HEAR, YE! HEAR, YE!
UP-NIH survey gathers feedback on how Filipino doctors deal with middle-ear effusion related to nasopharyngeal carcinoma
By Cherry Paraz, MD
Contributing Writer
Nasopharyngeal carcinoma (NPCA) is a disease common among Orientals. "If you look at the Southeast Asian region-the Philippines, Malaysia, Thailand, Southern China-you will see a greater concentration of NPCA compared with Caucasians or Indians," said Dr. Nathaniel Yang, a consultant of the department of otolaryngology-head and neck surgery at the University of the Philippines-Philippine General Hospital (UP-PGH).
Speaking at the regular forum of the UP National Institutes of Health (UP-NIH), Yang said, "It is a big problem in the Philippines because of probably the enviro-genetic problem." He recalled seeing at least two patients with NPCA every week at the outpatient department of PGH during his residency training.
The typical presenting symptoms of NPCA are middle-ear effusion and hearing loss. Yang observed that patients come in for hearing problems in one ear only to find out they have a tumor at the back of their nose. In an article in the Laryngoscope, Wei et al. noted that the symptoms are due to the mechanical or functional obstruction of the Eustachian tube, caused either by the tumor or as a side effect of radiotherapy.
Myringotomy with ventilation-tube insertion is a well-accepted surgical procedure to relieve middle-ear effusion. According to Wei et al., this procedure has its share of side effects including otorrhea, obstruction of the ventilation tube, formation of cholesteatoma, granulation tissue formation, scar formation, or retraction of the eardrum. Several studies published from 1987 to 2001 showed that otorrhea is a common occurrence after myringotomy with ventilation-tube insertion, particularly when it is done after radiotherapy. The chance of developing otorrhea postradiotherapy ranged from 44 to 90 percent.
Through the years, the treatment philosophy of middle-ear effusion has evolved, as seen in studies conducted mostly in Southern China, including Hong Kong and Taiwan. In 1992, Lau et al. wrote: "In view of the higher complication rate in the postradiotherapy group, the role of myringotomy and insertion of ventilation tube is reassessed." In 1998, Young and Sheen wrote that they preferred repeated myringotomies to ventilation-tube insertion. Finally in 2001, Chen et al. concluded that VT insertion is contraindicated in postirradiation patients.
These prompted Yang and Dr. Christine Joy Arquiza to conduct a survey of local clinical practice in the treatment of NPCA-related middle-ear effusion. They wanted to determine if the same complications could be found among Filipino NPCA patients and if the treatment strategy of Filipino otolaryngologists has changed because of this.
Questionnaires were distributed among practicing otolaryngo-logists and resident trainees during two consecutive conventions of the Philippine Society of Otolarygology-Head and Neck Surgery in 2002 to 2003. There was a 54-percent response rate among participants, which included 66 diplomates, 39 resident trainees, and 30 of unknown status.
The results showed that the primary preferred treatment of middle-ear effusion in NPCA was myringotomy with ventilation tube, which 79.3 percent of the respondents chose over myringotomy alone (9.6 percent), observation (6.7 percent), or other treatment (4.4 percent). Nine out of 10 practicing otolaryngologists chose observation, but none of the residents did. The difference is "probably because of a philosophy they espouse in the training institution where they're at," said Yang of the residents' hesitation to observe and not treat.
Overall, 58 percent of the respondents used self-fabricated ventilation tubes instead of commercial ones. The use of self-fabricated ventilation tubes was higher among residents (81 percent) than practicing otolaryngologists (51 percent). Short-acting commercially made ventilation tubes were used by 17.3 percent while the remaining 24.5 percent used long-acting tubes.
Yang explained that polyethylene tubes such as those of the Avocath are used because they are more affordable. He also noted that otolaryngologists only start using other kinds of tubes after graduation from their residency program.
