A novel pancreatic tumour and stellate cell 3D co-culture spheroid model.

BACKGROUND: Pancreatic ductal adenocarcinoma is a devastating disease with poor outcome, generally characterized by an excessive stroma component. The purpose of this study was to develop a simple and reproducible in vitro 3D-assay employing the main constituents of pancreatic ductal adenocarcinoma, namely pancreatic stellate and cancer cells. METHOD: A spheroid assay, directly co-culturing human pancreatic stellate cells with human pancreatic tumour cells in 3D was established and characterized by electron microscopy, immunohistochemistry and real-time RT-PCR. In order to facilitate the cell type-specific crosstalk analysis by real-time RT-PCR, we developed a novel in vitro 3D co-culture model, where the participating cell types were from different species, human and mouse, respectively. Using species-specific PCR primers, we were able to investigate the crosstalk between stromal and cancer cells without previous cell separation and sorting. RESULTS: We found clear evidence for mutual influence, such as increased proliferation and a shift towards a more mesenchymal phenotype in cancer cells and an activation of pancreatic stellate cells towards the myofibroblast phenotype. Using a heterospecies approach, which we coined virtual sorting, confirmed the findings we made initially in the human-human spheroids. CONCLUSIONS: We developed and characterized different easy to set up 3D models to investigate the crosstalk between cancer and stroma cells for pancreatic cancer.

Validity of code based algorithms to identify primary open angle glaucoma (POAG) in Veterans Affairs (VA) administrative databases.

PURPOSE: The validity of the International Classification of Diseases, 9th revision, Clinical Modification (ICD-9) code for primary open angle glaucoma (POAG) in the Department of Veterans Affairs (VA) electronic medical record has not been examined. We determined the accuracy of the ICD-9 code for POAG and developed diagnostic algorithms for the detection of POAG. METHODS: We conducted a retrospective study of abstracted data from the Michael E. DeBakey VA Medical Center's medical records of 334 unique patients with at least one visit to the Eye Clinic between 1999 and 2013. Algorithms were developed to validly identify POAG using ICD-9 codes and pharmacy data. The positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity and percent agreement of the various algorithms were calculated. RESULTS: For the ICD-9 code 365.1x, the PPV was 65.9%, NPV was 95.2%, sensitivity was 100%, specificity was 82.6%, and percent agreement was 87.8%. The algorithm with the highest PPV was 76.3%, using pharmacy data in conjunction with two or more ICD-9 codes for POAG, but this algorithm also had the lowest NPV at 88.2%. CONCLUSIONS: Various algorithms for identifying POAG in the VA administrative databases have variable validity. Depending on the type of research being done, the ICD-9 code 365.1x can be used for epidemiologic or health services database research.

Evaluation of travoprost as adjunctive therapy in patients with uncontrolled intraocular pressure while using timolol 0.5%.

