Extensor tendon transfer for fracture-related extensor pollicis longus rupture: Long-term outcome case series

BACKGROUND

Spontaneous rupture of the extensor pollicis longus (EPL) tendon following both nonoperative and operative treatment of distal radius fractures has been well described.

PURPOSE

The purpose of this study was to assess long-term outcomes of extensor indicis proprius to EPL tendon transfers for patients following distal radius fracture and EPL tendon repair.

STUDY DESIGN

Retrospective case series focusing on long-term clinical outcomes.

METHODS

A retrospective review was conducted for patients who sustained a distal radius fracture and subsequently underwent extensor tendon transfer from 2005-2015 at a private practice center. Outcome measures including index finger (IF) metacarpophalangeal (MCP) and thumb interphalangeal (IP) active range of motion (ROM), digital extension against resistance, subjective complaints, and QuickDASH scores were recorded at final follow-up.

RESULTS

Seven patients were included in the study. There were six females and one male subject, mean age of 54 ± 13 years at injury of EPL, and 5/7 involved the left upper extremity. For isolated function, 7/7 (100%) patients had isolated, active IF MCP extension, 6/7 (86%) could extend IF MCP and thumb IP against resistance. Mean IF MCP extension was 1° ± 2°, mean IF MCP flexion was 89° ± 2°, mean thumb IP extension was -5° ± 4°, and mean thumb IP flexion was 67° ± 15°. Mean QuickDASH score was 16 ± 14.

CONCLUSIONS

This series shows good long-term functional and patient reported outcomes in patients following extensor indicis proprius to EPL tendon transfers at a single center.

Understanding pharmaceutical exposure and the potential for effects in marine biota: A survey of bonefish (Albula vulpes) across the Caribbean Basin

Most research on pharmaceutical presence in the environment to date has focused on smaller scale assessments of freshwater and riverine systems, relying mainly on assays of water samples, while studies in marine ecosystems and of exposed biota are sparse. This study investigated the pharmaceutical burden in bonefish (Albula vulpes), an important recreational and artisanal fishery, to quantify pharmaceutical exposure throughout the Caribbean Basin. We sampled 74 bonefish from five regions, and analyzed them for 102 pharmaceuticals. We assessed the influence of sampling region on the number of pharmaceuticals, pharmaceutical assemblage, and risk of pharmacological effects. To evaluate the risk of pharmacological effects at the scale of the individual, we proposed a metric based on the human therapeutic plasma concentration (HTPC), comparing measured concentrations to a threshold of 1/3 the HTPC for each pharmaceutical. Every bonefish had at least one pharmaceutical, with an average of 4.9 and a maximum of 16 pharmaceuticals in one individual. At least one pharmaceutical was detected in exceedance of the 1/3 HTPC threshold in 39% of bonefish, with an average of 0.6 and a maximum of 11 pharmaceuticals exceeding in a Key West individual. The number of pharmaceuticals (49 detected in total) differed across regions, but the risk of pharmacological effects did not (23 pharmaceuticals exceeded the 1/3 HTPC threshold). The most common pharmaceuticals were venlafaxine (43 bonefish), atenolol (36), naloxone (27), codeine (27), and trimethoprim (24). Findings suggest that pharmaceutical detections and concentration may be independent, emphasizing the need to monitor risk to biota regardless of exposure diversity, and to focus on risk quantified at the individual level. This study supports the widespread presence of pharmaceuticals in marine systems and shows the utility of applying the HTPC to assess the potential for pharmacological effects, and thus quantify impact of exposure at large spatial scales.

Reliability of Assessing Distal Radius Fractures on a Smartphone Versus PACS

BACKGROUND

Communication between health care providers is becoming more intertwined with technology. During the pandemic, telehealth strategies grew exponentially. Remote viewing of imaging on a smartphone may offer efficient communication; however, the reliability of injury assessment when compared with traditional methods is not known. The purpose of this study was to evaluate intraobserver and interobserver reliability of distal radius fracture radiograph review for smartphone versus traditional Picture Archiving and Communication System (PACS).

