|Year : 1985 | Volume
| Issue : 1 | Page : 57-58
Polymethyl methacrylate (PMMA) intolerance
VK Dada, VK Kalra, SK Angra
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, India
V K Dada
Dr. R.P. Centre for Ophthalmic Sciences, A.I.I.M.S., New Delhi-110 029.
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Dada V K, Kalra V K, Angra S K. Polymethyl methacrylate (PMMA) intolerance. Indian J Ophthalmol 1985;33:57-8
The allergic reaction to Polymethyl Methacrylate is extremely rare,. This report highlights a rare allergic manifestation of Polymethyl methacrylate in a well fitted patient of keratoconus who had used contact lenses for the last 20 years.
| Case report|| |
A 48 year old lady presented with the complaints of watering, itching & photophobia with contact lenses for last two months. The symptomatology gradually increased with time. Patient did not give any history of urticarial rash, chronic sinusitis, asthma or eczema. She was not using mascara, perfumes or any local medication. There was no change in contact lens solution and the condition persisted even when the hard contact lens solution was not used at all. The lenses were fitting well on the cornea.
On examination, she showed dry eczematous lesions of the lids which were excoriated in the inner one third due to frequent rubbing. Cornea was keratonotic and was moderately advanced. Posterior segment and intraocular pressure were normal.
Lenses were withdrawn and there was dramatic recovery of lid and conjunctival inflammation.
"Patch Test" was done with various contact lens materials like PMMA, CAB (Cellulose Acetate Butyrate) and HEMA (Hydroxy ethyl methacrylate). The test was positive for PMMA and negative for the others. Replacement with CAB lenses did not show any reaction and the patient is tolerating them well without any allergic symptoms.
| Discussion|| |
Allergic inflammatory background can hinder successful outcome of any medical or surgical procedure. Same can hold true for contact lenses. To rule out allergic background for the future success every client should be screened through a set of questionnaire for eliciting the exact background and for future guidance. This should include personal & family history of any allergic disorder in the form of asthma, hay fever, eczema, dermatitis, rhinitis, spring catarrh etc. Besides this patch test on the skin with various contact lens materials may help us to find such reactions.
The allergic reaction in this patient after 20 years of successful use can probably be explained by the absorption of biodegraded
PMMA material with hapten of tear proteins to act as allergen.
| Summary|| |
A rare case of P.M.M.A. allergy in a well fitted case of keratoconus is described. Allergic symptoms subsided after changing the material. Patch test was positive with P.M.M.A. Genesis of allergic reaction is discussed.
| References|| |
Lowther E.L. and Bier N., 1977, Contact lens correction. Butterworths, London, Page 103.
Stone, J. and Phillips AJ., 1980, Contact lenses, Butterworths. London page 170.