Bundle Defects Research Articles

Optical coherence tomography shows progressive local nerve fiber loss after disc hemorrhages in glaucoma patients

The aim of this work is to investigate whether optic disc hemorrhages (ODH) lead to significant loss of nerve fibers at the lesion site over time and whether such a loss is reflected by visual field defects corresponding to the affected nerve fiber bundle. In this retrospective study of ten sequential glaucoma patients (ten eyes) with ODH, we used high-resolution OCT circular scans (Spectralis HRA + OCT, Heidelberg Engineering, Heidelberg, Germany) to determine peripapillary retinal nerve fiber layer (RNFL) thickness at the time of ODH presentation and at follow-up visit between 3 and 6 months. Corresponding perimetric data were analyzed for global (mean defect, MD) and localized progression of visual field defects. ODH were mostly located in the inferior quadrant as determined clinically and from fundus photographs. Iterative OCT imaging revealed a significant RNFL reduction in the affected quadrant relative to the respective quadrant in the fellow eye (RNFL change = -2.25 ± 2.69μm vs. 0.75 ± 2.78μm, p = 0.01) within 120 ± 43days. However, only three cases presented with new/progressive nerve fiber bundle defects corresponding to the lesion site within the given follow-up period. ODH lead to a significantly higher RNFL loss at the lesion site relative to the overall structural progression in glaucoma patients. However, this focal change is not generally reflected by respective nerve fiber bundle defects in the time frame investigated.

Bulk nickel–carbon nanotube nanocomposites by laser deposition

Nickel–carbon nanotube (CNT) nanocomposites have been processed in a bulk form using a laser deposition technique, commercially known as the laser engineered net shaping (LENS) process. Mechanical milling of the powder feedstock consisting of nickel powders and CNTs before laser deposition has resulted in not only a more homogeneous distribution of the nanotubes in the nickel matrix, but also two distinct scales of reinforcements within the composite. The larger reinforcement scale consists of submicrometre to micrometre sized bundles of CNTs while the smaller scale consists of individual (or cluster of a few) CNTs within the nickel matrix. High resolution transmission electron microscopy studies indicate that the nickel/CNT interface is well bonded without the presence of any significant interfacial reaction product. The degree of disorder and defects in the CNT bundles in the nickel matrix varied as a function of bundle size as revealed by Raman spectroscopy results.

Insight to the valence band electronic structure of metallicity selected single wall carbon nanotubes from a photoemission viewpoint

AbstractThe progress on separation of single‐walled carbon nanotubes according to their metallic character has allowed to access the unique electronic and optical properties long ago predicted. Whether the inevitable interactions of nanotubes in a bundle or single doping defects are in scope, the energies of charge carriers and lattice vibrations are modified. Based on this, we have made use of photoemission spectroscopy effectively to identify modifications of the underlying basic correlation effects in the electronic structure. Subsequently, we have deepened into the study of the valence band of metallicity sorted samples and we have recorded, depending on the actual type of interaction within a film of bundles of purely metallic single wall carbon nanotube bundles, a compelling evidence for both a 1D Tomonaga–Luttinger power law scaling and a 3D Fermi liquid.

Topological Defects in Twisted Bundles of Two-Dimensionally Ordered Filaments

Twisted assemblies of filaments in ropes, cables, and bundles are essential structural elements in both macroscopic materials and living organisms. We develop the unique, nonlinear elastic properties of twisted filament bundles that derive from generic properties of two-dimensional line-ordered materials. Continuum elasticity reveals a formal equivalence between the elastic stresses induced by bundle twist and those induced by the positive curvature in thin, elastic sheets. These geometrically induced stresses are screened by fivefold disclination defects in the lattice packing, and we predict a discrete spectrum of elastic-energy ground states associated with integer numbers of disclinations in cylindrical bundles. Finally, we show that elastic-energy ground states are extremely sensitive to the defect position in the cross section, with off-center disclinations driving the entire bundle to buckle and writhe.