METHODS

Eight evaluators (3 attending hand surgeons, 3 hand surgery fellows, 2 orthopedic residents) evaluated 26 distal radius fracture radiographs on 2 different viewers: smartphone or PACS. The reviewers were asked to record: (1) operative or nonoperative preference; (2) fracture classification (based on Fernandez and Jupiter); and (3) treatment strategy (volar plate, dorsal plate, pins, cast, bridge plate, or fragment-specific fixation). The percentage of intraobserver agreement was recorded for each observer. Reliability was calculated using Fleiss' kappa coefficient for intraobserver and interobserver agreement and graded by strength of correlation.

RESULTS

Intraobserver agreement averaged 97% when deciding between operative and nonoperative treatment, 76% for classification, and 84% for treatment. Kappa scores were graded as "excellent" for operative decision and "substantial" for classification and treatment. Attendings and fellows generally had higher agreement than that of residents. Interobserver agreement was graded as "substantial" for all categories for both PACS and smartphone.

CONCLUSIONS

Evaluation of radiographs on a smartphone for the purpose of treating distal radius fractures does not appear to be significantly different from an evaluation on traditional PACS.

Pulmonary Complications and Mortality in Patients with SARS-CoV-2 Undergoing Elective and Emergent Hand Surgery

Background  Patients acutely infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may have increased risk for postsurgical pulmonary complications and mortality, particularly with general anesthesia. Surgery is often delayed to mitigate risk; however, excessive delays may result in morbidity. Optimal criteria for delaying surgery in patients with or without symptoms are unknown. This study aimed to evaluate any complications following hand surgery in patients testing positive for SARS-CoV-2. Methods  We retrospectively reviewed patients with a positive polymerase chain reaction test within 60 days before or after hand surgery between March 31, 2020 and March 31, 2021. Patients were telephoned also to supplement records. Type of surgery, type of anesthesia, comorbidities, timing of surgery, onset of symptoms, and complications were recorded. Results  We identified 21 patients undergoing 26 procedures, of which 21 (81%) were emergency procedures and 5 (19%) were elective. Mean age was 37 years (range: 17-71). General anesthesia was used in 88% of cases, with mean duration of 110 minutes. SARS-CoV-2 was diagnosed on average 6 days preoperatively (range: 39 days preop-14 days postop). Positive tests were usually identified preoperatively (50%), versus day-of-surgery (25%) or postoperatively (25%). Patients were symptomatic in only 27% of cases, and completely asymptomatic in 73%. No asymptomatic patients developed complications. One patient suffered a fracture malunion after delayed surgery. Pulmonary complications were noted in 3 patients; all had prior pulmonary disease and underwent emergency surgeries under general anesthesia. Overall mortality rate was 0%. Conclusion  Pulmonary complications and mortality are low following hand surgery in asymptomatic patients with a positive SARS-CoV-2 test.

The Impact of Preoperative Symptom Duration on Patient Outcomes After Posterior Cervical Decompression and Fusion

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

To determine if decreased preoperative symptom duration is associated with greater clinical improvement in function and myelopathic symptoms after posterior cervical decompression and fusion (PCDF).

METHODS

All patients over age 18 who underwent primary PCDF for cervical myelopathy or myeloradiculopathy at a single institution between 2014 and 2020 were retrospectively identified. Patient demographics, surgical characteristics, duration of symptoms, and preoperative and postoperative patient reported outcomes measures (PROMs) including modified Japanese Orthopaedic Association (mJOA), Neck Disability Index (NDI), Visual Analogue Scale (VAS) Neck, VAS Arm, and SF-12 were collected. Univariate and multivariate analyses were performed to compare change in PROMs and minimum clinically important difference achievement (%MCID) between symptom duration groups (< 6 months, 6 months-2 years, > 2 years).

