Simulation for Teaching on Racial Microaggressions and Bystander Intervention - A Theory-Based Guide for Health Profession Education.

Microaggressions are words or behaviour that "subtly and unconsciously express a prejudiced attitude", and racial microaggressions express these attitudes towards people from racial minority groups. The "Bystander Effect" is when the presence of other people means that an individual is less likely to offer assistance or get involved in a situation - bystander intervention training aims to inform about the best ways to avoid this, equipping students with the necessary strategies. In health profession education, teaching on microaggressions and bystander intervention can be done with the use of simulation. Simulated patients (SPs) and environments would be the most appropriate modality of simulation to use, as roleplay would be central. This guide focuses on how to use simulation for teaching on racial microaggressions and bystander training for healthcare students including tips on preparing the students and SPs, planning for the implementation of the simulation training, setting ground rules, showing different scenarios, checking student understanding throughout, using debriefs and course evaluation feedback, and signposting students to available support afterwards. These are topics which are particularly relevant because there have been calls in recent years for healthcare education to be more inclusive and representative of current issues, as the COVID-19 pandemic and resurgence of the Black Lives Matter movement have highlighted curriculum gaps. So teaching students about this early is a good start, and simulation is an effective teaching method to help with this.

Corneal tomography and biomechanics in primary pterygium.

PURPOSE: To study the Scheimpflug's imaging and corneal biomechanics in primary pterygium. METHODS: A prospective observational study of 55 patients with unilateral primary nasal pterygium was done. The normal fellow eyes of patients with pterygium were taken as controls. Clinical parameters noted included visual acuity, values of corneal curvature by doing Scheimpflug imaging, wavefront aberrations in terms of higher and lower-order aberrations and corneal hysteresis (CH) as well as corneal resistance factor (CRF) values by using ocular response analyzer. RESULTS: Of the total 55 patients, mean age was 43.0 + 11.4 years (range: 20-72 years). Mean LogMar uncorrected visual acuity in pterygium eyes and control eyes was 0.21 + 0.20 and 0.12 + 0.15, respectively (p = 0.016). On Scheimpflug imaging the mean anterior corneal curvature values (Ka1/Ka2 D) were 41.09 + 3.38/44.33 + 2.29 in pterygium eyes, 43.13 + 1.79/43.98 + 2.17 in control eyes (p < 0.0005) and mean posterior corneal curvature (Kp1/Kp2 D) values were 6.14 + 0.39/6.53 + 0.43 in pterygium eyes and 6.13 + 0.28/6.46 + 0.47 in control eyes (p > 0.05). Analysis of corneal aberrations showed significantly higher corneal wavefront aberrations in pterygium eyes. Highest correlation of corneal astigmatism was noted with corneal area encroached by pterygium (ρ = 0.540 for LOA and 0.553 for HOA) and distance from pupillary center (ρ = 0.531 for LOA and 0.564 for HOA). Corneal biomechanical parameters including CH and CRF were found to be lower in the pterygium eyes, though not statistically significant (p value 0.60 and 0.59, respectively). CONCLUSION: Pterygium leads to deterioration of visual performance not only by causing refractive and topographic changes but also by causing a significant increase in corneal wavefront aberrations.

Diabetes Type 4: A Paradigm Shift in the Understanding of Glaucoma, the Brain Specific Diabetes and the Candidature of Insulin as a Therapeutic Agent.

In the present analysis, we aim at probing into many important mechanisms that serve to bridge conceptual gaps to fill up the mosaic of a picture revealing that glaucoma indeed is brain specific diabetes and more appropriately "Diabetes Type 4". Based on this conceptual substance, we weave a novel idea of insulin being a potential remedy for glaucoma. This analysis synthesizes upon the published literature on brain changes in glaucoma, possibility of isolated brain diabetes, insulin signaling glitches in glaucoma pathology, mitochondrial dysfunction and insulin resistance in glaucomatous eyes, insulin mediated regulation of intraocular pressure and its dysregulation in mitochondrial dysfunction. We also look into the role of amyloidopathy and taupathy in glaucoma pathogenesis vis-à-vis insulin signaling. At every step, the discussion reveals that insulin and other allied moieties are a sure promise for glaucoma treatment and management. In this article, we aim at synthesizing a persuasive and all inclusive picture of glaucoma etiopathomechanism centered on "insulin-hypofunctionality" in the central nervous system (i.e. brain specific diabetes). We start with considering the possibility of neurodegenerative diabetes that exists independent of the peripheral diabetes. Once that condition is met, then a metabolic conglomeration of this brain specific diabetes is deliberated upon leading us to understand the development of retinal ganglion cell apoptosis, intraocular pressure elevation, optic cupping and mitochondrial dysfunction. All these are the hallmarks and sufficient conditions to satisfy the diagnostic criteria for glaucoma. Immediate application of this analysis points towards glaucoma therapy centered upon improving what we have termed insulin-hypofunctionality.