PURPOSE: To evaluate the intraocular pressure-lowering efficacy and safety of travoprost 0.0015% and 0.004%, dosed daily in the evening compared with vehicle, in patients with open-angle glaucoma or ocular hypertension, whose intraocular pressure was not adequately controlled on timolol 0.5% twice daily (twice daily). METHODS: Subjects who qualified at screening began a run-in period dosing timolol twice daily for 3 weeks. If the subjects had an intraocular pressure of 24 to 36 mm Hg at 8 AM and 21 to 36 mm Hg at 10 AM and 4 pm in at least one eye on timolol, they were randomized to one of two concentrations of travoprost (0.0015% or 0.004%) or vehicle solution every day and were followed for 6 months. Four hundred twenty-six subjects were randomized. The mean intraocular pressure at 8 AM, 10 AM, and 4 PM in the patient's eye with the higher intraocular pressure was used for the analysis. RESULTS: Mean baseline values (25 mm Hg) for subjects at eligibility (while maintained on timolol) were not significantly different (P <.0001) among the treatment groups. The intraocular pressure was lowered an additional -5.7 to -7.2 mm Hg and -5.1 to -6.7 mm Hg in the travoprost 0.004% and 0.0015% concentrations, respectively. These changes were significantly (P < or =.0001) different from the vehicle group (-1.3 to -2.8 mm Hg). The intraocular pressure range on treatment at all visit times over the 6-month treatment period ranged from 17.9 to 19.2 mm Hg for travoprost 0.004% and 18.3 to 20.1 mm Hg for travoprost 0.0015% compared with 22.4 to 24.1 mm Hg for vehicle. Average hyperemia scores ranged from trace to mild (mean 0.5 on a scale of 0 = none/trace; 1= mild; 2 = moderate; 3 = severe) for all treatment groups. No iris pigmentation changes were observed in any patient during this study. There were no clinically or statistically significant changes from baseline in visual acuity, ocular cells and flare, fundus parameter, cup-to-disk ratio and visual field between the treatment groups. There were no serious adverse events reported for any treatment group. CONCLUSIONS: Travoprost produced clinically relevant and statistically significant additional intraocular pressure reductions from baseline when used adjunctively with timolol in subjects with open-angle glaucoma or ocular hypertension.

Central corneal thickness of Caucasians and African Americans in glaucomatous and nonglaucomatous populations.

OBJECTIVE: To determine whether there is a difference in central corneal thickness between African American and Caucasian patients. If present, a difference might alter the measurement of intraocular pressure and potentially the assessment and management of glaucoma in these populations. METHODS: Central corneal thickness was measured by means of ultrasound pachymetry in African American (n = 56) and Caucasian (n = 32) patients with suspected or confirmed glaucoma and control populations of African American (n = 26) and Caucasian (n = 51) subjects in whom there was no evidence of elevated intraocular pressure or glaucomatous optic nerve damage. Measurements of central corneal thickness were then compared between different subpopulations by means and population distribution analysis. RESULTS: A statistically significant difference was noted between the mean (+/-SD) central corneal thickness of all African American (including those with and without glaucoma) (right eye, 531.0 +/- 36.3 microm; left eye, 530.0 +/- 34.6 microm) and all Caucasian (including those with and without glaucoma) (right eye, 558.0 +/- 34.5 microm; left eye, 557.6 +/- 34.5 microm) patients. Similar results were found when subpopulations were tested. Distribution analysis of central corneal thickness measurements noted the largest cluster of African American patients around 520 to 540 microm, whereas the largest cluster of Caucasian patients was between 580 and 600 microm. CONCLUSIONS: African Americans were found to have thinner central cornea thickness measurements than Caucasians. This finding in African Americans may lead to lower applanation intraocular pressure readings compared with those of Caucasians, potentially resulting in an underestimation of the actual level of intraocular pressure.

Effects of atropine on anterior chamber depth and anterior chamber inflammation after primary trabeculectomy.

PURPOSE: To investigate the effects of postoperative atropine on central and peripheral anterior chamber depth and anterior chamber inflammation in patients undergoing primary trabeculectomy. METHODS: Two separate groups of patients who were phakic without previous intraocular surgery undergoing primary trabeculectomy were prospectively randomized to atropine or no atropine. In the first group of patients, 24 eyes of 21 patients undergoing primary trabeculectomy were prospectively randomized to atropine or no atropine, and their anterior chamber depth was measured. Central and peripheral chamber depths were measured using the EAS-1000 anterior segment analysis system (Nidek, Tokyo, Japan) before surgery and on postoperative days 1, 3, 7, 14, and 30. In the second group, 34 patients undergoing primary trabeculectomy were prospectively randomized to atropine or no atropine, and their anterior chamber reaction was documented. The amount of cells and flare was measured using the Kowa laser flare meter (FM-500) and cell counter (LC-500) (Kowa Electronics and Optics, Tokyo, Japan) preoperatively and on postoperative day 1, 7, and 30. RESULTS: Compared with preoperative measurements, a small (approximately 0.1 mm) but statistically significant deepening of the central and peripheral anterior chamber depth on days 1, 7, 14, and 30 was found in patients who used atropine. In the nonatropine group, no statistically significant change was found in central or peripheral anterior chamber depths at any time as compared with preoperative values. There was no statistically significant difference in the cell or flare counts between the atropine and nonatropine groups at any time. CONCLUSIONS: This study showed a small but statistically significant deepening of the anterior chamber with atropine. No statistically significant differences were observed in the cell or flare counts between atropine and nonatropine groups. Routine atropine use after trabeculectomy may not be necessary to reduce postoperative complications, such as shallowing of the anterior chamber or anterior chamber inflammation. In patients with a shallow anterior chamber, however, atropine would be expected to deepen the chamber.