RESULTS

Preoperative symptom duration groups differed significantly by sex and smoking status. Patients with < 6 months of preoperative symptoms improved significantly in all PROMs. Patients with 6 months-2 years of preoperative symptoms did not improve significantly in mJOA, Physical Component Scores (PCS), or NDI. Patients with > 2 years of symptoms failed to demonstrate significant improvement in mJOA, NDI, or Mental Component Scores (MCS). Univariate analysis demonstrated significantly decreased improvement in mJOA with longer symptom durations. Increased preoperative symptom duration trended toward decreased %MCID for mJOA and MCS. Regression analysis demonstrated that preoperative symptom duration of > 2 years relative to < 6 months predicted decreased improvement in mJOA and NDI and decreased MCID achievement for mJOA and MCS.

CONCLUSION

Increased duration of preoperative symptoms (> 2 years) before undergoing PCDF was associated with decreased postoperative improvement in myelopathic symptoms.

Management of Lunate Facet Escape after Distal Radius Fracture Volar Plating: Surgical Technique

Fractures involving the lunate facet of the distal radius (commonly called the volar ulnar corner or “critical corner”) are often difficult to recognize radiographically. “Lunate facet escape” refers to the displacement of this fragment after attempted distal radius fracture closed or open reduction methods. Lunate facet escape can have severe consequences including carpal collapse with pain, instability, and arthritis. Challenges to lunate facet fixation include irregular cortical contour that makes plate fixation difficult, as well as deforming forces by inserting structures. The goal of the management of a distal radius fracture with lunate facet involvement is first identification, then adequate stabilization until osseous healing occurs. However, subsequent lunate facet escape can pose a challenging clinical and surgical dilemma. Here we discuss our preferred approach to treat lunate facet escape after distal radius fracture volar locking plating failure.

Analyses of Orthopaedic Surgery Residency Interviews

Interviews are a critical component of orthopaedic surgery residency selection for both the applicant and the program. Some institutions no longer report Alpha Omega Alpha (AOA) designation or class rank, and US Medical Licensing Examination (USMLE) Step 1 recently switched to pass/fail scoring. During the coronavirus disease 2019 (COVID-19) pandemic, all Accreditation Council for Graduate Medical Education programs conducted virtual interviews and subinternship rotations were restricted. These changes offer significant challenges to the residency match process. The purpose of this study was to examine the residency applicant interview and ranking process at a large urban academic university setting. We hypothesized that large variability exists among evaluations submitted by faculty interviewers and also that applicant academic factors (i.e., USMLE Step 1 score) would show association with final ranking.

Methods

We retrospectively reviewed the 2020-2021 and 2021-2022 residency interview cycles, both conducted virtually due to the COVID-19 pandemic. Residency application (i.e., applicant demographic and academic backgrounds) and interview data (i.e., faculty interviewer scores) were recorded. Interobserver reliability among faculty interviewers was calculated. Statistical analysis was performed to determine factors associated with ranking of applicants.

Results

There were 195 included applicants from the 2020 and 2021 interview cycles. There was no true agreement of interviewers' scoring of shared applicants (kappa intraclass coefficient range 0-0.2). Applicant factors associated with being ranked include applying to the match for the first time, USMLE Step 1 and 2 scores, educational break (vs. consecutive completion of college and medical school in 4 years each), higher class rank, and greater interviewer scores. Factors associated with better rank included additional degrees (i.e., PhD or MBA), couples match, AOA designation, educational break, underrepresented minority status, and notable attributes (i.e., collegiate athletics or Eagle Scout participation). Factors associated with worse rank included male sex, international medical graduate, prior match history, science major, extended research (i.e., >1 year spent in a research role), and home medical school students.

Conclusions

There was significant variability and no reliability at our institution among faculty interviewers' applicant ratings. Being ranked was based more on academic record and interview performance while final rank number seemed based on applicant qualities. The removal of merit-based objective applicant measurements offers challenges to optimal residency applicant and program match.

Level of Evidence

III (retrospective cohort study).

