Discussion
This survey highlights the impact of protective measures due to the COVID-19 pandemic on the clinical ophthalmological examination. More than 75% of participants agreed that the protective measures taken made the ophthalmological examination conditions more difficult or changed them.
The necessity and effectiveness of slit lamp barriers in combination with face masks have been shown in several studies so far.11–13 However, these measures lead to major practical problems in the ophthalmological examination. Fogging occurs during slit lamp examination on both doctor’s and patient’s side as the face masks direct much of the exhaled air upwards, where it gets into contact with the lenses (spectacles, slit lamp oculars and funduscopy lenses).14 In contrast to other specialities examining the patient’s face, such as otorhinolaryngology, dentistry or maxillofacial surgery, masks can be kept on during the ophthalmological examination to protect the examiner and the patient. 87.6% of the participants reported fogging of the lenses, 69.9% fogging of the slit lamp oculars and 60.2% reported difficulties when operating the slit lamp due to the slit lamp protective barriers. In order to improve examination conditions, doctors are forced to change their examination methods (67.7% interrupted the examination several times, 47.5% pressed the patient’s mask with the fingers to the patient's face during the examination) or they risked their own health to improve visualization. Interestingly, significantly more men are willing to reduce their own protection for better examination conditions. In total, 43.6% of male participants removed their face mask or pulled it under their nose to prevent the tarnishing of the slit lamp oculars, but only 20% of female respondents did so. Additionally, in our study, significantly more men wore surgical masks instead of FPP2 masks (international equivalent standards are KN95 and N95), although the protection factor of FFP respirators are 12 to 16 times greater than those of surgical masks.15 These results coincide with the findings that men are typically more likely to engage in risky behavior.16
There are some alternative approaches to prevent tarnishing of the lenses that do not compromise personal safety: taping the upper margin of the face mask to prevent the air draft, using antifog or soap agents that leave behind a thin surfactant film that reduces surface tension or keeping the funduscopy lens in a warm water bowl at 40°C after disinfection with 70% ethanol. This method reduces the temperature difference and prevents fogging while ensuring decontamination.14 In our survey, it was notable that more men than women taped the upper edge of the face mask to their skin (women: 25.0% vs men: 38.5%), even though the gender difference was not significant. Furthermore, a particularly large number of women found it difficult to operate the slit lamp with the slit lamp barrier. This could be due to sex-typical physiognomic characteristics as women have a shorter arm span on average.17 18
Fortunately, only 1/15 SARS-CoV-2 infections could be traced to a contact with an infected patient, but in this case a male ophthalmologist was affected. However, as the mean incubation period of COVID-19 is 6.2 days and incubation periods go up to 14 days, contact tracing is not always possible and the exact number of transmissions from patient to physician cannot be verified.19
As almost one-third of the respondents felt that the COVID-19 protective measures reduced the overall quality of their slit lamp examination (31.0%) and even more felt that the quality of their fundoscopic examination was reduced (43.4%), there is a chance that pathologies might be overlooked. Even though artificial intelligence has been applied to fundus photographs, optical coherence tomography and visual fields and is achieving robust classification performance in the detection of diabetic retinopathy, age-related macular degeneration and glaucoma, it has not yet found its way into daily practice.20 Just 11.1% of participants tried to replace funduscopy with fundus photography. The examination by an ophthalmologist is irreplaceable for detecting pathologies in the retinal periphery, such as retinal tears. Furthermore, machine learning programmes are often not able to include the ambiguity and variability that is intrinsic to the nature of clinical observations.21
A limitation of this study is that self-reported surveys have well-known drawbacks. Moreover, due to the rapidly changing COVID-19 situation, the survey questions are not standardised, and it was not possible to conduct a validated survey.
