Abstract
Chronic otitis media is one of the commonest illnesses in otorhinolaryngological practice which requires medical attention. Intact tympanic membrane acts as a shield for round window niche to create a phase difference in sound wave conduction. 700 patients of age 10–70 years with inactive mucosal chronic otitis media were included in the study. Condition of tympanic membrane and site of tympanic membrane perforation was noted and audiometric analysis was performed. 338 (48.28%) were males and 362 (51.71%) were females. In 1400 membranes examined, 769 (54.85%) presented with perforation. 631 (82.03%) had unilateral perforation and 69 (17.97%) had bilateral perforations. In unilateral cases, 289 (37.50%) had right ear perforation and 342 (44.53%) left ear perforation. Single quadrant perforations were present in 168 (21.74%) membranes and 419 (54.55%) involved two quadrants. Three quadrant perforations were seen in 62 (8.09%) and 120 (15.63%) perforations involved all four quadrants. In 171 (22.26%) ears, perforation was present anterior to handle of malleus and in 243 (31.53%) it was present only posterior to handle. In 355 (46.21%) perforations, handle of malleus was involved. Perforations involving posterior half of tympanic membranes showed greater loss than those involving anterior or inferior half of membrane statistically. Maximum loss (51.56 ± 5.1 dB) was seen in perforation involving all four quadrants. In 631 unilateral cases, conductive loss was seen in 424 (67.10%), 101 (16.10%) showed sensorineural and 74 (11.80%) showed mixed loss. Out of 769 perforated ears having hearing loss, 251 (37.69%) had complaints for 5–10 years with mean loss of 51.15 ± 7.8 dB, 172 (25.68%) had COM for 1–5 years with loss of 39.26 ± 5.1 dB. A mean hearing loss of 52.18 ± 4.2 dB was seen in 110 (16.52%) patients suffering from COM for more than 10 years. 134 (20.12%) patients having disease less than 1 year reported hearing loss of 36.46 ± 8.2 dB. The effects of perforation of tympanic membranes on transmission of sound and its dynamics are not easy to correlate because of additional pathological changes in middle ear.
Keywords: Perforation, Position, Duration, Hearing loss, Quadrants
Introduction
Chronic otitis media (COM) has been identified in human skeleton from prehistoric times [1]. It is one of the commonest illness in otorhinolaryngological practice which requires medical attention, all the more in children of poor socio-economic status having in the past inadequate treatment and negligent medical care. According to a panel reporting to ‘Seventh post symposium research conference of the international symposium on recent advances in otitis media’ [2], chronic otitis media is defined by otorrhea of at least 6 weeks duration in the presence of a tympanic membrane(TM) perforation. Amongst the south-east Asian countries, prevalence rates in Thailand ranged from 0.9 to 4.7% while in India prevalence rate as reported by various research ranges from 3 to 7.74% [3]. It is different in rural and urban populations. The Saudi Arabian prevalence rate of 1.5% was taken as the eastern Mediterranean regional estimate. Prevalence of 1.5% amongst children in Brazilian slum was considered representative of South and Central America and a prevalence of 0.4% was considered representative of Europe [4].
An intact tympanic membrane transmits vibrations from its entire surface to the footplate of stapes through ossicular chain [5]. It also protects middle ear from infection and also acts as a shield for round window niche helping create a phase difference in conduction of sound waves through middle ear [6]. Perforation occurs in COM, which affects at least 0.5% of population [7]. Due to perforation, there is reduction in ossicular coupling caused by a loss in significant sound pressure difference across the TM. Many authors have documented relation between tympanic membrane perforation and hearing loss [8]. Chronic otitis media produces mild to moderate hearing loss in more than 50% cases. The hearing impairment in patients with COM has generally observed to be an increase in air conduction thresholds and normal bone conduction thresholds. Factors that influence the type and degree of deafness are the size and position of the tympanic membrane defect, impairment of ossicular chain and middle ear status that influence the sound conducting mechanism [9]. While many authors believe that site of perforation is associated with severity of hearing loss, few also recorded that there is no significant association [8].
