scholarly journals MICROBIAL BIOBURDEN OF ORTHOKERATOLOGY AND HYDROGEL CONTACT LENSES AND STORAGE CASES USING A HYDROGEN-PEROXIDE DISINFECTING SYSTEM

2021 ◽  
Vol 5 (1) ◽  
pp. e19-e31
Author(s):  
Ananya Datta ◽  
Erin S. Tomiyama ◽  
Kathryn Richdale

Background and objective: The fitting of orthokeratology (ortho-k) and multifocal soft contact lenses (SCL) is becoming increasingly popular worldwide for reducing the rate of myopia progression. However, overnight wear use of lenses and microbial contamination of contact lenses and storage vials has been shown to increase the risk of corneal inflammatory and infiltrative events (CIEs). Therefore, we conducted a pilot study to compare the rate, level, and type of microbial contamination of contact lenses and storage vialswhen participants wear ortho-k and SCL in combination with a hydrogen-peroxide disinfecting system. Material and Methods: A prospective, single-centre, randomized, crossover study was conducted to evalu-ate the rate and level of contact lens and storage vials contamination during the use of ortho-k and SCL along with a hydrogen-peroxide disinfecting solution over two 10 day wearing periods. Ocular signs and symptoms were assessed during lens wear at baseline and after each wearing period. In addition, contact lens and storage vials were collected, and the type and amount of microbial contamination were evaluated using viable culture and standard identification methods.Results: Twenty-five adults were enrolled, and 21 completed the study. One (5%) ortho-k lens, five (24%) ortho-k storage vials, one (5%) SCL and one (5%) SCL storage vial were contaminated (P > 0.05), predominantly with Gram-positive bacteria. None of the participants had contamination with both ortho-k and SCL. No significant differences were found between the ocular signs, including conjunctival redness and roughness, or conjunctival or corneal staining (all P > 0.05), irrespective of using ortho-k or SCL. Conclusion: This study provides the first data that directly compares microbial contamination of ortho-K versus SCL in patients using a hydrogen-peroxide disinfection system. However, the overall microbial contamination rate of contact lens storage vials was much lower (30%) than the previously reported study with ortho-k lens wear. The results support conducting a larger clinical trial designed to understand differences in microbial contamination with different lens materials and modalities.

2009 ◽  
Vol 31 (4) ◽  
pp. 26-27
Author(s):  
James Lonnen

There are an estimated 125 million contact lens wearers across the world, and the majority experience few complications; however, it is well known that contact lens wear is a risk factor for microbial keratitis (infection of the cornea of the eye). Owing to the ubiquitous distribution of micro-organisms, it is extremely di cult to prevent them from colonizing contact lens storage cases. Bacteria, fungi and protozoa have all been found in contact lens storage cases; these micro-organisms can adhere to the contact lens, which then acts as a vector to transport the microbes on to the surface of the eye. Bacteria such as Pseudomonas aeruginosa, fungi such as Fusarium solani and the protazoan parasite Acanthamoeba–to name but a few–can cause infection of the corneal epithelial cells, which, if untreated, can lead to blindness. It is therefore essential that wearers clean and disinfect their contact lenses and storage cases e ectively to minimize the risk of infection.


2013 ◽  
Vol 36 ◽  
pp. e40
Author(s):  
Riikka Järvinen ◽  
Sarianna Koivula ◽  
Maria Lehtovaara ◽  
Jari Ahlgren ◽  
Hanna Vaahtoranta-Lehtonen

2021 ◽  
Vol 26 (3) ◽  
pp. 2626-2630
Author(s):  
EVELINA MILCHEVA MARINOVA ◽  
◽  
DIMITAR STOIMENOV DABOV ◽  
YANI TODOROV ZDRAVKOV ◽  
EMILIA KRASIMIROVA NASEVA ◽  
...  

Objective: The purpose of our research is to emphasize the role of underestimated predisposing conditions for microbial keratitis in contact lens users, to draw attention to the complications of wearing contact lenses without ophthalmic examination, and to offer a short questionnaire for fast and easy estimation of the risk factors for bacterial keratitis. Methods: A series of 23 cases of healthy young individuals, treated for bacterial keratitis, provoked а research on the predisposing factors for its development. Results: 55% of the patients had started to wear contact lenses without specific examination. 75% had made mistakes in the hygiene and storage of the lenses. We identified risk factors for development of bacterial keratitis in all cases. Conclusions: A thorough anamnesis and ophthalmic examination are crucial in decision making about contact lens wearing because they could reveal some of the predisposing conditions for the occurrence of ocular complications. The usage of contact lenses without a prescription poses health risks and could have a negative impact on the social and healthcare system.