Incidence of brimonidine allergy in patients previously allergic to apraclonidine.

PURPOSE: This study was performed to determine the incidence of allergic reaction to brimonidine in patients who have previously demonstrated an allergic reaction to apraclonidine. METHODS: A retrospective chart review was performed to identify patients who had demonstrated an allergic reaction to apraclonidine of sufficient severity to result in drug discontinuation. Within this group, those patients subsequently treated with brimonidine were isolated and analyzed, and the incidence of allergy to brimonidine was determined. RESULTS: Forty-five patients were identified with a significant allergic reaction to apraclonidine that resulted in drug discontinuation. Of these patients, 22 subsequently received brimonidine. Follow-up on all patients was obtained for at least 15 months. All but two of the 22 patients were taking additional topical glaucoma medications, ranging from one to three additional agents with an average of 1.8+/-0.8 medications. Seventeen patients incurred no allergic reaction to brimonidine. Only five patients (22.7%) previously allergic to apraclonidine developed an allergic reaction to brimonidine. Three of these patients demonstrated only a follicular conjunctival reaction, one had conjunctival hyperemia, and one patient developed a periocular dermatitis. The allergic reactions developed at 8.2+/-1.2 months after initiation of brimonidine therapy. CONCLUSIONS: In this study, the risk of developing an allergic reaction to brimonidine in patients known to be allergic to apraclonidine is 22.7%. This lack of a strong cross-reactive allergic response possibly suggests different allergic mechanisms for these two medications. Therefore, brimonidine therapy in patients previously identified as being allergic to apraclonidine is safe and does not result in a cross-reactive response in the great majority of patients (or in nearly four of five patients).

Acquired Pseudo-Brown's syndrome immediately following Ahmed valve glaucoma implant.

A 76-year-old woman noted vertical and horizontal diplopia one day following placement of an Ahmed valve in the superonasal quadrant of her left eye. She was unable to elevate her left eye, especially in adduction. She refused implant removal and strabismus surgery alone failed to satisfactorily resolve her problem. On forced duction testing, the implant became wedged between the globe and orbit superonasally. Subsequent repositioning of the valve resulted in resolution of her motility problem. Implant-orbital disproportion can produce a pseudo-Brown's syndrome. Surgeons are encouraged to perform forced duction testing at the time of glaucoma implant placement to detect and prevent this complication.

Bilateral optic disk edema caused by sarcoidosis mimicking pseudotumor cerebri.

PURPOSE: To present a case of retrobulbar optic nerve and chiasm sarcoidosis that mimicked pseudotumor cerebri. METHODS: A 34-year-old, thin, black woman presented with transient visual obscurations, normal visual acuity, bilateral optic disk edema, and enlarged blind spots. Clinical, medical, and radiologic evaluations were consistent with pseudotumor cerebri. The patient improved while taking acetazolamide, but 6 months later her symptoms worsened. Neuroimaging disclosed enhancement of the optic nerve and chiasm. RESULTS: Despite administration of intravenous corticosteroids, the patient's vision worsened. Bilateral optic nerve sheath fenestrations were performed, and pathology disclosed sarcoidosis. CONCLUSION: Sarcoidosis of the optic nerves and chiasm may mimic pseudotumor cerebri.