There have been a lot of conflicting reports about incidence of hearing loss associated with tympanic membrane perforations depending upon size, site or duration [6]. The effects of perforation of tympanic membranes on transmission of sound and its dynamics are not easy to correlate because of additional pathological changes in middle ear [10]. A better understanding of effect of perforation on middle ear would help us anticipate the magnitude and incidence of hearing loss [11]. Positive correlation between duration and type of disease and development of hearing loss implies that earlier the attempts are made to control and treat the disease, better would be the outcome after treatment. With more such studies, clinicians will be able to predict whether hearing loss is only because of perforation or if middle ear changes are involved. The present study is an attempt to co-relate few of these parameters with hearing loss [11].
Aim and Objectives
The objective of this study was to record presentation of tympanic membranes in patients of COM, assess the effect of site and duration of tympanic membrane perforations and their correlation with type and degree of hearing loss.
Materials and Methods
This prospective observational study was carried out in Department of Otorhinolaryngology and Head Neck Surgery of a tertiary health care hospital in Bareilly, Uttar Pradesh, India after taking permission from Institutional ethical clearance committee. This study was carried out from October 2014 to September 2016.
Seven hundred patients of age group from 10 to 70 years clinically diagnosed with inactive mucosal type of chronic otitis media, and having healthy middle ear mucosa with normal eustachian tube function were included in the study. A written, informed and well understood consent was obtained after explaining the patients the study. For audiometric analysis, patients with causes of hearing loss not related to COM like presbycusis, trauma and patients on ototoxic medications were excluded.
In form of a questionnaire, a detailed history, demographic data along was recorded. Complete Ear examination was done with help of Welch Allyn Otoscope and Oto-endoscope. Condition of tympanic membrane and site of tympanic membrane perforation according to an imaginary line drawn along the handle of malleus was noted, middle ear mucosa and ossicles were examined.
The audiometric analysis was performed in patients using a clinical audiometer—Primus Audidata calibrated according to ISO standard in sound treated room. Frequencies selected for the purpose were 250–8000 Hz. Air and bone conduction threshold were determined with appropriate masking technique whenever indicated. Hearing level was defined as mean air conduction threshold at 500, 1000, 2000 and 4000 Hz and average of these frequencies was calculated to measure the hearing level. Air–bone–gap was also calculated. The diagnosis of CHL was made when ABG was ≥ 20 dB and SNHL if ABG was ≤ 20 dB. If ABG was ≥ 20 dB and bone conduction levels were impaired it was taken as mixed hearing loss. Hearing loss was classified according to WHO grading system.
The data collected was coded, entered into Epi info software database and various findings were analyzed statististically using Statistical package for social services v 23 for windows.
Observations
A total of 1400 ears of 700 patients were studied. Age ranged from 10 to 70 years. Mean age of presentation was 31.56 ± 7.85 years in males and 28.67 ± 9.40 in females. Out of 700 patients included in the study, 338 (48.28%) were males and 362 (51.71%) were females. A high proportion of patients, 607 (86.71%) belonged to younger age group of 10–40 years (Table 1).
Table 1.
Age and sex
| Age group in years | Male | Percentage | Female | Percentage | Total | Total (%) |
|---|---|---|---|---|---|---|
| 10–20 | 118 | 51.08 | 113 | 48.92 | 231 | 33.54 |
| 21–30 | 96 | 47.29 | 107 | 52.71 | 203 | 28.90 |
| 31–40 | 81 | 45.88 | 92 | 54.12 | 170 | 24.36 |
| 41–50 | 32 | 49.23 | 33 | 50.77 | 65 | 09.20 |
| 51–60 | 03 | 75.00 | 01 | 25.00 | 04 | 00.60 |
| 61–70 | 08 | 33.33 | 16 | 66.67 | 24 | 03.40 |
| Total | 338 | 362 | 700 | 100.00 |
In 1400 tympanic membranes examined, 769 (54.85%) presented with perforation. Normal healthy tympanic membrane was seen in 374 (26.57%) ears, while sclerotic patches were seen on 175 (12.50%) tympanic membranes. Dimeric membrane was seen in 41 (02.92%) whereas retraction was seen in 41 (02.92%) membranes (Table 2).
