Bicycling over a Lifetime Is Associated with Less Symptomatic Knee Osteoarthritis: Data from the Osteoarthritis Initiative.

INTRODUCTION: To evaluate the relationship between a history of bicycling and symptomatic and structural outcomes of knee osteoarthritis (OA), the most common form of arthritis. METHODS: This was a retrospective, cross-sectional study within the Osteoarthritis Initiative (OAI), where we investigated OAI participants with complete data on bicycling, knee pain, and radiographic evidence of knee OA. We used a self-administered questionnaire at the 96-month OAI visit to identify participation in bicycling during four time periods throughout a participant's lifetime (ages 12-18, 19-34, 35-49, and > 50 years old). Using logistic regression, we evaluated the influence of prior bicycling status (any history, history for each time period, number of periods cycling) on three outcomes at the 48-month OAI visit: frequent knee pain, radiographic OA (ROA), and symptomatic radiographic OA (SOA), adjusting for age and gender. RESULTS: 2607 participants were included; 44.2% were male; mean age was 64.3 (SD 9.0) years; body mass index was 28.5 (SD 4.9) kg/m 2 . The adjusted risk ratio for the outcome of frequent knee pain, ROA, and SOA among those who reported any history of bicycling compared to non-bicyclers was 0.83 (0.73-0.92), 0.91 (0.85-0.98), and 0.79 (0.68-0.90), respectively. We observed a dose-response among those who participated in bicycling during more time periods. CONCLUSIONS: People who participated in bicycling had a lower prevalence of frequent knee pain, ROA, and SOA. The benefit appeared cumulative. This study indicates that bicycling may be favorable to knee health and should be encouraged.

Gardening/yardwork in people with knee osteoarthritis is not associated with symptom or structural progression over 48 months: data from the Osteoarthritis Initiative.

OBJECTIVE: To evaluate the relationship of gardening/yardwork with symptomatic and structural progression in those with pre-existing radiographic knee osteoarthritis (OA) in the Osteoarthritis Initiative (OAI), an observational study designed to evaluate potential and known biomarkers and risk factors of knee OA. METHODS: We conducted a cohort study nested within the OAI, including participants ≥ 50 years old with radiographic OA in at least one knee at the time of OAI enrollment. A participant reported the level of gardening/yardwork activity in a self-administered survey. Logistic regression analyses were used to evaluate the association of gardening/yardwork on new frequent knee pain, Kellgren-Lawrence (KL) worsening, medial joint space narrowing (JSN) worsening, and improved frequent knee pain. RESULTS: Of 1808 knees (1203 participants), over 60% of knees had KL grade = 2, 65% had medial JSN, and slightly more than a third had frequent knee symptoms. Gardeners/yardworkers and non-gardners/yardworkers had similar "worsening" outcomes for new knee pain (29% vs. 29%), KL worsening (19% vs. 18%), and medial JSN (23% vs. 24%). The adjusted odds ratio (OR) for the "worsening" outcomes of new knee pain, KL worsening, and medial JSN worsening were 1.0 (0.7-1.3), 1.0 (0.8-1.3), and 1.1 (0.9-1.4), respectively. The gardeners/yardworkers had an adjusted OR of 1.2 (0.9-1.7) for improved knee pain compared with non-gardners/yardworkers. CONCLUSION: Gardening/yardwork is not associated with knee OA progression and should not be discouraged in those with knee OA. Key Points • Gardening/yardwork is not associated with knee OA symptomatic or structural progression. • Gardening/yardwork should not be discouraged in people with knee OA.

Knee cartilage change on magnetic resonance imaging: Should we lump or split topographical regions? A 2-year study of data from the osteoarthritis initiative.

OBJECTIVE: We challenge the paradigm that a simplistic approach evaluating anatomic regions (e.g., medial femur or tibia) is ideal for assessing articular cartilage loss on magnetic resonance (MR) imaging. We used a data-driven approach to explore whether specific topographical locations of knee cartilage loss may identify novel patterns of cartilage loss over time that current assessment strategies miss. DESIGN: We assessed 60 location-specific measures of articular cartilage on a sample of 99 knees with baseline and 24-month MR images from the Osteoarthritis Initiative, selected as a group with a high likelihood to change. We performed factor analyses of the change in these measures in two ways: (1) summing the measures to create one measure for each of the six anatomically regional-based summary (anatomic regions; e.g., medial tibia) and (2) treating each location separately for a total of 60 measures (location-specific measures). RESULTS: The first analysis produced three factors accounting for 66% of the variation in the articular cartilage changes that occur over 24 months of follow-up: (1) medial tibiofemoral, (2) medial and lateral patellar, and (3) lateral tibiofemoral. The second produced 20 factors accounting for 75% of the variance in cartilage changes. Twelve factors only involved one anatomic region. Five factors included locations from adjoining regions (defined by the first analysis; e.g., medial tibiofemoral). Three factors included articular cartilage loss from disparate locations. CONCLUSIONS: Novel patterns of cartilage loss occur within each anatomic region and across these regions, including in disparate regions. The traditional anatomic regional approach is simpler to implement and interpret but may obscure meaningful patterns of change.

