Alison Ng is a clinical scientist at the Centre for Ocular Research & Education, in the School of Optometry & Vision Science at the University of Waterloo.
Contact lenses provide a wealth of benefits to millions of people around the world. Contact lenses are regulated as medical devices, based on the potential risk of complications to wearers.1 A comprehensive summary of the classification, epidemiology, pathophysiology, management and prevention of contact lens-related complications is detailed in the BCLA CLEAR Contact Lens Complications report,2 which also equips the eye care professional with strategies for optimizing contact lens wear. The report opens by stating: “Contact lens-related complications are common, affecting around one third of wearers, although most are mild and easily managed.”
The report approached classification of contact lens complications by presumed etiology. As such, complications were grouped as follows:
|Corneal infection||Microbial keratitis|
|Corneal inflammation||Sterile keratitis|
|Metabolic conditions||May affect the corneal epithelium, stroma, or endothelium|
|Mechanical||Corneal abrasion, corneal erosion, lens binding, warpage/refractive error changes; superior epithelial arcuate lesion, mucin balls, conjunctival epithelial flaps, ptosis, discomfort|
|Toxic and allergic disorders||Papillary conjunctivitis, solution-induced corneal staining, incomplete neutralisation of peroxide, limbal stem cell deficiency|
|Tear resurfacing disorders/dry eye||Contact lens-induced dry eye, meibomian gland dysfunction, lid wiper epitheliopathy, lid parallel conjunctival folds, inferior closure stain, 3 and 9 o’clock stain, dellen, dimple veil|
|Contact lens discomfort||Potential for reduce comfortable wear time, reduced hours and days of wear and eventual drop out|
The grouping of complications listed above highlight that the lens wear experience involves interactions of the lens with different aspects of the eye, including the tear film, ocular surface, skin, endogenous and environment, microorganisms (both commensal and environmental), care products, and other antigens, which can give rise to conditions specific to contact lens wear. Contact lens wearers may also have concomitant or pre-existing conditions unrelated to lens wear (e.g. allergic eye disease or blepharitis) which may become an additional layer of consideration in the diagnosis and management of a contact lens complication.
The report summarizes 32 different contact lens complications. Using an evidence-based approach, the report describes in detail the prevalence, risk factors, pathophysiology, presenting signs and symptoms, differential diagnosis and management options, in addition to prevention and advice to wearers for each condition (or overarching group of conditions). Several useful summary tables are provided for an “at-a-glance” reference to complications, including a table highlighting the features and factors associated with different complications, which take into consideration presenting signs and symptoms, lens type and compliance.
Despite the exhaustive list of potential complications related to contact lens wear, corneal infection needs to be differentiated from the rest of the complications listed. Even though severe complications such as microbial keratitis are rare, it is the only complication of lens wear associated with the risk of significant visual loss. Any progressively painful red eye in a contact lens wearer needs to be managed appropriately and urgently for possible microbial keratitis. Many of the other complications outlined in the report are self-limiting on the cessation of lens wear and are associated with limited morbidity. All risk factors for complications presented in the report are described as modifiable and non-modifiable, providing practitioners with a valuable resource to enable evidence-based decision making to prevent the likelihood of the development of a complication. Treating even minor complications early is encouraged, to allow patients to enjoy a safe, successful and comfortable wearing experience, for many years to come.
- Zaki M, Pardo J, Carracedo G. A review of international medical device regulations: Contact lenses and lens care solutions. Cont Lens Anterior Eye 2019;42:136-46.
- Stapleton F, Bakkar M, Carnt N, et al. CLEAR – Contact lens complications. Cont Lens Anterior Eye 2021;44:330-67.