Table 2.
Tympanic membrane findings
| TM Finding | Right | Left | Total | % | ||
|---|---|---|---|---|---|---|
| Perforation | 358 | 51.50 | 411 | 58.70 | 769 | 54.85 |
| Retracted | 20 | 02.90 | 21 | 01.80 | 41 | 02.92 |
| Dimeric | 29 | 04.10 | 12 | 02.90 | 41 | 02.92 |
| TS Patch | 74 | 10.50 | 101 | 14.40 | 175 | 12.50 |
| Normal | 219 | 31.00 | 155 | 22.25 | 374 | 26.57 |
| Total | 700 | 100.00 | 700 | 100.00 | 1400 | 100.00 |
In 1400 ears examined of 700 patients, perforation was observed in 769 ears. 631 (82.03%) had unilateral perforation and 69 (17.97%) had bilateral perforations. In unilateral cases, 289 (37.50%) had perforation in right ear and 342 (44.53%) had perforation in left ear. Left side predominated with 411 (53.51%) while right side perforation was present in 358 (46.48%) ears.
On examining the perforations in tympanic membranes, 419 (54.55%) were involving two quadrants. Perforations involving three quadrants were seen in 62 (8.09%) membranes and 120 (15.63%) perforations involved all the four quadrants. Single quadrant perforations were present in 168 (21.74%) membranes. In 171 (22.26%) ears, perforation was present anterior to handle of malleus and in 243 (31.53%) it was present only posterior to handle. In 355 (46.21%) perforations, handle of malleus was involved (malleolar perforation). Mean hearing loss ranged from 24.00 ± 4.6 to 48.60 ± 5.5 dB in single quadrant perforations out of which maximum loss was seen in postero-superior perforations followed by postero-inferior perforations. Antero superior perforations showed the minimum hearing loss. This difference in mean hearing loss due to difference in place of perforation was found to be statistically significant (p value by Anova test < 0.05).
In our study, we divided perforations into anterior (AS, AI, AS + AI), posterior (PS, PI, PS + PI) and Mixed(AI + PI, AI + PI + PS, AI + PI + AS + PS). Perforations involving posterior half of tympanic membranes showed greater loss than those involving anterior half or inferior half of membrane. When perforation involve 2 quadrant, involvement of posterior part of tympanic membrane resulted in statistically higher hearing loss followed by inferior part in comparison to anterior part of tympanic membrane (p value by ANOVA < 0.001). Maximum hearing loss of 51.56 ± 5.1 dB was seen in perforation involving all the four quadrants. Perforations touching the handle of malleus had more hearing loss than those in which perforation margins were not touching the handle (Table 3).
Table 3.
Perforation site
| Site of perforation | Side of perforation | Total | Hearing loss in dB | |||||
|---|---|---|---|---|---|---|---|---|
| Right | Left | No | % | |||||
| No | % | No | % | |||||
| Single quadrant | ||||||||
| AS | 16 | 04.60 | 17 | 04.10 | 33 | 4.29 | 24.00 ± 4.6 | < 0.0001 (ANOVA) |
| PI | 16 | 04.60 | 19 | 04.60 | 35 | 4.55 | 32.40 ± 5.2 | |
| AI | 11 | 03.20 | 16 | 04.00 | 27 | 3.51 | 30.10 ± 7.8 | |
| PS | 30 | 08.10 | 43 | 10.60 | 73 | 9.37 | 48.60 ± 5.5 | |
| Two quadrants | ||||||||
| AI + AS | 56 | 15.60 | 55 | 13.20 | 111 | 14.45 | 28.40 ± 2.2 | < 0.0001 (ANOVA) |
| PS + PI | 59 | 16.60 | 75 | 18.20 | 134 | 17.45 | 48.90 ± 7.5 | |
| AI + PI | 78 | 21.80 | 96 | 23.40 | 174 | 22.66 | 36.40 ± 6.8 | |
| Three quadrants | ||||||||
| AI + PI + PS | 36 | 09.80 | 26 | 06.40 | 62 | 8.09 | 40.20 ± 6.5 | |
| Four quadrants | ||||||||
| AI + PI + PS + PI | 56 | 15.70 | 64 | 15.50 | 120 | 15.63 | 51.56 ± 5.1 | |
| Total | 358 | 100.00 | 411 | 100.00 | 769 | 100.00 | ||
Out of 631 cases having unilateral disease, in perforated ear conductive hearing loss had the highest prevalence 424 (67.10%), while 101 (16.10%) showed sensorineural hearing loss. Mixed hearing loss was present in 74 (11.80%). In contralateral ears or non-perforated ear, 530 (84.02%) had normal hearing while rest 101 (15.08%) had some form of hearing loss without presence of a perforation (Table 4). It was observed that in unilateral perforated presentation, hearing loss was majorly confined to perforated side and this difference was found to be statistically significant (Table 4).
