Transient visual blurring during a sexual intercourse in a young woman with surgically corrected myopia and unrecognized pigmentary glaucoma: A rare case report.

PURPOSE: To present a rare case of unilateral visual loss episodes occurred during sexual intercourse in a young patient affected by unrecognized pigmentary glaucoma and previously undergone myopic refractive surgery. CASE DESCRIPTION: The patient presented surgically flattened corneas and markedly asymmetric pigmentary glaucoma. CONCLUSIONS: Previous refractive surgery, sexual intercourse, and athletic lifestyle might be risk factors for acute pigment dispersion and chronic progression of pigmentary glaucoma in young myopic patients. During their ophthalmic examination prior to refractive surgery, greater attention should be paid to detect early signs of pigmentary dispersion, and awareness of these dangerous situations should be raised in affected patients.

PERG adaptation for detection of retinal ganglion cell dysfunction in glaucoma: a pilot diagnostic accuracy study.

It has been previously demonstrated that the adaptive phase changes of steady-state pattern electroretinogram (SS-PERG), recorded during 4-min presentation of patterned stimuli, are reduced in glaucoma suspects and patients compared to normal subjects. Our study aims at testing the hypothesis that adaptive changes of SS-PERG, recorded using the novel optimized Next Generation PERG (PERGx) protocol, differ between glaucoma patients and controls. In this pilot cross-sectional study, we included 28 glaucoma patients and 17 age-matched normal subjects. Both patients and controls underwent a full ophthalmologic examination, visual field testing, OCT and PERGx. The PERGx signal was sampled over 2 min (providing 1 noise and 9 signal packets) in response to alternating gratings generated on an OLED display. PERGx amplitude and phase were analyzed to quantify adaptive changes over recording time. Receiver operating characteristic (ROC) curves were used to study the diagnostic accuracy of PERGx parameters in distinguishing glaucoma patients from normal subjects. PERGx amplitude and phase data showed declining trends in both groups. PERGx amplitude slope and grand-average vector amplitude and phase were significantly different in patients compared to controls (p < 0.01), whereas phase angular dispersion was greater in patients but not significantly different between the two groups. The area under the ROC curves were 0.87 and 0.76 for PERGx amplitude slope and grand-average vector amplitude, and 0.62 and 0.87 for PERGx angular dispersion and grand-average vector phase, respectively. The PERGx paradigm resulted highly accurate in detecting the reduction of amplitude adaptive changes in glaucoma patients, presumably due to the loss of functional retinal ganglion cell autoregulation. Thus, PERG adaptation, recorded by this new protocol, might be helpful in the identification and diagnosis of early glaucomatous dysfunction.

Influence of aqueous humor convection current on IOL opacification.

BACKGROUND AND PURPOSE: The opacification of Akreos Adapt (Bausch & Lomb, Rochester; NY) intraocular lens (IOL) has been previously reported in Literature. A metabolic change in aqueous humour was considered as the main trigger factor to IOL opacification. We report our case and discuss the association with Ex-PRESS, highlighting the particular pattern of IOL opacification and its possible relation with the intraocular convective motions of the aqueous. MATERIAL AND METHODS: We analyzed our case using both digital slit lamp acquisition and OCT Visante (Zeiss, Germany) images. A literature review was conducted to evaluate our results with that previously reported. CONCLUSION: The role of a relative stationary flow was reported as suggested concurrent mechanism in IOL opacification phenomenon.

The mechanical behavior of vascular grafts: a review.

The development of intimal hyperplasia (IH) near the anastomosis of a vascular graft to artery is directly related to changes in the wall shear rate distribution. Mismatch in compliance and diameter at the end-to-end anastomosis of a compliant artery and rigid graft cause shear rate disturbances that may induce intimal hyperplasia and ultimately graft failure. The principal strategy being developed to prevent IH is based on the design and fabrication of compliant synthetic or innovative tissue-engineered grafts with viscoelastic properties that mirror those of the human artery. The goal of this review is to discuss how mechanical properties including compliance mismatch, diameter mismatch, Young's modulus and impedance phase angle affect graft failure due to intimal hyperplasia.

