A novel founder MYO15A frameshift duplication is the major cause of genetic hearing loss in Oman.

The increased risk for autosomal recessive disorders is one of the most well-known medical implications of consanguinity. In the Sultanate of Oman, a country characterized by one of the highest rates of consanguineous marriages worldwide, prevalence of genetic hearing loss (GHL) is estimated to be 6/10 000. Families of GHL patients have higher consanguinity rates than the general Omani population, indicating a major role for recessive forms. Mutations in GJB2, the most commonly mutated GHL gene, have been sporadically described. We collected 97 DNA samples of GHL probands, affected/unaffected siblings and parents from 26 Omani consanguineous families. Analyzing a first family by whole-exome sequencing, we identified a novel homozygous frameshift duplication (c.1171_1177dupGCCATCT) in MYO15A, the gene linked to the deafness locus DFNB3. This duplication was then found in a total of 8/26 (28%) families, within a 849 kb founder haplotype. Reconstruction of haplotype structure at MYO15A surrounding genomic regions indicated that the founder haplotype branched out in the past two to three centuries from a haplotype present worldwide. The MYO15A duplication emerges as the major cause of GHL in Oman. These findings have major implications for the design of GHL diagnosis and prevention policies in Oman.

Unilateral hearing impairment in Oman: a community-based cross-sectional study.

This report on unilateral hearing loss is based on the findings of a national survey on hearing loss and blindness in Oman. The survey of randomly selected households was conducted by trained healthcare personnel between Oct. 1, 1996, and Feb. 28, 1997. A total of 11,402 subjects of all ages were screened for hearing loss. Those who reported hearing impairment in either ear were subsequently reexamined by otologists in hospitals to confirm the findings and to determine the cause of the hearing loss. Based on these findings, we calculated that the prevalence of unilateral hearing impairment throughout Oman was 30.06 per 1,000 population (95% confidence interval [CI]: 29.80 to 30.31). Males had a significantly higher rate (36.67/1,000 [95% CI: 34.55 to 38.79]) than females (23.88/1,000 [95% CI: 21.82 to 25.94]). The causes of unilateral hearing loss were different from the reported causes of bilateral hearing loss. Impacted earwax (16.0% of cases) and otitis media with effusion (13.1%) were the most common identifiable causes of unilateral hearing loss; genetic causes were responsible for less than 2% of cases. Just over one-half of the hearing-impaired patients had only a mild hearing loss. Impairment rates varied in different regions of the country.

Magnitude of impacted earwax in Oman, its impact on hearing impairment and economic burden of earwax on health services.

BACKGROUND: Wax in ear canal causes a sizeable burden on resources of health services to a country. AIM: The magnitude of impacted wax, its effect in a survey and cost of managing this problem were reviewed in 2002. SETTINGS AND DESIGNS: A study was conducted during 1996 to estimate the magnitude and causes of hearing impairment and ear diseases in Oman. The authors further reviewed the data of community-based prevalence study to assess the role of impacted wax. MATERIALS AND METHODS: Trained physicians used portable audiometers to test the hearing status of each ear. They used otoscopes to examine the ear. Persons suspected to have hearing impairment or ear disease were reexamined by audiologists and otologists to determine the causes of hearing impairment. The resources for managing impacted wax were also calculated. RESULTS: In this survey, 11,402 subjects of all ages were examined. Prevalence of impacted wax was 11.7% (CI 95% 11.1-12.2). Impacted wax was significantly higher in females compared to males [RR = 1.22 (CI 95% 1.10-1.35)]. It was more common in residents of regions with humid environment than those of regions with less humidity [RR = 1.91 (CI 95% 1.67-2.18)]. Impacted wax in ear canal was associated with ear diseases. A total of 181,000 Omani people were estimated to have impacted wax in the ear canal. Managing impacted wax could cost 3.6 million US dollars to the ear care services. CONCLUSIONS: Impacted wax was a hindrance in the hearing survey and countries should plan to deal with earwax in such surveys. Its impact on hearing impairment and resource burden should be considered while formulating policies for ear care.

Skull base osteomyelitis: diagnostic and therapeutic challenges in atypical presentation.

OBJECTIVE: We sought to document the diagnostic and management difficulties in masked skull base osteomyelitis secondary to malignant otitis externa, with emphasis on establishing diagnostic criteria in recurrence. STUDY DESIGN: Retrospective analysis of 3 cases of inadequately treated malignant otitis externa in elderly diabetic individuals leading to recurrence and atypical manifestations of skull base osteomyelitis on contralateral side with or without multiple cranial nerve involvement. RESULTS: Two of the 3 cases died of the disease despite aggressive treatment. One case was treated successfully with combination of antipsuedamonal microbial drugs for 8 to 12 weeks and hyperbaric oxygen therapy. Major complications such as thrombosis of lateral sinus and internal jugular vein, meningitis, ophthalmoplegia, blindness, cervical spine erosion and paralysis of all cranial nerves with exception of Ist cranial nerve were observed. CONCLUSION: There is high morbidity and mortality associated with skull base osteomyelitis. In partially treated cases of malignant otitis externa, atypical symptoms and findings of unilateral severe otalgia, unremitting headache, and presence of high ESR, unilateral OME, constitute diagnostic clues of skull base osteomyelitis. Such cases require further investigation with CT, MRI, Technetium 99 and gallium 67 scintigraphy and aggressive management.

