Do psychedelics change beliefs?

Renewed interest in psychedelics has reignited the debate about whether and how they change human beliefs. In both the clinical and social-cognitive domains, psychedelic consumption may be accompanied by profound, and sometimes lasting, belief changes. We review these changes and their possible underlying mechanisms. Rather than inducing de novo beliefs, we argue psychedelics may instead change the impact of affect and of others' suggestions on how beliefs are imputed. Critically, we find that baseline beliefs (in the possible effects of psychedelics, for example) might color the acute effects of psychedelics as well as longer-term changes. If we are to harness the apparent potential of psychedelics in the clinic and for human flourishing more generally, these possibilities must be addressed empirically.

Comparison of double-plate Molteno and Ahmed glaucoma valve in patients with advanced uncontrolled glaucoma.

BACKGROUND AND OBJECTIVE: To compare double-plate Molteno (DPM) with the Ahmed glaucoma valve (AGV) in the treatment of eyes with complicated glaucoma. PATIENTS AND METHODS: This matched, retrospective, case-control study was based on diagnosis, number of previous operations, and age. There were 30 patients in each group and only patients with a minimum of 6 months follow up were included. Double-plate Molteno or Ahmed glaucoma valve insertion was performed on each patient to control intractable glaucoma. Success was defined as IOP <22 mm Hg and >4 mm Hg on the last two visits, a decrease of no more than 2 lines in the visual acuity, and no additional surgical intervention to control IOP. RESULTS: The Kaplan-Meier estimated probability of success at 12 and 24 months was 73% and 56% with DPM and 60% and 50% for AGV (P = 0.72). Mean IOP measured 13.36 +/- 5.2 mm Hg following DPM and 16.7 +/- 5.6 mm Hg following AGV at 12 months (P = 0.026) and 13.3 +/- 5.1 mm Hg with DPM and 19 +/- 5.8 mm Hg with AGV at 24 months (P = 0.009). Of the patients involved in the study, 83.5% exhibited hypertensive phase (HP) of AGV vs 43.5% of DPM (P = 0.04). AGV had a tendency to fail earlier (5 months +/- 7 following AGV vs 13 months +/- 13 following DPM, P = 0.07, t-test). Patients with either a second valve insertion or valve removal were 7/30 of AGV vs 1/30 in DPM (P = 0.05). Stent removal was needed by 10/30 DPM and 8/30 AGV had needling/5-FU. CONCLUSIONS: The percentage of patients free from failure was similar between the two groups at 36 months. DPM is associated with lower mean IOP in the long term compared to AGV.

Open-angle glaucoma secondary to blood clot in the Schlemm's canal following scleral buckle surgery and its treatment with tPA.

Obstruction of the episceral venous system can present with glaucoma. We present two patients who were referred to us for management of acute glaucoma with presumed episceral venous compression. The first patient had open-angle glaucoma with probable elevated episcleral venous pressure and blood in the Schlemm's canal, following a 360 degrees scleral buckle surgery. The second patient had open-angle glaucoma from delayed peribulbar hemorrhage following uncomplicated cataract surgery with blood in the Schlemm's canal. Both patients were successfully treated with intracameral injection with tissue plasminogen activator (tPA).

Surgical repair of leaking filtering blebs.

PURPOSE: To report the surgical management of leaking filtering blebs occurring after blebitis or persistent hypotony. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Twenty-two eyes of 20 patients with late bleb leak, blebitis or endophthalmitis, hypotony maculopathy, or bleb dysesthesia on presentation to the glaucoma service who required surgical bleb revision from 1990 through 1999. INTERVENTION: Pedicle flap, partial excision, and advancement or free conjunctival autologous graft techniques for surgical bleb revision. Type of bleb revision was dependent on the dimensions of the bleb and quality of surrounding conjunctiva. MAIN OUTCOME MEASURES: Preoperative and postoperative intraocular pressure (IOP), status of bleb leak, reoperation for glaucoma, or requirement for postrevision glaucoma medical therapy, with success defined as the need for two or fewer glaucoma medications after revision. RESULTS: Eighty-six percent (19/22) of eyes that underwent surgical bleb revision had resolution of leak and IOP control using two or fewer medications after one or more bleb revisions. The preoperative IOP (mean +/- standard deviation) was 3.7 +/- 2.6 mmHg (range, 0-8 mmHg). After an average follow-up of 21 months (range, 8-108 months), the IOP was 11.0 +/- 4.4 mmHg for patients taking 0.6 +/- 1.0 glaucoma medications. Eighteen percent (4/22) of eyes required two or more bleb revisions. In one eye, an IOP spike of 36 mmHg developed after revision, which required laser suture lysis on two occasions before the IOP was significantly lowered. The three failures were: one eye that required three or more medications for IOP control, a patient whose eye had a persistent leak after revision and who was not mentally competent to undergo repeat revision, and one eye that required combined glaucoma and cataract surgery after revision. CONCLUSIONS: Surgical bleb revision has a high success rate of closing late bleb leaks, maintaining glaucoma control, and preserving vision, with few postoperative complications. The appropriate surgical procedure for revision must be based on the individual clinical situation and can result in successful bleb revision.