Strength Training Is Associated With Less Knee Osteoarthritis: Data From the Osteoarthritis Initiative.

OBJECTIVE: We aimed to evaluate the relationship of a history of strength training with symptomatic and structural outcomes of knee osteoarthritis (OA). METHODS: This study was a retrospective, cross-sectional study within the Osteoarthritis Initiative (OAI), a multicenter prospective longitudinal observational study. Data were collected at four OAI clinical sites: Memorial Hospital of Rhode Island, the Ohio State University, the University of Pittsburgh, and the University of Maryland/Johns Hopkins. The study included 2,607 participants with complete data on strength training, knee pain, and radiographic evidence of knee OA (male, 44.2%; mean ± SD age 64.3 ± 9.0 years; mean ± SD body mass index 28.5 ± 4.9 kg/m2 ). We used a self-administered questionnaire at the 96-month OAI visit to evaluate the exposure of strength training participation during four time periods throughout a participant's lifetime (ages 12-18, 19-34, 35-49, and ≥50 years old). The outcomes (dependent variables) were radiographic OA (ROA), symptomatic radiographic OA (SOA), and frequent knee pain. RESULTS: The fully adjusted odds ratios (95% confidence interval) for frequent knee pain, ROA, and SOA among those who participated in strength training any time in their lives were 0.82 (0.68-0.97), 0.83 (0.70-0.99), and 0.77 (0.63-0.94), respectively. Findings were similar when looking at the specific age ranges. CONCLUSION: Strength training is beneficial for future knee health, counteracting long-held assumptions that strength training has adverse effects.

Association Between Walking for Exercise and Symptomatic and Structural Progression in Individuals With Knee Osteoarthritis: Data From the Osteoarthritis Initiative Cohort.

OBJECTIVE: To assess the relationship between walking for exercise and symptomatic and structural disease progression in individuals with knee osteoarthritis (OA). METHODS: We assessed a nested cohort of participants age 50 years or older within the Osteoarthritis Initiative, a community-based observational study in which subjects were enrolled between 2004 and 2006. We focused on 4 dichotomous outcomes from baseline to the 48-month visit, involving determination of the frequency of knee pain and radiographic severity of knee OA on posteroanterior semiflexed knee radiographs. The outcomes assessed included 1) new frequent knee pain, 2) worsening of radiographic severity of knee OA based on the Kellgren/Lawrence grade, 3) progression of medial joint space narrowing, and 4) improved frequent knee pain. We used a modified version of the Historical Physical Activity Survey Instrument to ascertain those subjects who reported walking for exercise after age 50 years. The survey was administered at the 96-month visit (2012-2014). RESULTS: Of 1,212 participants with knee OA, 45% were male and 73% reported walking for exercise. The mean ± SD age was 63.2 ± 7.9 years, and the mean ± SD body mass index was 29.4 ± 4.6 kg/m2 . The likelihood of new frequent knee pain was reduced in participants with knee OA who walked for exercise as compared to those who were non-walkers (odds ratio [OR] 0.6, 95% confidence interval [95% CI] 0.4-0.8), and progression of medial joint space narrowing was less common in walkers compared to non-walkers (OR 0.8, 95% CI 0.6-1.0). CONCLUSION: In individuals with knee OA who were age 50 years or older, walking for exercise was associated with less frequent development of knee pain. These findings support the notion that walking for exercise should be encouraged for people with knee OA. Furthermore, we offer a proof of concept that walking for exercise could be disease modifying, which warrants further study.

Increased risk of incident knee osteoarthritis in those with greater work-related physical activity.