Optimal endothelialisation of a new compliant poly(carbonate-urea)urethane vascular graft with effect of physiological shear stress.

OBJECTIVE: to define the optimal seeding conditions of a new stress free poly(carbonate-urea)urethane (CPU) graft with compliance similar to that of human artery with honeycomb structure engineered during the manufacturing process to enhance adhesion and growth of endothelial cells. METHODS: (111)Indium-oxine radiolabeled human umbilical vein endothelial cells (HUVEC) were seeded onto CPU grafts at (a) concentrations from 2-24x10(5)cells/cm(2)and (b) incubated for 0.5, 1, 2, 4 and 6 h. Following incubation, graft segments were subjected to three washing/gamma counting procedures and scanning electron microscopy (SEM). Cell viability was measured using a modified Alamar blue(TM)assay. To test physiological retention a pulsatile flow phantom was used to subject optimally seeded (16x10(5), 4 h) CPU grafts to arterial shear stress for 6 h with real time acquisition of scintigraphic images of seeded grafts using a nuclear medicine gamma camera system. RESULTS: the seeding efficiency of 54+/-13% post three washes was achieved using 16x10(5)cells/cm(2). Similarly in SEM micrographs a seeding density of 16x10(5)cells/cm(2)resulted in a confluent monolayer. Seeded CPU segments incubated for 4 h exhibited significantly higher resistance to wash-off than segments incubated for 30 min (p <0.05). Exposure of seeded grafts to pulsatile shear stress resulted in some cell loss with 67+/-3% of cells adherent following 6 h of perfusion with ongoing metabolic activity. Thus, optimal conditions were 16x10(5)cells/cm(2)at 4 h. CONCLUSIONS: the optimal seeding conditions have been defined for "tissue-engineered" vascular graft which allow complete endothelialisation and high cell-to-substrate strength that resists hydrodynamic stress.

Ultrasonographic evaluation of optic disc swelling: comparison with CSLO in idiopathic intracranial hypertension.

PURPOSE: To determine the accuracy and reproducibility of ultrasonographic (US) readings of optic disc elevations in patients with papilledema compared with confocal scanning laser ophthalmoscope (CSLO) measurements. METHODS: One randomly selected eye of 22 patients with idiopathic intracranial hypertension (IIH) and a variable degree of optic disc swelling underwent five and three repeated measurements of disc height using high-resolution ultrasonography (Biovision unit; Quantel Medical, Clermont-Ferrand, France) and CSLO (Heidelberg Retina Tomograph [HRT]; Heidelberg Engineering, Heidelberg, Germany), respectively. The same procedure was assessed in 14 subjects with variable degrees of physiologic optic disc cupping. US and HRT measurements from each group were individually compared with each other to estimate the accuracy of US readings in both disc conditions in comparison with HRT data. RESULTS: Ultrasonographic readings were positively correlated with HRT measurements in both swollen (r = 0.62, P: = 0.002) and excavated disc (r = 0.84, P: < 0.0002). The 95% limits of agreement between the instruments were 0.24 +/- 0.59 mm (mean +/- 2 SD) and 0. 05 +/- 0.3 mm for swelling and cupping measurements, respectively. The coefficient of variation was 7.63% and 1.8% for swelling and 7. 93% and 5.91% for cupping, with US and HRT, respectively. CONCLUSIONS: The results indicate that US and CSLO readings are correlated i: both disc swelling and cupping conditions, but to a different extent because of a significant discrepancy in papilledema. US assessment can be considered highly reproducible. Combined US and HRT optic disc analysis may be recommended in papilledema evaluation as long as a better correlation can be demonstrated in further studies.

In vivo femoropopliteal arterial wall compliance in subjects with and without lower limb vascular disease.