Bleb infections: clinically different courses of "blebitis" and endophthalmitis.

BACKGROUND AND OBJECTIVES: To assess the differences in history, clinical course, and response between five cases of blebitis and three cases of endophthalmitis following mitomycin trabeculectomy. PATIENTS AND METHODS: The authors conducted a retrospective review of eight consecutive cases of bleb-related infection following successful mitomycin trabeculectomy. RESULTS: All patients with blebitis responded to treatment with return of visual acuity and intraocular pressure to preinfection levels. In the three cases of endophthalmitis, one patient underwent enucleation, one had a final visual acuity of counting fingers, and the third had a visual acuity of 20/60. CONCLUSIONS: Blebitis, a limited form of bleb-related infection with thin, cystic, leaky blebs, responds to intensive topical antibiotic treatment, returning visual acuity and IOP to preinfection levels. Bleb-related endophthalmitis causes a more virulent form of bleb-related infection that involves thin- or thick-walled blebs, with or without leakage, and poor visual prognosis despite immediate intensive topical, systemic, and intravitreal antibiotic administration combined with core vitrectomy.

Bleb infections: clinically different courses of "blebitis" and endophthalmitis.

1. Researchers have recently introduced the term "blebitis" to describe a limited form of bleb-related infection (with infection and inflammation limited to the bleb and the peri-bleb area, with or without anterior chamber involvement) in contrast to the more classic form of endophthalmitis. 2. Bleb-related endophthalmitis is the virulent form of bleb-related infection in which patients present with rapidly worsening visual acuity, redness, and pain with diffuse conjunctival congestion, opalescent blebs (with or without epithelial defects) with intense fibrin and/or hypopyon in the anterior chamber, and florid vitritis. 3. Blebitis and bleb-related endophthalmitis are two distinct bleb-related infections, each with different presentations, prognoses, and outcomes. It is important that clinicians recognize this and treat patients accordingly.

Clinical features of five pedigrees genetically linked to the juvenile glaucoma locus on chromosome 1q21-q31.

BACKGROUND: Primary juvenile glaucoma is a rare form of glaucoma that typically affects individuals between 3 and 20 years of ages and is inherited as an autosomal dominant trait. One gene responsible for this condition has been localized to the 1q21-q31 region of chromosome 1. To investigate the clinical features of this form of glaucoma, the authors have examined the affected members of five pedigrees demonstrating genetic linkage to the 1q21-q31 locus. METHODS: Clinical characterization of 23 affected patients was performed. Genetic linkage to the 1q21-q31 locus was confirmed by segregation of the disease trait in each pedigree with genetic markers located in the 1q21-q31 region. RESULTS: The clinical features of affected members of the five pedigrees presented are generally homogeneous. The average age of diagnosis was 18.5 years (range, 5-30 years), and the average initial intraocular pressure was 38.5 mmHg (range, 30-53 mmHg). Eighty-seven percent of affected individuals were myopic and 83% of affected individuals required surgical treatment for glaucoma. There were no uniformly associated systemic or ocular conditions. One possible nonpenetrant carrier was identified and a difference in phenotypic expression of the presumed disease gene was observed in a pair of affected monozygotic twins. We also identified two pedigrees with juvenile glaucoma and three pedigrees affected by the pigment dispersion syndrome that are not genetically linked to the 1q21-q31 region. CONCLUSION: The form of juvenile glaucoma caused by a gene located in the q21-q31 region of chromosome 1 is generally phenotypically homogeneous. The severe elevation of intraocular pressure typically seen in affected patients suggests the product of the predisposing gene may participate in the outflow function of the eye.