Topical cyclosporine to control ocular surface disease in patients with chronic glaucoma after long-term usage of topical ocular hypotensive medications.

PURPOSE: To evaluate changes in ocular surface and central corneal sub-basal nerve fiber layer (SBNFL) after topical cyclosporin therapy in chronic glaucoma patients on long-term topical antiglaucoma therapy. METHODS: A prospective comparative study of ocular surface evaluation of chronic glaucoma patients on long-term topical therapy treated concurrently with a topical cyclosporine 0.05% twice daily for 6 months and controls was done. The study parameters evaluated at recruitment and at the 6-month follow-up included details of topical antiglaucoma medications, visual acuity, intraocular pressure, ocular surface evaluation parameters (TBUT, Schirmers I, ocular surface staining scores and ocular surface disease (OSD) index score (OSDI)), central corneal sensation (Cochet Bonnett aesthesiometer), and central confocal microscopy to study the SBNFL density (SBNFLD). RESULTS: Thirty-two eyes of 16 patients with chronic glaucoma and 30 eyes of 15 normal subjects as controls were studied. Mean TBUT, pre/post CsA treatment was 8.67±3.01/12.24±1.83 s (P=0.007). Mean conjunctival/corneal staining scores pre/post CsA treatment were 3.38±1.93/1.50±0.718 (P=0.00) /5.19±1.82/1.81±0.78 (P=0.098), respectively. Mean OSDI pre/post CsA treatment scores were 30.63±14.61/14.76±6.06 (P=0.007). Mean corneal sensations scores pre/post CsA treatment were 4.64±0.46/4.94±0.39 (P=0.002). Central corneal SBNFLD pre and post CsA treatment was 8811.35±2985.29/10335.13±4092.064 µm/mm(2) (P=0.0001). CONCLUSIONS: Schirmer's test, ocular surface staining scores, OSDI, corneal sensations, and corneal SBNFLD showed a statistically significant improvement following a 6-month concurrent topical CsA therapy.

Circadian cycle-dependent EEG biomarkers of pathogenicity in adult mice following prenatal exposure to in utero inflammation.

Intrauterine infection or inflammation in preterm neonates is a known risk for adverse neurological outcomes, including cognitive, motor and behavioral disabilities. Our previous data suggest that there is acute fetal brain inflammation in a mouse model of intrauterine exposure to lipopolysaccharides (LPS). We hypothesized that the in utero inflammation induced by LPS produces long-term electroencephalogram (EEG) biomarkers of neurodegeneration in the exposed mice that could be determined by using continuous quantitative video/EEG/electromyogram (EMG) analyses. A single LPS injection at E17 was performed in pregnant CD1 dams. Control dams were injected with same volumes of saline (LPS n=10, Control n=8). At postnatal age of P90-100, 24-h synchronous video/EEG/EMG recordings were done using a tethered recording system and implanted subdural electrodes. Behavioral state scoring was performed blind to treatment group, on each 10s EEG epoch using synchronous video, EMG and EEG trace signatures to generate individual hypnograms. Automated EEG power spectrums were analyzed for delta and theta-beta power ratios during wake vs. sleep cycles. Both control and LPS hypnograms showed an ultradian wake/sleep cycling. Since rodents are nocturnal animals, control mice showed the expected diurnal variation with significantly longer time spent in wake states during the dark cycle phase. In contrast, the LPS-treated mice lost this circadian rhythm. Sleep microstructure also showed significant alteration in the LPS mice specifically during the dark cycle, caused by significantly longer average non-rapid eye movement (NREM) cycle durations. No significance was found between treatment groups for the delta power data; however, significant activity-dependent changes in theta-beta power ratios seen in controls were absent in the LPS-exposed mice. In conclusion, exposure to in utero inflammation in CD1 mice resulted in significantly altered sleep architecture as adults that were circadian cycle and activity state dependent.

