Distinguishing Uveitis Secondary to Sarcoidosis From Idiopathic Disease: Cardiac Implications.

Uveitis, Sarcoidosis, Idiopathic Disease, Cardiac Implications

2018 Jan 11. doi: 10.1001/jamaophthalmol.2017.5466. [Epub ahead of print]

Distinguishing Uveitis Secondary to Sarcoidosis From Idiopathic Disease: Cardiac Implications.

Abstract

IMPORTANCE:

Idiopathic disease is the most frequent diagnosis in a uveitis clinic. The need to distinguish sarcoidosis from idiopathic uveitis is controversial. However, cardiac involvement in sarcoidosis can be life-threatening.

OBJECTIVE:

To report a series of patients with uveitis and cardiac sarcoidosis to illustrate the importance of categorizing the causes of uveitis.

DESIGN, SETTING, AND PARTICIPANTS:

This retrospective observational case series reviewed the medical records of 249 patients with uveitis who were referred to the Casey Eye Institute between July 1, 2008, and February 28, 2017.

MAIN OUTCOMES AND MEASURES:

We describe patients who initially received a diagnosis of idiopathic uveitis but subsequently received a diagnosis of sarcoidosis. Clinical data, including ophthalmologic findings, were collected. We summarized the number of patients who initially presented with idiopathic uveitis, the number of patients who recived a classification of idiopathic uveitis after evaluation, the number of patients who underwent chest computed tomography or an electrocardiogram, and the number of patients with ocular sarcoidosis.

RESULTS:

Of 33 patients with sarcoidosis, 21 (63.6%) were women and the mean (SD) age was 53.5 (13.8) years. Of 249 patients, the referring diagnosis was idiopathic uveitis for 179 (72%). After history, examination, and laboratory testing, 127 (51%) were still considered to have idiopathic disease. Fifty-three of the 179 patients (30%) with idiopathic disease underwent chest computed tomography scanning. A diagnosis of presumed sarcoidosis, usually on the basis of a chest computed tomography scan, was made in 19 patients (36.2%). As 14 patients (5.6%) were previously known to have sarcoidosis, 33 patients (13.3%) were evaluated with definite or presumed ocular sarcoidosis. We obtained electrocardiograms as a screen for cardiac sarcoidosis on 14 (42.4%) of these patients. Nine patients with abnormal electrocardiogram results were referred to cardiologists. Four of the 19 patients (21.1%) who were referred for idiopathic uveitis but subsequently received a diagnosis of presumed sarcoidosis were found to have episodes of ventricular tachycardia that required implantable cardiac defibrillators. Distinguishing ocular sarcoidosis from idiopathic uveitis had potentially life-saving implications for these patients.

Uveitis, Sarcoidosis, Idiopathic Disease, Cardiac Implications  CONCLUSIONS AND RELEVANCE:

The present case series shows the potential utility of distinguishing sarcoidosis-associated uveitis from idiopathic uveitis. We suggest that patients older than 40 years with a history of idiopathic uveitis be evaluated with chest computed tomography and an electrocardiogram if sarcoidosis is suggested on ophthalmic examination.

PMID:
29327057
DOI:
10.1001/jamaophthalmol.2017.5466

Technique for Preparing Ultrathin and Nanothin Descemet Stripping Automated Endothelial Keratoplasty Tissue

Technique,Ultrathin, Nanothin, Descemet Stripping, Automated, Endothelial Keratoplasty

2018 Jan 11. doi: 10.1097/ICO.0000000000001510. [Epub ahead of print]

Technique for Preparing Ultrathin and Nanothin Descemet Stripping Automated Endothelial Keratoplasty Tissue.

Abstract

PURPOSE:

To describe and report outcomes of our single-pass microkeratome technique for preparation of ultrathin (UT, ≤100 μm) and nanothin (NT, ≤50 μm) Descemet stripping automated endothelial keratoplasty (DSAEK) grafts.

METHODS:

To prepare NT-DSAEK grafts, a pachymetry nomogram specific to each technician and individual microkeratome head was developed based on accumulated precut and postcut pachymetry data from previous DSAEK grafts. Mean graft thickness as well as precut and postcut endothelial cell counts (ECCs) of NT-DSAEK, UT-DSAEK, and Descemet membrane endothelial keratoplasty (DMEK) grafts between July 2015 and July 2017 were calculated and compared statistically. Endothelial cell loss was evaluated using calcein AM stains and ImageJ analysis. Postcut graft thickness and rates of perforation/tissue loss for NT-DSAEK grafts between May and July 2017 were calculated to determine overall graft preparation success rates.

RESULTS:

Mean postcut graft thickness for all grafts within the NT range was 41.0 ± 6.4 μm (range 26-50 μm). Mean ECC did not differ between NT-DSAEK, UT-DSAEK, and DMEK grafts (P = 0.759 and 0.633, respectively). The overall tissue loss rate from attempted NT-DSAEK was 4.8%. Excluding cases of perforation, the chance of achieving NT thickness was 60% and within the traditional UT range was 100%.

Technique,Ultrathin, Nanothin, Descemet Stripping, Automated, Endothelial Keratoplasty CONCLUSIONS:

We propose the term “NT-DSAEK” for grafts ≤50 μm. The described nomogram allows for standardized creation of NT grafts with a low tissue loss rate. This technique is safe and does not result in significant ECC loss compared with UT-DSAEK and DMEK grafts. Further studies are necessary to corroborate the postsurgical results of NT grafts.

PMID:
29329121
DOI:
10.1097/ICO.0000000000001510

Association of Novel Oral Antithrombotics With the Risk of Intraocular Bleeding

Antithrombotics, Risk, Intraocular Bleeding

2017 Dec 14. doi: 10.1001/jamaophthalmol.2017.5677. [Epub ahead of print]

Association of Novel Oral Antithrombotics With the Risk of Intraocular Bleeding.

Abstract

IMPORTANCE:

Novel oral anticoagulation and antiplatelet therapies have become a mainstay of treatment for thromboembolic disease. However, the safety profile of these medications has not been completely characterized.

OBJECTIVE:

To determine the risk of developing intraocular hemorrhages with novel oral antithrombotic therapy compared with that of traditional antithrombotic agents.

DESIGN, SETTING, AND PARTICIPANTS:

In this retrospective cohort study, a large national insurance claims database was used to generate 2 parallel analyses. All patients with incident use of dabigatran etexilate or rivaroxaban between January 1, 2010, and September 30, 2015, were compared with patients with incident use of warfarin sodium. Similarly, patients with new use of prasugrel hydrochloride were compared with those with new use of clopidogrel bisulfate. Both analyses required the patient to be in the insurance plan for at least 24 months prior to initiation of therapy and excluded patients with any previous diagnosis of intraocular hemorrhages or any prescription for the comparator medications. Furthermore, the antiplatelet analysis required a diagnosis of acute coronary syndrome or a myocardial infarction within 60 days of initiation of pharmacologic therapy. The anticoagulant analysis excluded patients with end-stage renal disease, renal transplants, and those with heart valve disease.

MAIN OUTCOMES AND MEASURES:

Incident intraocular hemorrhages at 90 and 365 days. Multivariate Cox proportional hazards regression models were used to compare the hazard ratio (HR) of developing an intraocular hemorrhage in individuals taking novel agents compared with those taking traditional medications.

RESULTS:

A total of 146 137 patients taking warfarin (76 714 women and 69 423 men; mean [SD] age, 69.8 [11.8] years) were compared with 64 291 patients taking dabigatran or rivaroxaban (31 576 women and 32 715 men; mean [SD] age, 67.6 [11.7] years). Cox proportional hazards regression revealed a decreased hazard for developing an intraocular hemorrhage with dabigatran or rivaroxaban at 365 days (HR, 0.75; 95% CI, 0.58-0.97; P = .03), but not at 90 days (HR, 0.73; 95% CI, 0.22-2.63; P = .13). A total of 103 796 patients taking clopidogrel (37 578 women and 66 218 men; mean [SD] age, 68.0 [11.3] years) were compared with 8386 patients taking prasugrel (1988 women and 6380 men; mean [SD] age, 61.0 [9.6] years) and no increased hazard for developing an intraocular hemorrhage with prasugrel was seen at 90 days (HR, 0.75; 95% CI, 0.29-1.92; P = .55) or 365 days (HR, 1.19; 95% CI, 0.69-2.04; P = .53).

Antithrombotics, Risk, Intraocular Bleeding  CONCLUSIONS AND RELEVANCE:

These results suggest a decreased risk of intraocular hemorrhage associated with novel direct thrombin inhibitors and direct factor Xa inhibitors, but no difference for P2Y12 inhibitors compared with traditional vitamin K anticoagulation and antiplatelet therapy, respectively.

PMID:
29242919
DOI:
10.1001/jamaophthalmol.2017.5677

Association of Sex With the Global Burden of Cataract

Sex,Cataract

2017 Dec 14. doi: 10.1001/jamaophthalmol.2017.5668. [Epub ahead of print]

Association of Sex With the Global Burden of Cataract.

Abstract

IMPORTANCE:

Eye disease burden could help guide health policy making. Differences in cataract burden by sex is a major concern of reducing avoidable blindness caused by cataract.

OBJECTIVE:

To investigate the association of sex with the global burden of cataract by year, age, and socioeconomic status using disability-adjusted life-years (DALYs).

DESIGN, SETTING, AND PARTICIPANTS:

This international, comparative burden-of-disease study extracted the global, regional, and national sex-specific DALY numbers, crude DALY rates, and age-standardized DALY rates caused by cataract by year and age from the Global Burden of Disease Study 2015. The DALY data were collected from January 1, 1990, through December 31, 2015, for ever 5 years. The human development index (HDI) in 2015 was extracted as an indicator of national socioeconomic status from the Human Development Report.

MAIN OUTCOMES AND MEASURES:

Comparisons of sex-specific DALY estimates due to cataract by year, age, and socioeconomic status at the global level. Paired Wilcoxon signed rank test, Pearson correlation, and linear regression analyses were performed to evaluate the socioeconomic-associated sex differences in cataract burden.

RESULTS:

Differences in rates of cataract by sex were similar between 1990 and 2015, with age-standardized DALY rates of 54.5 among men vs 65.0 among women in 1990 and 52.3 among men vs 67.0 among women in 2015. Women had higher rates than men of the same age, and sexual differences increased with age. Paired Wilcoxon signed rank test revealed that age-standardized DALY rates among women were higher than those among men for each HDI-based country group (z range, -4.236 to -6.093; P < .001). The difference (female minus male) in age-standardized DALY rates (r = -0.610 [P < .001]; standardized β = -0.610 [P < .001]) and the female to male age-standardized DALY rate ratios (r = -0.180 [P = .02]; standardized β = -0.180 [P = .02]) were inversely correlated with HDI.

CONCLUSIONS AND RELEVANCE:

Although global cataract health care is progressing, sexual differences in cataract burden showed little improvement in the past few decades. Worldwide, women have a higher cataract burden than men. Older age and lower socioeconomic status are associated with greater differences in rates of cataract by sex. Our findings may enhance public awareness of sexual differences in global cataract burden and emphasize the importance of making sex-sensitive health policy to manage global vision loss caused by cataract.

Sex,Cataract
PMID:
29242928

 

Temporal changes in retinal vascular parameters associated with successful panretinal photocoagulation in proliferative diabetic retinopathy

retinal, vascular, panretinal photocoagulation, proliferative, diabetic retinopathy

 

Acta Ophthalmol. 2017 Nov 29. doi: 10.1111/aos.13617. [Epub ahead of print]
Temporal changes in retinal vascular parameters associated with successful panretinal photocoagulation in proliferative diabetic retinopathy: A prospective clinical interventional study.

Torp TL1,2, Kawasaki R3, Wong TY4, Peto T2,5, Grauslund J1,2.
Author information
Abstract
PURPOSE:
We aimed to investigate changes in retinal vascular geometry over time after panretinal photocoagulation (PRP) in patients with proliferative diabetic retinopathy (PDR).
METHODS:
Thirty-seven eyes with PDR were included. Wide-field fluorescein angiography (Optomap, Optos PLC., Dunfermline, Scotland, UK) was used to diagnose PDR at baseline and to assess activity at follow-up month three and six. At each time-point, a trained grader measured retinal vessel geometry on optic disc (OD) centred images using semiautomated software (SIVA, Singapore I Vessel Assessment, National University of Singapore, Singapore) according to a standardized protocol.
RESULTS:
At baseline, the mean age and duration of diabetes were 52.8 and 22.3 years, and 65% were male. Mean HbA1c was 69.9 mmol/mol, and blood pressure was 155/84 mmHg. Of the 37 eyes with PDR, eight (22%) eyes had progression at month three and 13 (35%) progressed over six months. Baseline characteristics, including age, sex, duration of diabetes, HbA1c, blood pressure, vessel geometric variables and total amount of laser energy delivered did not differ by progression status. However, compared to patients with progression of PDR, patients with favourable treatment outcome had alterations in the retinal arteriolar structures from baseline to month six (calibre, 154.3 μm versus 159.5 μm, p = 0.04, tortuosity 1.12 versus 1.10, p = 0.04) and in venular structures from baseline to month three (fractal dimension 1.490 versus 1.499, p = 0.04, branching coefficient (BC) 1.32 versus 1.37, p = 0.01).
CONCLUSION:
In patients with PDR, successful PRP leads to alterations in the retinal vascular structure. However, baseline retinal vascular geometry characteristics did not predict treatment outcome.
© 2017 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

retinal, vascular, panretinal photocoagulation, proliferative, diabetic retinopathy  KEYWORDS:

NAVILAS ; SIVA ; clinical; computer-assisted; humans; panretinal photocoagulation; proliferative diabetic retinopathy; prospective; retinal vessel geometry
PMID: 29193789 DOI: 10.1111/aos.13617

Survival of corneal nerve/sheath structures in organ-cultured donor corneas

Survival, corneal nerve, sheath, donor corneas

2017 Nov 29. doi: 10.1111/aos.13614. [Epub ahead of print]

Survival of corneal nerve/sheath structures in organ-cultured donor corneas.

Abstract

PURPOSE:

To study the morphology of human corneal nerves in eye bank organ-cultured corneas and in corneal grafts post-transplantation.

METHODS:

Thirty-seven organ-cultured corneas were divided into: Group-A, anterior 300-400 μm of 20 corneas used for Descemets stripping endothelial keratoplasty, and Group-B, 17 full-thickness corneas unsuitable for transplantation. Corneas whole mounts were stained for nerves using acetylcholinesterase technique and examined by NanoZoomer digital pathology microscope. Central and sub-Bowman’s stromal nerves and the sub-basal nerve plexus including perforation sites and terminal bulbs were studied. Ten eyes were imaged following penetrating keratoplasty using in-vivo confocal microscopy (IVCM) for the presence of sub-basal and stromal nerves at 1, 4-5 and 7-8 weeks postoperatively (five eyes) and in all the other five eyes, the final follow-up was at 12 weeks.

RESULTS:

Fifteen of twenty (75%) corneas had stromal nerves in Group-A and 15 of 17 (88.2%) in Group-B. Average number of stromal nerves entering peripherally were 9.1 (range: 1-36). 7.5 in Group-A and 10.8 in Group-B. Central stromal nerves were seen in eight samples in Group-A and nine in Group-B. Many stromal nerves terminated abruptly without demonstrable continuity through Bowman’s membrane. No terminal bulbs or sub-basal nerves were detected. In-vivo confocal microscopy (IVCM) showed 4 of 5 in 9 of 10 (90%) donor corneas had stromal nerves 1 week postoperatively, which remained present in 8 of 10 (80%) corneas at 4-5 weeks and in 9 of 10 (90%) at 7-8 weeks postoperatively. All 5 corneas analysed at 12 weeks showed the same stromal nerves from 1 to 12 weeks postoperatively. Sub-basal nerves were absent in all corneas over the 12-week study period.

CONCLUSION:

This study provides further insight into the behaviour of corneal nerves in transplanted corneas. Corneal stromal nerves/nerve-sheaths are preserved in organ-cultured eye bank eyes and persist post-transplantation up to 3 months. These could provide directional guidance to regenerating nerves from host stroma.

 Survival, corneal nerve, sheath, donor corneas   KEYWORDS:

corneal nerves; corneal transplant; eye bank; in vivo confocal microscopy

PMID:
29193851
DOI:
10.1111/aos.13614

Comparative evaluation of progression rate in keratoconus before and after collagen crosslinking

progression, keratoconus, collagen, crosslinking

2017 Nov 9. pii: bjophthalmol-2017-311017. doi: 10.1136/bjophthalmol-2017-311017. [Epub ahead of print]

Comparative evaluation of progression rate in keratoconus before and after collagen crosslinking.

Abstract

PURPOSE:

To compare the rate of disease progression in keratoconus before and after corneal collagen crosslinking (CXL).

METHODS:

145 eyes were followed without CXL (no-CXL group) for a median duration of 31 months whereas 45 eyes were followed up for 41 months before (pre-CXL) and after (post-CXL) accelerated, epithelium-off crosslinking. Progression was defined based on significant slope found in linear mixed effect models against time. Swept-source optical coherence tomography was used for measurement of anterior steep keratometry, anterior flat keratometry (Ant Kf), anterior average keratometry (Ant Avg K); posterior steep keratometry, posteriorflat keratometry (Post Kf), posterior average keratometry (Post Avg K) and corneal thickness.

