vib85012.htm

Braille Instruction for Blind Diabetic Adults with Decreased Tactile Sensitivity

RANDALL K. HARLEY, Ph.D.; JAMES W. PICHERT, Ph.D.; MERRIE MORRISON, R.N., M.A.

Dr. Harley is professor of special education, George Peabody College for Teachers, Vanderbilt University, Nashville, Tennessee. Dr. Pichert is assistant professor of education in the Medicine, Diabetic Research and Training Center, Vanderbilt University. Ms. Morrison is a doctoral student in special education, George Peabody College for Teachers, and an adjunct professor in the Departments of Health and Sociology, Austin Peay State University, Clarksville, Tennessee.

George Peabody College for Teachers, Vanderbilt University, Nashville, TN 37203

Abstract: Special educators may assume that diabetic persons who are blind and have decreased tactile sensitivity cannot be taught to read braille. This article describes a three-part study that compared the tactile sensitivity and braille-discrimination ability of blind diabetic and blind nondiabetic adults. In the first phase, the diabetic subjects required 80 percent more stimulation before reporting any tactile sensation on a modified Optacon. In the second phase, no significant difference was found in the subjects' ability to discriminate standard and enlarged braille characters. In the third phase, four tactually irnpaired blind diabetic adults received training and demonstrated ability in leaming to read enough braille for use in daily living.

Adults with diabetes are subject to two serious complications-retinopathy, which results in blindness, and neuropathy, which causes decreased sensitivity of the hands. Special educators sometimes assume that diabetic patients who have both complications-blindness and decreased tactile sensitivity-are unable to take full advantage of tactile aids that have been developed for the use of those who became blind from other causes. This assumption may have led some to conclude that braille, and similar training should not be offered to blind diabetic individuals. Although all blind diabetics may not need to learn to read braille, many could benefit from this training, which could help make them more independent at home and perhaps more employable.

Partial support for the study was provided by Grant No. P60 AM 20593 from the National Institutes of Health. The authors wish to thank Alan Koenig and Cynthia English for their help as graduate research assistants on the study.

This article discusses the previous research on the tactile sensitivity of blind diabetic adults and describes a three-part study that was designed to determine whether it is feasible to train these people to read braille. A case study approach also was used to learn whether a systematic instructional program in how to read braille would prove successful with four blind diabetic adults with diminished tactile sensitivity.

Previous Research

The effects of diabetic neuropathy on the hands is rarely discussed in the literature. This lack of data is distressing because the effects are common, have clinical significance, and have been widely recognized by teachers of braille and by orientation and mobility (O&M) instructors (Ellenberg, 1976). Persons with diabetic neuropathy, especially men and the aged, usually encounter more difficulty mastering braille skills than do nondiabetics. According to Ellenberg (1976, p.1,637), "The difference is independent of social, intellectual, cultural, or educational background or motivation, but is traceable to impairment of the finer tactile sensations of the fingers as a result of neuropathy. "

Three clinical investigations explored the differences between the tactile sensitivity of diabetics and nondiabetics who were blind. Heinrichs and Moorhouse (1969) measured the tactual thresholds of 10 sighted subjects, 10 blind nondiabetic subjects, and 10 diabetic blind subjects. No significant differences were found between the sighted subjects and the blind nondiabetic subjects. However, all tactile perception thresholds were significantly higher in the blind diabetic subjects; the two subjects with the highest thresholds were aware of sensory loss in their fingers. It was found that four of the blind diabetic subjects readily learned to read braille, one had moderate difficulty in doing so, two experienced great difficulty, two could not learn braille, and the remaining subject did not try. Clinical results from this study indicated that the mean two-point threshold in the diabetic Subjects was 2.5 mm (as compared to 1.6 mm in the blind nondiabetic subjects). Since the distance between dots in standard braille is 2.2 mm, the authors suggested that "the difficulty of the diabetic subjects in reading braille is probably related to an inability to perceive the individual points clearly" (Heinrichs & Moorhouse, 1969, p. 72).