Allergic fungal sinusitis: can we predict the recurrence?

OBJECTIVE: The goal of the present study was to find out if recurrence can be predicted in cases of allergic fungal sinusitis. We also studied the influence of postoperative corticosteroid therapy on recurrence following surgery. STUDY DESIGN AND SETTING: This study was conducted at the ENT Department of Al Nahdha Hospital, which is a tertiary referral and teaching hospital in Muscat, Sultanate of Oman. The study is a retrospective analysis of 32 cases of allergic fungal sinusitis. Age, sex, extent of disease, and preoperative serum IgE levels were compared in patients who had recurrence with those who did not. We also studied the incidence, onset, and severity of recurrence in patients who received systemic corticosteroid as postoperative therapy and compared these values to those who received nasal corticosteroid spray only. RESULTS: No statistically significant difference was noted in the parameters of age, sex, extent of disease, and preoperative serum IgE levels when these values were compared in the group of patients who had recurrence (8 patients) with the group of patients who did not (32 patients). No statistically significant difference was found in the incidence of recurrence in patients in whom systemic corticosteroids were used postoperatively (17 patients) compared with patients who used nasal corticosteroid spray only (15 patients). However, when the patient had a recurrence, when it occurred it was earlier and more severe in patients who used nasal corticosteroid spray only (4 patients). CONCLUSIONS: At the present time, it is not possible to predict recurrence using parameters of age, sex, extent of disease, and serum IgE levels. Larger number of patients preferably in a prospective multicenter meta study are required to address this issue. Though use of systemic corticosteroid does not decrease the incidence of recurrence, it may delay the onset of recurrence and decrease the severity of recurrence.

Causes of severe to profound deafness in Omani paediatric population.

The study includes a retrospective analysis of causes of deafness in 1400 Omani children who were detected to be suffering from severe to profound levels of hearing impairment. A standard form was used to collect various details from the otolaryngologists all over the country. The time period included is from 1986 to 2000. The rate of consanguineous marriage in the parents of the affected children was 70%, and 67.8% of these children had a sibling suffering from hearing impairment. There has been a rapid evolution of the antenatal, perinatal and neonatal care delivery in Oman during last couple of decades. The Omani paediatric population has been well covered (>90%) under the vaccination protocols including rubella. It has helped in reducing the share of infectious diseases towards the hearing impairment. The study is an attempt to identify various causes of the identifiable causes of severe to profound hearing impairment in Omani paediatric population which is the first attempt of this kind in this country. Relevant literature has been reviewed.

Hearing Health Practices and Beliefs among over 20 year-olds in the Omani Population.

OBJECTIVES: The objective of this study was to investigate hearing health practices and beliefs among people over 20 years old in the Omani population. METHODS: This descriptive study was conducted in Oman during 2007-2008. Arabic speaking health staff interviewed a total of 598 selected people from urban and rural Oman and also industrial workers using a closed ended questionnaire with 15 questions. Participants' responses to the hearing practice related questions were graded into excellent (≥20 points), average (10 to 19) and poor (<10 points). The responses to the questions about hearing beliefs were grouped into excellent (≥25 points), good (5 to 24), average (-4 to 4), poor (-24 to -5) and very poor (<-25) grades. We calculated the frequencies, percentage proportions and 95% confidence intervals of the different grades of beliefs and hearing practice. The rates were also compared among different subgroups. We performed regression analysis to identify predictors of good hearing practice and scientific beliefs. RESULTS: Among the 598 participants, an 'excellent' grade of hearing practice and belief was noted in 386 (64.5% [95% CI 60.7-68.4]) and average in 205 (34.3% [95% CI 29.5 - 37.1]). Being in the 20 to 39 years age group (OR =1.67) and an urban resident (OR= 0.53) were both predictors of an excellent grade of hearing practice, while male gender (OR = 1.71) and illiteracy (OR= 1.80) were predictors of scientific beliefs. CONCLUSION: We noted high levels of good hearing practice and low levels of modern scientific beliefs among Omani participants. The Ear Health Care program of Oman should focus on improving the knowledge about healthy hearing so that attitudes and hearing practices are improved and noise-induced hearing loss can be prevented or delayed.

Adult tonsillectomy and day care surgery.

