogenesis.