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

Posted Posted in cornea

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

Posted Posted in cornea

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

Posted Posted in glaucoma

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

Posted Posted in Retina

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