Based purely on recall, 45.4 percent of respondents said that otorrhea occurred less than 25 percent of the time after myringotomy with ventilation-tube insertion. One-third of respondents said they encountered it less than 25 percent of the time after myringotomy alone. Twenty-nine percent of respondents did not encounter otorrhea after myringotomy with ventilation-tube insertion while 42.8 percent did not note otorrhea after myringotomy alone.
Of all the respondents, only 15.6 percent were aware of internationally accepted guidelines or treatment protocols for the management of NPCA-related middle-ear effusion.
The survey revealed that the majority of Filipino otolaryngologists prefer to treat NPCA-related middle-ear effusion using myringotomy with ventilation-tube insertion despite their observation of postoperational development of otorrhea. Based on the high complication rates in published literature and the concordance of a local survey, Yang and Arquiza recommended that the local treatment philosophy be reevaluated. This can be done by either accepting the results in published literature and adopting a more conservative treatment strategy or by conducting a local study comparing the complication rates between patients with and without ventilation tube.
Either way, implications exist for the Philippine Board of Otolaryngology-Head and Neck Surgery, resident trainees, and practicing otolaryngologists, Yang and Arquiza said. The board has to take a closer look at the required number of myringotomies with ventilation-tube insertion for residents to attain eligibility, which has led to the practice of performing surgical procedures "for the sake of the resident." Lastly, practicing otolaryngologists have an obligation to present the benefits and complications of the treatment strategy to patients, hopefully resulting in a general decline in the number of myringotomies with ventilation-tube done in the private setting.
Blindness decline
Meanwhile Dr. Leo Cubillan of the Institute of Ophthalmology noted a decline in the incidence of blindness in the country as shown by the third National Survey on Blindness conducted in 2002.
The prevalence of bilateral blindness in 2002 was at 0.58 percent, down by 17 percent from the 1995 rate of 0.7 percent. "We're still above the 0.5-percent cutoff," Cubillan noted, but the country is making steady progress in easing the burden of blindness.
In terms of absolute number, however, the 0.58-percent prevalence rate still meant about 400,000 Filipinos are blind in both eyes based on the 2002 population of 79.5 million. Cubillan explained that although the 17-percent drop in prevalence rate from 1995 to 2002 was significant, the absolute number of blind persons remained high because of the increase in population, especially the elderly groups.
At the same time, 1.07 percent of Filipinos are blind in one eye while 1.64 percent have bilateral low vision and 1.33 percent have low vision in one eye.
A blind person is defined as one who has visual acuity less than 3/60 in the better eye. Low vision is defined as visual acuity greater than or equal to 3/60 but less than 6/18. As expected, most of the visually impaired individuals belonged to the older age groups.
Cataract is still the most common cause of visual impairment, although its share has dropped from 77 percent in 1995 to 62 percent in 2002 because of the nationwide program on cataract surgery. Other causes of visual impairment were errors of refraction, glaucoma, and corneal opacity.
The 2002 survey employed a multistage, cluster random sampling, with each of the 16 regions constituting one cluster. Nine barangays were randomly chosen per cluster, and 50 households were picked per barangay. Team members composed mostly of staff from the Institute of Ophthalmology were sent to various parts of the country from October 2001 to May 2002. Visual-acuity tests were administered to members of the selected households. A total of 29,888 persons were screened. The mean age of respondents was 27 years old. Males made up 49.2 of the respondents while females comprised 50.8 percent.
The World Health Organization says that blindness is a public-health problem when its prevalence is at least one percent. The goal of the WHO is to reduce the prevalence to less than 0.5 percent in all countries by 2020. Based on the results of the recent survey, the Philippines appears to be on track with the success of the Vision 2020 program.
The first national survey in 1987 reported a prevalence of 1.07, much higher than the desired 0.5 percent. The prevalence dropped to 0.7 percent in 1995 and then to 0.58 in the 2002 surveys, largely through the efforts of the National Committee on Sight Prevention which was established to oversee all sight-preservation programs. The fourth national survey eyes to expand coverage by including childhood blindness and eye diseases.
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