Table 4.
Type of hearing loss in unilateral perforations
| Type of hearing loss | Unilateral perforation | ||||
|---|---|---|---|---|---|
| Diseased ear | Contralateral ear | P value | |||
| No | % | No | % | ||
| Conductive hearing loss | 424 | 67.10 | 59 | 9.42 | 0.0004998 (Pearson’s Chi squared test with simulated p value) |
| Sensorineural hearing loss | 101 | 16.10 | 22 | 3.46 | |
| Mixed hearing loss | 74 | 11.80 | 20 | 3.10 | |
| Normal hearing | 32 | 05.00 | 530 | 84.02 | |
| Total | 631 | 100.00 | 631 | 100.00 | |
Hearing loss was seen in majority 67(99.00%) of bilateral perforated ears. It was observed that person with bilateral perforation have no side preponderance about type of hearing loss and this observation was statistically proved (p > 0.05) (Table 5).
Table 5.
Type of hearing loss in bilateral perforations
| Type of hearing loss | Bilateral perforation | ||||
|---|---|---|---|---|---|
| Right ear | Left ear | Right ear | |||
| Number | % | Number | % | ||
| Conductive hearing loss | 50 | 72.00 | 56 | 81.00 | 0.4298 (Fisher’s exact test for count data with simulated p-value) |
| Sensorineural hearing loss | 04 | 05.80 | 05 | 07.50 | |
| Mixed hearing loss | 09 | 13.00 | 06 | 08.50 | |
| Normal hearing | 06 | 09.20 | 02 | 01.00 | |
| Total | 69 | 100.00 | 69 | 100.00 | |
Out of 700 patients and 769 perforated ears included in the study, a mild hearing loss was present in 255 (33.30%) ears. Moderate hearing loss was noted in 294 (38.20%) ears while moderately severe to sever hearing loss was seen in 204 (26.40%) ears. Profound hearing loss was present in 16 (02.10%) of ears examined (Table 6).
Table 6.
Degree of hearing loss
| Degree of hearing loss | No. of perforated ears | |
|---|---|---|
| No. | Percentage | |
| Mild (25–40 dB) | 255 | 33.30 |
| Moderate (41–60 dB) | 294 | 38.20 |
| Moderately severe (61–75 dB) | 125 | 16.20 |
| Severe (76–90 dB) | 79 | 10.20 |
| Profound (> 90) | 16 | 02.10 |
| Total | 769 | 100.00 |
Out of 769 perforated having any kind of hearing loss, 251 (37.69%) were having complaints for 5–10 years and were having a mean hearing loss of 51.15 ± 7.8 dB, whereas 172 (25.68%) were suffering from COM for 1–5 years with hearing loss of 39.26 ± 5.1 dB. A mean hearing loss of 52.18 ± 4.2 dB was seen in 110 (16.52%) patients suffering from COM for more than 10 years. Patients in which disease had manifested for less than year constituted 134 (20.12%) and showed a mean hearing loss of 36.46 ± 8.2 dB.
This was found that duration of disease was statistically associated with amount of hearing loss (p value < 0.001) (Table 7).
Table 7.
