Impairment of contrast visual acuity as a functional correlate of retinal nerve fibre layer thinning and total macular volume reduction in multiple sclerosis.

OBJECTIVES: To analyse the association between retinal nerve fibre layer thickness (RNFLT) and total macular volume (TMV) as measured by optical coherence tomography, and contrast sensitivity (CS) measured by Functional Acuity Contrast Testing (FACT) in relapsing-remitting multiple sclerosis; and to investigate whether FACT testing by a contrast box device is feasible in multiple sclerosis (MS). METHODS: fact was performed using the Optec 6500 P vision testing system with best correction under photopic and mesopic conditions without glare. The Area Under the Log Contrast Sensitivity Function (AUC) was calculated. RNFLT and TMV were assessed by Stratus optical coherence tomography. All participants underwent visual acuity testing (Snellen), spherical refractive error testing and cylindrical refractive error testing. RESULTS: 85 relapsing-remitting multiple sclerosis patients (170 eyes) and 35 healthy controls (HC, 70 eyes) were measured. AUC Day and Night were lower in MS than in HC (p<0.001) when correcting for age, as were mean RNFLT and TMV (p<0.001 and p=0.018, respectively). Both RNFLT and TMV predicted contrast sensitivity in MS (AUC Day: standardised coefficient ß=0.277, p<0.001, and ß=0.262, p<0.001, respectively; AUC Night: ß=0.202, p=0.009 and ß=0.222, p=0.004, respectively, linear regressions). In HC, there was no correlation between RNFLT or TMV and contrast sensitivity. CONCLUSION: (1) Contrast sensitivity is reduced in MS versus HC; (2) RNFL and TMV as morphological measures of retinal axonal loss are predictors of contrast sensitivity as a functional visual parameter in MS but not in HC; and (3) FACT with the contrast box is a novel, feasible and rapid method to assess contrast sensitivity in MS.

Patterns of retinal nerve fiber layer loss in multiple sclerosis patients with or without optic neuritis and glaucoma patients.

OBJECTIVE: Optical coherence tomography (OCT) has gained increasing attention in multiple sclerosis (MS) research and has been suggested as outcome measure for neuroprotective therapies. However, to date it is not clear whether patterns of retinal nerve fiber layer thickness (RNFLT) loss are different in MS compared to other diseases such as glaucoma and data on RNFLT loss in MS patients with or without optic neuritis (ON/NON) have remained inconsistent or even contradictory. METHODS: In this large cross-sectional study we analyzed the patterns of axonal loss of retinal ganglion cells in MS eyes (n=262) with and without history of ON (MS/ON: 73 eyes; MS/NON: 189 eyes) and patients eyes with glaucomatous optic disc atrophy (GA: n=22; 39 eyes) in comparison to healthy control eyes (HC: n=406 eyes). RESULTS: We found that significant average and quadrant RNFLT loss is detectable by OCT in both MS and GA patients compared to healthy controls (p<0.01). The age- and gender adjusted average and quadrant RNFLT did not differ significantly between MS and GA patients (p>0.05). Average (p<0.0001) and quadrant (p<0.05) RNFL thinning is significantly more severe in MS/ON versus MS/NON eyes, and the extent of RNFL thinning varies across quadrants in MS/ON eyes with the highest degree of RNFLT loss in the temporal quadrant (p<0.001). CONCLUSION: RNFLT reduction across all four quadrants in MS patients as a whole as well as in MS/NON eyes argues for a diffuse neurodegenerative process. Superimposed inflammatory attacks to the optic nerve may cause additional axonal damage with a temporal preponderance. Future studies are necessary to further evaluate the capacity of OCT to depict disease specific damage patterns.

Colorimetric analysis of three editions of the Velhagen-Broschmann pseudoisochromatic colour plates.

PURPOSE: Chromatic variations across different copies and different editions of pseudoisochromatic tests and violation of underlying principles of construction for individual plates can influence test results. METHODS: We analysed the colorimetric characteristics of three different editions of Velhagen-Broschmann pseudoisochromatic plates (30th edition printed in 1995, 31st edition printed in 1997, 32nd edition printed in 2000). One hundred and twelve coloured dots of 18 plates were chosen from each edition. We measured RGB and CIE XYZ values using a spectrophotometer. Differences in lightness and chromaticity between corresponding dots of different editions were analysed in terms of Delta L* and Delta u'v', respectively. For each plate deviations from dichromatic confusion lines were analysed. Furthermore, we determined the relative luminance of a target compared to its background in terms of the Weber contrast. RESULTS: The mean Delta L* across editions was 2.05 (+/-1.4) and the mean Delta u'v' was 0.0078 (+/-0.0029). For two plates the deviations of targets from dichromatic confusion lines exceeded suggested values. For a number of plates, the lightness contrast between the symbol and its background was high. Comparison with psychophysical data showed that these colour plates are easily detectable by colour-deficient observers. CONCLUSIONS: Lightness and chromatic variation across the three editions was moderate except for a small number of plates perhaps due to inaccuracies in the printing process. The design of several plates should be revised according to standard principles of construction of colour deficiency tests.