Clinical experience with apraclonidine 0.5%.

PURPOSE: This study describes our long-term experience with apraclonidine 0.5% in the treatment of chronic glaucoma in clinical practice. METHODS: A retrospective review was performed of all consecutive patients treated with apraclonidine 0.5%, specifically studying the magnitude of IOP reduction, incidence of allergic reaction, frequency of ineffectiveness, and its additivity to other anti-glaucoma medications. Patients previously treated with this agent or in whom multiple simultaneous medication changes were made were excluded. RESULTS: A total of 174 patients were included in this study and followed up to 24 months. For 38 patients (21%), the drug was found to be ineffective at some point during the study. A similar number of patients developed an allergic reaction to the medication. Intraocular pressure lowering ranged from 19 to 26% overall, and 22.5 to 29% in those responding to apraclonidine 0.5%. CONCLUSION: In this study, apraclonidine 0.5% was shown to be effective in reducing intraocular pressure, both for short-term situations and for longer periods of treatment, up to 24 months.

Acquired supranuclear ocular motor paresis following cardiovascular surgery.

Acquired supranuclear ocular motor paresis is a rare disorder characterized by impaired saccadic and smooth pursuit eye movements in one or more directions of gaze. Vestibularly induced eye movements, however, are preserved. Six adult patients developed an acquired supranuclear ocular motor paresis following cardiopulmonary bypass surgery. Neuroimaging studies were normal in two patients and were consistent with small vessel ischemia in four patients. The mean cardiopulmonary bypass time was 132.3 min, and mean circulatory arrest time was 38.7 min; these were not outside established norms for this type of surgery. Patients undergoing cardiopulmonary bypass procedures with deep hypothermia are at risk for acquired supranuclear ocular motor paresis, but the development of this syndrome may not be predictable by duration of circulatory arrest or cardiopulmonary bypass times.

Early successful treatment of postoperative necrotizing pseudomonas scleritis after trabeculectomy.

PURPOSE: The authors describe a patient who developed pseudomonas scleritis after a routine trabeculectomy. METHOD: The patient underwent trabeculectomy for poorly controlled intraocular pressure and progressive visual field loss. On the second postoperative date he developed severe pain, significant anterior chamber reaction, and hypotony. Scleral cultures taken at the time of surgical choroidal drainage grew pseudomonas aeruginosa. RESULT: Surgical reconstruction of the necrotic scleral area and intensive antibiotic treatment lead to a successful outcome. CONCLUSION: Early recognition and aggressive treatment with antibiotics initially, followed by surgical debridement of necrotic tissue, resulted in an unexpected successful outcome in a patient with pseudomonas scleritis.

Picosecond neodymium:yttrium lithium fluoride (Nd:YLF) laser peripheral iridotomy.

PURPOSE: We evaluated the picosecond neodymium:yttrium lithium fluoride (Nd:YLF) laser for performing peripheral iridotomies of predetermined size and shape in various types of irides. METHODS: In the first part of the study, we determined operating parameters from performing 60 iridotomies in human cadaver eyes. Subsequently, using the parameters obtained in cadaver eyes, iridotomies were created in eyes of patients with primary angle-closure glaucoma. RESULTS: In the cadaver eyes, the optimal parameters were a rectangular cutting pattern of 0.3 x 0.3 mm, 500-microns cutting depth, 50-microns spot separation, 200 to 400 microJ of energy per pulse, 200 to 400 pulses per second, and no focal offset distance. In 18 eyes of 11 patients, iridotomies with well-defined margins and size were created. Minimal hemorrhage occurred intraoperatively in ten of 18 eyes (55.6%), which did not affect the outcome of the procedure. Increases of postoperative intraocular pressure at one hour averaged 3.5 +/- 5.1 mm Hg, with an increase of more than 10 mm Hg in three eyes (16.7%), and a maximum of 12 mm Hg. We observed no corneal or retinal damage. CONCLUSION: The picosecond Nd:YLF laser seems to be an effective instrument for reliably performing peripheral iridotomies of precise size and shape using low energy per pulse levels. This laser, unlike the argon laser, is successful independent of iris thickness or color and can easily make a larger iridotomy than is often possible with the Nd:YAG laser.