OBJECTIVE: Occupations involving greater physical activity may increase risk for knee osteoarthritis (OA). Existing studies have not evaluated work-related physical activity before OA onset. Hence, we aimed to evaluate the association between work-related physical activity and knee OA incidence. METHODS: We performed a person-based longitudinal study using Osteoarthritis Initiative (OAI) data among people who volunteered or worked for pay without baseline radiographic knee OA or knee pain. Bilateral knee radiographs were obtained at baseline and annual follow-ups. We defined radiographic OA as Kellgren-Lawrence grade ≥2. Questions from the Physical Activity Scale for the Elderly at baseline and annual OAI visits provided information about work-related physical activity level and hours. We performed logistic regression with work-related physical activity level ( mainly sitting , standing and some walking , walking while handling some materials ) and hours as predictors. The outcome was incident person-based radiographic OA within the ensuing 12 months, over 48 months. RESULTS: Among 951 participants (2819 observations), higher work-related physical activity levels had greater adjusted ORs for incident radiographic OA (people with jobs with standing and some walking : 1.11 (0.60-2.08), and walking while handling some materials : 1.90 (1.03-3.52), when compared with those with mainly sitting work-related activity ). There was no association between number of hours worked and incident radiographic OA. CONCLUSIONS: People performing work that require walking while handling some materials have greater odds of incident knee OA than those with jobs mostly involving sitting. Strategies are needed to mitigate risk factors predisposing them to radiographic OA.

A novel approach to studying early knee osteoarthritis illustrates that bilateral medial tibiofemoral osteoarthritis is a heritable phenotype: an offspring study.

To assess the potential of studying offspring of people with and without knee osteoarthritis to understand the risk factors and heritability for knee osteoarthritis. We selected two groups of Osteoarthritis Initiative (OAI) participants from one clinical site: (1) participants with bilateral radiographic medial tibiofemoral osteoarthritis and (2) those without tibiofemoral osteoarthritis. We then invited biological offspring ≥ 18 years old to complete an online survey that inquired about osteoarthritis risk factors and symptoms. Among the survey respondents, we recruited ten offspring of members from each group for a clinic visit with bilateral knee posterior-anterior radiographs and magnetic resonance imaging of the right knee. We established contact with 269/413 (65%) eligible OAI participants. Most (227/269, 84%) had ≥ 1 eligible biological offspring, and 213 (94%) were willing to share information about the new family study with their offspring. Our survey was completed by 188 offspring from 110 OAI participants: mean age of 43.0 (10.4) years, mean body mass index of 23.7 (5.9) kg/m2, 65% female. Offspring obesity (OR = 2.7, 95% CI 1.0-7.3), hypertension (OR = 3.7, 95% CI 1.2-11.3), and Heberden's nodes (OR = 3.6, 95% CI 1.0-13.2) were associated with parental osteoarthritis status; however, adjusted models were not statistically significant. Radiographic tibiofemoral osteoarthritis (16/18 knees vs. 2/20 knees) and meniscal abnormalities (7/9 vs. 2/10 index knees) were more common among offspring with parental osteoarthritis status than not. We established the potential of a novel offspring study design within the OAI, and our results are consistent with bilateral radiographic medial tibiofemoral osteoarthritis being a heritable phenotype of osteoarthritis.

The Role of Adjunctive Therapies in the Management of Invasive Sino-Orbital Infection.

OBJECTIVE: Invasive sino-orbital fungal infections are life-threatening complications of immunonosupression that are difficult to treat. Currently there are no standard treatment guidelines. The most widely accepted therapy includes parenteral anti-fungal therapy and surgical debridement of sinuses with orbital exenteration, a procedure that is not only disfiguring, but may increase morbidity. Injection of retrobulbar Liposomal Amphotericin B (L-AMB) is an alternative approach that provides local administration to infected tissues. The adjunct use of anti-fungal retrobulbar injections not been extensively reviewed in treating sino-orbital infection. We are reporting the multimodal approach of using L-AMB retrobulbar injections in combination with sinus debridement, intravenous (IV) anti-fungal therapy, and hyperbaric oxygen (HBO) for the management of sino-orbital infection. METHOD & RESULTS: Review of literature of 12 cases and retrospective evaluation of one patient with sino-orbital Aspergillus flavus infection on chemotherapy for T-cell acute lymphocytic leukemia treated with retrobulbar Amphotericin B, IV anti-fungal agents, and hyperbaric oxygen therapy. Clinical characteristics, radiographic features, management techniques, and clinical outcomes are described. CONCLUSION: Retrobulbar Amphotericin B injection may be an effective adjunct to hyperbaric oxygen and parenteral anti-fungals in the control of sino-orbital fungal infections.