Long-term efficacy of argon laser trabeculoplasty. A 10-year follow-up study.

PURPOSE: Argon laser trabeculoplasty (ALT) is commonly used in the treatment of open-angle glaucoma. Varying success rates in lowering intraocular pressure (IOP) and controlling glaucoma are reported in studies with follow-up periods from 1 to 5 years, and few reports are available with follow-up to 10 years. The authors retrospectively reviewed the efficacy of ALT in patients followed up to 10 years. METHODS: Ninety-three patients with open-angle glaucoma underwent 360 degrees ALT. Mean follow-up was 52 +/- 43 months (mean +/- standard deviation; range, 1-132 months). Successful treatment at the time of final follow-up was defined as a decrease in IOP of 3 mmHg or greater from pretreatment level, IOP of 19 mmHg or less, stable visual field, stable optic nerve, and no further laser or surgical intervention. RESULTS: The decrease in IOP was 8.9 +/- 5.4 mmHg at 1 year, 10.0 +/- 4.2 mmHg at 5 years, and 8.9 +/- 5.2 mmHg at 10 years. The probability of success at 1 year was 77%, at 5 years 49%, and at 10 years 32%. Failure was most common in the first year after treatment (23%), and thereafter failure occurred at a rate of 5% to 9% per year. The mean decrease in IOP for all 93 eyes at time of maximum follow-up was 6.1 +/- 7.1 mmHg. CONCLUSION: Argon laser trabeculoplasty is an effective means for reducing IOP in many patients followed for an extended time. However, up to one half of eyes within 5 years of ALT and two thirds of eyes within 10 years may require additional laser or surgical intervention for glaucoma control.

Holmium laser sclerectomy. Success and complications.

PURPOSE: To investigate the safety and efficacy of holmium YAG laser sclerectomy, a new laser filtration procedure. METHODS: The authors performed holmium YAG laser sclerectomy on 49 eyes of 46 patients (mean follow-up, 12.3 +/- 1.1 months). RESULTS: Mean preoperative intraocular pressure (IOP) was 26.9 +/- 1.3 mmHg; postoperative mean IOP on last follow-up visit was 19.7 +/- 1.6 mmHg. Thirty (61%) of 49 eyes achieved a final IOP of 5 to 22 mmHg, 29 (59%) of 49 had a final IOP of 5 to 19 mmHg, and 21 (43%) of 49 had a final IOP of 5 to 15 mmHg. Sixteen (73%) of 22 eyes treated postoperatively with 5-fluorouracil (5-FU) had a final IOP of 21 mmHg or less. Twenty-seven percent of eyes lost one or more lines of vision, and 36% of eyes gained one or more lines of vision; there was no median change in visual acuity. Complications included suprachoroidal hemorrhage in 7 (14%) of 49 eyes and intraoperative vitreous hemorrhage in 2. Seventeen (35%) of 49 eyes required a second IOP-lowering procedure. CONCLUSION: Holmium YAG laser sclerectomy is an effective means to perform glaucoma filtration surgery. This is a full-thickness filtering procedure, with all of the risks attendant.

Management of encapsulated filtration blebs.

Increased intraocular pressure (IOP) in encapsulated filtration blebs was evaluated in 49 eyes of 49 patients followed for 6 to 48 months (mean +/- standard deviation, 19.7 +/- 12.6 months). Intraocular pressure increased from 10.2 +/- 7.5 mmHg at 1 week postfiltration surgery to a peak of 26.1 +/- 10.7 mmHg at 3 weeks postoperatively and then decreased to 16.2 +/- 5.0 mmHg at 16 weeks and remained stable through the follow-up period. Thirty-nine eyes had a final IOP of 19 mmHg or less; 35 eyes required medical therapy alone (antiglaucoma drops, oral carbonic anhydrase inhibitors, and/or digital massage) with a final IOP of 14.1 +/- 3.8 mmHg; and 14 eyes required surgical reintervention for medically uncontrolled IOP elevation, and five of these eyes required two or more surgical reoperative procedures. Vigorous medical therapy, including glaucoma medications, topical steroids, and digital massage, is particularly important for encapsulated blebs during the first 2 months after surgery. After this period, IOP decreases and often remains sufficiently reduced to avoid further surgical intervention.