Laparoscopic treatment of endometriosis and effects on quality of life: a retrospective study using the short form EHP-5 endometriosis specific questionnaire.

Complete surgical eradication is considered the mainstay of treatment for endometriosis. The aim of the present study was to investigate patients' own assessment of whether their laparoscopic treatment made a difference to their quality of life, as well as to assess local recurrence rates. We performed a retrospective analysis of 49 women who had laparoscopic treatment for endometriosis at our unit between 1 January 2008 and 1 January 2010. Patients were sent the Short Form EHP-5 questionnaire and asked to score their quality of life in relation to endometriosis symptoms, prior to the surgery and up to 48 months afterwards. Subgroup analysis of stage I/II and stage III/IV disease was performed as well as stratification of the period post-operation into 12-24, 25-36 and 37-48 months for follow-up analysis. Overall, the patients reported improvement in quality of life scores with a significant drop in mean scores from 46.9 pre- to 27.5 post-surgery, signifying benefits from the surgical intervention. All subgroups reported improvement in quality of life scores. The overall symptom recurrence rate was 18.3%. We conclude that patients, post-laparoscopic treatment of endometriosis, experience significant improvement in their quality of life, regardless of stage and this can be quantified and qualified.

Outcome of phacoemulsification in eyes with cataract and cornea opacity partially obscuring the pupillary area.

OBJECTIVE: To evaluate the intra-operative difficulties and postoperative visual outcome following phacoemulisification and intraocular lens (IOL) implantation in eyes with cataract and a coexisting corneal opacity partially obscuring the pupillary area. MATERIALS AND METHODS: The study included 205 eyes of 205 patients with cataract, an extensive corneal opacity partially obscuring the pupillary area and a corrected distance visual acuity (CDVA) of less than 40/200 who had undergone phacoemulisification with IOL implantation by a single surgeon. The patients were followed up on day 1, day 7, 1 month and 3 months postoperatively. Intra-operative and post operative course and CDVA were evaluated. RESULTS: Seventy nine percent of the patients underwent phaco-emulsification via superior clear corneal approach while the rest were operated via temporal clear corneal approach. Trypan blue (0.06%) dye assisted capsulorrhexis was successfully completed in all eyes with additional maneuvers including posterior synechiolysis and sphincterotomy. Nucleotomy with primary chop technique and phacoemulsification were performed uneventfully in all but one eye, which was converted to an extra capsular cataract extraction (ECCE). A foldable intraocular lens was implanted in 76 eyes, rigid IOL in 128 eyes and 1 eye was left aphakic. The pre-operative CDVA of less than 40/200 improved to 20/60 at the end of 3 months follow up. CONCLUSIONS: Phacoemulsification and intraocular lens implantation provides ambulatory and useful vision in eyes with coexisting cataract and corneal opacity.

Trypan blue staining of filtering bleb in eyes with operate trabeculectomy.

OBJECTIVE: To report the use of trypan blue staining of the filtering bleb to assess its functional status in eyes undergoing phacoemulsification after trabeculectomy. SUBJECTS AND METHODS: This retrospective study was conducted at a tertiary eye care centre in North India and studied 33 eyes of 33 patients ( with previously operated trabeculectomy), who underwent phacoemulsification. Trypan blue dye (0.06%) was used to stain the anterior capsule. After completion of phacoemulsification, the staining of the trabeculectomy bleb was noted as diffuse, patchy, minimal or no staining. RESULTS: Of the 33 eyes, 13 had diffuse staining (39.4%, mean IOP = 9.3 ± 2.2 mm Hg), 7 (21.2%, mean IOP= 15.5 ± 1.8 mm Hg) had patchy staining, 4 had minimal staining (12.1%, mean IOP= 17.5 ± 0.5mm Hg) and nine (27.3%, mean IOP= 19.3 ± 1.6 mm Hg) had no staining. These staining patterns were labeled as groups 1 - 4 respectively. Statistical analysis showed that the difference between the IOPs in Group 1 - 2 and between Group 2 - 3 was not significant statistically (p=0.682 and 0.665 respectively). However the differences between the IOPs between Groups 1 - 3, 1 - 4, 2 - 4, and 3 - 4 were found to be highly significant statistically (p less than 0.0005). CONCLUSIONS: Trypan blue dye can be used to test the amount of sub conjunctival filtration in eyes undergoing phacoemulsification cataract surgery.