"Jumbo" braille, which utilizes an enlarged braille cell with greater distances between dots, may help circumvent the problem alluded to by Heinrichs and Moorhouse. Jumbo braille equipment and books can be obtained from three important sources of educational materials for the blind and visually iinpaired: (1) the American Printing House for the Blind, which publishes the Illinois Braille Series (a braille reading series that starts with an enlarged braille cell in Volume 1 and progresses to a smaller cell in the latter stages of the reader), (2) the Howe Press of the Perkins School for the Blind, which produces the jumbo braille writer and slate, and (3) the Library of Congress's section of books for the blind and physically handicapped. However, it should be noted that the limited number of books printed that are available from the Library of Congress may indicate that such books are not popular.

McBride and Mistretta (1982) compared tactile thresholds of 32 diabetic and 27 nondiabetic sighted subjects and again found that diabetic subjects had a small but significantly higher mean tactile threshold. Also, high tactile thresholds of diabetics were found to be significantly correlated with the presence of insulin therapy and longer duration of diabetes. The latter correlation was in contrast to Heinrichs and Moorhouse (1969), who found no significant correlation between tactile thresholds and the duration of diabetes. McBride and Mistretta did not present data concerning their diabetic subjects' braille reading skills, however, as their subjects were sighted.

One potential problem with the McBride and Mistretta study was the procedure for determining tactile sensitivity. McBride and Mistretta used the Semmes-Weinstein asthesiometer, a modified Von Frey hairs technique, to measure quantitatively the subjects' tactile thresholds. They found the asthesiometer to be "a simple, rapid, and risk-free procedure [that provides] more objective information since an actual threshold can be measured" (p. 314), Although there is no reason to question their data, their procedures, like most convenient ways of measuring tactile sensitivity, may be subject to the idiosyncracies of pressure and the individual tester's rate of application. Therefore, we decided to seek an alternative, which will be discussed later.

The use of a modified Optacon (and, more recently, an Optacon Tactile Tester) has been a recent development in measuring tactile sensitivity (Arezzo & Schaumburg, 1980; Arezzo, Schaumburg, & Petersen, 1983; Bleecker, in press). The Optacon was designed as a print-reading machine for the blind. It is a compact device that converts visual images of printed symbols into direct tactile representations that a blind reader can feel and identify with the tip of one finger. The Optacon reader moves a small camera containing 144 photo-transistors over the printed letters; the image is transformed simultaneously into tactile letters on an array containing 144 vibrating pins. When the Optacon is used to measure tactile sensitivity, the camera unit is removed, and a digital voltmeter is attached to provide a quantitative measure of the intensity of a stimulus.

Arezzo and Schaumburg (1980) used the modified Optacon to test the sensory thresholds of 100 nondiabetic subjects and 24 diabetic subjects, as well as to explore the reliability of the instrument. Blindfolded subjects placed their index finger on the array and reported when sensations appeared or disappeared on ascending and descending trials. For nondiabetic subjects, a strong, positive correlation was found between tactile threshold and age. Among diabetic subjects, considerably more variability in thresholds was noted. Nine of the 24 diabetic subjects were found to have tactile thresholds that were more than two standard deviations above the normal mean threshold. After Optacon testing, medical reports indicated that six of these nine subjects had peripheral neuropathy; the remaining subjects had no symptoms of neurological impairment.

Tactile-threshold measurements were taken with the modified Optacon over a three-month period. Data were remarkably consistent across the testing period. Arezzo & Schaumburg (1980, p. 463) concluded "that the modified Optacon is a reliable device for the rapid assessment of finger-tip sensation and is potentially useful for the repeated screening for peripheral nerve dysfunction in large populations." Arezzo, Schaumburg and Peterson (1983) and Bleecker (in press) also report evidence supporting the reliability and validity of the modified Optacon as a measure of tactile sensitivity.

