Assessment of corneal thickness in soft contact lens users using anterior segment optical coherence tomography

2018 ◽  
Vol 19 (4) ◽  
pp. 216
Author(s):  
MohamedA Hamed ◽  
NehalA Hasan ◽  
AhmedH Aldghaimy ◽  
DoaaA Ahmed
2018 ◽  
Vol 9 (1) ◽  
pp. 160-165 ◽  
Author(s):  
Takashi Ono ◽  
Yosai Mori ◽  
Ryohei Nejima ◽  
Takuya Iwasaki ◽  
Shiro Amano ◽  
...  

Chestnut burrs, the thorny encapsulation of chestnut fruit, can sometimes cause corneal injuries and ulceration, with poor prognoses. We report a case of corneal perforation and damaged anterior lens capsule due to a chestnut burr, using anterior segment optical coherence tomography (AS-OCT). A 67-year-old woman with a chestnut burr injury in her right eye was referred to our hospital. Her right best-corrected visual acuity (BCVA) was 0.8. Slit-lamp examination and AS-OCT showed perforation involving the endothelial layer at the center of the cornea. The iris and anterior lens capsule were damaged. Cell infiltration was observed around the wound. Bacterial examination showed gram-positive cocci but no fungi. The patient was diagnosed with a corneal perforation and bacterial keratitis. Levofloxacin 1.5% and cefmenoxime treatments were initiated and a soft contact lens was placed to seal the wound. On day 3, there was no improvement in the corneal cell infiltration, but AS-OCT suggested that the inner wound had closed. A culture test revealed the presence of Propionibacterium acnes, which was sensitive to both levofloxacin and cefmenoxime. Therefore, we continued the same antibiotic treatment. On day 26, the opacification and cell infiltration at the center of the cornea had improved. AS-OCT showed healing of the corneal wound with reduction in the central corneal thickness. Her BCVA improved to 1.0. AS-OCT was a valuable tool to noninvasively observe wound shape and detect the presence of any intracorneal foreign bodies.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Lele Cui ◽  
Ming Li ◽  
Meixiao Shen ◽  
Fan Lu ◽  
Jianhua Wang

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrew Kwok-cheung Lam ◽  
Kenny Kin-hei Lau ◽  
Ho-yin Wong ◽  
Jasmine Pui-kwan Lam ◽  
Man-for Yeung

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.


2021 ◽  
Author(s):  
Andrew Kwok-cheung Lam ◽  
Kenny Kin-hei Lau ◽  
Ho-yin Wong ◽  
Jasmine Pui-kwan Lam ◽  
Man-for Yeung

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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