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

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
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.

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

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
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.

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

2021 ◽  
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

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.

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

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.

scholarly journals The structure of soft contact lens users and the incidence of papillary conjunctivitis in the analyzed groups according to the data of “Krugozor” ophthalmology clinic

The Eye ◽  
2020 ◽  
Vol 22 (4(132)) ◽  
pp. 30-35
Author(s):  
O. V. Dubovtseva ◽  
N. A. Bakalova
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Moderate Degree ◽  
Soft Contact ◽  
Wear Time ◽  
Soft Contact Lenses ◽  
Soft Contact Lens ◽  
Vision Correction ◽  
Lens Wear ◽  
Giant Papillary Conjunctivitis

Introduction. Vision correction by contact lenses is one of the most common and effective methods for correcting refractive errors in children and adults. Compliance with rules of soft contact lenses (SCLs) wearing is one of the most important conditions for a safe use, while violation of compliance is usually the main cause of complications.Purpose. To study the structure of contact lens wearers by ametropia and lens wearing time as well as to determine the relationship between the incidence of giant papillary conjunctivitis (GPC) with lens wear time and overwear time.Material and methods. A retrospective analysis of 1 000 records (1 000 patients) of patients who underwent vision correction by SCLs in “Krugozor” ophthalmology clinic in the year 2019 was carried out. Mean age of patients was 24.95 ± 8.62 years. Age, type and degree of ametropia, material (hydrogel, silicone hydrogel or biocompatible hydrogel), lens replacement schedule, presence of complications, lens overwear time and daily wear time were taken into account.Results. Most SCLs users are patients between 21 and 30 years old (47%) who have a moderate degree of ametropia (52%). Most of them (46%) preferred monthly replacement SCLs, 29% – bi-weekly replacement SCLs, 9% preferred daily replacement lenses, while quarterly replacement lenses were used by 16%. Only 26.9% of SCL users complied with the instructions for lens wear, while for 29.4% of them lens overwear time amounted to up to 14 days, for 34.1% – up to 28 days, and for 9.6% – more than 1 month. More than half (56%) of patients mainly wore SCLs during 16 hours a day, one in five (22.7%) used SCLs during 12 hours a day, and 12.6% – up to 20 hours a day. 8.7% wore lenses during up to 7 days. The incidence of GPC in patients who did not comply with replacement schedule and were overwearing lenses was significantly higher (38.71%) than in patients who followed the replacement schedule (3.21%).Conclusion. More than half of the users comprised young people with a moderate degree of myopia. The most commonly used SCLs were monthly replacement. It was discovered that only one in four wearers followed recommendations of manufacturers and replaced lenses on time. Lens overwear may lead to a development of a giant papillary conjunctivitis (GPC). 

scholarly journals STUDY OF THE OPTICAL POWER OF NANOPHOTONIC SOFT CONTACT LENSES BASED ON POLY (2- HYDROXYETHYL METHACRYLATE) AND FULLERENE

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Aleksandra Debeljković Mitrović ◽  
Dragomir Stamenković ◽  
Manuel Conte ◽  
Božica Bojović ◽  
Spomenko Mihajlović
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Measurement Techniques ◽  
Optical Power ◽  
Soft Contact ◽  
Standard Material ◽  
Soft Contact Lenses ◽  
Soft Contact Lens ◽  
Power Cylinder

In this paper results of comparative study of the optical power of soft contact lenses (SCL) made of standard material for SCL and nanophotonic materials with different measurement techniques used for the final contact lens controllers are presented. Three types of nanophotonic soft contact lenses were made of standard polymacon material (Soleko SP38TM) incorporated with fullerene C60, fullerol C60(OH)24 and fullerene metformin hydroxylate C60(OH)12(OC4N5H10)12. For the purposes of material characterization for potential application as soft contact lenses, the optical properties of the soft contact lenses were measured by Rotlex and Nidek device. With Rotlex device the following optical results were obtained: optical power and map of defects, while with the Nidek device: optical power, cylinder power and cylinder axis. The obtained values of optical power and map of defects showed that the optical power of synthesized nanophotonic soft contact lens is same to the nominal value, while this was not the case for the standard soft contact lens. Also, the quality of the nanophotonic soft contact lens is better than the standard one. Hence, it is possible to synthesize new nanophotonic soft contact lenses of desired optical characteristics, implying possibilities for their application in this field.

scholarly journals Characterization of nanophotonic soft contact lenses based on poly (2-hydroxyethyl methacrylate) and fullerene

2013 ◽  
Vol 67 (6) ◽  
pp. 861-870 ◽  
Author(s):  
Aleksandra Debeljkovic ◽  
Lidija Matija ◽  
Djuro Koruga
Keyword(s):  
Contact Lens ◽  
Near Infrared ◽  
Contact Lenses ◽  
Base Material ◽  
Optical Power ◽  
Sem Analysis ◽  
Hydroxyethyl Methacrylate ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
Soft Contact Lens

This work presents comparative research of characteristics of a basic and new nanophotonic material, the latter of which was obtained by incorporation fullerene, C60, in the base material for soft contact lenses. The basic (SL38) and nanophotonic materials (SL38-A) for soft contact lenses were obtained by radical polymerization of 2-hydroxyethyl methacrylate and 2-hydroxyethyl methacrylate and fullerene, which were derived by the technology in the production lab of the company Soleko (Milan, Italy). The materials were used for production of soft contact lenses in the company Optix (Belgrade, Serbia) for the purposes of this research. Fullerene was used due to its apsorption transmission characteristics in ultraviolet, visible and near infrared spectrum. For the purposes of material characterization for potential application as soft contact lenses, network parameters were calculated and SEM analysis of the materials was performed while the optical properties of the soft contact lenses were measured by a Rotlex device. The values of the diffusion exponent, n, close to 0.5 indicated Fick's kinetics corresponding to diffusion. The investigated hydrogels could be classified as nonporous hydrogels. With Rotlex device, values of optical power and map of defects were showed. The obtained values of optical power and map of defects showed that the optical power of synthesized nanophotonic soft contact lens is identical to the nominal value while this was not the case for the basic lens. Also, the quality of the nanophotonic soft contact lens is better than the basic soft contact lens. Hence, it is possible to synthesize new nanophotonic soft contact lenses of desired optical characteristics, implying possibilities for their application in this field.

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