Diagnosing Glaucoma With TC-OCT Variables

Staff
6/5/2014

Data from the Advanced Imaging for Glaucoma Study suggests that the diagnosis of glaucoma can be improved with time-domain optic coherence tomography measurements of the optical disc and circumpapillary retinal nerve fiber layer variables, which had better diagnostic accuracy than macular retinal variables. Combining the top RNFL and optic disc variables significantly improved diagnostic performance. Clinically, or-logic classification was the most practical analytical tool with sufficient accuracy to diagnose early glaucoma.

Ninety-six age-matched normal and 96 perimetric glaucoma participants were included in this observational, cross-sectional study. Support vector machine, or-logic, relevance vector machine and linear description function were used to analyze the performances of combined TD-OCT diagnostic variables.

The area under the receiver-operating curve (AROC) was used to evaluate the diagnostic accuracy and to compare the diagnostic performance of single and combined anatomic variables. The best RNFL thickness variables were the inferior (AROC=0.900), overall (AROC=0.892) and superior quadrants (AROC=0.850). The best optic disc variables were horizontal integrated rim width (AROC=0.909), vertical integrated rim area (AROC =0.908) and cup/disc vertical ratio (AROC=0.890). All macular retinal thickness variables had AROCs of 0.829 or less. Combining the top three RNFL and optic disc variables in optimizing glaucoma diagnosis, the support vector machine had the highest AROC, 0.954, followed by or-logic (AROC=0.946), linear discrimination function (AROC=0.946) and relevance vector machine (AROC=0.943). All combination diagnostic variables had significantly larger AROCs than any single diagnostic variable. There were no significant differences among the combination diagnostic indices.
J Glaucoma 2014;23:129-135.
Wang M, Lu A, Varma R, Schuman J, et al.


Cosmetic Facial Fillers and Severe Vision Loss
California physicians have
observed vision loss from central retinal artery occlusion occurring after cosmetic facial enhancement, with a result of irreversible blindness in three patients, and a small amount of recovery in a fourth patient who received aggressive therapy. This is an adverse effect of off-label use of cosmetic facial fillers in the forehead that is not typically mentioned to patients. The filler presumably enters the central retinal artery via the external-internal carotid anastomoses, and becomes embedded in the retinal tissues. Physicians performing cosmetic enhancement surgery involving facial fillers need to be aware of this and should include significant vision loss as a possible rare complication of off-label use.
JAMA Ophthalmol 2014;132:637-639.
Carle M, Roe R, Novack R, Boyer D.


A Mediterranean Diet, Vitamin D And Dry-Eye Syndrome
Researchers evaluating the
association between a Mediterranean dietary pattern (MeDi) and vitamin D levels on dry-eye syndrome have found no association between adherence to the MeDi and a beneficial effect on DES. Higher vitamin D levels had a small, favorable, but likely statistically insignificant effect on DES symptoms.

Male patients (n=247) seen at the Miami Veterans Affairs eye clinic with normal eyelid, corneal and conjunctival anatomy were recruited to participate in this cross-sectional study. Patients filled out the 2005 Block Food Frequency Questionnaire and the Dry Eye Questionnaire 5, and underwent measurement of tear film parameters. The serum level of 25-hydroxy vitamin D was also measured. The main outcome measures included the association among MeDi, vitamin D levels and DES.

Mean patient age was 69 years (r: 55 to 95). Using latent class analysis to categorize the presence or absence of disease and quantify its severity, researchers found that adherence to the MeDi was positively associated with the risk of having DES (r: 1.25; 95 percent confidence interval, 1.06 to 1.47; p=0.007) and with increasing disease severity. Vitamin D levels were not significantly associated with the presence or severity of disease. However, higher levels of vitamin D were associated with decreased DES symptoms, with a -1.24 decrease in median Dry Eye Questionnaire score for every 10-U increase in vitamin D levels (p=0.01).
Cornea 2014;33:437-441.
Galor A, Gardener G, Pouyeh B, Feuer W, Florez H.


Lutein: A New Dye for Chromovitrectomy
Brazilian researchers evaluating
the feasibility, advantages and safety of a novel, lutein-based dye for improving identification and removal of the vitreous, internal limiting membrane and epiretinal membrane during chromovitrectomy found that the new dye improved intraoperative identification of the internal limiting membrane and posterior hyaloid/vitreous.

The researchers prospectively evaluated 12 eyes that underwent pars plana vitrectomy using the novel dye in patients with macular hole, epiretinal membrane or proliferative diabetic retinopathy/tractional diabetic macular edema. One surgeon performed standard chromovitrectomy and completed a postoperative questionnaire to compare the novel dye staining with that of the available dyes. The peeled membranes were evaluated histologically, and follow-up examinations were performed on postop days one, seven, 30, 90 and 180; best-corrected visual acuity, optical coherence tomography, fluorescein angiography, autofluorescence and visual fields were performed.

The green dye was deposited on the posterior pole because of its higher density than the balanced saline solution; vigorous dye flushing into the vitreous cavity was unnecessary. The dye stained the posterior hyaloid/vitreous base by deposition onto the vitreous; brilliant blue stained the internal limiting membrane. The epiretinal membrane was poorly stained. Postop, the BCVA improved in all eyes, without clinical toxicity or toxicity on images/visual fields. Histology showed effective removal of the internal limiting membrane and the epiretinal membrane in all eyes.
Retina 2014;34:262-272.
Mala M, Furlani B, Souza-Lima A, Martina D, et al.