Lotrafilcon B with HydraGlyde moisture matrix or Samfilcon A: Contralateral comparison study for comfort.

PURPOSE: The purpose of this study was to compare two new silicone hydrogel contact lens (CL) models of lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®) and samfilcon A (Bausch and Lomb Ultra®) using the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) test.
METHODS: This prospective study included 30 patients between the ages of 19 and 35 years. Lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®) and samfilcon A (Bausch and Lomb Ultra®) CLs were fitted on the right and the left eye of the patients, respectively. All of the patients have not used any CLs before. After 4 weeks, the CLs were compared by asking the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) test.
RESULTS: The mean scores of CLDEQ-8, frequency and intense of discomfort, dryness, blurry vision, frequency of needing to blink eye, and removal of the CL were assessed. There was no statistically significant difference between two groups (P > 0.05).
CONCLUSION: The main reasons for CL discontinuation are dryness and discomfort. These two new CLs used new advanced technology have a good compliance among the first-time CL users.

Introduction

Myopia, affecting approximately one-third of the US population and over 90% of the population in some East Asian countries,[1] is the most prevalent refractive error and a public problem.

Contact lens (CL) use for refractive error is common among young and adults. It has been estimated that there are approximately 140 million wearers of CLs worldwide.[2] Despite the development of newer materials for soft CLs, discontinuation of CL wear due to several factors is still an important factor that limits the number of successful wearers.[34] The possible causes of CL intolerance are multifactorial (preexisting tear dysfunction and CL chemical features-CL wettability, and environmental factors such as humidity, temperature, and blink characteristics).[56] It is well known that ocular surface symptoms such as comfort-related problems and dryness which are common in some 30%–50% of lens wearers at the end of the day[789] are the main reasons for CL dropout.[10]

The 2013 Tear Film Ocular Surface Society Workshop on Contact Lens Discomfort described the 8-item Contact Lens Dry Eye Questionnaire (CLDEQ-8).[11] The CLDEQ-8 including several questions is a short form of the CLDEQ test that was designed to evaluate CLs such as discomfort, dryness, and blurry vision among CL wearers. The sum of scores of the test was related to the general opinion of lenses.

Lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®) and samfilcon A (Bausch and Lomb Ultra®) are two new CLs with different technologies that were introduced with the promise of comfort and good wettability.

As we know, there are no studies comparing these two new CLs. In this study, the aim is to compare two new CL models, lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®) and samfilcon A (Bausch and Lomb Ultra®) using the CLDEQ-8 test.

Methods

This prospective and single-blind study included 30 patients who were examined at the CL Unit of Ankara Ataturk Training and Research Hospital. Lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®) and samfilcon A (Bausch and Lomb Ultra®) CLs were fitted on the right eye and the left eye of the patients, respectively. Informed consent was obtained from all patients. The present study was approved by the Local Ethics Committee, and the study was conducted by the Declaration of Helsinki. Patients, included in this study were between the ages of 19 and 35 years, with myopic lens correction from − 0.50 D to − 6.0 D in each eye. All the patients have not used any CLs before. Patients with clear cornea and having no other ocular eye disease, spending at least 3 h each day using a computer or electronic device, and wearing the CLs which were started for this study for a minimum of 8 h per day during a month were included in this study (Registration No. 26379996/118).

All the patients were used the same CL solutions (Bio True Solutions-Bausch and Lomb).

After 4 weeks, the CLs were compared by asking the CLDEQ-8 test. CLDEQ-8 test consists of five questions related to the CL which was used. This test is useful to assess the frequency and severity of CL-related disorders, dryness, and blurred vision with scores that grade each response. A lower CLDEQ-8 score shows less CL-related symptoms and good CL compliance.

Statistical analysis

Statistical analysis of the data obtained in this study was performed using the Statistical Package for Sciences (SPSS) software for Windows, version 20 (SPSS Inc., Chicago, IL, USA) program. Continuous variables were analyzed using Kolmogorov–Smirnov test for normal distribution. Independent-samples t-test was used to compare the mean of the two groups, which provided the normal distribution assumption and the homogeneous variance. The P value for statistical significance was accepted as <0.05.

Results

Characteristics of the CLs are summarized in Table 1.

Table 1

Characteristics of the contact lenses

	Samfilcon A	Lotrafilcon B with HydraGlyde moisture matrix
Lens material technology	Moisture seal technology	Smart shield technology
Water content	46%	33%
Oxygen transmission	163 Dk/t	138 Dk/t
Base curve	8.5 mm	8.6 mm
Diameter	14.2 mm	14.2 mm
Center thickness	0.07 mm at−3.00 D	0.08 mm at−3.00 D
Spherical power	+6.00 D-−12.00 D	+8.00 D-−12.00 D

The mean age of the patients was 24.7 ± 4.3 (19–35). Refraction error is similar between eyes of each patients, and the mean value of myopic refractive error was 2.1 ± 0.7 in both eyes. Characteristics of the subjects are summarized in Table 2.

