Dear Editor:
We are grateful to the authors for reading and providing suggestions for our article. The article has been written in April 2020, when India was getting ready for restarting the practices after lockdown.[1] As we are learning to live with the coronavirus disease 2019 (COVID-19) pandemic and our understanding is improving with every passing day, the guidelines may also require modifications. The goal is to continue practicing safely to prevent blindness and avoid the spread of pandemic as well.
Our point-by-point clarifications are as follows.
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There have been controversies on sodium hypochlorite/hydrogen peroxide cleaning for Goldmann applanation tonometer (GAT) prism after every use versus alcohol wipes cleaning for many years and there are publications favoring both, keeping in mind the practically possible solutions. Since we are revisiting those for restarting our practices, the consensus was to use the sodium hypochlorite solution and not hydrogen peroxide because of its easy availability. Further to be used only twice a day, as it is a corrosive agent and can spoil GAT prisms. Since coronavirus is susceptible to alcohol, it was advised to continue the practice of alcohol wipes cleaning after every use.
We completely agree regarding the slit-lamp cleaning after every patient, however, that is beyond the scope of this article as the purpose of this article is to supplement glaucoma-specific guidelines to the previously published general guidelines for ophthalmologists.
Use of 0.5% sodium hypochlorite is recommended since 1998 and is also recommended by the manufacturer's as provided in the article references (Reference no 8 and 11 in our article),[2,3] however, for 0.1%, the evidence is indirect as it has been reported to be useful for ophthalmic instruments and not particularly for GAT prism. The statement for cleaning instruments with 0.1% hypochlorite as well as a reference has been mentioned in our article.[4]
In an ideal world, both health care workers and patients should be using the N-95 mask during the procedure, and we agree that during the procedure, 3-ply surgical masks should be used. However, at the time of writing this article as per the Indian Council of Medical Research (ICMR), the 3-ply surgical/cloth masks were recommended for the patients. As we are learning more and more about mask usage, with changing guidelines, and depending on the availability of types of masks, the practices could be updated.
The standards for glaucoma care do not change with the current pandemic and so do the recommendations to use GAT for every patient. However, there are multiple places in India where Schiotz tonometers are being used, hence, its sterilization procedure is described for its safe usage, wherever it is being used. The authors do not promote the use of the Schiotz tonometer. Similarly, the standard protocols for using I-care and Tonopen remain the same and do not require modification. Those are mentioned for the sake of completion of the safe usage of tonometers and to reduce the apprehension of their usage during the COVID-19 pandemic.
The authors do not advise any indications or contraindications for perimetry usage and have left it to the physician's discretion for the given patient. The recommendation at the time of this article, when WHO had only allowed emergency procedures, was to minimize the patient's time spent in the clinic. Further, it was only in April that Carl Zeiss had released its recent recommendation for a perimetry bowl cleaning procedure after every patient. The perimetry bowl could be a source of droplet deposition thereby facilitating the spread of coronavirus. Further, there is a user's apprehension of spoiling the bowl surface by cleaning it with alcohol solution, it was recommended to use only if deemed necessary for glaucoma management as per the standard guidelines.
We are thankful to the authors for providing an additional link for recent perimetry cleaning protocols.
We would like to mention once again that with the change in the COVID-19 pandemic every day, the guidelines may require modifications on a regular basis, and readers are advised to keep themselves updated.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
- 1.Tejwani S, Angmo D, Nayak BK, Sharma N, Sachdev MS, Dada T, et al. Preferred practice guidelines for glaucoma management during COVID-19 pandemic. Indian J Ophthal. 2020;68:1227–80. doi: 10.4103/ijo.IJO_1724_20. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Sood D, Honavar SG. Sterilisation of tonometers and gonioscopes. Indian J Ophthalmol. 1998;46:113–6. [PubMed] [Google Scholar]
- 3.Junk AK, Chen PP, Lin SC, Nouri-Mahdavi K, Radhakrishnan S, Singh K, et al. Disinfection of tonometers: A report by the American Academy of Ophthalmology. Ophthalmology. 2017;124:1867–75. doi: 10.1016/j.ophtha.2017.05.033. [DOI] [PubMed] [Google Scholar]
- 4.Cleaning guidelines for the prevention of COVID-19 infections. Updated on 30th April by Finnish Institute of Occupational health. [Last accessed on 2020 Jul 17]. Available from: https://wwwttlfi/en/cleaning-guidelines-for-the-prevention-of covid-19-infections .