A Biomechanical Evaluation of Auricular Cartilage Autografts in Orbital Floor Defect Repair.

OBJECTIVE: Auricular cartilage is used as a surgical implant in the management of orbital floor fractures. However, no specific parameters exist regarding the use/limitations of this potential graft. In order to determine the mechanical efficacy of adult auricular cartilage grafts, a mechanical model was developed and studied for structural threshold size limits. METHODS: Thirty-seven cadaveric auricular cartilage specimens were tested in a laboratory. A plexiglass baseplate was created with four different sized holes, defined as 1.0×, 1.2×, 1.4×, and 1.6× the mean minor axis of the specimens. Each specimen was used to bridge one hole under increasing loads until mechanical failure. Structural stiffness at three different loading stages, structural failure strength, and percent failure of the entire system for each defect size was calculated. RESULTS: Specimens tested on 1.0×, 1.2×, 1.4× and 1.6× defects demonstrated 0%, 0%, 20%, and 60% system failure rates, respectively. Structural stiffness curves showed a similar trend, with ANOVA demonstrating a significant difference in mechanical properties between defect sizes (p = 0.03). The curve representing 1.6 × defect size demonstrated significantly reduced structural stiffness relative to 1.0×, 1.2×, and 1.4× curves. There was no statistical difference between 1.2× and 1.4× testing sets (p = 0.09). CONCLUSION: A clinically significant biomechanical and functional threshold exists between 1.2×and 1.4× defect sizes. Given a mean minor axis of 2.06 cm, orbital blow-out defects <2.4 cm (1.2 × 2.06 cm) are suitable for auricular cartilage grafts; fractures >2.4 cm may require a more rigid material. Cartilage grafts that allow failure, however, may better protect the globe in subsequent injury.

Multidetector CT of nasolacrimal canal morphology: normal variation by age, gender, and race.

PURPOSE: To accurately characterize anatomical age, gender, and racial differences in normal nasolacrimal canal morphology and to describe a new, accurate technique for measuring nasolacrimal canal parameters based on high-resolution CT. METHODS: The CT images of 72 patients were reviewed retrospectively and grouped according to age, gender, and race. Patients with history of long-term sinusitis, facial trauma, or nasolacrimal duct pathology were excluded from study. Variations in nasolacrimal duct length, minimal and maximal diameter, and other metrics were recorded and compared across each category. All patient records were deidentified to protect privacy. RESULTS: Nasolacrimal canal length and volume were significantly greater in men than those in women. A trend was noted for greater canal cross-sectional diameter in patients older than 50 years when compared with that in younger patients. Significant differences in canal diameters were noted at the canal apex and base of older patients compared with those of younger patients. The cross-sectional area of the canal base was greater in black patients than that in Caucasian patients. CONCLUSIONS: Although some significant age, gender, and racial variations of nasolacrimal canal morphology exist, these do not fully explain the epidemiology of primary acquired nasolacrimal duct obstruction. The new method described here for measuring nasolacrimal canal metrics is straightforward and theoretically more accurate than those previously defined in the literature.

Metastatic pancreatic carcinoma to the orbital apex presenting as a superior divisional third cranial nerve palsy.

Metastatic tumors to the orbit are rare, especially from a primary pancreatic carcinoma. A 59-year-old man presented with 4 weeks of right eye pain and eyelid swelling. There was right upper eyelid ptosis associated with a right supraduction deficit consistent with a superior divisional third cranial nerve (CN III) palsy. Magnetic resonance imaging revealed a right orbital apex lesion. A right orbital exenteration was performed for intractable and severe pain. Surgical pathology demonstrated a poorly differentiated carcinoma that was ultimately felt to be derived from the pancreas. In this report, we describe the clinical and neurological imaging findings of a superior divisional CN III palsy as the presenting manifestation of a presumed metastatic pancreatic carcinoma to the orbital apex, and review the neuroanatomy of CN III with particular emphasis on the anatomical bifurcation of the nerve into a superior and inferior division.

Longitudinal evidence on punctal plug use in an elderly population.