Repositioning of Ahmed glaucoma valve tube in the anterior chamber with prolene sutures to manage tube-endothelial touch.

BACKGROUND: Corneal endothelial damage is a known complication of aqueous shunt surgery. OBJECTIVE: To describe a new technique for repositioning the Ahmed glaucoma valve tube in a case of tube-endothelial touch. CASE: A patient with advanced glaucoma, having undergone Ahmed glaucoma valve (AVG) implantation, developed localized corneal endothelial damage due to contact between the tube and superior corneal endothelium. Two 10-0 prolene anchor sutures were passed over the tube in the anterior chamber, repositioning it away from the endothelium, thus preventing further damage to the corneal endothelium. Resolution of corneal oedema was noted without affecting the tube drainage and intraocular pressure. CONCLUSION: Intracameral repositioning of the shunt tube using prolene sutures is a useful technique for correcting the tube malposition.

Does an iridotomy provide protection against narrowing of the anterior chamber angle during Valsalva maneuvre in eyes with primary angle closure.

PURPOSE: To evaluate changes at the anterior chamber angle during Valsalva manoeuver, in eyes having primary angle closure (PAC) and a patent laser peripheral iridotomy. METHODS: Twenty-three eyes of 23 consecutive patients underwent a recording of applanation tonometry, measurement of the anterior chamber angle recess, angle opening distance, iris thickness, anterior chamber depth, and pupil size on ultrasound biomicroscopy before and during the Valsalva maneuver. The Valsalva manoeuver was standardized to a pressure of 40 mmHg for 15 s, using a manometer. RESULTS: The mean baseline intraocular pressure changed from 18.86+3.79 to 26.73+4.73 mmHg during Valsalva, (P<0.0001). The anterior chamber angle recess narrowed from 16.62+6.24 to 6.5+4.02 degrees (P<0.0001). There was a significant increase in the thickness of the ciliary body from 0.92+0.25 to 1.17+0.31 mm (P=0.0006) and in the iris thickness from 0.47+0.17 to 0.57+0.11 mm (P=0.007). A significant increase in pupillary diameter (P=0.008) and a decrease in the angle opening distance (P<0.0001) also occurred during Valsalva, whereas there was no significant change in the anterior chamber depth (P=0.056). The angle recess during Valsalva had a positive correlation with the baseline anterior chamber angle (r=0.41, P=0.05) and a negative correlation with the ciliary body thickness (r=-0.52, P=0.046). CONCLUSIONS: The induction of Valsalva maneuver in day-to-day activities can lead to significant anterior segment angle shallowing and can lead to progression from the PAC stage to primary angle closure glaucoma in such predisposed eyes. The presence of a patent laser iridotomy may not prevent irido trabecular apposition during the Valsalva maneuver.

Is the ISNT rule violated in early primary open-angle glaucoma--a scanning laser tomography study.