Hearing loss in relation to duration of disease
| Duration of disease | Perforated ear | Mean hearing loss (in dB) | P value | |
|---|---|---|---|---|
| Number | % | |||
| Less than 1 year | 134 | 19.14 | 36.46 ± 8.2 | < 0.001 (ANOVA test) |
| 01–05 years | 172 | 24.42 | 39.26 ± 5.1 | |
| 05–10 years | 251 | 35.85 | 51.15 ± 7.8 | |
| Greater than 10 years | 144 | 20.59 | 52.18 ± 4.2 | |
| Total | 769 | 100.00 | ||
Discussion
Ediale et al. [8] noted that a high proportion of study participants were within the younger age group of 10–39 years which is in agreement to our study. Similar findings were reported by Sood et al. [6] in their study in which 79% patients were less than 40 years of age. Bhusal et al. [11] observed that 70% patients were from age group 15–24 years.
When both tympanic membranes were examined, they showed 288 (37.50%) perforations on right side and 342 (44.53%) on the left side. Bilateral perforations were present in 138 (17.97%) membranes. Tympano-sclerotic patches, dimeric membranes and retracted tympanic membrane were the other findings noted. Kamal et al. [12] observed in their study that 46.7% patients had a perforation in left ear, 26.7% had a perforation in both ears and 26.7% had perforation in their right ear. Shrikrishna et al. [13] observed that 46.7% of the perforations were present on right side whereas 53.3% had perforations on the left side. Ibekwe et al. [14] in their study noted that bilateral TM perforation was seen in 24.2% patients while right and left TM were perforated in 33.9% and 41.9% respectively.
In our study, we observed that 319 (41.53%) perforations were involving two quadrants. Perforations involving single quadrant were 167 (21.74%) in which majority were postero-superior quadrants. Perforations involving anterior half of tympanic membranes were seen in 111 (14.45%) perforations and those involving posterior half were seen in 134 (17.45%) perforations. Perforations involving both the halves were seen in 356 (46.35%) perforations.
In a study conducted by Kaur et al. [15], 38% had perforations in anterior half out of which AS were 5%, AI were 27% and AS + AI were 5.85% whereas perforations were present in posterior half which comprised of PI (20%), PS (8%) and PS + PI (0.8%). Also, 33% perforations involved both anterior and posterior quadrants and 30% perforations included all the four quadrants. Two quadrants perforations were seen in around 44% perforations and 9.2% perforations were seen in single quadrants. This is in sharp contrast to our study. Sood et al. [6] in their study reported 80% perforations involving multiple quadrants and 11% postero-inferior and 8% antero-inferior perforations. Singh et al. [5] in her study observed that hearing loss was slightly greater in posterior perforation than the anterior and multiple quadrant involving perforations. In their study, Pannu et al. [9] noted that malleolar perforations were present in 18% patients whereas 82% had non malleolar perforations. In our study 46.21% perforations were malleolar.
Out of 631 patients with unilateral disease, 424 (67.10%) were having a conductive hearing loss in diseased ear whereas mixed hearing loss was present in 74 (11.80%) cases. Sensorineural hearing loss was observed in 101 (16.10%) patients. In contralateral ear, normal hearing was present in 530 (84.02%) ears. The relation between ear having disease and presence of hearing loss in it was statistically significant.
Conductive hearing loss is the most common finding in our study. Ediale et al. [8] suggested that this is due to loss of membrane surface area which is doing the amplification of sound waves. High prevalence of conductive hearing loss was seen by studies done by Maharajan et al. [16] and Bhusal et al. [11]. In a study conducted by Mohammad et al. [17], 80.8% cases were suffering from conductive hearing loss and 17.17% cases had mixed hearing loss. 2.01% patients were suffering from sensorineural hearing loss. Kumar et al. [18] noted that 92.18% cases had conductive hearing loss whereas 7.82% had mixed hearing loss. Sensorineural hearing loss was not seen in any patient. Kabdwal et al. [19] in a study of 80 patients observed a mild hearing loss in 37.70% patients and 11.47% had moderate hearing loss. The moderately severe hearing loss was seen in 4.91% cases of mucosal disease. Muftah et al. [20] in their study reported that mild hearing loss was seen in 37.3% patients and moderate loss in 25.5% patients. Severe hearing loss was seen in 3.9% patients. Ediale et al. [8] noted that 67.5% patients had mild conductive hearing loss. Darad et al. [21] reported mild hearing loss in 79% patients followed by moderate hearing loss in 19% patients.
