Fixation Stability and Deviation in Optical Coherence Tomography Angiography Using Soft Contact Lens Correction in Myopes

Abstract ObjectiveTo compare fixation deviation and stability with soft contact lens correction and device built-in auto-focus system during optical coherence tomography angiography (OCTA).MethodsThis observational study measured OCTA metrics first with contact lens correction, followed by removal of contact lenses, using the device auto-focus system at a University Optometry Clinic, Hong Kong. All participants were habitual soft contact lens wearers with either low or high myopia. OCTA measurements were obtained using a spectral domain OCTA. Fixation deviation was distance (in pixels) of the fovea to the center of the OCTA measurement grid. Fixation stability was test-retest repeatability (TRR) and coefficient of variation (CV) of fixation deviation from three consecutive OCTA measurements. OCTA metrics included vessel length density (VD), perfusion density (PD), and foveal avascular zone (FAZ) area. Averaged OCTA metrics were calculated from three measurements and compared between the two correction methods.ResultsThe mean ± SD spherical equivalent of 74 eyes from 74 myopes measured was -1.94D ± 0.75D in low myopes (n=37) and -7.97D ± 1.31D in high myopes (n=37). When corrected with contact lenses, visual acuities of high myopes (median [IQR], -0.06 [0.08] logMAR) and low myopes (0.02 ± 0.08 logMAR) were similar (P = 0.060), and with similar fixation deviation (5.0 ± 2.2 pixels vs 5.3 [3.6] pixels; P = 0.689). High myopes had poorer fixation stability than low myopes (TRR: 10.2 pixels vs 7.5 pixels; CV: 65% vs 54%, respectively). The worst fixation stability occurred when high myopes were corrected using the auto-focus system (TRR: 12.5 pixels, CV: 72%). The difference in VD and PD was within 1mm-1 and 1%, respectively. The FAZ area was similar.Conclusions High myopes had more stable fixation when corrected when wearing contact lenses. Subjects with good contact lens corrected visual acuity should wear their contact lenses during OCTA measurements.

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Fixation stability and deviation in optical coherence tomography angiography using soft contact lens correction in myopes

Scientific Reports ◽

10.1038/s41598-021-91403-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Andrew Kwok-cheung Lam ◽

Kenny Kin-hei Lau ◽

Ho-yin Wong ◽

Jasmine Pui-kwan Lam ◽

Man-for Yeung

Keyword(s):

Optical Coherence Tomography ◽

Contact Lens ◽

Optical Coherence Tomography Angiography ◽

Contact Lenses ◽

Foveal Avascular Zone ◽

Optical Coherence ◽

Soft Contact ◽

Soft Contact Lens ◽

Fixation Stability ◽

Auto Focus

AbstractTo compare fixation deviation and stability with soft contact lens correction and device built-in auto-focus system during optical coherence tomography angiography (OCTA). This observational study measured OCTA metrics first with contact lens correction, followed by removal of contact lenses, using the device auto-focus system at a University Optometry Clinic, Hong Kong. All participants were habitual soft contact lens wearers with either low or high myopia. OCTA measurements were obtained using a spectral domain OCTA. Fixation deviation was distance (in pixels) of the fovea to the center of the OCTA measurement grid. Fixation stability was test–retest repeatability (TRR) and coefficient of variation (CV) of fixation deviation from three consecutive OCTA measurements. OCTA metrics included vessel length density (VD), perfusion density (PD), and foveal avascular zone (FAZ) area. Averaged OCTA metrics were calculated from three measurements and compared between the two correction methods. The mean ± SD spherical equivalent of 74 eyes from 74 myopes measured was − 1.94D ± 0.75D in low myopes (n = 37) and − 7.97D ± 1.31D in high myopes (n = 37). When corrected with contact lenses, visual acuities of high myopes (median [IQR], − 0.06 [0.08] logMAR) and low myopes (− 0.02 ± 0.08 logMAR) were similar (P = 0.060), and with similar fixation deviation (5.0 ± 2.2 pixels vs 5.3 [3.6] pixels; P = 0.689). High myopes had poorer fixation stability than low myopes (TRR: 10.2 pixels vs 7.5 pixels; CV: 65% vs 54%, respectively). The worst fixation stability occurred when high myopes were corrected using the auto-focus system (TRR: 12.5 pixels, CV: 72%). The difference in VD and PD was within 1 mm−1 and 1%, respectively. The FAZ area was similar. Difference in OCTA metrics was small in each refractive group (< 1 mm−1 in VD, and < 2% in PD). High myopes had more stable fixation when corrected when wearing contact lenses. Subjects with good contact lens corrected visual acuity should wear their contact lenses during OCTA measurements.