In summary, there is a dearth of research on the teaching of braille reading to tactually impaired blind diabetics. Although the personal experience of professionals such as Kolterman (1978) supports the use of jumbo braille, and a common sense rationale for jumbo braille exists (Heinrichs & Moorhouse, 1969), it is not possible to formulate appropriate instructional guidelines on such a basis. Research is needed to determine whether jumbo braille or an expanded dot cell is needed for tactually impaired blind diabetics. An investigation is also needed to ascertain whether instruction in braille reading is effective with this population. The purpose of this article is to report a study that began to do these things. The study was conducted in three phases: (1) a norming phase in which the reliability and validity of using the modified Optacon for tactile testing were assessed, (2) an experimental phase in which the tactile sensitivity and braille-symbol discrimination skills of age-matched blind diabetic and sighted nondiabetic volunteers were tested, and (3) a case study phase in which four blind diabetic adults with diminished tactile sensitivity were given individual training in reading braille.

Phase 1: Norming

Although the first author had a great deal of experience teaching the use of the Optacon in his work with blind persons, none of us had previously used it as a tactile tester. After modifying an Optacon as Arezzo and Schaumburg (1980) did, we conducted three reliability and validity tests. First, two of us tested 20 sighted nondiabetic adults who ranged in age from 18 to 69. The intercorrelation between the results of the two tests was .69. This result was somewhat lower than we had anticipated. However, it was not surprising, for two reasons: (1) the range of values in the tested sample was very narrow and (2) the modified Optacon has limitations as a tactile tester Arezzo & Schaumburg, 1980). We considered the result acceptable enough to pursue work in the norming phase, and thus proceeded to test the stability of the tactile sensitivity measure over time. Five sighted nondiabetic individuals were tested once a week for six weeks. Cronbach's alpha was .95, indicating that the results were stable over time. Taken together, these results provided suitable confidence in the reliability of the tactile testing procedure.

The last test conducted during the norming phase assessed the discriminant validity of the procedure. Twenty diabetic adults from the Diabetes Research and Training Center at Vanderbilt University had their tactile sensitivity assessed by an examiner who did not know their medical conditions. Half the subjects had clinically diagnosed peripheral neuropathy and the other half had no record of neuropathic involvement. The two groups contained an equal number of men and women, who were matched for age. The group with known neuropathy averaged 6.3 volts (the normal ranges are from 2 to 4 volts) versus 4.7 volts for the group with no clinical evidence of neuropathy (t18 = 2.25, P< .05). On questioning, the examiner correctly identified seven of the 10 subjects who had diagnosed neuropathy, but falsely identified three of those who had not been so diagnosed. Although it is certainly not ideal, the procedure seems to have an acceptable level of discriminant validity.

Phase 2: Experimental

The research questions that were addressed in this phase were these:

1. Is there a difference in tactile sensitivity between blind diabetic persons and sighted nondiabetic persons?
2. Is there a difference in the ability of blind diabetic persons and sighted nondiabetic persons to discriminate braille characters?
3. Is there a difference in the performance of blind diabetic persons on standard-size and jumbo braille characters?

Experiment 1. Experiment 1 was designed to compare the tactile sensitivity of blind diabetic persons and sighted nondiabetic persons. Nineteen blind diabetic adults, who ranged in age from 25 to 77, were recruited from the diabetes and retinopathy outpatient clinics at Vanderbilt University Medical Center. An age- and sex-matched comparison group was recruited from students, staff, and faculty at the university. The tactile sensitivity of the subjects was measured according to the procedure described previously, and the results indicated substantial differences between the two groups (see Table 1). The blind diabetic group required 80 percent more stimulation before reporting any tactile sensation, which was statistically significant (t36 = 4.5, p<.0I). The result of Experiment I thus replicates the other studies that have shown deficits in tactile sensitivity in blind patients with diabetes.

Table 1. Tactile Sensitivity (in volts) of Diabetic Blind Persons and Nondiabetic

Sighted Persons

Subjects Mean (SD)

Diabetic blind persons

(n = 19) 7.322(2.89)

Nondiabetic sighted

persons (n = 19) 4.04 (1.39)

2 t(36)=4.5, p<.0l.