Mean hearing loss of 51.56 ± 5.1 dB was seen in perforations which were total/subtotal or present in all the four quadrants. Perforations present in postero-superior quadrant also resulted in high degree of hearing loss (48.60 ± 5.5 dB). Perforations present in inferior half of membranes resulted in 36.40 ± 6.8 dB of hearing loss. The results of study conducted by Kumar [18] are in agreement with our study. Sood et al. [6] reported multi quadrant perforations presenting with 39.34 ± 9.47 dB hearing loss and those having postero-inferior perforations having 34.82 ± 10.79 dB hearing loss. In Anterior half perforations, average hearing loss was 33 dB. The difference was not statistically significant in their studies. Berger et al. [22] in their study found out perforations of postero-superior quadrant had largest air–bone–gap. Similarly Maharajan et al. [16] and Nepal et al. [23] showed statistically significant relationship between site of perforation and hearing loss. However Ibekwe et al. [14] in his study concluded that location of perforation is only significant in cases of chronic perforations whereas has no significance in acute cases. Darad et al. [21] concluded that malleolar perforations had higher hearing loss. Pannu et al. [9] observed that hearing loss for anterior perforation was 31.56 ± 13.77 dB whereas it was 36.29 ± 10.17 dB and 49.39 ± 10.26 dB for multiple quadrant perforations.
The insignificant difference in mean hearing loss of antero-inferior and postero-inferior quadrant perforation might be because of round window niche location. These perforations are not much effective in removing round window phase difference. In between perforations involving two quadrants located over antero-superior + antero-inferior or postero-inferior + postero-superior quadrants, the loss is greater in posterior perforations as they cause loss of round window phase difference. Mehta et al. [24] in their experimental model study and later clinical work contradicted the popular concept of posterior perforations causing higher hearing loss than anterior perforations.
Not many studies have shown co-relation between duration of disease and degree of hearing loss. Out of 700 patients presenting with perforations, about 144 (20.59%) patients gave a history of disease present for more than 10 years. Patients having complaint for less than 1 year formed only 134 (19.14%) of total patients. Pannu et al. [9] reported that 28% patients were having symptoms for less than 1 year and 35% for 1–5 years. 37% patients had disease since more than 5 years.
In patients presenting with disease more than 10 years, the average hearing loss was 52.18 ± 4.2 dB, while in patients who had symptoms for less than 1 year the mean hearing loss came out to be 36.46 ± 8.2 dB. Maharajan et al. [16] and Pannu et al. [9] in their study found a strong relation between duration of ear discharge and hearing loss whereas Sood et al. did not found any significance between duration of disease and level of hearing loss. Cusimano [25] suggested that hearing loss does not change with respect to age of onset of COM, but the duration of COM does exert a significant influence. Hussona et al. [26] noted similar results in their study.
Conclusion
In our study we concluded that maximum hearing loss is seen in postero-superior quadrants and minimum in antero-superior quadrants. When all the four quadrants were involved in perforation, the hearing loss was seen to maximum. Even though most common type of hearing loss was seen to be conductive type, presence of sensorineural and mixed type of hearing loss shows that even in mucosal disease, we cannot rule out involvement of inner ear. On correlating hearing loss with duration of disease we found that longer the duration of disease more are the chances of increased mean hearing loss. This denotes associated middle ear changes. If chronic otitis media patients are diagnosed and treated well in time, high auditory loss can be avoided. Also patients can be advised for early intervention if perforations are seen in areas which show higher hearing loss.
Funding
No funding was received for this project from any person or institution.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interest.
Ethical Approval
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional ethical clearance committee vide letter no IEC/28/2014 and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Footnotes
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