FDA and ISO Classification

SOFT CONTACT LENS

1. Fda & Iso classification… Ashwin Ankush Pawar Roll no 03 Sixth sem TY B.optometry ( MGM SCHOOL OF BIOMEDICAL SCIENCES )

2. Topics to be covered What is fda?
Fda classification
What is iso Iso classification examples

3. What is fda ?? fda stands for food and drug administration It is a federal agency Of department of Health and human services Responsible for safety , efficacy And security of human and veterinary drugs .

4. Fda classification Fda has classified Soft contact lens material According to their water content and ionic charge . water content stands for the Quantity of water contained in that material ie. Soft contact lens Ionicity - Ionic charge on the surface

5. The adsorption of lysozyme And human Serum albumin (hsa) Onto hydrogel contact lens Was investigated As a function of lens surface charge Anionic cationic and non ionic Contact lens were deposited usinG single protien Solution of identical ph and osmolarity.

6. Ionic contact lens Have negative charge on it by which Positively charged protiens gets Attracted on it . Non ionic Contact Lens Are coated in order to Reduce negative surface Charge which reduces The attraction of protien deposits.

7. The main drawback with this system is that different materials containing different monomers can be classified within the same material group Drawback –

8. What is iso ??? Iso stands for International organization for standardization. The specific classification of contact lens or contact lens material is given by Prefix
Stem Series suffix
Group suffix
Dk range
Modification code

9. The prefix is a term assigned to a material to designate a specific chemical formulation Stem – they are of two types
Filcon stem for material which contains _> 10% water by mass (hydrogel materials) Focon stem for materials containing _< 10% water by mass ( non hydrogel materials)

10. The series suffix used in cases in which the original ratio of monomer of an existing contact lens polymeric material is changed to make new material. For eg of capital a letter is added then the subsequent changes in ratio will be designated by next letter of alphabet. It differentiates copolymers of unchanged monomer units . The group suffix represented by roman numerals which indicates range of water content and ionic character of material .

11. This table shows the oxygen permeability of the material is classified!!!

12. The modification code designated by letter (m) denotes whether the lens has surface modification which renders the surface characteristic different to bulk material. Such treatment include plasma treatment , acid/base hydrolysis and incorporation of a material which migrates to the surface . Certain types of tinted lenses may also be considered as surface modified . In case of an unmodified surface, this suffix is omitted .

13. Examples: In order To demonstrate using BS en iso classification system, the acuvue 2 lens would be classified as follows ; Prefix – eta
Stem – filcon
Series suffix – A
Group suffix- 4 Dk range – 1 Modification code- none the lens can therefore be classified as (etafilcon A) 4️⃣ 1

14. Example - In order to demonstrate Cibasoft lens the classification be as follows …. Prefix- Teli Stem – Filcon Series suffix – A
Group suffix – 1 Dk range – 3 the lens therefore be classified as teli filcon a (1) (3) .

15. Questions ???? What does fda stands for ?? What does iso stands for?? What is prefix stem and suffix ?? What is modification code ?? What does filcon and focon stands for?? What is the drawback of fda classification system ??

16. References – Nathan Efron contact lens manual
Google Google images Researchgate article Contact lens modules

17. Thank you !!!