1,720,970 research outputs found
Optic nerve diameters and perimetric thresholds in idiopathic intracranial hypertension
No full textIdiopathic 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
Amniotic membrane transplantation associated with a corneal patch in a paediatric corneal perforation.
No full textPattern electroretinogram in treated ocular hypertension: a cross-sectional study after timolol maleate therapy
No full textTo 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
Hyperemic responses of the optic nerve head blood flow to chromatic equiluminant flicker are reduced by ocular hypertension and early glaucoma
No full textWe evaluated in ocular hypertension (OHT) and early glaucoma (EOAG) patients the optic nerve head (ONH) blood flow response (RFonh) to chromatic equiluminant flicker. This stimulus generates neural activity dominated by the parvo-cellular system. Eleven EOAG, 20 OHT patients, and 8 age-matched control subjects were examined. The blood flow (Fonh) at the neuroretinal rim was continuously monitored by laser Doppler flowmetry before, during, and after a 60-s exposure to a 4 Hz, red-green equiluminant flicker stimulus RFonh was expressed as percentage Fonh-change during the last 20 s of flicker relative to baseli Responses were collected at a number of temporal sites. The highest RFonh value was used for subsequent analysis. As compared to controls, both OHT and EOAG patients showed a decrease
Underestimate of tonometric readings after photorefractive keratectomy increases at higher intraocular pressure levels
No full textPURPOSE:
To determine whether tonometric readings of increases in intraocular pressure (IOP) during the water-drinking test (WDT) are affected by variations in central corneal thickness (CCT) induced by photorefractive keratectomy (PRK).
METHODS:
Data from 30 randomly selected eyes of 30 patients (18 men and 12 women; mean age, +/- SD: 33.9 +/- 7.6 years) undergoing bilateral PRK for myopia (-6.57 +/- 2.39 D) were obtained. Objective refraction, anterior radius of corneal curvature (R), CCT, and IOP measurements at baseline and at different time intervals after ingestion of 1 L of water within 5 minutes, were performed before and 6 months after PRK. All measured IOPs were recalculated by a correction factor for R and CCT and expressed as corrected intraocular pressure (IOPC) measurements.
RESULTS:
The mean R +/- SD was 7.84 +/- 0.20 and 8.76 +/- 0.34 mm, and the mean CCT was 544.83 +/- 19.69 and 453.97 +/- 29.95 microm, before and after PRK, respectively. The mean IOP at baseline was 15.05 +/- 2.78 and 9.83 +/- 2.56 mm Hg, and during WDT was 18.32 +/- 3.42 and 11.42 +/- 3.10 mm Hg at 10 minutes, 18.59 +/- 2.99 and 11.54 +/- 2.54 mm Hg at 20 minutes, 17.80 +/- 2.85 and 10.87 +/- 2.22 mm Hg at 30 minutes, 16.35 +/- 3.02 and 10.26 +/- 2.21 mm Hg at 45 minutes, and 14.90 +/- 2.52 and 9.81 +/- 2.32 mm Hg at 60 minutes, before and after PRK, respectively. The mean IOPC at baseline was 13.64 +/- 2.33 and 13.05 +/- 2.98 mm Hg, and during WDT was 16.61 +/- 2.77 and 15.08 +/- 3.59 mm Hg at 10 minutes, 16.96 +/- 2.69 and 15.33 +/- 2.96 mm Hg at 20 minutes, 16.10 +/- 2.50 and 14.42 +/- 2.60 mm Hg at 30 minutes, 14.92 +/- 2.72 and 13.62 +/- 2.65 mm Hg at 45 minutes, 13.82 +/- 2.27 and 13.05 +/- 2.55 mm Hg at 60 minutes, before and after excimer laser treatment, respectively. Pre- and postoperative IOPs and percentages of IOP increase differed significantly (P < 0.05), in particular at the peak, as did IOPCs but not the percentages of increase in IOPC, apart from the highest values.