Experiment 2. Experiment 2 was designed to determine whether blind diabetic persons with diminished tactile sensitivity performed less well on a braille-character discrimination task than did the sighted nondiabetic persons in the control group, and whether they performed better on jumbo or on standard-size braille characters. The first step was to construct a suitable measurement tool. A 20-item multiple choice Braille Discrimination Test (BDT) was constructed from a pool of 50 standard-size braille cell items that had been pretested on 50 nondiabetic blindfolded undergraduate students. The task was to match a stimulus cell with one of five choices. The 20 items were selected from an item analysis that showed them to have a difficulty index of .30-.70 and a positive item total-test-score intercorrelation. These 20 standard-size items and 20 corresponding jumbo braille items were individually embossed on BrailonTM, a heavy plastic paper. The test took 20 to 50 minutes to administer.

Subjects in Experiment 2 were 10 of the blind diabetic individuals who participated in Experiment 1 who had no experience with braille. An age-matched control group of 10 nondiabetic sighted persons with no previous braille experience was recruited from students, staff, and faculty at Vanderbilt University. Each subject completed the BDT by selecting which braillelike cell from the group of five alternatives matched the stimulus cell from each of the 40 items. The results appear in Table 2. They suggest that the blind subjects with diabetes were only somewhat less able to identify the matching braille character than those in the control group. The difference was not statistically significant.

*Brailon is a trademark owned by American Thermoform.

Table 2. Number of Correct Items Identified on the Braille Discrimination Test by the Diabetic Blind Subjects and the Nondiabetic Sighted Subjects2

Standard Braille Jumbo Braille Total

Subjects (20 Items) (20 Items) (40 Items)

Diabetic blind persons (n = 10) 8.9 10.7 19.6

Nondiabetic sighted persons

(n = 10) 11.1 13.2 24.3

2No differences were statistically significant.

The within-subjects comparison on jumbo versus standard-sized braille characters also was not statistically significant. Even if we had increased the power of the test by adding more subjects, we doubt whether differences of this magnitude would have practical significance. The results were surprising because the literature and field reports suggest that jumbo braille may be preferred for tactually impaired blind diabetic adults. However, in both experiments the subjects were given unlimited time to perform tasks. Several subjects took a long time to complete the discrimination tasks. Carefully controlled time limitations may have made a difference in favor of the enlarged braille cell.

We cannot conclude that blind diabetic individuals are poor candidates for braille training. Our results seemed to indicate that there is reason to believe that they could be successful, given appropriate training. This assumption led to the third phase of the study, in which four of the blind diabetic individuals who had participated in Experiments 1 and 2 were given braille training tailored to their needs. All four subjects were referred by counselors at Tennessee Services for the Blind as potential braille students. Descriptions of the subjects, an overview of the training procedures, and the individual case summaries follow.

Phase 3: Case Studies

Subjects. There is no typical blind diabetic adult with reduced tactile sensitivity. The four blind diabetic adults described in this section were each unique in many respects (see Table 3). Each subject had a special set of health problems. The first subject was Mrs. B, a 58-year-old black woman who was bothered by an arthritic condition. The second subject was Mr. H, a 37-yearold white man with severe kidney problems. The third subject was Mr. E, a 65-year-old black man who was recovering from a major heart attack. The fourth subject was Mr. J, a 57-year-old black man who was impaired motorically by a previous stroke. Mrs. B was the only employed subject. Mr. H was participating in a local rehabilitation program for the blind. Mr. E and Mr. J were retired but living alone and taking care of their needs independently.

The four subjects also had several characteristics in common. All had reduced visual acuity to such an extent that reading print was no longer feasible. All subjects desired to learn to read braille as an aid to independent living skills. In addition, one subject wanted to learn braille for use in employment.