Visual Field Profile of Optic Neuritis

To evaluate visual field abnormalities after an episode of optic neuritis among participants in the Optic Neuritis Treatment Trial. Three readers independently evaluated 10 443 visual fields from 454 patients and classified visual field abnormalities into 21 different monocular categories representing 3 general types of visual loss: diffuse, localized, and artifactual. Classification frequency was determined and reader agreement was evaluated. The association of visual field abnormality classifications with mean deviation, pattern standard deviation, visual acuity, and foveal threshold was assessed. At baseline, diffuse loss accounted for 66.2% of the abnormalities in the affected eyes but only 6.2% of the abnormalities in the fellow eyes. During years 1 through 15, the affected and fellow eyes exhibited predominantly localized loss in the nerve fiber bundle region (partial arcuate, paracentral, and arcuate defects). At year 1, 35.7% of the abnormalities in the affected eyes and 34.4% in the fellow eyes consisted of localized defects. At year 15, 39.5% of abnormalities in the affected eyes and 26.3% in the fellow eyes consisted of localized defects. Foveal threshold was highly correlated with visual acuity and contrast sensitivity in the affected eye at baseline (-0.82 vs 0.79, respectively), 6 months (-0.84 vs 0.81), and 1 year (-0.84 vs 0.79). Diffuse and central loss were more predominant in the affected eye at baseline, and nerve fiber bundle defects (partial arcuate, paracentral, and arcuate) were the most predominant localized abnormalities in both the affected and fellow eyes during the study.

Erstsymptome und Befunde bei Meningeomen des N. opticus

While evaluating radiotherapy results in patients with primary and secondary optic nerve sheath meningiomas (ONSM) treated between 1993 and 2002, a large amount of data about early signs and symptoms has been collected which might be helpful for establishing an early diagnosis. We have reviewed the charts of the patients available at the Centre of Ophthalmology, collecting especially pretreatment data. 112 patients, 4 with bilateral tumours, 83 % female were included. Mean age was 51.7 years. Visual acuity loss with relative afferent pupillary defect was the main symptom and sign in primary ONSM (38 patients). Median interval between first symptoms and diagnosis was 12 months. Optic discs were in approximately one half atrophic, the other half were swollen, and only rarely normal (3 cases only). Retinociliary shunt vessels were seen in 10 cases. Nerve fibre bundle defects were the major visual field finding (including constriction and central scotoma). Visual acuity was better than 0.5 (20 / 40) in 46 % and worse than 0.1 (20 / 200) in 30 %. In secondary ONSM, the interval to diagnosis was with a median of 6 months shorter than in primary ONSM. Approximately half of the optic discs were atrophic, only 6 % were swollen. Even here nerve fibre bundle defects were dominating, only 7 % had vertical hemianopic defect. Visual acuity was better than 0.5 (20 / 40) in 30 % and in worse than 0.1 (20 / 200) 22 %. 45 % had ocular motility disorders. Vertical hemianopic defects were surprisingly rare. The high rate of nerve fibre bundle defects and the relatively high number of patients with good visual acuity might explain why this disorder is occasionally mistaken for glaucoma. A typical clinical appearance can be outlined: mainly mid-aged women, slowly progressing visual loss, frequently motility disorders, relative afferent pupillary defect, nerve fibre bundle defects and atrophic or--mainly in primary ONSM--swollen optic disc form the characteristic picture.

Life and Death of Sensory Hair Cells Expressing Constitutively Active TRPML3

The varitint-waddler mutation A419P renders TRPML3 constitutively active, resulting in cationic overload, particularly in sustained influx of Ca(2+). TRPML3 is expressed by inner ear sensory hair cells, and we were intrigued by the fact that hair cells are able to cope with expressing the TRPML3(A419P) isoform for weeks before they ultimately die. We hypothesized that the survival of varitint-waddler hair cells is linked to their ability to deal with Ca(2+) loads due to the abundance of plasma membrane calcium ATPases (PMCAs). Here, we show that PMCA2 significantly reduced [Ca(2+)](i) increase and apoptosis in HEK293 cells expressing TRPML3(A419P). The deaf-waddler isoform of PMCA2, operating at 30% efficacy, showed a significantly decreased ability to rescue the Ca(2+) loading of cells expressing TRPML3(A419P). When we combined mice heterozygous for the varitint-waddler mutant allele with mice heterozygous for the deaf-waddler mutant allele, we found severe hair bundle defects as well as increased hair cell loss compared with mice heterozygous for each mutant allele alone. Furthermore, 3-week-old double mutant mice lacked auditory brainstem responses, which were present in their respective littermates containing single mutant alleles. Likewise, heterozygous double mutant mice exhibited severe circling behavior, which was not observed in mice heterozygous for TRPML3(A419P) or PMCA2(G283S) alone. Our results provide a molecular rationale for the delayed hair cell loss in varitint-waddler mice. They also show that hair cells are able to survive for weeks with sustained Ca(2+) loading, which implies that Ca(2+) loading is an unlikely primary cause of hair cell death in ototoxic stress situations.