Gonioscopic ab interno Nd:YLF laser sclerostomy in human cadaver eyes.

We explored the potential of the picosecond Nd:YLF laser to perform gonioscopic ab interno sclerostomy in human cadaver eyes. Full-thickness sclerostomies were created in 12 such eyes and confirmed by external scleral and histopathologic examination. Optimum parameters for successful completion of a sclerostomy were: a rectangular pattern of 0.3 mm by 0.3 mm, a repetition rate of 1000 pulses per second, an energy-per-pulse of 400 mJ, and a spot separation between 10 and 50 microns, with no focal offset. The Nd:YLF laser reliably created successful gonioscopic sclerostomies with minimal adjacent thermal damage in human cadaver eyes.

Low mature TGF-beta 2 levels in aqueous humor during uveitis.

PURPOSE: To investigate whether transforming growth factor-beta 2 (TGF-beta 2), a strong immunosuppressive factor normally present in aqueous humor, is involved in the inflammatory process of clinical uveitis. METHODS: Mature TGF-beta 2 levels were determined in aqueous humor samples of 9 patients with Fuchs' heterochromic cyclitis, aqueous humor samples of 21 patients with other uveitis entities, and vitreous fluid samples of 19 patients with uveitis by using a commercially available sandwich ELISA: Total TGF-beta 2 levels in ocular fluids were measured after heat activation. Aqueous humor samples from patients with cataract and glaucoma and vitreous fluid samples from eye bank eyes were tested as controls. Albumin levels, determined by radial immunodiffusion, were used as a measure of the disruption of the blood aqueous barrier. RESULTS: Significantly lower mature TGF-beta 2 levels were detected in aqueous humor samples of patients with uveitis, compared to the two control groups without intraocular inflammation. Samples of patients with uveitis without detectable mature TGF-beta 2 did contain latent TGF-beta 2 levels (504 to 6024 pg/ml). In aqueous humor, there was a significant negative correlation between mature TGF-beta 2 and albumin levels. No mature TGF-beta could be detected in vitreous fluid. Total TGF-beta 2 levels in vitreous fluid were significantly lower in samples from patients with uveitis than in samples from eye bank eyes. CONCLUSION: These results indicate that the mature TGF-beta 2 levels in aqueous humor and the total TGF-beta 2 levels in vitreous fluid are reduced during ocular inflammation. In aqueous humor, this might be caused by binding of mature TGF-beta to serum proteins, for instance, alpha 2-macroglobulin, or by a disturbance in the activation process of latent TGF-beta 2.

A human cadaver eye model for anterior and posterior segment laser applications.

We have developed a cadaver eye model that allows anterior and posterior segment laser procedures to be performed under closely simulated in vivo conditions. The model consists of a reusable container with an artificial cornea with a refractive power and an anterior radius of curvature similar to those of the human cornea, and a fresh cadaver eye, prepared by removing the cornea and adjusting the biometric parameters to normal values. This cadaver eye model appears to be a valuable tool for teaching and practicing anterior and posterior segment laser procedures, as well as for research on new laser systems and applications.

Wound healing modulation in glaucoma filtration surgery.

In some cases, modulation of wound healing, in association with glaucoma filtration surgery, results in lower postoperative intraocular pressures than would occur without such therapy. Treatments affecting wound healing increase the likelihood of achieving long-term filtration, especially in eyes with a poor surgical prognosis. After summarizing the wound-healing process following filtration procedures, we review the mechanism of action, the effectiveness, and the complications associated with some of the most commonly used wound healing inhibitors and then discuss new alternatives currently under investigation. Although much progress has been made, the challenge remains to develop new drugs or combinations of drugs that are less toxic and can yield more predictable results.