PURPOSE: The purpose of this study was to determine whether changes in Medicare reimbursement for punctal plug insertion were associated with a decrease in the incidence of insertion and dry eye diagnosis. METHODS: Incident cases of dry eye syndrome (DES) diagnoses and punctal plug insertions among Medicare beneficiaries were identified from Medicare 5% Part B from 1994 to 2008, using a 3-year look-back. Dry eye syndrome diagnoses and punctal plug insertion codes were ascertained from the international classification of diseases and current procedural terminology codes. Medicare payment data were obtained from the Centers for Medicare and Medicaid Services from 1994 to 2008 for punctal plug insertion. Rates were calculated for both the incidence of DES and the use of punctal plugs. RESULTS: From 2001 to 2008, inflation-adjusted Medicare reimbursement for punctal plug insertion decreased 55.1%, whereas the Medicare population-adjusted incidence of dry eye diagnosis increased 23.3%. Nine percent of individuals diagnosed with DES between 1991 and 2008 underwent punctal plug placement with a mean of 2.0 plugs placed per patient. Total punctal plug placement increased 322.2% between 1994 and 2003, and then reached a plateau. First-time punctal plug insertion rates within 365 days of DES diagnosis increased 111.8% from 1994 to 2002, and then declined 47.0% from 2002 to 2008. CONCLUSIONS: Although the frequency of DES diagnosis in the Medicare population has increased over time, first-time punctal plug insertion rates, especially within the first year following DES diagnosis, have declined coincidently with the increasing presence of a medical alternative and declining Medicare payment. Choice of therapies may have cost and care implications.

Nodular fasciitis presenting in an adult woman.

The authors report a 30-year-old Caucasian woman with nodular fasciitis presenting as a nontender lesion to right temporal area. The lesion was removed by en bloc excision and the base was cauterized. Six months later, the patient returned to the clinic for possible recurrence of lesion or for residual lesion; the patient was then injected with a total of 1 cc of kenalog at 20 mg/kg. Two weeks later, the lesion had greatly subsided and the patient was satisfied with the esthetic appearance. Nodular fasciitis is a rare reactive growth with even fewer cases of recurrence. In young patients, steroid injection is an alternative to repeat resection.

Can methylphenidate objectively provide relief in patients with uncontrolled blepharospasm? A pilot study using surface electromyography.

PURPOSE: To determine whether there is an objective benefit to prescribing Ritalin for patients with uncontrolled blepharospasm exists. METHODS: Seven subjects with benign essential blepharospasm, who were being treated with botulinum toxin injections and Ritalin LA, were recruited for this pilot study. Patients were asked to participate during the period of time when symptoms were beginning to return. Subjects underwent video and surface electromyography (sEMG) monitoring before and 2 hours after the administration of Ritalin. Mean sEMG potential for each eye was compared before and after the administration of Ritalin. Subjects also rated their disability based on a previously developed and reproducible blepharospasm functional disability scale. Functional Disability Scores were compared, and post-Ritalin treatment benefit was determined. RESULTS: The mean voltage of the sEMG was lower in 13 of 14 eyes after the administration of Ritalin. For the right eye, the voltage decreased by 50% (106.4 ± 13.6 mV to 52.7 ± 7.1 mV, p = 0.015), and for the left eye, by 31% (81.9 ± 9.7 mV to 56.6 ± 6.1 mV, p = 0.031). The Functional Disability Scores were also lower after the administration of Ritalin than before (p = 0.016). CONCLUSIONS: A significant decrease in mean voltage after the administration of Ritalin was found in this preselected group of patients. Subjective improvement with decreased disability and increased functional benefit was also found in all subjects. Based on the results of this study, a randomized, controlled study comparing Ritalin versus placebo is needed to determine whether Ritalin should be routinely prescribed for benign essential blepharospasm during the symptomatic window period.

Effect of reading on surface electromyogram recordings in patients with blepharospasm.

PURPOSE: To compare the surface electromyogram recordings between patients with benign essential blepharospasm and controls while maintaining primary gaze and reading in downgaze. METHODS: A university-based, prospective case series of 7 benign essential blepharospasm patients and 7 normal patients. Bilateral lower eyelid preseptal orbicularis oculi muscle potentials were recorded via surface electromyogram and video while performing a standardized 60-second task that was divided in 3 equal 20-second subtasks. Specifically, patients were asked to maintain primary gaze for the first 20-second interval, to read quietly for the second interval, and again maintain primary gaze for the third 20-second interval. Fourteen trials capturing bilateral recordings were performed in each group; qualitative and quantitative analysis of the surface electromyogram recordings was performed and compared both between patient groups and between subtasks. Blepharospasm patients were also asked to describe the effect of reading on their spasms. Specifically, they were asked before the study if reading lessened or worsened their spasms and then were asked poststudy if their symptoms lessened or worsened during the reading task. RESULTS: The mean surface electromyogram potential of the orbicularis muscle was significantly less in normal eyes when compared with blepharospasm eyes for each task. Furthermore, the mean surface electromyogram potential during the reading task was significantly reduced when compared with the primary gaze task in all eyes. Only blepharospasm patients noticed this reduction subjectively. CONCLUSIONS: Although conventional wisdom regarding blepharospasm suggests that reading is an exacerbating factor, short durations of reading seem to relieve spasms. This may be due to the effect of downgaze on the blink reflex and may offer possible areas of investigation for novel blepharospasm treatments.