Table 3. Characteristics of Case-Study Subjects

Otber Optacon

Subjects Age Sex Race Conditions (volts)a

Mr. J 57 Male Black Stroke 5.9

Mr. H 37 Male White Kidney 6.5

problems

Mr. E 65 Male Black Heart 16.5

attack

Mrs. B 58 Female Black Arthritis 5.5

2Normal = 4 volts.

All subjects had reduced tactile sensitivity ranging from a threshold of 5.5 to 16.5 on the modified Optacon test. All subjects preferred the jumbo rather than the standard-size braille dots, although the BDT indicated that only two subjects showed a measurable improvement with the jumbo braille characters.

Training program. The training period for the four subjects ranged from 10 to 18 weeks, and the total training time ranged from 10 to 50 hours. Subjects received from one to five training sessions per week, and each session lasted from 30 to 60 minutes. Each subject received training from a different braille teacher; each of the four teachers was experienced in teaching braille reading.

Before we decided to work with the subjects, we evaluated their desire to learn braille. We found that all subjects wanted to learn braille and were willing to allocate the time needed for the training sessions. The programs for each subject were sequenced so that embossed readiness materials were introduced at the beginning and the subjects moved into the discrimination of braille cells early in their programs. Mr. H did not need the readiness materials, and started braille cell discrimination patterns from the beginning. Enlarged- dot patterns were used for all the subjects, but each subject was given an opportunity to use standard sized dot-cell materials.

Mrs. B

Mrs. B was working as a pillow stuffer in a workshop for blind persons-a position she had held since 1973. Before she became blind, she was a cook in a local restaurant. Her highest educational level was tenth grade. She was unable to read print or braille. Her visual limitation was so severe that she required a cane for mobility. The onset of blindness from diabetic retinopathy began in 1972, and her visual acuity was limited to light perception at the time of the study. During the training period, Mrs. B was taking AnacinTM for arthritis, a medication for high blood pressure, and insulin for diabetes.

Braille reading needs. Mrs. B wanted to learn braille for reading clock faces, elevator buttons, and telephone numbers. After completing her first lesson, she decided that a realistic goal would be to learn the braille numbers 1 to 10, so she would be able to use an elevator. She also wanted to be able to read emergency telephone numbers and the telephone number of her physician.

Assessment. In the beginning, Mrs. B's tactile sensitivity was assessed with a modified Optacon and a braille dot test. She was able to detect vibrations in the tactile display of the Optacon at 5.5 volts in the index finger of both the right and the left hand. She was able to match nine of 20 standard braille-cell items and 11 of 20 jumbo items in the BDT. In subsequent lessons, with standard braille, she said that these small braille cells made her "nervous" and she preferred to use the larger jumbo cells in reading.

Program. The focus of the program for Mrs. B centered on the discrimination of the first 10 letters of the braille alphabet (which also represent the digits 0-9 when paired with a special braille symbol called a "number sign"). Since she was able easily to discriminate braille-dot readiness materials, little time was spent on these activities. The enlarged cells of Volume 1 of the Illinois Braille Series were used in the early part of her program. Later, special drill dot sheets in jumbo braille were designed for her. These simulated the dots used for designating the floors by the buttons on an elevator. Practice sheets with a few important telephone numbers were also used in later lessons with Mrs. B.

One difficulty in planning a program for Mrs. B was finding a suitable time and place for her lessons. Since she worked during the day, she preferred to have her lessons during her lunch period. This meant that we could give her a lesson for only 30 minutes one day a week, the other 30 minutes of that period were used for eating lunch. This arrangement continued for 10 weeks and practice materials were given after each lesson for home use. In one lesson, she was given an enlarged wooden block with holes for six pegs to practice setting up the various braille configurations. She particularly liked this block simulation, and asked to take it home for further practice.

In the first lessons, Mrs. B read "A" through "E" with a high degree of accuracy. However, as she proceeded with letters "F" through "J," she had difficulty remembering the configurations, especially the reversals (e.g., "E" and "I," "D" and "F," and "H" and "J"). On her pillow stuffing job she worked a great deal with her fingers, and she complained that her fingers were raw and insensitive, which made it difficult for her to discriminate the braille dots.