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Characterization of Soft Contact Lens Fitting Using Ultra-Long Scan Depth Optical Coherence Tomography

Journal of Ophthalmology ◽

10.1155/2017/5763172 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Lele Cui ◽

Ming Li ◽

Meixiao Shen ◽

Fan Lu ◽

Jianhua Wang

Keyword(s):

Optical Coherence Tomography ◽

Contact Lens ◽

Contact Lenses ◽

Repeated Measurements ◽

Optical Coherence ◽

Soft Contact ◽

Soft Contact Lenses ◽

Soft Contact Lens ◽

Good Repeatability ◽

The Right

Objectives. To evaluate the centration and movement of soft contact lenses and to verify the repeatability of two repeated measurements of the lens centration and movement using ultra-long scan depth optical coherence tomography (UL-OCT). Methods. A 1-day Acuvue® Define™ lens was tested on both eyes of 10 subjects (5 males and 5 females; mean age, 31.6 years). The centration and blink-induced movement of the contact lens were measured using UL-OCT at 5 min and 30 min after insertion. The measurements were repeated once at each checkpoint. Results. Good repeatability was found in the lens centration and movement between the two repeated measurements at either checkpoint. The values of the lens movement were 0.457 ± 0.248 mm and 0.402 ± 0.229 mm at 5 min and decreased to 0.197 ± 0.065 mm and 0.211 ± 0.110 mm at 30 min after insertion for the right and left eyes, respectively (P<0.05). Conclusions. The custom-built UL-OCT presented good repeatability of centration and movement in Define lenses at 5 min and 30 min after insertion. Most of the lenses were centered temporal and inferior to the cornea during the first 30 min wearing period. Compared with 5 min after insertion, the lens was centered better and exhibited less movement at 30 min.

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Characterization of Soft Contact Lens Edge Fitting during Daily Wear Using Ultrahigh-Resolution Optical Coherence Tomography

Journal of Ophthalmology ◽

10.1155/2018/3463595 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Lele Cui ◽

Sisi Chen ◽

Weihe Zhou ◽

Kaixuan Sheng ◽

Lei Zhang ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Contact Lens ◽

Contact Lenses ◽

Optical Coherence ◽

Soft Contact ◽

Ultrahigh Resolution ◽

Soft Contact Lenses ◽

Soft Contact Lens ◽

Lens Wear ◽

Peripheral Cornea

Purpose. To determine conjunctival overlap over the edge of soft contact lens and to visualize the peripheral postlens tear film (PoLTF) underneath soft contact lenses using ultrahigh-resolution optical coherence tomography (UHR-OCT). Methods. Twenty participants (4 males and 16 females, 23.0 ± 3.7 years) were fitted with two different types of soft contact lenses randomly. The limbus with lens was imaged with the UHR-OCT at the horizontal meridian every two hours up to 6 hours during lens wear. The conjunctival overlap was ranked as the percentage of the edge covered by the conjunctiva. The frequency of occurrence for visualized peripheral PoLTF was determined. Results. The average conjunctival overlaps at insertion were 49% and 73% for galyfilcon A and balafilcon A lenses and increased significantly to 84% and 90% by 6 hours of lens wear (P<0.001). Lenses with rounded edges had more conjunctival overlap than the lenses with angled edges (P=0.014). There were significant decreases for PoLTF on the conjunctiva (P=0.014) and peripheral cornea (P=0.004) over the study period compared to insertion. The percentage of subjects with PoLTF on the conjunctiva (32.5%) and peripheral cornea (36%) were greater in subjects wearing balafilcon A lenses (P=0.017). Conclusions. Increased conjunctival overlap over the lens edges and reduced PoLTF underneath the peripheral region of soft contact lenses were shown during lens daily wear. The lens edge configuration may play a role in conjunctival response and peripheral PoLTF.

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