Do temporal artery duplex ultrasound findings correlate with ophthalmic complications in giant cell arteritis?

OBJECTIVE: Ophthalmic complications are common in acute GCA. Do temporal artery ultrasound and clinical parameters correlate with the occurrence and severity of ophthalmic complications? METHODS: The results of temporal artery ultrasound examinations are compared with the occurrence of anterior ischaemic optic neuropathy (AION), central retinal artery occlusion (CRAO), branch retinal artery occlusion (BRAO), diplopia and amaurosis fugax in 222 consecutive patients with newly diagnosed, active GCA. RESULTS: Temporal artery ultrasound displayed vasculitic wall swelling (halo), stenoses and/or acute occlusions in 84% (58% in 67 large-vessel GCA patients and 95% in 155 patients without proximal arm vasculitis). Ophthalmic complications occurred in 64 (29%), AION in 30 (14%), CRAO in 7 (3%), BRAO in 2 (1%), amaurosis fugax in 16 (7%) and diplopia in 9 patients (4%). Ophthalmic complications were insignificantly more common if temporal artery ultrasound was positive (31 vs 17%; P = 0.11) as a greater number of patients without arm vasculitis showed eye involvement (34 vs 18%; P = 0.02). The number of pathological temporal artery segments, presence of stenoses or bilateral findings did not correlate with ophthalmic complications. Age >or= 72 yrs at diagnosis correlated with a higher incidence of ophthalmic complications. CONCLUSION: Ophthalmic complications occurred less frequently if proximal arm vasculitis was present. Findings of temporal artery ultrasound did not correlate with eye complications.

Trypan-blue-assisted anterior continuous curvilinear capsulorhexis in a case of ocular pemphigoid.

PURPOSE: To report on trypan-blue-assisted anterior continuous curvilinear capsulorhexis (ACCC) in a case of ocular pemphigoid. METHODS: Interventional case report. RESULTS: Due to the reduced visibility especially in the corneal periphery caused by the ocular pemphigoid, trypan blue 0,06% (Acri.Blue) was used to stain the anterior capsule of the lens. Then anterior continuous curvilinear capsulorhexis was performed. Due to the blue staining, the visualization of the margin of the rhexis was always good and phacoemulsification procedure was successfully performed afterwards. During the follow-up period of 12-months-postsurgically, no exacerbation of the ocular pemphigoid occurred. CONCLUSIONS: The use of trypan blue staining of the anterior capsule enabled the surgeon to perform a safe anterior continuous curvilinear capsulorhexis and a subsequent phacoemulsification in ocular pemphigoid. No progression of the ocular pemphigoid was seen within the 12-months-post-surgery period.

Inadvertent scleral perforation in eye muscle versus retinal detachment buckle surgery.

PURPOSE: Inadvertent scleral perforation is a recognized complication of eye muscle and retinal detachment buckle surgery. If these operations are performed by the same surgeon, it is unknown which of these procedures has a higher risk of scleral perforation. METHODS: In the period from 1999 until 2004, 427 eyes of 317 patients were operated using eye muscle surgery and 81 eyes of 80 patients with retinal detachment buckle surgery. All operations were performed by the same surgeon (JK). In a retrospective, single-center, comparative, observational study, the records of these patients were assessed to determine the number of scleral perforations with retinal damage or drainage of subretinal fluid. RESULTS: In the group receiving retinal detachment buckle surgery there were two cases of scleral perforation. In one case, scleral perforation occurred during buckle installation and in the other case during placement of a cerclage. The rate of scleral perforation was 2.5 % per patient and per eye in this group. In the group receiving eye muscle surgery no scleral perforations occurred. CONCLUSION: The number of scleral perforations was higher in retinal detachment buckle surgery than in eye muscle surgery, with all procedures having been performed by the same surgeon.