AIMS: To evaluate the relevance of the ISNT rule with reference to the optic nerve head, in differentiating normal and early glaucoma eyes and neuroretinal rim (NRR) area ratios as measures of glaucomatous optic neuropathy by confocal scanning laser ophthalmoscopy (Heidelberg retina tomography (HRT) II). METHODS: The study included 136 control eyes and 63 eyes of early primary open-angle glaucoma. Each patient underwent a complete ophthalmic examination, HRT II (software 2.01) and achromatic automated perimetry using the Humphrey field analyzer Full threshold program 30-2 or 24-2. Topographic HRT parameters (disc area and rim area) were compared between the groups. To assess the statistical significance of differences between the study groups, the Student's t-test was used. RESULTS: The ISNT rule was applicable in 71% of normal eyes and 68% of early glaucoma eyes. The superior to inferior area ratio was 0.96+/-0.01 in the normal group and 0.90+/-0.02 in the glaucoma group. There was a loss of approximately a quarter of the NRR in the inferotemporal and superotemporal quadrants. The inferonasal sector showed the least loss of NRR (4.34%). CONCLUSION: The inferior NRR is marginally wider than the superior NRR in about 2/3 of normal eyes, but could not be clinically appreciated in many of these. The characteristic configuration of a normal optic disc with the rim width being greatest in the inferior disc region followed by the superior disc region was maintained even in most patients with early glaucoma.

Prospective, long-term evaluation of steroid-induced glaucoma.

PURPOSE: To evaluate the intraocular pressure (IOP) after cessation of steroid use in steroid-induced glaucoma and its control with medication or surgery. METHODS: Thirty-four eyes of 34 patients having steroid-induced glaucoma were prospectively evaluated after cessation of steroid for IOP, visual acuity, and optic disc status at 3 months, and every 3 months for 18 months. RESULTS: Topical steroid use (73.5%) was the most frequent cause for glaucoma. The baseline IOP was 35.47+/-12.59 mmHg. The baseline vertical cup-disc ratio correlated with duration of steroid use (P=0.014) and the baseline IOP (P<0.0001). In 25 patients (73.5%), IOP could be controlled by topical medications alone, whereas nine patients (26.5%) required surgery. The mean baseline IOP in eyes requiring surgery was 49.67+/-13.28 mmHg and in eyes managed medically, 30.36+/-7.51 mmHg (P=0.002). The vertical cup-disc ratio in surgically treated patient was 0.87+/-0.13:1 as compared to 0.71+/-0.15:1 (P=0.012) in the medically treated group. At 6, 12, and 18 months follow-up, 22 (64.7%), 33 (97.1%), and all 34 (100%) patients were off treatment, respectively. CONCLUSIONS: Patients with steroid-induced glaucoma, who were

Study of biometric parameters in family members of primary angle closure glaucoma patients.

OBJECTIVES: To measure ocular biometric parameters in all possible untreated family members of index primary angle closure glaucoma (PACG) patients and to correlate these values among affected, unaffected, and suspected family members. METHODS: Anterior chamber depth (ACD), axial length (AL), lens thickness (LT), relative lens position, and central corneal thickness (CCT) were measured in first- and second-degree relatives of index patients. These biometric parameters were compared among the relatives and index patients as well as among affected, unaffected, and suspected family members. RESULTS: Of the 108 family members included in the study, 34 (31.6%) were affected with primary angle closure, 19 (17.6%) were suspect, and 55 (50.7%) were unaffected family members. In comparison to index cases, ACD was 14.56% more in affected, 21.7% more in primary angle closure suspects and 34.92% more in unaffected family members. LT was 10.73, 11.1, 16% less and AL was 0.11, 3.53 and 5.37% more in affected, suspected, and unaffected family members, respectively. Lens position and CCT were not statistically different in the various subgroups. CONCLUSIONS: ACD is narrowest, lens thickest, and AL shortest in family members affected with PACG compared to suspected and unaffected members. Although LT and ACD could change with advancing age, AL appears to be a marker to identify members at risk of angle closure glaucoma.

Corneal topographic response to intraocular pressure reduction in patients with vernal keratoconjunctivitis and steroid-induced glaucoma.

