EVALUATION OF HEARING IN PATIENTS WITH BETA THALASSEMIA MAJOR

This prospective study was conducted in Basrah Teaching Hospital to evaluate the hearing of β thalassemia major patients, and to find the association between desferoxamine (DFO) therapy and hearing loss (HL). Pure tone eudiometry (PTA) and tympanometry was done to determine hearing thresholds of (23) β thalassemia major patients and (50) non thalassemic subjects. All subjects were more than 4 year old to allow PTA to be done. The criteria of evaluation included a full otological history, drug history, otological examination, audiological evaluation using PTA and tympanometry. This study found that (6) out of (23) thalassemic patients and (6) out of (50) non thalassemic patients have hearing loss. From those thalassemic patients with HL, (5) patients have conductive hearing loss (CHL) and one have sensorineural hearing loss (SNHL), while the non thalassemic patients with HL all have CHL, also we found that (3) out of (5) thalassemic patients not on desferoxamine therapy have HL. In conclusion, β thalassaemia major has no significant statistical association with hearing problems, and there is no significant statistical association between desferoxamine therapy and hearing loss. Introduction he first branchial arch contributes Meckel's cartilage, which includes the malleus head and neck, incus body and short process, and anterior malleolar ligament. It also contributes the tensor tympani and the first three hillocks of His. The second branchial arch contributes Reichert's cartilage, which includes the manubrium of the malleus, the long process of the incus, and most of the stapes. It also contributes the last three Hillocks of His. the first branchial pouch contributes the Eustachian tube, mastoid air cells, and inner layer of the tympanic membrane. The first branchial cleft contributes the external auditory canal (EAC) and outer layer of the tympanic membrane. Bony labyrinth developed from otic capsule which encapsulates the otocyst that’s later on forms the membranous labyrinth. The external ear consists of pinna and external auditory canal which divided into cartilaginous and bony parts. the tympanic membrane separates the external from the middle ear by its three layers. The tympanic cavity is an air-containing cavity in the petrous part of the temporal bone contains the ossicular chain with its associated muscles, the aperture of the Eustachian tube, and vascular system. The cochlea is a coiled bony tube, snailshaped makes about 2.5 turns in the temporal bone. It is divided into three compartments; the scala tympani, scala vestibule, and scala media. T