We would like to comment on the manuscript entitled “Direct application of bFGF without edge trimming on human subacute tympanic membrane perforation” by Lou et al. . This work showed that topical application of fibroblast growth factor-2 (FGF-2) improved the closure rate of traumatic tympanic membrane perforations (TMPs). The study is very careful and interesting, and suggests an alternative therapeutic method for traumatic TMPs. However, the indications for FGF-2 application to subacute TMPs should be further explored.

In the cited work, although the closure rate in the FGF-2-treated group was significantly greater than that in the observational group (91.7% vs. 52.9%), the average closure time in the latter group was significantly shorter than that of the former group (9.2 ± 2.9 days [range 6–16 days] vs. 18.1 ± 11.4 days [range 3–65 days]) . Therefore, it is not appropriate to treat subacute TMPs by direct application of FGF-2. It is well-known that traumatic TMPs exhibit high spontaneous healing rates; some perforations may spontaneously heal even 3 months after injury . A few perforations in the FGF-2-treated group would probably have healed spontaneously even with conservative treatment alone.

Some clinical and experimental studies have shown that topical application of FGF-2 alone shortened the closure time and improved the closure rate . However, topical application of FGF-2 has certain disadvantages. First, FGF-2 is not readily available (and is expensive); conservative treatment is simple and inexpensive; topical application once or twice per day is inconvenient for patients; and it is difficult for patients to self-control FGF-2 doses. Overdoses of FGF-2 cause otorrhea and ear discomfort and increase the risk of middle-ear infection .

In the future, it would be interesting to explore risk factors mitigating against spontaneous healing of traumatic TMPs, and the indications for FGF-2 application to subacute TMPs. Previous studies have suggested that perforations >50% of the TM, close to the malleus or annulus, in patients with pre-existing myringosclerosis, and in patients undergoing ear-syringing interventions are less likely to heal spontaneously . It would have been interesting if the cited authors studied the healing effects of FGF-2 on such perforations. In addition, the dryness of some perforations may result in formation of yellow crusts and outward epithelial migration during healing, thus delaying healing and resulting in closure failure . Such phenomena usually develop within 2 weeks of injury, and topical application of FGF-2 alone may be very beneficial in patients with such subacute perforations.