She continued to work on the letters "A" through "J" and the numbers 1 to 9. Later, the number sign was introduced in combination with these letters in patterns similar to the arrangements on elevator buttons. Aluminum tape was used to make them feel more like the actual numbers on the elevator. However, she resisted moving to a smaller standard braille size as used on elevators.

Results. Mrs. B did well in one lesson and subsequently forgot the configurations in the next lesson. At the end of 10 weeks, she was having difficulty remembering certain braille configurations. At the end of her training period, she was able to discriminate only eight of 20 standard-size and 11 of 20 jumbo cells of the BDT. Her modified Optacon sensitivity score remained essentially the same as at the beginning. She continued to complain that the numbness of her fingers caused by the pillow-stuffing job was making it difficult to match the dot- shaped patterns. She remained inconsistent in identifying the dot numbers on a simulated elevator control panel.

Conclusion. Mrs. B made moderately slow progress during a short intervention program that consisted of one lesson per week. She learned seven letters from "A" to "G" and the corresponding dot figurations for the numbers "1" to "7." In the tactile discrimination program, Mrs. B showed a definite preference for the enlarged braille cell. Her measured.loss of sensitivity may have been a contributing factor to her difficulty with braille. Diabetes or the roughening of her fingers on the job may or may not have caused her decrease in sensitivity; her lack of practice on the braille training exercises was probably a more important factor. One 30-minute lesson per week was probably insufficient for her to learn the braille cell configurations. Mrs. B demonstrated that she could feel the braille dots, but could not remember the configurations. Of the four subjects, Mrs. B was given the least amount of training and showed the least improvement. She did, however, have sufficient tactile-discrimination ability to identify both standard-size and enlarged dot braille cells.

Mr. H

Mr. H had been a research analyst with the Tennessee Department of Transportation since 1967. Before that, he had been a production worker on an assembly line. His highest level of education was a high school certificate from a rural high school. Mr. H had four children and a wife who was employed by the state.

Mr. H became blind at age 36 from diabetic retinopathy a year prior to this study. He had been taking insulin since his early teens and was also taking hypertension medication at the time of his training. Kidney disease had caused him much trouble; during his training, it caused him to be absent frequently from classes at the Rehabilitation Center of Tennessee Services for the Blind. His visual acuity consisted of "rapid movements" in the right eye and "light perception " in the left eye, but this condition fluctuated over a long period.

Braille reading needs. Mr. H wanted to learn to read and write braille well enough to be able to use a computer so he could return to his former job as a research analyst. He also was a keypunch operator, and he wanted to be able to continue in that kind of work as well.

Assessment. Mr. H's tactile sensitivity on the modified Optacon was 7.5 volts for his dominant hand. He identified 69 of 75 cards of the Roughness Discrimination Test -a test of tactile sensitivity used for evaluating readiness in braille reading. The test consists of squares of sandpaper of different grades of roughness. The task is to indicate which of four squares is different from the others. Mr. H was able to match 17 of 20 items in jumbo braille and 11 of 20 standard-size cell problems of the BDT. In subsequent lessons, he continued to prefer the larger braille cells. In his assessment, as in his training lessons, he was meticulous in completing the braille discrimination tasks, taking a long time with each item.

Program. Since the purpose of the program for Mr. H was to learn braille to obtain employment, a long-term goal was set of learning Grade 2 braille with all its contractions. He had a relatively high ability to discriminate braille cells, and so little time was spent in tactile-readiness activities. Mr. H started Volume 1 of the Illinois Braille Series in his first lessons at the Rehabilitation Center. He learned the first five letters, "A" through "E," easily, using the expanded cells of that series.