PURPOSE: To study the corneal topographic response to IOP reduction in vernal keratoconjunctivitis (VKC) with steroid-induced glaucoma. METHODS: A total of 42 eyes of 21 patients with VKC and steroid-induced glaucoma (Group I) and 66 eyes of 33 patients with VKC without glaucoma (Group II) underwent an evaluation by Orbscan topography. In eyes with glaucoma, the IOP was controlled medically and the corneal topography was repeated at 3 months to evaluate effect on corneal parameters. RESULTS: The mean baseline IOP was 36.40+/-13.08 mmHg in Group I, 14.67+/-4.62 mmHg in Group II (P<0.0001). The IOP after treatment at 3 months follow-up was 15.00+/-5.41 mmHg in Group I (P<0.0001). In Group I, the mean maximum Sim K decreased from 44.86+/-3.21 D to 43.87+/-2.62 D (P=0.031) and mean posterior corneal elevation decreased from 64.9+/-22.36 microm to 35.7+/-28.91 microm at 3 months after reduction of IOP (P=0.001). There was a significant positive correlation between the reduction in the IOP and the decrease in the posterior corneal elevation (r=0.664, P=0.001). CONCLUSION: Eyes with VKC with and without glaucoma have similar corneal topography. Increased IOP associated with steroid-induced glaucoma and VKC may contribute to an increase in the corneal curvature and posterior corneal elevation. These changes may be reversed by a reduction in the IOP with medical therapy.

Phacoemulsification with nondominant hand.

PURPOSE: Evaluation of on axis phacoemulsification surgery through temporal incision using nondominant hand with surgeon sitting at the head end, inpatients with against-the-rule astigmatism. METHODS: Eighty eyes of 80 patients who underwent phacoemulsification through a temporal clear corneal tunnel for age-related cataract and against-the-rule astigmatism were enrolled and divided into four equal groups. In Group 1A, the surgeon was sitting at the head end for the left eye performing surgery with the left hand (nondominant hand). In group 1B, the surgeon was seated at the temporal side and surgery was performed in the left eye with dominant right hand. In group 2A, the surgeon was sitting at the head end for the right eye and performed surgery holding the phacoemulsification hand piece in his right hand. In group 2B, the surgeon sat on the temporal side of the right eye and performed phacoemulsification with his right hand. The patients were followed up on day 7, 1 month, and 3 months. Parameters evaluated included average phaco power, effective phaco time, uncorrected and best-corrected visual acuity, keratometry, intraocular pressure, surgically induced astigmatism, pachymetry, and endothelial cell counts. RESULTS: The phaco time and phaco power among the four groups were comparable (phaco time: P=0.368; phaco power: P=0.294). The four groups were also comparable on parameters like surgically induced astigmatism (P=0.674), change in postoperative keratometric astigmatism (P=0.584), endothelial cell loss (0.921), change in ultrasonic pachymetry (P=0.476), and intraocular pressure (P=0.942). No intraoperative or postoperative complications were observed in any of the groups. The mean uncorrected visual acuity at 3 months in group 1 was 0.723+/-0.21; in group 2 it was 0.756+/-0.21; in group 3 it was 0.748+/-0.22, and in group 4 it was 0.732+/-0.23. The best-corrected visual acuity was 0.96+/-0.10, 0.97+/-0.11, 0.95+/-0.13, and 0.96+/-0.10 in the four groups at 3 months. CONCLUSION: Phacoemulsification surgery can be successfully performed with nondominant hand with a good surgical outcome. The technique gives an alternative approach where surgeon does not have to shift the position to perform on-axis phacoemulsification.

An evaluation of the darkroom prone provocative test in family members of primary angle closure glaucoma patients.

PURPOSE: To compare ocular biometric parameters with darkroom prone provocative test (DRPPT) in family members of primary angle closure glaucoma (PACG) patients. METHODS: One hundred and forty-nine family members of 46 PACG patients underwent ocular examination included slit lamp biomicroscopy, gonioscopy, fundus examination using +90 D lens, Goldmann applanation tonometry, darkroom prone provocative test, perimetry on Humphrey's field analyzer II and optic disc evaluation using HRT II. Ultrasonic ocular biometry and the DRPPT were then performed. IOP>or=8 mmHg rise from baseline with iridocorneal touch was considered as a positive test. RESULTS: Of the 149 family members examined, 55 (36.9%) were found to have PACG. Forty (72.7%) of these had subacute PACG and 15 (27.3%) were found to have chronic PACG. Thirty-nine (70.3%) of the affected members showed a positive DRPPT. Mean anterior chamber depth (ACD) was 2.03+/-0.3, 2.3+/-0.4, 2.7+/-0.3 mm (P=0.0001) and mean lens thickness was 4.41+/-0.39, 3.99+/-0.5, 3.93+/-0.4 mm (P=0.0001) in DRPPT positives, borderlines and negatives respectively. ROC curve (ACD) plotted showed cutoff value of 2.07 mm (sensitivity 88.57%) for screening. CONCLUSION: Anterior chamber is shallowest, lens is thickest and axial length is shortest in affected and DRPPT positive, family members of PACG patients.