Nonarteritic Ischemic Optic Neuropathy After LASIK With Femtosecond Laser Flap Creation

Non-arteritic ischemic optic neuropathy (NAION) has been reported after laser in situ keratomileusis (LASIK) performed with a microkeratome flap (1,2). Its occurrence has been attributed to the pressure elevation caused by the suction ring. The suction ring placed during hyperopic LASIK transiently elevates the intraocular pressure (IOP) to levels exceeding 65 mm Hg. We examined a 53-year-old man who developed unilateral NAION after bilateral simultaneous uncomplicated hyperopic LASIK in which flap creation was performed using the IntraLase femtosecond laser (IntraLase Corp., Irvine, CA) with a low-pressure suction ring. To the best of our knowledge, NAION has not been reported in this setting. Preoperative refractive errors were +5.50 +0.50 ×105 for the right eye and +5.25 +0.50 ×90 for the left eye with best-corrected visual acuities of 20/20 in both eyes. Preoperatively, IOPs were normal and family history was negative for glaucoma. The LASIK surgeon reported that results of a preoperative dilated fundus examination was unremarkable except for small optic discs and cup/disc ratios. The procedure was uneventful. In each eye, the IntraLase femtosecond laser was used to create superiorly hinged flaps of 110 μm thickness, and stromal ablation was performed. Corneal topography after LASIK surgery revealed a hyperopic LASIK ablation pattern. On the first postoperative day, best-corrected visual acuities were 20/20 in the right eye and 20/200 in the left eye. The right optic disc was normal, and the left optic disc was edematous. There was a relative afferent pupillary defect in the left eye. Visual field examination showed a dense nerve fiber bundle defect in the left eye (Fig. 1).FIG. 1: On postoperative day 1 after bilateral hyperopic LASIK procedures with femtosecond flap creation, fundus photographs (A) show left segmental optic disc edema, and visual fields (B) show a corresponding left eye defect.In the two reported cases of NAION after LASIK surgery (1,2), flap creation was performed using a mechanical microkeratome, with an associated sudden increase in IOP to 60-70 mm Hg, followed by a rapid IOP decrease upon suction release. Our patient is unusual because during IntraLase laser treatment, the IOP did not exceed 30-40 mm Hg (3,4). The mechanism of NAION under these circumstances is unknown. Ahmet Maden, MD Safiye Yilmaz, MD Nazife Sefi Yurdakul, MD Department of Ophthalmology Izmir Atatürk Training and Research Hospital Izmir, Turkey [email protected]

Stepwise Decline in Visual Field After Serial Sildenafil Use

Stepwise Decline in Visual Field After Serial Sildenafil Use

Visual field defects in acute optic neuritis - distribution of different types of defect pattern, assessed with threshold-related supraliminal perimetry, ensuring high spatial resolution