Mr. H practiced his braille lessons about 50 minutes per day for five days each week. He had no trouble reading for at least 30 to 40 minutes without losing tactile sensitivity. His reading speed continued to improve during the first six weeks of training. However, his progress was suddenly interrupted because of physical problems. He was able to complete only about three months of training during a five-month period.

Mr. H seemed to lose tactile sensitivity during the latter stages of his illness, but we did not have the opportunity to measure it. Lessons had to be conducted with a full-sized jumbo cell.

Results. Mr. H's progress was irregular during the five-month period. During that time, he was able to keep only 60 to 100 scheduled appointments for training lessons. He completed all of Grade 1, including the braille alphabet, the numbers, and punctuation signs, but finished only three lessons in Grade 2 contractions. Mr. H's main concern was his health. He was still highly motivated and had much support from his family.

Conclusion. Mr. H made relatively good progress during a five-month intervention program that consisted of five lessons per week. He learned all of Grade 1 braille, and perhaps could have learned more if he did not have to miss lessons because of his health problems. In the tactile discrimination program, Mr. H showed a definite preference for jumbo braille. Of the four subjects, Mr. H was given the most intensive training and showed the greatest improvement. He also demonstrated sufficient tactile-discrimination ability to identify both standard-size and enlarged-dot cells.

Mr. H did not achieve the long-term goal of learning Grade 2 braille during the course of the study. Given enough time, he should be able to reach his goal in spite of diminished tactile sensitivity.

Mr. E

Mr. E was the oldest subject in the study. A former professional photographer and nursing assistant, he had been living alone and unemployed for six years. His highest educational level was one year of college. Mr. E had sudden visual loss in both eyes at age 60. Secondary glaucoma had developed in both eyes as a result of diabetes, and his vision had deteriorated to "light perception" just before his training period. Sometimes his vision fluctuated to an occasional "object perception." Mr. E was taking insulin and needed assistance in measuring the amount of insulin because of his reduced visual acuity.

Braille reading needs. Mr. E wanted to learn enough braille so he could identify braille labels on clothes and food items in his kitchen. However, he stated his greatest need was to learn enough braille to read the Bible.

Assesment. Mr. E's tactile sensitivity, as measured by the modified Optacon, was a high 16.5 volts in his right (dominant) hand and 14.7 volts in his left hand. In spite of his low level of tactile sensitivity, he matched eight of 20 braille-dot patterns in jumbo braille and 14 of 20 similar patterns in standard braille on the BDT. He was deliberate in each task, taking about three minutes per item. Mr. E continued to prefer the jumbo cells throughout his training period.

Program. The focus of the program for Mr. E was to teach him to read and write Grade 1 braille for use in daily living skills. Since he took a relatively long period to discriminate braille-dot patterns, a carefully planned series of braille readiness materials was used to develop his tactile sensitivity before proceeding to the discrimination of braille cells. The sequence of patterns used in the American Printing House for the Blind's beginning reading series for children was used with Mr. E. Later, his objective was to learn to read and emboss the letters of the alphabet in a program of two lessons per week for 15 weeks. Near the end of his training program, Mr. E was hospitalized because of a severe heart attack.

Results. By the end of the 15-week period, Mr. E had learned to read and to emboss the words representing the colors of his clothes and the foods in his kitchen. He was also able to "read" a few familiar Bible verses in Grade 1 braille. All these materials were embossed in jumbo braille owing to Mr. E's preference for the enlarged dot cells. The goal of learning enough Grade 1 braille for daily living skills was accomplished. His goal of learning enough braille to read Bible selections was accomplished only for specially transcribed Grade 1 materials. He was not able to learn the Grade 2 contractions well enough to read a Bible independently.

Conclusions. Mr. E's program was successful in that he learned enough braille for use in daily living skills. His motivation to succeed was his greatest strength, and his poor health was his greatest weakness. Of the four subjects, Mr. E demonstrated the most reduced tactile sensitivity and showed the second greatest iinprovement in learning to read braille. He also showed that he had sufficient tactile discrimination ability to identify both standard-size and enlarged-dot cells.