2018 ◽  
Vol 2 (2) ◽  
pp. e14-e21
Author(s):  
Melissa Barnett ◽  
Jonathon Ross ◽  
Blythe Durbin-Johnson

Abstract Objectives: The purpose of this study was to evaluate the performance (i.e. vision, comfort and fit) of spherical and front-surface toric scleral lenses in subjects with regular, healthy corneas. Methods: Scleral lenses were fitin the eyes (n = 16) of healthy subjects (n = 9) with regular corneas, absent of pathology, and studied using an observational, multi-visit design. Lens fit was objectively evaluatedby an experienced practitioner.Following 1 month of successful lens wear, participants completedsubjective satisfaction surveys regarding the scleral lens wearing experience. Results:  According to participant surveys, scleral lenses were subjectively preferred over soft toric or gas permeable contact lenses in 88% of eyes, including in all eyes fit with a front-surface toric scleral lens (n = 3). Seventy-five percent (75%) of eyes achieved visual acuity of 0.1 logMAR or better, while all eyes with prior spectacle wear achieved visual acuity with a scleral lens within 1 Snellen line of spectacle correction. Seventy-five percent (75%) of eyes achieved good subjective comfort with a scleral lens. No participants reported poor subjective vision and/or comfort. Conclusions:  Our findings suggest that subjects preferred the performance of a scleral lens (spherical or front-surface toric) compared to a soft toric or gas permeable contact lens. Moreover, scleral lenses may provide a viable, alternative contact lens modality option for patients considering discontinuation of traditional soft toric and/or rigid contact lens wear; so long as the factors associated with hypoxia remain minimized. Key Words:  scleral lens; scleral contact lens; front-surface toric scleral lens; lens performance; normal eyes; healthy eyes


2018 ◽  
Vol 41 ◽  
pp. S41
Author(s):  
Samuele Tosatti ◽  
Olof Sterner ◽  
Rudolf Aeschlimann ◽  
Stefan Zuercher ◽  
Charles Scales ◽  
...  

2020 ◽  
Vol 5 (1) ◽  
pp. e000476
Author(s):  
Anna Stellwagen ◽  
Cheryl MacGregor ◽  
Roger Kung ◽  
Aristides Konstantopoulos ◽  
Parwez Hossain

ObjectiveMicrobial keratitis is a sight-threatening complication of contact lens wear, which affects thousands of patients and causes a significant burden on healthcare services. This study aims to identify compliance with contact lens care recommendations and identify personal hygiene risk factors in patients who develop contact lens-related microbial keratitis.Methods and analysisA case–control study was conducted at the University Hospital Southampton Eye Casualty from October to December 2015. Two participant groups were recruited: cases were contact lens wearers presenting with microbial keratitis and controls were contact lens wearers without infection. Participants underwent face-to-face interviews to identify lens wear practices, including lens type, hours of wear, personal hygiene and sleeping and showering in lenses. Univariate and multivariate regression models were used to compare groups.Results37 cases and 41 controls were identified. Showering in contact lenses was identified as the greatest risk factor (OR, 3.1; 95% CI, 1.2 to 8.5; p=0.03), with showering daily in lenses compared with never, increasing the risk of microbial keratitis by over seven times (OR, 7.1; 95% CI, 2.1 to 24.6; p=0.002). Other risks included sleeping in lenses (OR, 3.1; 95% CI, 1.1 to 8.6; p=0.026), and being aged 25–39 (OR, 6.38; 95% CI, 1.56 to 26.10; p=0.010) and 40–54 (OR, 4.00; 95% CI 0.96 to 16.61; p=0.056).ConclusionThe greatest personal hygiene risk factor for contact lens-related microbial keratitis was showering while wearing lenses, with an OR of 3.1, which increased to 7.1 if patients showered daily in lenses. The OR for sleeping in lenses was 3.1, and the most at-risk age group was 25–54.


2009 ◽  
Vol 86 (10) ◽  
pp. 1150-1153 ◽  
Author(s):  
Adam Blacker ◽  
G Lynn Mitchell ◽  
Mark A. Bullimore ◽  
Bill Long ◽  
Joseph T. Barr ◽  
...  

2019 ◽  
Author(s):  
Motohiro Itoi ◽  
Koji Kitazawa ◽  
Hisayo Higashihara ◽  
Chie Sotozono

AbstractPurposeTo evaluate the impact of removal of rigid gas-permeable (RGP) contact lenses on the anterior and posterior cornea surfaces of eyes with keratoconus.MethodsEight eyes of 8 patients with keratoconus (KC) (age 34.3 ± 15.3 years; range 19–60 years) were enrolled. Anterior segment optical coherence tomography (AS-OCT) was performed at 1, 5, 10, 20, and 60 minutes after the patients removed their RGP contact lenses. Measurements included anterior and posterior best-fit sphere (BFS); elevation values and corneal surface areas; corneal thickness at the thinnest point; and the anterior-posterior ratio of the corneal surface (As/Ps) between 1 minute and 60 minutes after RGP contact lens removal.ResultsAnterior and posterior elevation values and corneal surface areas showed significant increases, whereas anterior and posterior BFS and central corneal thickness decreased significantly (P < 0.01) between 1 minute and 60 minutes after RGP contact lens removal. No statistically significant differences were found in the As/Ps ratio during the first hour after suspending RGP contact lens wear.ConclusionsWe found that the patients with keratoconus experienced significant changes in both the anterior and posterior corneal shape for 60 minutes after removal of RGP contact lenses.


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