To assess the pattern and the local spatial frequency distribution of visual field defects (VFDs) in eyes with clinically diagnosed optic neuritis (ON) and their currently unaffected fellow eyes, using threshold-related, slightly supraliminal perimetry, ensuring high spatial resolution. Records obtained with the Tübingen Automatic perimeter (TAP, Oculus Inc., Dudenhofen, Germany) and the Octopus 101 perimeter (Haag-Streit Inc, Koeniz, Switzerland), using a standardized grid of 191 static targets within the central 30 degrees visual field, were analysed retrospectively. VFDs were assigned to 15 classes. Visual fields (VF) from 99 patients (26 male and 73 female subjects, aged from 18 to 51 years) with clinically diagnosed, acute ON (52 right eyes, 48 left eyes affected, one bilateral involvement) were evaluated. Central scotomas were the most common finding in associated eyes, covering 41% of all VFDs in affected eyes. Nerve fibre bundle defects were found in 29% and paracentral scotomas in 14% of all VFDs. Fellow eyes were perimetrically normal in 65% of the clinically monocular ONs. Nerve fibre bundle defects were found in 21% and diffuse scotomas in 9% of the fellow eyes. Central scotomas and retinal nerve fibre bundle defects are the most common VFDs in acute ON. Small central and paracentral scotomas that most probably would have been missed by automated thresholding perimetry with its relatively coarse grid could be detected by threshold-related, slightly supraliminal strategy. Of the fellow eyes in clinically apparent monocular optic neuritis, 35% present with visual field defects.

Idiopathic Intracranial Hypertension in a Transgender Man

We report a case of idiopathic intracranial hypertension (IIH) in a transgender man. To our knowledge, no such case has been described previously. A 33-year-old man presented to the neuro-ophthalmology clinic at the University of Florida in January 2007. He was complaining of headaches and blurred vision. IIH had been diagnosed 8 months earlier, and he was treated with 1,500 mg/day acetazolamide. He reported being a transgender woman-to-man who had undergone bilateral mastectomies and testosterone treatment that had been discontinued 18 months earlier. Our examination disclosed a patient who weighed 168 lbs with height of 5 feet 3 inches. Blood pressure was 118/72 mm Hg with a pulse of 84/min. Best-corrected visual acuities were 20/15 in each eye. Color vision was normal by Ishihara plate testing. Ophthalmoscopy showed optic disc edema in both eyes (Fig. 1). Humphrey visual fields showed nerve fiber bundle defects and enlarged blind spots in both eyes (Fig. 2). Results of a CT angiogram with attention to the venous phase was normal. A lumbar puncture disclosed an opening pressure of 300 mm H2O with normal constituents.FIG. 1: Optic disc edema is present in both eyes.FIG. 2: Humphrey visual fields show nasal defects and enlarged blind spots in both eyes.Because of side effects from acetazolamide, 80 mg/day furosemide was substituted for acetazolamide. For headache control, he was treated with 150 mg/day topiramate. On a follow-up 1 month later, visual field defects had improved. However, 2 months later, the visual field defects worsened, and he underwent an optic nerve fenestration in the right eye. One week postoperatively, visual field defects had improved in the left eye, but the right eye remained stable. On month later, visual field defects had improved in both eyes. IIH is found most commonly in overweight women in their reproductive years. It may also be caused by dural sinus thrombosis (5,6), a reduction in corticosteroid therapy, or hormonal imbalance (7-10), vitamin A, anabolic corticosteroids, tetracycline, lithium, and pregnancy (11-13). Our patient had prior use of testosterone. Despite the availability of transgender medicine for decades, we were unable to find a published report of IHH in patients who change gender. Clinton Sheets, MD Marc Peden, MD John Guy, MD Department of Ophthalmology University of Florida Gainesville, Florida [email protected]