Comparison of ultrasound biomicroscopic parameters after laser iridotomy in eyes with primary angle closure and primary angle closure glaucoma.

PURPOSE: To study changes in anterior segment morphology after laser peripheral iridotomy (LPI) in primary angle closure (PAC) and primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM). METHODS: Ninety-three eyes of 93 patients underwent anterior segment evaluation including gonioscopy, disc evaluation with + 90D lens, applanation intraocular pressure, and standard achromatic perimetry. UBM was performed before and 2 weeks after Nd:YAG LPI to measure the trabecular-iris angle (TIA), the angle-opening distance (AOD 250/500), and the central anterior chamber depth (ACD). RESULTS: The superior TIA widened from a mean of 7.54+/-3.15 to 15.66+/-6.69 degrees (P=0.0001), the inferior TIA increased from a mean of 9.0+/-4.7 to 15.9+/-6.8 degrees (P=0.0001) after LPI in PAC. In PACG, the mean superior angle changed from 4.55+/-2.5 to 6.12+/-3.8 degrees (P=0.4) and the inferior angle increased from 4.75+/-2.0 to 7.9+/-3.7 degrees (P=0.1). The mean ACD increased from 2.19+/-0.36 to 2.30+/-0.36 mm in PAC group (P=0.0003), with no significant change seen in the PACG group (1.79+/-0.32 vs 1.82+/-0.33 mm, P=0.13). CONCLUSION: LPI leads to a widening of the anterior chamber angle and a deepening of the anterior chamber in eyes with PAC. It does not significantly change any anterior segment parameters in eyes with PACG.

Narrowing of the anterior chamber angle during Valsalva maneuver: a possible mechanism for angle closure.

PURPOSE: To evaluate changes at the anterior chamber angle during Valsalva maneuver in eyes suspected to have a primary adult glaucoma. METHODS: Seventy-six consecutive patients underwent recording of applanation tonometry, measurement of the anterior chamber angle recess, angle opening distance, angle recess area, scleral spur-iris root distance, iris thickness, iridociliary angle, ciliary body thickness, anterior chamber depth, and pupil size on ultrasound biomicroscopy before and during the Valsalva maneuver. The Valsalva maneuver was standardized to a pressure of 40 mmHg for 15 seconds, using a manometer. RESULTS: The mean baseline intraocular pressure changed from 19.5+/-4.1 mmHg to 29.5+/-4.8 mmHg during Valsalva (p<0.0001). The anterior chamber angle recess narrowed from 17.9+/-9.5 to 7.8+/-9.2 degrees (p=0.0001). The angle recess area diminished from 0.15+/-0.14 mm2 to 0.14+/-0.12 mm2 (p=0.03) and the scleral spur to iris distance decreased from 0.19+/-0.2 mm to 0.16+/-0.18 mm (p=0.0001). The iridociliary angle narrowed from 72.6+/-33.5 degrees to 62.5+/-32.8 degrees (p=0.04). There was a significant increase in the thickness of the ciliary body, from 0.99+/-0.19 mm to 1.12+/-0.16 mm (p=0.001) and in iris thickness from 0.47+/-0.07 mm to 0.55+/-0.09 mm (p=0.0001). There was no significant change in the angle opening distance, anterior chamber depth, or pupillary diameter. A significant narrowing of the angle to less than 5 degrees was seen in 37 eyes, with iridocorneal apposition present in 28 eyes. After multivariate regression analysis it was found that the baseline ciliary body thickness and angle recess were significant predictors of narrowing of the angle (R2=96.1%). CONCLUSIONS: Significant elevation of the intraocular pressure, narrowing of the anterior chamber angle recess, thickening of the ciliary body, and increase in the iris thickness is seen during the Valsalva maneuver. The Valsalva maneuver may lead to angle closure in eyes anatomically predisposed to primary angle closure glaucoma.