Analysis of the anatomic changes of the aging facial skeleton using computer-assisted tomography.

PURPOSE: The bony skeleton serves as the scaffolding for the soft tissues of the face; however, age-related changes of bony morphology are not well defined. This study sought to compare the anatomic relationships of the facial skeleton and soft tissue structures between young and old men and women. METHODS: A retrospective review of CT scans of 100 consecutive patients imaged at Duke University Medical Center between 2004 and 2007 was performed using the Vitrea software package. The study population included 25 younger women (aged 18-30 years), 25 younger men, 25 older women (aged 55-65 years), and 25 older men. Using a standardized reference line, the distances from the anterior corneal plane to the superior orbital rim, lateral orbital rim, lower eyelid fat pad, inferior orbital rim, anterior cheek mass, and pyriform aperture were measured. Three-dimensional bony reconstructions were used to record the angular measurements of 4 bony regions: glabellar, orbital, maxillary, and pyriform aperture. RESULTS: The glabellar (p = 0.02), orbital (p = 0.0007), maxillary (p = 0.0001), and pyriform (p = 0.008) angles all decreased with age. The maxillary pyriform (p = 0.003) and infraorbital rim (p = 0.02) regressed with age. Anterior cheek mass became less prominent with age (p = 0.001), but the lower eyelid fat pad migrated anteriorly over time (p = 0.007). CONCLUSIONS: The facial skeleton appears to remodel throughout adulthood. Relative to the globe, the facial skeleton appears to rotate such that the frontal bone moves anteriorly and inferiorly while the maxilla moves posteriorly and superiorly. This rotation causes bony angles to become more acute and likely has an effect on the position of overlying soft tissues. These changes appear to be more dramatic in women.

Acne agminata limited to the eyelids.

A 45-year-old woman had a 1-year history of multiple small papules on both upper eyelids that waxed and waned in size and disappeared in the vicinity of a steroid injection site. Acne agminata (lupus miliaris disseminatus faciei, acnitis, papular tuberculid) is a rare form of necrotizing granulomatous inflammation of the dermis that has received scant attention in the ophthalmologic literature. The diagnosis is reached by excluding other forms of necrotizing granulomatous dermatitis based on clinical and histologic features.

Myobloc for the treatment of benign essential blepharospasm in patients refractory to botox.

PURPOSE: A small percentage of cases with essential blepharospasm or hemifacial spasm will become resistant to botulinum toxin A (Botox). We present our experience treating these patients with botulinum toxin B (Myobloc). METHODS: We reviewed all charts of patients in one physician's practice who received botulinum toxin B after becoming refractory to botulinum toxin A. For each treatment session, patients were evaluated for side effects, relief of spasms, and duration of treatment effect. RESULTS: Data were collected on 16 patients and a total of 93 treatment visits. Average total dosage was 3,633 U per treatment session. Mean duration of beneficial effect was 7.3 weeks and was most commonly rated as fair to excellent. Side effects for botulinum toxin B occurred at a higher rate than is typical for botulinum toxin A. Most common side effects were pain on injection (100%), ptosis (32.3%), facial or mouth droop (22.6%), dry mouth (17.2%), dry eye (9.7%), exposure keratitis (7.5%), and blurred vision (5.4%). The rate of occurrence of side effects appears to be dose-dependent. CONCLUSIONS: Botulinum toxin B is a useful treatment for cases that have become refractory to botulinum toxin A. The duration of beneficial effect is shorter than for type A. The side effect profile is similar to that for toxin type A except for pain on injection and the occurrence of dry mouth. Side effects occurred at a higher frequency than with botulinum toxin A, and the pattern suggests that botulinum toxin B spreads more diffusely. Side effects appear to be dosage-related.