For critical instruments of group A, detergents with a cleaning effect and non-protein-fixing treatment agents are used prior to disinfection, which meet the requirements for medical devices class 1 (detergent) or 2a (disinfectant). The cleaning product used can be equipped with or without antimicrobial effect. If a product is used which does not have an anti-microbial effect, personnel protection must be ensured with suitable measures (protective clothing). In general, therefore, any cleaning product, combined cleaning and disinfecting product or cleaning product with disinfectant activity recommended for this purpose by the manufacturer and which is a medical device may be used. It is important that products are used here whose ingredients do not cause protein fixation and thus make cleaning and subsequent disinfection more difficult. Such ingredients are e.g. antimicrobial agents from the group of aldehydes and alcohols, so that the use of disinfectants containing aldehydes and alcohols is not recommended for this purpose. When selecting a detergent with disinfectant action, care must also be taken to ensure that at least one bactericidal and limited virucidal activity is present under the conditions of use. In this way, personnel protection, which is the main concern in this case, can be ensured. In general, the manufacturer's instructions regarding concentration, temperature and exposure time must be strictly observed when using the cleaning and disinfecting agents. The AKI recommends using freshly prepared solutions every day, which should be changed more frequently if necessary in the case of heavy contamination. When carrying out cleaning or disinfectant cleaning, care must be taken to ensure that above all English instruments, such as tubes and cannulas, as well as instruments with cavities are continuous and also have contact with the cleaning and disinfectant solution from the inside. After cleaning, the instruments must always be rinsed with sufficiently clear running water to prevent detergent residues from being carried over into the subsequent disinfection bath. This also removes any dirt that may still be adhering.

Basically, ophthalmic instruments should be subjected to mechanical alkaline cleaning, since eyes are among the vCJD risk material. However, since alkaline residues may remain on and in particular in instruments that could endanger the patient, a pH-neutral mechanical or standardized manual reprocessing can be used as an alternative. In this context, it is important to ensure good cleaning performance of the products and subsequent steam sterilization at 134 °C with a holding time of 18 min.

There are defined reprocessing steps for surgical instruments and thus also for ophthalmological instruments (see also Robert Koch guideline). For disinfection/cleaning, a rough distinction can be made between manual and mechanical reprocessing. Since the present text suggests a manual procedure, we would like to comment only on this at this point. If manual cleaning is intended, the used instruments are "wet deposited". This means treatment in a disinfectant bath. Such treatment is carried out for reasons of personal health protection (see UVV). The disinfectant used for this purpose must be approved for surgical instruments in order to prevent material damage. A released, combined disinfectant and cleaning agent can also be used for this purpose. Own mixtures of cleaner and disinfectant are not permitted, as the disinfection effect can be negatively influenced.

They refer to discussions regarding the manual or mechanical reprocessing of eye surgery instruments. In principle, mechanical methods of cleaning and disinfection should be preferred today. Many recommendations and leaflets call for the preference of thermal over chemo-thermal and chemical methods of disinfection. Mechanical cleaning and disinfection in a closed rinsing system also serves essentially to protect personnel. Also, only mechanical methods are reproducible in a comprehensible, exact and validated manner, thus meeting the requirements of the operator ordinance. The concern of doctors and nursing staff about the sensitive instruments is no longer justified today. Especially for the instruments of the eye surgery there are baskets and sieve trays with holders in which they are safely stored. The rinsing mechanism of the trolley for holding the baskets and sieve trays must be aligned in such a way that the instruments are not ejected from the holders, which would be the case with the usual rinsing technique for surgical instruments. If the rinsing method and technique are used correctly, mechanical cleaning is more gentle than manual cleaning. In aseptica 7 (3); 2001: 18-19 a practical example of the reprocessing of microsurgical instruments is reported.

Taking into account the RKI notice "The variant of Creutzfeldt-Jakob disease", published in the Federal Health Gazette April 2002, ophthalmic instruments should be reprocessed mechanically using an alkaline cleaning procedure (pH value > 10, 55 °C, 10 min exposure time) and then steam sterilized for 5 min at 134 °C. However, if users or surgeons fear that alkaline cleaning agents will not be completely rinsed from or to eye instruments, a pH-neutral, possibly enzymatic cleaning process can also be carried out, but then the final steam sterilization at 134 °C with a contact time of 18 min must be carried out. When reprocessing by machine, it must of course be ensured that both alkaline cleaners and neutralizing agents used in the first rinse cycle, as well as neutral cleaning agents, are rinsed off the inner and outer surfaces of the ophthalmic instruments without leaving any residue.

According to the information available to us, a pH value of 5 is acceptable. Fully demineralised water (without any additives) already has this pH value in some cases. According to information from doctors, alkaline additives (pH > 7) are undesirable. Carryover from previous rinses into the last rinse cycle must be avoided. If additives are dispensed in the last rinse cycle, it is essential to clarify their suitability for instruments used by ophthalmologists with the manufacturer of the product dispensed.

How many wash cycles are required depends primarily on the performance of the existing cleaning system and the degree of contamination. The aim is to clean residual oil, dust etc. from surfaces. If you have achieved satisfactory results with your procedure so far, we recommend that you continue to adopt this approach. For treatment of brand-new instruments, see "AKI Red Brochure", 9th edition, Page 17.

In principle, a washer-dryer based process for ophthalmic instruments can also be validated according to DGKH, DGSV and AKI guidelines. There are however a few restrictions which must be observed. In the ophthalmology sector, verifying cleaning performance using blood-contaminated artery clamps is unfavourable as such high levels of blood contamination is unusual in this application and hence the term 'minimum cleaning performance' is somewhat inappropriate. However, it is possible to meet requirements. When verifying the cleaning of real instruments, the protein contamination is usually so low that the acceptance criteria will not be applicable. An automatic monitoring of the flow of all English instruments would be technically possible, but hardly affordable. For example, English cannulae in particular must be protected from blockage by filters or must be specially checked after reprocessing. Since the English cannulas cannot be dried by the drying fan and mostly they remain full of rinse water due to the high capillary action, they cleared briefly using compressed air after the process. It is advisable to check the pH-value randomly by catching the escaping water with a pH-strip. There are some hospitals that have good long-term experience with alkaline cleaning and this type of check.