RESULTS:

The patients in pre-CXL group were significantly younger (26.3±5.48 years) compared with the patients in no-CXL group (32.7±10.24 years) (P=0.004). Significant differences were observed during baseline examination for all parameters (P≤0.035) between pre-CXL and no-CXL groups except Ant Cyl and Post Cyl. During observation period, statistically significant differences were noted between pre-CXL and no-CXL groups in the progression rate of Ant Kf, Ant Avg K, Post Kf and Post Avg K (P≤0.045). After CXL, the progression rate in post-CXL group was comparable to that in no-CXL group. All corneal parameters remained stable in no-CXL group throughout the follow-up period.

CONCLUSIONS:

Serial tomographic examination is useful to document disease progression before and after CXL. In our study, a decrease in progression rate of corneal parameters was noted after CXL. In cases with stable corneal parameters over time, careful monitoring can be considered instead of collagen crosslinking.

progression, keratoconus, collagen, crosslinking:

cornea; imaging; treatment other

PMID:
29122823
DOI:
10.1136/bjophthalmol-2017-311017

Effect of Cornea Preservation Time on Success of Descemet Stripping Automated Endothelial Keratoplasty: A Randomized Clinical Trial

Cornea Preservation, Descemet Stripping Automated Endothelial Keratoplasty

2017 Nov 10. doi: 10.1001/jamaophthalmol.2017.4989. [Epub ahead of print]

Effect of Cornea Preservation Time on Success of Descemet Stripping Automated Endothelial Keratoplasty: A Randomized Clinical Trial.

Abstract

IMPORTANCE:

Demonstrating that success of Descemet stripping automated endothelial keratoplasty is similar across donor cornea preservation times (PTs) could increase the donor pool.

OBJECTIVE:

To determine whether the 3-year rate of graft success using corneal donor tissue preserved 8 to 14 days is noninferior to that of donor tissue preserved 7 days or less.

DESIGN, SETTING, AND PARTICIPANTS:

A multicenter, double-masked, randomized noninferiority clinical trial was conducted from April 16, 2012, to June 5, 2017, at 40 clinical sites (70 surgeons) in the United States, with donor corneas provided by 23 US eye banks. A total of 1090 individuals (1330 study eyes) underwent Descemet stripping automated endothelial keratoplasty (1255 eyes [94.4%] for Fuchs endothelial corneal dystrophy).

INTERVENTIONS:

Descemet stripping automated endothelial keratoplasty with random assignment of a donor cornea with a PT of 7 days or less (0-7d PT) or 8 to 14 days (8-14d PT).

MAIN OUTCOMES AND MEASURES:

Graft success at 3 years.

RESULTS:

Of the 1090 participants (1330 study eyes; 60.2% women and 39.8% men; median age at enrollment, 70 years [range, 42-90 years]), the 3-year cumulative probability of graft success was 95.3% (95% CI, 93.6%-96.9%) in the 0-7d PT group and 92.1% (95% CI, 89.9%-94.2%) in the 8-14d PT group (difference, 3.2%). The upper limit of the 1-sided 95% CI on the difference was 5.4%, exceeding the prespecified noninferiority limit of 4%. The difference was mostly owing to more primary donor failures in the 8-14d PT group, with the conditional probability of failure after the first month being 2.4% in the 0-7d PT group and 3.1% in the 8-14d PT group. In preplanned secondary analyses, longer PT was associated with a lower rate of graft success (unadjusted hazard ratio for graft failure per additional day of PT, 1.10; 95% CI, 1.03-1.18; P = .008 [PT analyzed as days]), with success rates of 96.5% (95% CI, 92.3%-98.4%) for PT of 4 days or less, 94.9% (95% CI, 92.5%-96.6%) for PT of 5 to 7 days, 93.8% (95% CI, 91.0%-95.8%) for PT of 8 to 11 days, and 89.3% (95% CI, 84.4%-92.7%) for PT of 12 to 14 days (P = .01 [PT analyzed as categorical variable]).

CONCLUSIONS AND RELEVANCE:

The 3-year success rate in eyes undergoing Descemet stripping automated endothelial keratoplasty was high irrespective of PT. However, the study was unable to conclude that the success rate with donor corneas preserved 8 to 14 days was similar to that of corneas preserved 7 days or less with respect to the prespecified noninferiority limit. Although longer PT was associated with a lower success rate, the difference in rates was small when PT was less than 12 days.