OBJECTIVE: The purpose of this study was to further the development of a compliant vascular graft with a preliminary assessment of the elastic properties of the femoropopliteal artery in subjects with and without lower limb peripheral vascular disease. METHODS: This prospective controlled study was set in a university department of surgery. Using an ultrasound scan wall tracking system with the simultaneous measurement of brachial blood pressure, measurements of femoropopliteal artery wall motion were undertaken in 11 patients with peripheral vascular disease (group 1), in 11 older control subjects who were matched for blood pressure, age, and sex (group 2), and in 12 younger control subjects (group 3). Diametrical compliance and stiffness index were determined for the common femoral artery, the proximal superficial femoral artery, the distal superficial femoral artery (DSFA), and the midgenicular popliteal artery. RESULTS: All the arterial segments in group 1 showed a trend towards increased stiffness and less compliance than the group 2, age-matched control vessels, with significantly lower distensibility noted at the common femoral artery (mean compliance of 6.2% vs 14.1% mm Hg(-1) x 10(-2), respectively; P <.05) and the DSFA (mean compliance of 2.2% vs 1.9% mm Hg(-1) x 10(-2), respectively; P <.05). The popliteal artery segment in group 3 proved to be more compliant and less stiff than did the same vessel in group 2 (8.5% vs 4.7% mm Hg(-1) x 10(-2), respectively; P <.01). In all three study groups, the DSFA was consistently noted to be the least distensible vessel segment. CONCLUSION: Lower limb peripheral vascular disease is associated with a reduction in femoropopliteal artery elasticity. Age alone appears to have a minimal effect on the compliance of the proximal half of the femoropopliteal segment. The elastic properties of the femoropopliteal vessel are subject to marked variation along its course. To minimize compliance mismatch, the degree of elasticity engineered into a vascular graft must reflect that observed in vivo.

A new device for ocular surgical training on enucleated eyes.

OBJECTIVE: To develop a reliable inexpensive device for teaching ocular surgical procedures and practicing experimental techniques on enucleated eyes. DESIGN: Teaching device trial. PARTICIPANTS: Thirty enucleated porcine eyes. METHODS: A Plexiglas ocular bulb holder was secured with its base support to a polyvinylchloride pillar on a modified polystyrene trial head. MAIN OUTCOME MEASURE: The convenience and reproducibility of both laser and surgical ocular techniques performed with this new device were evaluated. RESULTS: This model allows curvilinear capsulorrhexis and phacoemulsification of porcine lenses through a corneal tunnel incision and insertion of a soft foldable acrylic intraocular lens into the capsular bag. Argon and neodymium:YAG laser iridotomy and retinal argon laser photocoagulation can also be performed with this model. CONCLUSIONS: This inexpensive device is useful for teaching both surgical and laser ocular procedures.

Conservative treatment of adnexal, epibulbar and intraocular neoplasms by means of electron microbeams: a preliminary study.

At present, episcleral plaque brachytherapy and charged particle or photon irradiation are the most commonly employed methods in ocular and adnexal conservative treatments. In the near future, a different therapeutic approach to these malignancies could be represented by a new device based on electron beam emission. The equipment used consists of an electron accelerator originally developed for intraoperative radiotherapy, modified to fit ocular pathologies. Adequate collimators and an enhanced mechanical accuracy are required for this special practice. An operative planning for epibulbar, adnexal and intraocular tumors is described, discussing its rationale for possible applications. Experimental tests using phantoms and Gafchromic(R) films are in progress. As all conservative treatments, the main gaol of this activity is the maintenance of a good visual function.

Effect of prolonged pulsatile shear stress in vitro on endothelial cell seeded PTFE and compliant polyurethane vascular grafts.