Accuracy of Combined GDx-VCC and Matrix FDT in a Glaucoma Screening Trial

To assess the advantage in glaucoma screening of the use of scanning laser polarimetry with customized cornea compensation (GDx-VCC) combined with Matrix Frequency Doubling Technology (M-FDT) testing. In a nonpopulation-based prepublicized trial, self-recruited white participants were screened for glaucoma with GDx-VCC, with M-FDT, and by independent clinical examination. Cases with possible glaucoma as found with any of the screening methods underwent a detailed clinical investigation to verify or exclude glaucoma. Sensitivity, specificity, accuracy, likelihood ratios, and predictive values were calculated using different threshold criteria for GDx-VCC alone, M-FDT alone, and for various combinations. Of the 233 attendees, 181 participants (345 eyes) successfully underwent the GDx-VCC and M-FDT measurements. Thirty-nine eyes of 24 participants had glaucoma (11.3% prevalence among eyes tested successfully). All but 2 of the glaucomatous eyes had only early damage. Evaluated separately, the criterion GDx-VCC NFI (normal threshold < or =30) performed best, with 97.0% specificity, 88.8% accuracy, and 25.6% sensitivity; but with only 8.5 positive likelihood ratio (PLR). For paired criteria, the best combination of GDx-VCC-screening test with M-FDT-screening test provided 99.6% specificity, 91.3% accuracy, and 28.6 PLR. For NFI combined with GDx-VCC nerve fiber bundle defect criterion, specificity was 99.0%, accuracy 89.6%, and PLR 18.0. However, the sensitivities in the 2 cases fell to 12.0% and 18.0%. For a triple combination of M-FDT-screening test with the latter pair of criteria, sensitivity increased to 41.7% and PLR (13.6) still remained clinically useful. In a self-recruited white population with relatively high risk for mild glaucomatous damage, a combination of GDx-VCC together with M-FDT could usefully be employed for mass glaucoma screening.

Nervenfaserverlaufsausfälle bei prächiasmaler Läsion

Prechiasmal lesions of the visual pathway are produced by visual field defects that either affect only one eye or, if both eyes are affected, they are clearly different. Typically, the defects respect the vertical meridian. This report of a case shows that the classical nerve fibre bundle defect must be taken into consideration for differential diagnosis. In a 67-year-old patient, a meningeoma of the sphenoid was diagnosed that had spread into the optic canal. Examination of the visual field showed an inferior altitudinal nerve fibre bundle defect. Apparently the retinal pattern of nerve fibres remains intact even when approaching the optic chiasm. Nerve fibre bundle defects are therefore sometimes found in prechiasmal lesions and should be considered for differential diagnosis (e. g., in the case of a suspected low tension glaucoma).

Physical and Functional Interaction between Protocadherin 15 and Myosin VIIa in Mechanosensory Hair Cells

Hair cells of the mammalian inner ear are the mechanoreceptors that convert sound-induced vibrations into electrical signals. The molecular mechanisms that regulate the development and function of the mechanically sensitive organelle of hair cells, the hair bundle, are poorly defined. We link here two gene products that have been associated with deafness and hair bundle defects, protocadherin 15 (PCDH15) and myosin VIIa (MYO7A), into a common pathway. We show that PCDH15 binds to MYO7A and that both proteins are expressed in an overlapping pattern in hair bundles. PCDH15 localization is perturbed in MYO7A-deficient mice, whereas MYO7A localization is perturbed in PCDH15-deficient mice. Like MYO7A, PCDH15 is critical for the development of hair bundles in cochlear and vestibular hair cells, controlling hair bundle morphogenesis and polarity. Cochlear and vestibular hair cells from PCDH15-deficient mice also show defects in mechanotransduction. Together, our findings suggest that PCDH15 and MYO7A cooperate to regulate the development and function of the mechanically sensitive hair bundle.

CHARACTERISTICS OF VISUAL FIELD DEFECTS BY SCANNING LASER OPHTHALMOSCOPE MICROPERIMETRY AFTER RADIAL OPTIC NEUROTOMY FOR CENTRAL RETINAL VEIN OCCLUSION

To evaluate visual field defects after radial optic neurotomy (RON) for the treatment of central retinal vein occlusion (CRVO) by using scanning laser ophthalmoscope microperimetry. Thirteen eyes of 13 patients with severe vision loss (< or = 20/200) from CRVO who underwent pars plana vitrectomy and RON had postoperative Goldmann kinetic perimetry, scanning laser ophthalmoscope microperimetry, and fluorescein angiographic evaluation. After a mean follow-up of 8 months, 6 of the 13 patients had visual improvement by > or = 2 lines. Eight patients developed an anastomosis at the radial cut. Postoperatively, sectorial visual field loss arising from the optic head was found by Goldmann perimetry in six patients, and a thin nerve fiber bundle defect was found in three patients. Four patients had no detectable visual field defect shown by Goldmann perimetry, but microperimetry demonstrated an absolute nerve fiber bundle defect arising from the radial cut at the optic disk for three of these patients. Visual field loss after RON for the treatment of CRVO is a frequent complication. The etiology of this visual loss appears to be a combination of mechanical trauma to the nerve fiber layers and ischemia of the optic disk circulation.

