**5. Examination and diagnosis**

Up to 90% of infants born with CLP suffer from OME before their first birthday [2]; therefore, it is recommended that otologic tests be conducted as soon as possible after birth to ascertain whether fluid has collected in the middle ear [21, 32]. The use of a pneumatic otoscope is the fastest and most direct method used for the inspection of the eardrum for color and contour and determining whether fluid has collected in the middle ear. It should be noted that the effectiveness of a pneumatic otoscope to test for OME depends on the experience and skill of the clinicians, the patient's full cooperation, and the anatomical structure of the ear canal [2].

Another method for inspecting the eardrum is videotelescopy. A telescope is placed against the eardrum through the external ear canal, and a charge‐coupled device (CCD) camera cap‐ tures images of the eardrum. The resulting magnified images can be presented on a mon‐ itor, thereby allowing clinicians to accurately diagnose middle ear effusion [33]. Guo and Shiao conducted a prospective study on the diagnostic efficacy of videotelescopy, pneumatic otoscopy, and tympanometry for the detection of pediatric OME. Their results demonstrate that the sensitivity, specificity, and accuracy of the videotelescopy were 97.8, 100, and 98.0%, respectively. These values significantly exceed the accuracy of conventional tests using pneu‐ matic otoscope and tympanometry [33]. Videotelescopy provides clinicians with visual infor‐ mation with which to validate the accuracy of the pneumatic otoscopy.

Pneumatic otoscopy and even videotelescopy are difficult to administer on newborns and small infants with CLP. Thus, objective acoustic immittance testing plays an important role in the diagnosis of OME in CLP patients [34]. Tympanometry is the most commonly used acoustic immittance test to measure pressure changes in the middle ear and the compliance of the eardrum [27]. Chen et al. found that the specificity of tympanometry, when used to test for OME in infants with CLP, was relatively low (only 59.6%). When used to test infants within 9 months of age, specificity dropped to only 37.5% [28]. Furthermore, when infants are crying or unable to cooperate during testing, it can be difficult to maintain airtight conditions in the ear, thereby preventing successful completion of the examination.

Pure tone audiometry can also be used to facilitate the diagnosis of OME; the results may reveal conductive or mixed hearing loss. The cooperation of children is required for this procedure, which means that it may be unsuitable for children under 3 years of age [35]. For patients in this age group, spectral gradient acoustic reflectometry (SGAR) may be an effective alternative to pure tone audiometry in the diagnosis of OME. SGAR transmits ultrasound waves to the eardrum, whereupon a microcomputer is used to filter, record, and analyze the ultrasound waves reflected back. SGAR is an efficient diagnostic tool for the detection of OME, requiring less than one second to complete the procedure. Although the sensitivity and specificity are somewhat low, SGAR is a noninvasive test that is unaffected by crying, cerumen, client cooperation, or the quality of the air seal in the ear, thereby making it useful for testing difficult infants [28, 36–38].
