The number of outpatient and surgical cases decreased due to the COVID-19 pandemic has also been reported in ophthalmology [7–9, 14–16]. Our hospital saw a reduction in the number of outpatients: 255,456 in 2019, 217,675 in 2020, 230,796 in 2021, and 197,673 in 2022. The reduction rates compared to 289,611 outpatients in 2018 (before the pandemic) were 11.8% in 2019, 24.8% in 2020, 20.3% in 2021, and 31.7% in 2022. The number of outpatients increased and decreased in line with the fluctuating number of COVID-19 cases in Japan. The COVID-19 pandemic is led to a significant number of patients at our hospital to cancel their appointments.
In this study, 16.5% of the patients interrupted visits due to fear of infection. The most frequent number of changed medical appointments was one, occurring in 65.1% of the patients, while 0.7% of the patients interrupted the visits eight times. A previous study compared the frequency of changes in ophthalmic treatment appointments in the United States before and during the initial stages of the pandemic [7]. The proportion of patients who attended all scheduled visits before and at the initial stage of the pandemic was 82.0% and 59.3%, respectively. In this study, the number of outpatients at our hospital decreased by approximately 50% during the state of emergency due to the first wave of the COVID-19 outbreak (April 7-May 25, 2020) compared to that before the pandemic. The number of patients who modified appointments may have been higher during the first-wave.
In this study, 55.6% of the patients had a lower MD value after the interruption of visits than the MD value predicted by the MD slope; 13.3% experienced a decrease in the MD values by 2 dB or more. To effectively treat glaucoma, regular follow-ups, choice of treatment strategy, taking into account IOP, VF, and adherence, are necessary. Decreased adherence in patients with glaucoma due to the pandemic has been previously reported [9–13]. Adherence in this study was possibly lower, as in previous reports, for patients with worsened MD values. In Turkey, 163 patients with glaucoma visited outpatient consultations during the four weeks after the 82 days of lockdown [17]. Of these, nine (5.5%) had a visual acuity value that worsened by two or more levels. Their IOP increased from 20.5 ± 5.3 mmHg before the lockdown to 28.1 ± 7.2 mmHg after the lockdown. This study reaffirmed that an increased IOP leads to visual field progression.
According to the logistic regression analysis on factors associated with a worsening of -2 dB or more in MD values after the interruption of visits, patients with a long period of interruption and high IOP before interruption require careful monitoring. Additionally, lowered adherence in patients with glaucoma may also be involved. Considering that longer treatment periods decrease treatment continuation rates, adherence is predicted to be poor if the interruption period is prolonged. As ocular hypertension is a risk factor for the progression of glaucomatous visual field impairment [2], patients with high IOP values before interruption experience mild visual field progression.
This study is an actual survey of outpatient care. Our study had some limitations. First, the study’s retrospective design made it difficult to confirm adherence during visit interruptions. Therefore, it was difficult to evaluate whether lowered adherence correlated with visual field progression. Regardless of whether the visit was interrupted, patients with a higher IOP before the interruption of visits may have experienced progressive visual field defects. Because some patients who frequently interrupted their visits were transferred to a nearby doctor based on the attending physician’s recommendation, it was challenging to accurately assess the impact of visit interruptions. For the evaluation of visual field progression following the interruption of visits, we only investigated a single MD value. It was challenging to study the MD slope after the interruption of visit due to the short period following the interruption.
During the study period, 16.5% of the patients with glaucoma had interrupted visits due to fear of infection. In 55.6% of the patients, visual field impairment was worse than expected because of the interruption of visits. The evaluation of visual function through periodic examinations is important for the treatment of glaucoma.