CONCLUSIONS:
Corneal changes after PRK for myopia may induce an uneven underestimate of the IOP increases. The inadequacy of a correction factor to compensate for CCT and R at high IOP levels indicates that other biomechanical factors may play a role when the cornea is subjected to dynamic actual IOP variation. Such increase of the well-known underestimate of IOP after PRK at higher actual IOPs may have significant clinical implications in tonometric assessment of subjects at risk of glaucomatous damage
Influence of aqueous humor convection current on IOL opacification
No full textBackground 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
Combined deep sclerectomy and descemet stripping automated endothelial keratoplasty
No full textPURPOSE:
The aim of this study was to evaluate a novel surgical combination of Descemet stripping automated endothelial keratoplasty (DSAEK) and deep sclerectomy (DS) for the management of concomitant corneal endothelial decompensation and uncontrolled glaucoma.
METHODS:
This retrospective case series noncomparative study included 9 eyes of 6 consecutive patients with coexistence of corneal edema resulting from Fuchs dystrophy or pseudoexfoliation keratopathy and medically uncompensated glaucoma; these patients underwent combined DSAEK and DS with mitomycin C and an absorbable collagen implant. Corneal graft clarity, endothelial cell density, visual acuity, intraocular pressure (IOP), and identification of complications were assessed over a 2-year follow-up.
RESULTS:
All eyes obtained graft clarity throughout the follow-up, with a final average endothelial cell decrease of -36% from baseline, and showed improved vision and good IOP control without hypotensive therapy. Measured at 3 and 24 months postoperation, the mean visual acuity improvement was 154% and 372% and IOP decrease was 51.1% and 46.4%, respectively. Two anterior segment complications occurred in 2 (22%) patients' eyes. This consisted of a graft dislocation and a modest IOP elevation, treated successfully.
CONCLUSIONS:
Combined DSAEK and DS was longitudinally associated with good corneal graft survival and IOP control, with few complications. These findings suggest that this surgical approach is a viable option for patients with coexisting glaucoma and corneal endothelial dysfunction. Our study should stimulate a multicenter, randomized, controlled trial of our technique
Ultrasonographic evaluation of optic disc swelling: comparison with CSLO in idiopathic intracranial hypertension
No full textTo 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
Effect of epigallocatechin-gallate on inner retinal function in ocular hypertension and glaucoma: A short-term study by pattern electroretinogram
No full textBACKGROUND:
Epigallocatechin-gallate (EGCG) is a powerful antioxidant with suggested neuroprotective action. The aim of this study was to evaluate the effect of short-term supplementation of EGCG on inner retinal function in ocular hypertension (OHT) and open-angle glaucoma (OAG).
METHODS:
Eighteen OHT and 18 OAG patients (perimetric mean deviation: >-10 dB) were randomly assigned to assume oral placebo or EGCG over a 3-month period in a randomized, placebo-controlled, double-blind, cross-over design clinical trial (clinicaltrials.gov identifier: NCT00476138). Pattern-evoked electroretinograms (PERGs) to 1.6 cycles/degree square-wave gratings, counterphased at 16 reversals/second, and standard automated perimetry (Humphrey 30-2) were assessed at the study entry (baseline), and after 3 months of placebo or EGCG.
RESULTS:
After EGCG, PERGs of OAG, but not OHT patients were increased in amplitude, compared either to baseline values (mean amplitude change: 0.06 log microV, p < 0.05) or to PERG amplitude values found in the same patients after placebo administration (mean change: -0.02 log microV, p not significant; difference between EGCG and placebo: 0.08 log microV, p < 0.05). In both OHT and OAG patients, standard automated perimetry did not show significant changes after either EGCG or placebo. In individual OAG patients, the magnitude of PERG amplitude increment after EGCG was inversely related (r = -0.8, p < 0.01) to corresponding baseline amplitudes.
CONCLUSIONS:
Although this study cannot provide evidence for long-term benefit of EGCG supplementation in OAG, and the observed effect is small, the results suggest that EGCG might favourably influence inner retinal function in eyes with early to moderately advanced glaucomatous damage
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