Cornea Preservation, Descemet Stripping Automated Endothelial Keratoplasty REGISTRATION:

clinicaltrials.gov Identifier: NCT01537393.

PMID:
29127431
DOI:
10.1001/jamaophthalmol.2017.4989

Oxygen venular saturation correlates with a functional loss in primary open-angle glaucoma and normal-tension glaucoma patients

Oxygen, saturation, open-angle glaucoma, normal-tension glaucoma

2017 Nov 1. doi: 10.1111/aos.13575. [Epub ahead of print]

Oxygen venular saturation correlates with a functional loss in primary open-angle glaucoma and normal-tension glaucoma patients.

Abstract

PURPOSE:

To investigate whether there are differences in retinal oxygen saturation in upper and lower visual field hemispheres in primary open-angle glaucoma (POAG) and in normal-tension glaucoma (NTG).

METHODS:

This study enrolled POAG and NTG patients exhibiting differences between the upper and lower total deviation (TD) that were either more than 10 or <5 dB. Retinal oxygen saturation measurements in these patients with glaucoma were performed by a non-invasive spectrophotometric retinal oximeter. The Student’s t-test was used for statistical analysis.

RESULTS:

Evaluations of the worse and better hemifields in the patients with POAG who exhibited differences in the upper and lower hemifield TD that was <5 dB (n = 25) showed that there were no statistically significant differences for the retinal venous saturation of oxygen (SaO2 ). However, there was a higher mean SaO2 in the worse (57.0 ± 7.5%) versus the better (54.3 ± 7.0%) hemifield in the patients with NTG (n = 22; p = 0.007). Evaluations of the patients with more than a 10-dB difference in the upper and lower hemifield TD showed statistically significant differences for the retinal venous SaO2 in the venous vessels between the POAG (n = 19) and the NTG (n = 26) patients.

CONCLUSION:

Although there was no significant difference in retinal SaO2 in the venules between the better and worse hemifield when the difference between the better and worse hemifield in the patients with POAG was <5 dB, there was a higher SaO2 in the venous vessels in the worse hemifield in the patients with NTG.

 

Oxygen, saturation, open-angle glaucoma, normal-tension glaucoma

 

KEYWORDS:

normal-tension glaucoma; oxygen saturation; primary open-angle glaucoma; visual field defect

Changes in oxygen saturation and the retinal nerve fibre layer in patients with optic neuritis

oxygen saturation, retinal nerve fibre layer, optic neuritis

2017 Nov 1. doi: 10.1111/aos.13571. [Epub ahead of print]

Changes in oxygen saturation and the retinal nerve fibre layer in patients with optic neuritis – a pilot study.

Abstract

PURPOSE:

Assessment of retinal oxygen saturation, thickness of a retinal nerve fibre layer (RNFL) and functional changes in the optic nerve during optic neuritis (ON) in patients with multiple sclerosis (MS).

METHODS:

Thirty-two patients with ON due to MS within 3 months of onset of symptoms were enrolled [22 females, 10 males, age 34 ± 9 years, median 32.5 years, 22 patients with the clinically isolated syndrome (CIS), 10 patients with relapsing-remitting from of MS (RRMS)]. All patients were examined using optical coherence tomography (OCT model 4000, Carl Zeiss Meditec, Dublin, CA, USA), automatic optical oximetry (Oxymap ehf, Reykjavik, Iceland) and using visual evoked potentials (VEP) (Metronic Keypoint® , Minneapolis, MN, USA).

RESULTS:

Arterio-venous difference (AVD) was increased in patients ON affected eye compared to patients’ unaffected eye (PUE) [34.2 ± 4.7 versus 31.3 ± 4.6, p = 0.044 (mean ± standard deviation)]. No statistically significant difference was found in vessel oxygen saturation as well as in RNFL thickness in ON affected eyes when compared to unaffected MS eyes and healthy individuals. Significantly lower optic nerve conduction velocity was found in the affected eye when compared to unaffected MS eye and healthy (p < 0.0001 for both comparisons). No correlation between oxygen saturation values and VEP was observed in patients with MS.

CONCLUSION:

The AVD in oxygen saturation is altered in patients with acute ON. In the early stage of ON, AVD could reflect inflammatory and metabolic changes in the affected eye. Therefore, oximetry could be used as another diagnostic method in MS patients in suspicion of ON. This result would be promising for future investigation in this field.

KEYWORDS oxygen saturation, retinal nerve fibre layer, optic neuritis:

multiple sclerosis; optic neuritis; optical coherence tomography; oximetry