Table 2

Characteristics of the patients

Parameters	Subjects (n=30)
The mean myopic refraction error	2.1±0.7 D (−0,50/−3.75 D)
The mean age of the patients	24.7±4.3 (19-35)
Female/male (n)	20/10

The mean scores of CLDEQ-8 in lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®) group were 6.8 ± 6.4, in samfilcon A (Bausch and Lomb Ultra®) group was 5.1 ± 4.8. There was no statistically significant difference between two groups (P = 0.25). Comparison of CLDEQ-8 scores between lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®) and samfilcon A (Bausch and Lomb Ultra®) groups is summarized in Table 3.

Table 3

Comparison of contact lens dry eye questionnaire-8 scores between lotrafilcon B with HydraGlyde moisture matrix (Air Optix Plus HydraGlyde®) and samfilcon A (Bausch and Lomb Ultra®) groups

CLDEQ-8 test	Lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®)	Samfilcon A (Bausch and Lomb Ultra®)	P*
Frequency of discomfort	0.8±0.1	0.6±0.1	0.33
Intense of discomfort	0.4±01	0.2±0.1	0.39
Frequency of dryness	0.6±0.1	0.4±0.1	0.31
Intense of dryness	1.0±0.2	0.6±0.1	0.18
Frequency of blurry vision	0.6±0.1	0.4±0.1	0.57
Intense of blurry vision	0.7±0.2	0.4±0.1	0.29
Needing to blink eye	1.0±0.2	0.8±0.1	0.42
Needing removal of CL	1.5±0.2	1.5±0.2	0.90
Mean scores of CLDEQ-8	6.8±6.4	5.1±4.8	0.25

*P value is calculated by independent-samples t-test. CLDEQ-8=Contact lens dry eye questionnaire-8, CL=Contact lens

Discussion

The problems about using CL are related to discomfort such as dryness and end of the day discomfort.[5912] CL surfaces that do not have constant wettability during the day cause blurring and discomfort. A wettable CL supports spreading of a stable tear film over the lens, reducing dryness symptoms, and blurring.

CL-related dry eye is accepted in the evaporative category according to the 2007 Dry Eye Workshop.[13] According to the environment exposures, rapid rotation of siloxane groups in silicone hydrogel lens materials is an important problem. This migration makes lens surfaces hydrophobic and reduces wettability of the surface.[1415] This causes heterogeneity of tear film spreading and reduced CL compliance through the day.[141516] Reduced tear breakup time due to the increased tear evaporation related to CL wear is associated with increased tear and lens osmolality, which may exacerbate dryness symptoms.[161718] In addition, reversible changes in corneal and conjunctival inflammation were shown in patients who wear soft CL which may be related to dryness symptoms.[19]

Advanced lens design and surface treatments with plasma or internal wetting agents have improved CL comfort and vision.[202122]

New technology with the addition of EO45BO10 (HydraGlyde), poly (oxyethylene), and poly (oxybutylene), the material is used in lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®) CLs. This material targets internal and external siloxane groups resulting in maintenance of low wetting angle (<10°) with improved wettability.[23] Smart shield Technology-plasma treatment of the surface in the lotrafilcon B lenses improve deposit resistance and increase the wettability of the lens.[2324] Lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde®) CL has 33% of water content in the monthly silicone hydrogel category.

Another new technology, consisting of two-phase reaction, is used in the samfilcon A (Bausch and Lomb Ultra®) CLs.[25] In phase 1, a unique combination of short and long chain silicone polymers makes a flexible silicone matrix with channels for oxygen transmission. In phase 2, polyvinylpyrrolidone (PVP) which is a high water affinity material and makes the lens containing water everywhere on the lens not just at its surface.[25] PVP wraps around the silicone polymer to make the surface and polymer hydrophilic. As a result of Moisture Seal technology, samfilcon A (Bausch and Lomb Ultra®) CLs, having 46% of water content in the monthly silicone hydrogel category, keep moisture all the day and provide a smooth optical surface to help prevent dehydration blur.

There are several studies evaluating CL comfort using CLDEQ-8 test.[262728] In this study, we used the CLDEQ-8 test to evaluate the CL-related symptoms of the two newly produced CLs in the same CL wearer's. The lower CLDEQ-8 scores in our study indicated that these two new CLs using two different technologies have an effect on improving the CL-related disorders such as discomfort and dryness.

The main limitation of our study is small sample size. Furthermore, it would be better to assess and compare the corneal and conjunctival cytological changes after wearing these two new CLs and carry out on the patients, who discontinued CLs using before because of dryness and discomfort.

Conclusion

Comfort and clear vision without dryness are main factors of CL wear satisfaction. A wettable CL surface is essential to reduce friction and surface deposition with improving optical quality and comfort. Although longer follow-up is required, it seems that both of these new CLs may be good options for the first-time CL users. New studies with CLs using two novel technologies are needed in patients who have CL-related discomfort and dryness.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

The authors declare that there are no conflicts of interests of this paper.