OBJECTIVE: To evaluate the safety of adult tonsillectomy as a day care surgery METHODS: Records of 664 patients above the age of 12 years, who underwent tonsillectomy were analysed. These patients were operated in our department within January 1999 and September 2002. Only 13 patients (1.95%) had post operative bleeding and were readmitted after discharge. The data of these patients were collected from medical records as well from the morbidity meeting proceedings and was reviewed retrospectively. Statistical analysis was done by using 'one sample t-test'. RESULTS: Overall incidence of post operative bleeding was 1.95%. None of our pateients bled with 12 hours of Surgery, 0.3% had bleeding between 12 to 24 hours after tonsillectomy and 1.65% encountered bleeding between 24 hours to the 6th post operative day. Bleeding was not major in majority of patients as only 0.45% of the patients required second anesthesia to control the bleeding and only 0.35% of patients required blood transfusion to replace the lost blood volume. In addition, higher incidence of bleeding was seen in males, in the older age group of 31-40 years, patients with obstructive sleep aponea and in patients where tonsillectomy was done by electrocautry dissection. CONCLUSION: Based on these observations, we conclude that Adult tonsillectomy can be safely preformed in our setup.

Endonasal carbon-dioxide laser assisted dacryocystorhinostomy verses external dacryocystorhinostomy.

This is a prospective, non-randomized study to evaluate and compare the results, morbidity and surgical time for endonasal carbon-dioxide laser assisted dacryocystorhinostomy and external dacryocystorhinostomy. 70 consecutive patients of chronic dacryocystitis with nasolacrimal duct obstruction were selected for the study. 36 patients under went endonasal CO2 laser assisted dacryocystorhinostomy and 34 had external dacryocystorhinostomy. Selection of the type of operation was left to the patient's choice. All the patients had preoperative counseling and both the procedures were explained in detail with their advantages and disadvantages. Patients not willing for the external incision were selected for endonasal laser assisted dacryocystorhinostomy and others were operated via external approach. Silicone tubes were put in all the patients for three months after surgery. The final follow up was 12 months after the removal of silicone tubes. The patency of the lacrimal passage was confirmed by irrigation, and patients were questioned about their symptoms.The success rates, 12 months after removal of silicone tubes were 100% in endonasal CO2 laser assisted dacryocystorhinostomy and 88.24% in external dacryocystorhinostomy. The surgical time of endonasal laser assisted dacryocystorhinostomy was 38 minutes as compared to 62 in external dacryocystorhinostomy. Complication rate in both groups was almost equal.Thus, we came to the conclusion that Endonasal CO2 laser assisted dacryocystorhinostomy is a better surgical option to external dacryocystorhinostomy in cases of chronic dacryocystitis with nasolacrimal duct obstruction, with shorter surgical time.

The prevalence and causes of hearing impairment in Oman: a community-based cross-sectional study.

A community-based nationwide survey for hearing loss was conducted in Oman in 1996-97. Audiometric tests and ear examinations were conducted for 12,400 persons in phase I. For children aged less than 4 years, subjective screening tests were used. In phase II, otologists examined the hearing-impaired subjects to determine the cause. The prevalence of bilateral hearing impairment was 55/1000 (95% CI 51.08-59.47). Gender difference was not significant. The rates were 325/1000 and 17/1000, respectively, in the > or = 60-year and < 10-year age groups. Presbyacusis and middle ear diseases, respectively, were the causes of 33% and 20% of bilateral hearing impairment. In 30% of the bilateral hearing-impaired subjects, the cause could not be determined. The prevalence of bilateral disabling hearing loss was 21/1000 (95% CI 18.07-23.29). Noise-induced trauma was responsible for only 1.4% of cases of disabling hearing loss. Establishing primary ear care, introducing hearing screening for neonates and schoolchildren, promoting safe preventive practices for ear care, strengthening secondary-level ear care services and introducing comprehensive rehabilitative initiatives for the hearing-disabled are recommended to reduce the hearing loss rates.

Double disability: the hearing-impaired blind in the Sultanate of Oman.

A survey to estimate the magnitude and causes of blindness and hearing loss was undertaken in Oman in 1996-97. An analysis correlating blindness with hearing loss is presented. Twenty-eight subjects among 11,400 examined had double disability, with a prevalence rate of 2.46/1000 (95% CI 1.55-3.36). Females and older age groups had a higher risk of double disability than did males (relative risk (RR) 3.95, 95%, CI 1.34-8.1) and younger age groups (RR 9.91, 95% CI 3.9-21.2). Twenty-five per cent of subjects with double disability had curable blindness, while 33% had preventable blindness. Only 10% of subjects with double disability had curable causes of hearing loss. The number of cases with double disabilities in Oman might decrease, due to the improved healthcare in last two decades. However, the increase in the aging population necessitates intervention to prevent double disability. An emphasis on the prevention of blindness could address the problem more effectively.