The effect of anterior chamber depth on endothelial cell count after filtration surgery.

Eighteen patients undergoing glaucoma filtration surgery underwent specular microscopic examination 1 day prior to surgery and 4 to 6 months after surgery. Patients were evaluated postoperatively for the presence of iridocorneal or lenticular-corneal touch, anterior chamber depth, and inflammation. Ten eyes that maintained their anterior chamber following glaucoma filtration surgery did not have a significant decrease in corneal endothelial cell density. However, eight eyes that developed a shallow anterior chamber with iridocorneal touch had a mean (+/- SD) decrease of 265 +/- 185 cells (12.4%) peripherally and 250 +/- 243 cells (11.6%) centrally in corneal endothelial cell count. None of the patients with iridocorneal touch developed corneal edema after a mean follow-up of 44.4 +/- 18.0 months. Iridocorneal touch after glaucoma filtration surgery is associated with loss of endothelial cells yet appears to be well tolerated by the cornea.

Homologous and heterogenous bone grafting in podiatric surgery.

Homologous and heterogenous bone grafting as it might be used in podiatric surgery is reviewed with emphasis on histologic events observed. New bone proliferation, resorption, revascularization, and remodeling are contrasted with autogenous bone grafts, which are generally thought to be the preferred surgical option.

The development of encapsulated filtering blebs.

The development of an encapsulated filtering bleb (Tenon's cyst) complicated 56 of 409 consecutive filtering operations (13.7%) performed during a 40-month period after January 1983. Fifteen eyes (27.8% of encapsulated blebs) required surgical revision. The recognition of bleb encapsulation occurred 20.4 +/- 12.7 days (mean +/- standard deviation) postoperatively. Prolonged duration of beta-adrenergic antagonist therapy was associated with an increased frequency of bleb encapsulation (180.6 +/- 128.5 weeks without encapsulation, 229.0 +/- 129.3 weeks with encapsulation, P less than 0.009). Bleb encapsulation occurred in 42 of 272 eyes with previous argon laser trabeculoplasty, but in only 4 of 85 eyes without any previous anterior segment laser (P less than 0.01). Encapsulated filtering blebs developed in 4 of 12 (33.3%) eyes with congenital glaucoma and 4 of 9 (44.4%) eyes with juvenile glaucoma (P less than 0.0002). The intraocular pressures (IOPs) in the eyes with encapsulated filtering blebs were significantly elevated at 1, 2, and 3 postoperative weeks, and at final follow-up compared with eyes without bleb encapsulation.

Long-term efficacy of argon laser trabeculoplasty.

Long-term efficacy of 360 degrees argon laser trabeculoplasty was studied in 118 eyes of 93 patients with uncontrolled chronic open-angle glaucoma. The mean intraocular pressure (IOP) decrease was 8.9 +/- 5.4 mmHg (mean +/- standard deviation [SD] in 71 eyes at 1 year, 9.3 +/- 4.3 mmHg (mean +/- SD) in 51 eyes at 3 years, and 10.3 +/- 3.9 mmHg (mean +/- SD) in 28 eyes at 5 years. The probability of success at 4 years (decrease in IOP greater than or equal to 3 mmHg, IOP less than or equal to 19 mmHg, stable visual field, stable optic nerve, and no further laser or surgical intervention) was 52%. Pretreatment IOP, diagnosis, previous operations, age, and sex were not significant determinants for success or failure. Eyes receiving argon laser trabeculoplasty before cataract surgery maintained control of IOP after surgery. Failure was most common in the first year after treatment (23%), and thereafter failure occurred at a rate of 7 to 10% per year.

Failed laser trabeculoplasty requiring surgery in open-angle glaucoma.

Argon laser trabeculoplasty (ALT) has been successful in controlling open-angle glaucoma, but a significant number of patients still require filtration surgery. Concern that post-laser inflammatory changes or alterations of structural anatomy with damage to the trabecular meshwork may adversely affect the outcome of filtration surgery prompted a retrospective review of 87 consecutive eyes with open-angle glaucoma that required filtration surgery following failed ALT. The follow-up period was at least 6 months, with a mean of 18 months (6 to 38 months). Posterior lip sclerectomy was chosen for 69 eyes and trabeculectomy for 18 eyes. The overall success rate of filtration surgery during the follow-up period was 92%. There was no recognized difference in the response to filtration surgery following ALT.