Mr. J

Mr. J had become totally blind six years earlier as the result of diabetic retinopathy. He was not receiving insulin treatment at the time of this study. He was observed to have some sporadic involuntary spastic movements of the right index finger, especially when he read braille characters. Mr. J reported having a severe stroke in 1968, but it was not determined whether the stroke had any effect on his right hand.

Braille reading needs. Mr. J wanted to learn braille so he could develop a system for labeling canned and frozen foods and to read the numbers on the elevators of his apartment building (he lived on the tenth floor). Although he received help in buying groceries, he was unable to identify the food once it was placed in his refrigerator or in his cabinet.

Assessment. Mr. J's tactile sensitivity was assessed with a modified Optacon and the BDT. He was able to detect vibrations in the tactile display of the Optacon at 5.5 volts in the index finger of his dominant hand. He was able to match nine of 20 jumbo items and 10 of 20 standard braille-cell items on the braille dot test. Mr. J also was observed to have difficulty in tracking braille dots horizontally across a page.

Program. A tactile intervention prograrn was initiated to enable Mr. J to discriminate letters in jumbo braille. It was designed to enable Mr. J to acquire increasingly more difficult levels of tactile discrimination. The lessons proceeded from discriminating differences in braille characters to matching braille configurations. Tracking skills were also an important part of the program. Mr. J completed 36 lessons of 45 minutes each over a six month period.

Results. Mr. J was beginning to identify braille letters and some whole words at the conclusion of his training program. Post test results indicated that he had made progress in braille discrimination. An analysis revealed that a majority of errors involved missed dots, added dots, and reversals. His performance on the BDT showed no clear preference for either jumbo or standard-size dot braille.

Conclusions. Mr. J made fair progress during a six-month program that consisted of an average of 1 1/2 lessons per week. He improved in tracking skills and in his ability to identify braille letters and words. Of the four subjects, Mr. J received the longest period of training and the most individualized program to suit his special needs. He demonstrated that he could develop sufficient discrimination ability to identify both standard-size and enlarged-dot braille cells.

Summary

All four subjects discussed in the case study section were blind diabetic adults with reduced tactile sensitivity for whom braille reading was found to be feasible. Two subjects completed Grade 1 braille, one learned to identify letters and a few words, and one learned seven letters and numbers. Three of the four subjects expressed a preference for jumbo-sized cefls, and one subject did not indicate a preference. The subjects' health problems were important in relation to their ability to proceed with the braille lessons, although their health problems did not interfere with their high motivation to learn braille. Despite their diminished tactile sensitivity, all four subjects had sufficient ability and motivation to learn enough braille for use in daily living skills. The implication of the study for braille instructors is that blind diabetic adults present a challenge, but their condition should not necessarily be an excuse for denying them training.

Conclusions

The following conclusions can be drawn from the results of the three phases of the study:

1. Blind diabetic adults have less tactile sensitivity than do sighted nondiabetic adults.

2. Blind diabetic adults can identify braille characters as well as can nondiabetic blind adults (especially if given sufficent time).

3. Blind diabetic adults can identify standard-size as well as jumbo braille characters. However, the subjects in the third phase of the study preferred the enlarged braille cell (which certainly could prove useful in the initial stages of teaming to read braille).

4. Blind diabetic adults with diminished tactile sensitivity can learn braille sufficiently to use it in daily living skills.

Because the experiments were a pilot study with a limited number of subjects, a larger study containing more subjects with a variety of physical, educational, and psychological characteristics is needed to draw conclusions that can be generalized to the large population of blind diabetic adults. Even so, teachers of diabetic blind adults with reduced tactile sensitivity should at least consider the option of teaching braille to these persons, especially if these blind adults need the skills to be able to live independently.

References

Arezzo.J. & Schaumburg, H. (1980), The use of the Optacon as a screening device: A new technique for detecting sensory loss in individuals exposed to neurotoxins. Journal of Occupational Medicine, 22(7), 461-464.

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