Pregnancy associated, optic disc drusen related visual loss

30-year-old, right-handed womanpresented with a 2-day history ofcentral blurred vision in the left eye.She had no pain in her eye or on eyemovements, and no headache, nausea,diplopia, meningism or dizziness. Shewas 28 weeks pregnant with her firstchild. She had no other medical historyof note and was not on any medication.Her visual acuity (VA) was 6/6 in theright eye and 6/12 in the left. She had aleft relative afferent pupil defect(RAPD). Her ocular motility examina-tion was full and her Ishihara score was17/17 in the right eye and 3/17 in theleft. Visual field examination to con-frontation showed a full field in theright eye and a concentric peripheralconstricted field in the left. Fundalexamination showed bilateral blurringof the disc margin. Remaining neuro-logical examination was unremarkable.Due to her pregnancy she was trans-ferred to the joint care of the neuro-logist and obstetricians.Differential diagnosis at the timeincluded asymmetric optic neuritis,idiopathic intracranial hypertension,sinus venous thrombosis, a space-occu-pying lesion and Leber hereditary opticneuropathy.The patient’s blood pressure, haema-tological tests including full bloodcount, urea and creatinine, C-reactiveprotein, folate, Vitamin B12, liver func-tion tests, thrombophilia screen, coagu-lation screen and autoimmune profilewere all within the normal range.Magnetic resonance imaging of thebrain and magnetic resonance venog-raphywere bothnormal.Ophthalmologyreview showed that VA was now 6/6in each eye and the Ishihara score wasfull in both eyes but the patient had aleft RAPD, although ocular motilitywas normal. Visual field examinationshowed extensive loss of field in botheyes (Fig. 1). Fundal examinationshowed pallor of the disc in the lefteye (Fig. 2) and autofluorescence con-firmed the presence of drusen bilater-ally (Fig. 3). As the subject waspregnant, we were unable to performan angiogram. Optical coherence ima-ging of the retinal nerve fibre layershowed loss of the nerve fibre layerin both eyes (Fig. 4). A diagnosis ofpregnancy-associated, drusen-relatedischaemic optic neuropathy wasconcluded.Optic disc drusen are hyaline, often cal-cified bodies located in the pre-laminarportion of the optic disc and are foundin up to 2% of the population(Auw-Haedrich et al. 2002). There aretwo types visible or buried and theyare often associated with anomalous ret-inal vasculature. Visual field defects asso-ciated with drusen are well known andmay be found in up to 87% of patientswith drusen, especially the superficial type(Mustonen 1983); these are often nervefibre bundle defects (arcuate), generalizedfield constriction or enlargement of theblind spot (Lorentzen 1966). The defectsmayappearin thefirsttwo decadesoflife,increase in extent and prevalence with ageandprogressslowly(ofteninaglaucoma-tous pattern) (Mustonen 1983). They areoften unnoticed by the patient becausecentral visual loss, as in our patient, isuncommon (Mustonen 1983).Visual acuity is normally well pre-served (Wilkins & Pomeranz 2004) butoccasionally a more rapid central loss ofvision may occur, as in our case. This

Genetic and physical maps of jerker ( Espnje) on mouse chromosome 4

The jerker mutation causes degeneration of cochlea and vestibular sensory hair cells in mice. A frame-shift mutation in the actin bundling gene Espin ( Espn) leads to hair bundle defects by disrupting the actin filament assembly in stereocilia. Previously, jerker was mapped to distal mouse chromosome 4. Here, analyzing 2536 informative meioses derived from two intersubspecific intercrosses, we localize jerker to a 0.51±0.14 cM interval on chromosome 4. The following order and distances of genes and markers were determined: D4Mit180—0.44±0.13 cM— Hes2, Espn je —0.08±0.06 cM— D4Mit356—0.28±0.1 cM— D4Mit208. A 300 kb physical bacterial artificial chromosome (BAC) contig was generated containing the Espn je locus. The human homologous region maps to 1p36.31. We present a detailed high-resolution genetic and physical map of markers located at distal chromosome 4 and demonstrate concordance of Espn with jerker.

