INTRODUCTION TO NONCLINICAL SAFETY EVALUATIONS OF ocular medical devices

BASIC REGULATORY REQUIREMENTS

when Developing a regulatory Strategy for an ophthalmic medical device, it’s important to know the class of medical device.

• Class I devices represent a low risk to harm and are mostly exempt from premarket submissions eg. sunglasses

• Class II represents a moderate risk, which requires a premarket notification (510(k)). eg. contact lenses

• the highest risk of medical device represents Class III. often requires PMA. eg. intra-ocular lenses

The use of FDA guidance and FDA Recognised standards is recommended to facilitate information submission to FDA. guidance is available for: contact/Intra-ocular lenses, aqueous shunts, glaucoma surgical devices, kerato-prosthesis, visco-surgical devices.

a Major concern of regulatory authorities is Biocompatibility: this is the ability of a device material to perform with an appropriate host response in a specific situation. Biocompatibility is assessed for all (New) devices with direct and indirect patient contact. it is required for all submission types: PMA, HDE, IDE, 510 (k) and De Novo requests.

The FDA guidance can be found in the 2016 CDRH’s Biocompatibility document ISO 10993-1 corrected version 2018-10 'biological evaluation of medical devices - Part 1’. this new version contains recent updates About nanomaterials, which can pose specific challenges to the biological evaluation due to their potentially unique properties. There is also revised information on Absorbable material because if a medical device is intended to change during its lifetime, such as those that are Polymerised and/or Degraded in situ, the Evaluation shall consider al the different Device states.

SAMPLE PREPARATION

Sample preparation is another critical milestone for the approval of any new ophthalmic medical device. the sample can be compared to the Classical test article (TA) when the TA is identical to the medical device in its final finished form in formulation, processing, Sterilization, and geometry and no other chemicals have been added such as fillers, Additives, cleaning agents or Mould release agents. or, It can be compared to previously marked device is the medical device in its final finished form is identical to the previously marketed device in formulation, processing and Sterilisation. When chemical information is requested by the regulatory authorities, it should include descriptive information of the chemical, its composition, amounth of weight percent and total amount per medical device and/or in depth chemical testings.

examples when FDA may request Additional chemistry information are for devices made from materials Intended to change or devices made from Chemicals with known toxicities (Carcinogenicity), where new biocompatibility testing is rarely conducted; also when devices are made from novel materials.

In addition to chemical testings, FDA may ask to evaluate the patient exposure to the device components or chemical(s). Exposure assessments may include chemicals and related impurities that may be available over time or when There is a repeat use of the device.

Extractable’s / leachable’s studies may be added to Optimise estimation of exposure during clinical use. safety assessments can be conducted in order to evaluate patient exposure to the device or device component. safety assessments may include known data from toxicological literature or material supplier. Derived tolerable intake (TI) or Threshold of toxicological concern (TTC) for unknowns, if TI cannot be derived.

The FDA table below lists various official FDA Guidance Documents and regulatory guidances easily to download. You can search for documents by using key words, and you can narrow or filter your results by product, date issued, FDA Organisational unit, type of document, subject, draft or final status. For example of a search for CDRH (center for Device and Radiological Health) guidance documents using ‘ophthalmic’ as a keyword.

TAKE HOME MESSAGES

1. when designing a regulatory strategy for an ocular medical device it remains important to Realise that evaluation can include both a review of relevant existing preclinical and clinical data and actual testing. Such an evaluation might result in the conclusion that no testing is needed if the material has a demonstrable safe history of use in a specified role and physical form that is equivalent ot that of the medical device under design.

2. use Recommendations of 2016 CDRH biocompatibility guidance for ophthalmic devices that do not have a specific FDA guidance and/or FDA-recognised standard document

3. use Attachment A of the 2016 CDRH Biocompatibility guidance when considering endpoint assessments for CDRH submissions

4. chemistry information Doesn't often always require analytic chemistry testing

medical ocular devices & Artificial intelligence

from the back of the eye to the front, artificial intelligence (AI) is expected to give ophthalmologists & ocular scientists new automated tools for Diagnosing and treating ocular diseases. within ocular medicine, Computerised analytics are being viewed as the path toward more efficient and more objective ways to interpret the flood of images in modern ocular practices.

On 11 April 2018 the US Food and Drug administration (FDA) announced the Marketing approval of the first medical device IDx-DR to use aI to detect more than a mild Liver of diabetic retinopathy, the most common cause of vision loss among diabetic patients and the leading cause of vision Impairment. this approval decision paves the wave for Similar AI devices to enter the market.