OBJECTIVES: Compliance mismatch between graft and native artery, and failure of the graft to develop an endothelial lining are the two main factors in graft failure. The objective of this study was to assess a new compliant graft for effective cell attachment and cell retention at physiological levels of pulsatile shear stress over a 6-hour period of physiological pulsatile flow. DESIGN: Laboratory haemodynamic study. MATERIALS AND METHODS: Human umbilical vein endothelial cells labelled with 111In-oxine were seeded on compliant polyurethane (CPU) and polytetrafluoroethylene (PTFE) vascular grafts. These were then exposed to varying shear stresses of up to 13.8 +/- 0.6 dyn/cm2 using a pulsatile flow model. Dynamic scintigraphy images were acquired using a gamma camera linked to an on-line computer during 6 h of perfusion and data presented as mean +/- standard error of mean. RESULTS: Mean seeding efficiencies were significantly different at 4,316 +/- 505 and 825 +/- 504 CPM/cm2 on the CPU and PTFE grafts, respectively (p = 0.018). The flow experiment showed a higher percentage of cells retained on the CPU graft after exposure to shear stress caused by pulsatile flow compared to PTFE with respect to time. After 6 h pulsatile perfusion there was a significantly higher proportion of initial cells attached to CPU graft compared to PTFE graft (73 +/- 8% vs 42 +/- 8%, p = 0.018). The areas under the time activity curves over the 6-hour period were 280 +/- 26.4 for CPU and 176.0 +/- 30.0 for PTFE, confirming a significant greater total cell loss from PTFE compared with CPU grafts (51 +/- 7.0% vs 23 +/- 8.3%, p = 0.018, Wilcoxon matched-pairs signed-ranks test). CONCLUSIONS: This flow model provides an effective method of assessing cell retention on graft materials under physiological conditions over a 6-hour period; CPU combines both excellent compliance and endothelial cell attachment rates after 6 h exposure to shear stress.

Optic nerve diameters and perimetric thresholds in idiopathic intracranial hypertension.

AIMS/BACKGROUND: Idiopathic intracranial hypertension (IIH) is a central nervous disorder characterised by abnormally increased cerebrospinal fluid (CSF) pressure leading to optic nerve compression. An indirect estimate of increased CSF pressure can be obtained by the ultrasonographic determination of optic nerve sheaths diameters. Computerised static perimetry is regarded as the method of choice for monitoring the course of the optic neuropathy in IIH. The aims were to compare the echographic optic nerve diameters (ONDs) and the perimetric thresholds of patients with IIH with those of age-matched controls, and to examine the correlation between these two variables in individual patients with papilloedema. METHODS: Standardised A-scan echography of the mid orbital optic nerve transverse diameters and automated threshold perimetry (Humphrey 30-2) were performed in 20 patients with IIH with variable degree of papilloedema (according to the Frisén scheme) and no concomitant ocular diseases. Echographic and perimetric results were compared with those obtained from 20 age-matched controls. RESULTS: When compared with controls, patients with IIH showed a significant increase in mean ONDs and significantly reduced mean perimetric sensitivities. In individual patients with papilloedema, the transverse ONDs correlated negatively with Humphrey mean deviation values and positively with pattern standard deviation values. CONCLUSION: These results indicate that OND changes in IIH are associated with perimetric threshold losses, and suggest that IIH functional deficits may be related to the degree of distension of optic nerve sheaths as a result of an increased CSF pressure.

Pattern electroretinogram in treated ocular hypertension: a cross-sectional study after timolol maleate therapy.

To investigate pattern electroretinogram changes in treated ocular hypertension, we evaluated pattern electroretinogram recordings of 48 hypertensive eyes following an 8-month timolol maleate therapy. During treatment, 27 of 48 eyes had normalized intraocular pressures (15-18 mm Hg), while 21 retained elevated values (21-25 mm Hg). Twenty-eight eyes with untreated hypertension (22-25 mm Hg) lasting at least 8 months, as well as 32 untreated, normotensive eyes served as controls. When compared to untreated normotensive controls, timolol-treated eyes with either elevated or normalized intraocular pressures showed reductions in the mean electroretinographic amplitudes. However, these amplitude reductions were substantially greater in treated eyes with elevated pressures as compared to those with normalized ones. Untreated hypertensive controls showed pattern electroretinogram reductions, with respect to normal values, that were comparable to those of treated hypertensive eyes, but larger than those of treated normotensive ones. These results indicate that, in treated ocular hypertension, pattern electroretinogram losses tend to be associated with moderately increased intraocular pressures in the range of 21-25 mm Hg. Electroretinographic abnormalities may be, at least in part, prevented only by lowering intraocular pressure into a normal range.