Ion-irradiation-induced defects in bundles of carbon nanotubes

We study the structure and formation yields of atomic-scale defects produced by low-dose Ar ion irradiation in bundles of single-wall carbon nanotubes. For this, we employ empirical potential molecular dynamics and simulate ion impact events over an energy range of 100–1000 eV. We show that the most common defects produced at all energies are vacancies on nanotube walls, which at low temperatures are metastable but long-lived defects. We further calculate the spatial distribution of the defects, which proved to be highly non-uniform. We also show that ion irradiation gives rise to the formations of inter-tube covalent bonds mediated by carbon recoils and nanotube lattice distortions due to dangling bond saturation. The number of inter-tube links, as well as the overall damage, linearly grows with the energy of incident ions.

Comparison of 24???2 and 30???2 Perimetry in Glaucomatous and Nonglaucomatous Optic Neuropathies

To determine whether the 24-2 Humphrey visual field (HVF) (Humphrey, San Leandro, CA) strategy provides information comparable to that provided by the 30-2 strategy in patients with optic nerve disease. In part A of the study, an occluder device was designed to cover the additional outer 22 points tested in the 30-2 strategy of 187 HVFs from neuro-ophthalmology patients with nonglaucomatous optic neuropathy and 206 HVFs from patients with glaucoma. This device converted the gray scale and probability plots of the 30-2 HVF to a 24-2 field. Fields were initially read using the occluder and then were read in a masked manner without the occluder and compared. In part B, 15 healthy volunteers performed both 30-2 and 24-2 HVFs. Testing time and global indices were compared. Ninety-five percent of the fields in the neuro-ophthalmology patients, 96% of the fields in patients under observation for suspected glaucoma, 98% of the fields in patients with ocular hypertension, and 100% of the fields in patients with glaucoma were read similarly with the 24-2 and 30-2 strategies. In the few cases in which a discrepancy was noted between the 24-2 and the 30-2 fields, appropriate clinical management would not have been compromised by using the 24-2 strategy. Most of these cases were in patients with idiopathic intracranial hypertension and very subtle nerve fiber bundle defects. The 24-2 strategy had a significantly lower pattern standard deviation (P < 0.01) and corrected pattern standard deviation (P = 0.05) than did the 30-2 strategy. In addition, the 24-2 strategy shortened the standard threshold testing time by 28% in normal volunteers (P < 0.0001 ). In most cases, the 24-2 testing strategy provides information comparable to that provided by the 30-2 strategy in a shorter time and with less variability. A 30-2 HVF may be warranted in patients under observation for evolving idiopathic intracranial hypertension.

Perimetric findings in carotid obstructive disease

The ocular complications of carotid disease are well known and generally occur in high-degree stenosis (>90%). However, the ocular manifestations of carotid disease, in cases of stenosis >70% but without carotid occlusion, have rarely been studied. Generally, this degree of stenosis is not associated with signs and symptoms of ocular ischemia. The aim of this paper is to study cases of uni- or bilateral stenosis >70%, without signs or symptoms of ischemic ocular syndrome, in order to investigate the ocular functional aspects and to detect the earliest complications to the eye. Thirty-six eyes from eighteen patients with uni- or bilateral stenosis >70%, but without occlusion of internal carotid artery and without any evidence of retinal ischemia, were examined using automated perimetry. Visual field (VF) defects were found in a high percentage of the patients (83%). Mere nerve fiber bundle defects were the most common alterations (53%), followed by mere global reduction of light sensitivity (27%). The high frequency of localized defects in patients without ocular hypertension and glaucomatous optic disc alterations suggests that carotid disease may cause functional damage to the eye. A subclinical chronic ischemic retinopathy may be detected by VF analysis. Probably, it is due to a generalized subclinical chronic ischemic cerebrovascular syndrome. This retinopathy has a multifactorial genesis and, in particular, it might be the result of a decreased arterial perfusion and of microembolization phenomena.