Identification of characteristic aroma compounds for spicy in Iris lactea var. chinensis.

Iris lactea var. chinensis (Fisch.) Koidz has a unique floral fragrance that differs from that of other Iris spp.; however, its characteristic aroma composition remains unknown. This study aimed to identify the floral fragrance components of I. lactea var. chinensis during different flowering stages using headspace solid-phase microextraction in conjunction with gas chromatography mass spectrometry, electronic nose, and sensory evaluation. During the three flowering phases (bud stage, bloom stage, and decay stage), 70 volatile organic compounds (VOCs), including 13 aldehydes, 13 esters, 11 alcohols, 10 alkanes, 8 ketones, 7 terpenes, 7 benzenoids, and 1 nitrogenous compound, were identified. According to principal component analysis, the primary VOCs were (-)-pinene, ß-irone, methyl heptenone, phenylethanol, hexanol, and 2-pinene. A comparison of the differential VOCs across the different flowering stages using orthogonal partial least squares discriminant analysis and hierarchical clustering analysis revealed that 3-carene appeared only in the bud stage, whereas hexanol, ethyl caprate, ethyl caproate, linalool, (-)-pinene, and 2-pinene appeared or were present at significantly increased levels during the bloom stage. The phenylethanol, methyl heptenone, 3-methylheptane, and ß-irone reached a peak in the decay stage. The odor activity value and sensory evaluation suggested that "spicy" is the most typical odor of I. lactea var. chinensis, mainly due to 2-methoxy-3-sec-butylpyrazine, which is rare in floral fragrances.

Dynamic simulation of the effect of soft toric contact lenses movement on retinal image quality.

PURPOSE: To report the development of a tool designed to dynamically simulate the effect of soft toric contact lens movement on retinal image quality, initial findings on three eyes, and the next steps to be taken to improve the utility of the tool. METHODS: Three eyes of two subjects wearing soft toric contact lenses were cyclopleged with 1% cyclopentolate and 2.5% phenylephrine. Four hundred wavefront aberration measurements over a 5-mm pupil were recorded during soft contact lens wear at 30 Hz using a complete ophthalmic analysis system aberrometer. Each wavefront error measurement was input into Visual Optics Laboratory (version 7.15, Sarver and Associates, Inc.) to generate a retinal simulation of a high contrast log MAR visual acuity chart. The individual simulations were combined into a single dynamic movie using a custom MatLab PsychToolbox program. Visual acuity was measured for each eye reading the movie with best cycloplegic spectacle correction through a 3-mm artificial pupil to minimize the influence of the eyes' uncorrected aberrations. Comparison of the simulated acuity was made to values recorded while the subject read unaberrated charts with contact lenses through a 5-mm artificial pupil. RESULTS: For one study eye, average acuity was the same as the natural contact lens viewing condition. For the other two study eyes visual acuity of the best simulation was more than one line worse than natural viewing conditions. CONCLUSIONS: Dynamic simulation of retinal image quality, although not yet perfect, is a promising technique for visually illustrating the optical effects on image quality because of the movements of alignment-sensitive corrections.

On-eye performance of custom wavefront-guided soft contact lenses in a habitual soft lens-wearing keratoconic patient.

PURPOSE: To assess visual, optical, and fitting characteristics for wavefront-guided soft contact lenses produced for one habitual soft lens-wearing moderate keratoconic eye. METHODS: A process for production and evaluation of custom wavefront-guided soft contact lenses was developed. Wavefront aberrations were quantified with the COAS-HD wavefront sensor (Wavefront Sciences); soft contact lenses containing both high and low order aberrations were designed with custom software and produced using an ophthalmic lens lathe. Photopic high and low contrast logMAR visual acuity were recorded with the lens in place over an artificial 5-mm pupil and residual 2nd to 10th order root-mean-square (RMS) aberrations were analyzed over a 5-mm pupil. Comparisons were made to the eye's habitual toric soft contact lens using t tests. RESULTS: Photopic high contrast values for habitual and final custom contact lenses for a 5-mm pupil were 0.07+/-0.06 and -0.08+/-0.05, respectively. Photopic low contrast values were 0.73+/-0.06 and 0.62+/-0.07, respectively. Habitual and final custom correction low order RMS over a 5-mm pupil were 2.08 and 0.34 microm, and high order RMS levels were 0.77 and 0.39 microm, respectively. CONCLUSIONS: The final custom contact lens showed 1.5 lines of improvement for photopic high contrast (P=.03) and 1 line for photopic low contrast (P=.11) over a 5-mm pupil compared to habitual correction. Low and high order aberrations were reduced by 84% and 50% over a 5-mm pupil, respectively. Further improvements in performance of custom lenses may be achieved with further wavefront iterations.

Changes of higher order aberration with various pupil sizes in the myopic eye.

PURPOSE: To investigate the effect of pupil diameter on higher order aberration in myopic eyes. METHODS: One hundred and two eyes of 51 normal subjects were evaluated with the Nidek OPD-Scan. RESULTS: All types of aberration increased significantly with increasing pupil size (P<.001). However, optical aberrations had a less pronounced increase in C3(-1) and C3(+1) , more pronounced increase in C4(0) with pupil area increased (P<.05), 2nd coma (C5(-1) and C6(+1)) and high order astigmatism (C4(-2), C4(+2) C6(-2), C6(+2) with larger pupil diameter. Compared with the aberrations of each high order aberration at 4 mm, the average increase root mean square values were 1.54, 1.59, 1.71, and 1.87 on S3, S4, S5, and S6 respectively, with a 5-mm pupil, whereas increased root mean square values were 1.46, 1.88, 1.51, and 1.60 for a 6-mm-diameter pupil. CONCLUSION: For an equal increase of pupil size, not all Zernike polynomial coefficients induced equivalent increase of values. Coma-like aberrations increased less with pupil dilation. Spherical-like aberration showed only a small increase from 4 mm to 5 mm pupil size, but a larger increase from 5 mm to 6 mm pupil size. Other higher order aberrations (S5 and S6) increased slightly with pupil dilation. Coma-like aberration was larger than spherical aberration, and larger than other higher order aberrations for all pupil sizes.