Summary of Contact Lens Fitting and Complications
Contact Lens Fitting & Complications: Student Guide
Introduction
Contact lenses are widely used for refractive correction, but they can cause a variety of problems that impact vision, comfort, and ocular health. This guide summarizes common contact lens-related problems and practical management strategies, focusing on soft hydrogel and GP (gas permeable) lens issues. It breaks complex concepts into clear sections with examples, quick checks, and actionable steps for clinical practice.
Definition: Contact lens-related problem — any symptom, sign, or clinical finding that reduces visual quality, causes discomfort, or threatens ocular health in a patient wearing contact lenses.
Overview of Common Problems
- Reduced vision
- Discomfort or pain
- Lens surface problems (wettability, deposits)
- Mechanical complications (edge lift, inversion)
- Corneal changes (desiccation, warpage, central clouding)
- Acute events (foreign body, torn lens)
General Approach to Problem Solving
- Take a focused history: onset, duration, whether problem is present with spectacles, lens age, cleaning regimen, overnight wear, unilateral vs bilateral symptoms.
- External and slit-lamp examination: check lens position, movement, edge alignment, corneal staining, tear break-up time (TBUT), and lens surface.
- Simple diagnostic tests: pinhole for refractive causes, lens inversion check, over-refraction (OR), fluorescence staining, evaluate lens fit and centration.
- Manage by cause: replace or refit lens, adjust cleaning or care, change base curve or material, refer for pathology if needed.
Reduced Vision (Contact Lens–Associated)
Key causes
- Incorrect prescription or residual refractive error
- Inverted lens or mislocated lens
- Lens contamination or deposits
- Poor surface wettability
- Defective lens material or damage (tears, edge nicks)
- Corneal abnormalities (edema, punctate keratitis, infectious keratitis)
Definition: Over-refraction (OR) — a refraction performed while the patient is wearing the contact lens to determine residual refractive error.
Clinical steps
- Confirm whether spectacle vision is similarly affected; if both, consider corneal or intraocular pathology and refer as needed.
- Perform pinhole testing to help rule out media or macular problems.
- Inspect lens for inversion, deposits, edge lift, or tears.
- If incorrect Rx is suspected, perform OR and consider lens replacement.
Practical example: A patient reports blurred vision after a month of wear. Pinhole improves acuity, and slit-lamp shows heavy deposits. Management: remove, clean or replace lens, reinforce cleaning regimen, consider different lens material with better wettability.
Poor Surface Wettability
Types
- Initial poor wettability (new lenses with residual polishing agents)
- Acquired wettability issues (deposits, tear-film changes)
Definition: Wettability — the ability of the tear film to spread over the lens surface, affecting comfort and optical quality.
Management
- Pre-soak new lenses for at least 24 hours before dispensing.
- Use laboratory solvent or cleaner (e.g., Boston Lab Cleaner) to remove residual polish.
- Recondition lens surface with a wetting solution; light polishing only if necessary.
- If progressive or persistent, consider lenses designed for improved wettability or change to alternative material.
Lens Inversion and Edge Problems
Presentation
- New wearers often report awareness or mild irritation with inverted lenses, especially thin lenses.
- Signs: standoff of lens edge (edge lift), excessive movement, discomfort, localized staining.
Management
- Inspect lens orientation at slit lamp; look for inversion marks or edge configuration.
- Use lenses with inversion marks or change to lens designs with more stable edges (examples: Acuvue, FreshLook have orientation
Zaregistruj se pro celé shrnutíAlready have an account? Sign in
Contact Lens Problems
Klíčové pojmy: Always take a focused lens history including onset, lens age, and cleaning regimen, Use pinhole and over-refraction to differentiate refractive vs corneal causes of reduced vision, Pre-soak new lenses 24 hours and use lab cleaner to improve initial wettability, GP wearers commonly develop 3 and 9 o’clock staining from peripheral corneal desiccation, Inspect for inverted lenses and edge lift when patients report lens awareness or discomfort, Toric lens rotation is more problematic with oblique axes and high cylinder powers; consider stabilization or refit, Remove lens immediately for trapped foreign body, torn lens, or acute severe pain and irrigate the eye, Assess TBUT and Schirmer; TBUT < 5 seconds is a relative contraindication to CL wear, Replace heavily deposited hydrogel lenses or move to daily disposables for patients with recurrent deposits, Corneal warpage from rigid lenses requires cessation of wear and serial topography/keratometry monitoring, For multifocal/aspheric soft lenses, set patient expectations and follow up 3–4 days after dispensing, PMMA-related central corneal clouding resolves with discontinuation and switching to breathable materials if needed