Routine Postoperative Aspirin for VTE Chemoprophylaxis in Primary Total Ankle Arthroplasty

Category:

Ankle Arthritis; Ankle; Other

Introduction/Purpose:

The use of low-dose aspirin for postoperative venous thromboembolism (VTE) chemoprophylaxis has been widely studied and validated in adult reconstruction surgery with little to no reported adverse reactions. In total ankle arthroplasty (TAA) literature, low-molecular-weight heparin (LMWH) has been the predominant chemoprophylactic agent used, despite little evidence supporting it. To date, no studies have assessed the role of aspirin for VTE chemoprophylaxis after total ankle arthroplasty and no formalized clinical practice guideline exists. The purpose of this study was to evaluate outcomes of a large consecutive series of patients undergoing primary TAA at a single institution, in relation to routine postoperative aspirin administration.

Methods:

A prospective telephone survey and retrospective chart review was performed of patients undergoing primary TAA at a single institution by two fellowship trained foot and ankle surgeons. All patients were prescribed oral aspirin 81 mg BID for at least 2 weeks postoperatively, (or while weight-bearing was restricted). The primary outcome variable was postoperative development of deep vein thrombosis (DVT), pulmonary embolism (PE), or VTE related mortality within 3 months postoperatively. Venous ultrasounds were also queried. The secondary outcome variable was assessment of aspirin related adverse reaction including delayed wound healing and gastrointestinal (GI) bleeding. Patients with a history of bleeding disorder or history of prior VTE requiring non-Aspirin VTE chemoprophylaxis were excluded.

Results:

There were 217 patients included for retrospective review, and 81 patients completed the telephone survey (34% response rate). Concomitant procedures included gastrocnemius recession (104), teno-Achilles lengthening (20), ligament repair (17), tendon repair (3), tendon transfer (12), and plantar fasciectomy (1). The cohort included 119 males (54.8%), with a mean age 62.6 +/- 10.3 years (range 24 to 88), and mean BMI 30.6 +/- 5.6 (range 21.3 to 52.6). There were no GI bleeding or VTE events, yet 46/217 (21.2%) cases of delayed wound healing. Eleven patients underwent venous ultrasounds that all were negative. Sex (p=0.458), age (p=0.443), and BMI (p=0.335) were not associated with delayed wound healing, but current/former smoking status trended toward significant association (p=0.077). Time to weight-bearing was mostly bi-modal, between 1.5-3.5 weeks (37.8%) or 5.5-7.5 weeks (45.1%). Time to weight-bearing approached significance with delayed wound healing (p=0.05), which may represent surgeon intervention to promote healing.

Conclusion:

This study demonstrates effective use of aspirin in preventing VTE events after primary TAA in patients without risk factors for VTE and PE, which is cheaper and more widely available all around the world. Further randomized controlled studies may better elucidate any role of aspirin with regards to delayed wound healing, which had an an approximate incidence of 20% in our cohort. Limitations of the study include those inherent to a retrospective review, such as lack of a control group.

Preoperative Opioid Use Results in Greater Postoperative Opioid Consumption After Thumb Basal Joint Arthroplasty

Purpose

Thumb basal joint arthroplasty surgery is a common hand surgery after which patients often require opioids. To better understand safe opioid consumption patterns, this study sought to identify risk factors for filling a second prescription and/or prolonged opioid use (prescription over 6 months after the surgery). Preoperative opioid use was hypothesized to show an association with greater postoperative opioid use.

Methods

A retrospective review of consecutive patients who underwent primary thumb basal joint arthroplasty was conducted, yielding 110 patients for analysis. Demographic and clinical data were collected. Opioid prescription data were extracted from 6 months before the surgery to 9 months after the surgery using a state prescription drug monitoring program. Bivariate and multivariate analyses were performed for filling a second opioid prescription or filling an opioid prescription over 6 months after the surgery.

Results

All the patients filled their initial postoperative prescription. Of the 110 patients, 26.4% filled an opioid prescription before the surgery, 42% filled a second postoperative prescription, and 14.5% were still consuming opioids over 6 months after the surgery. Patients using preoperative opioids had 7-fold higher odds of filling a second opioid prescription and 37-fold higher odds of prolonged use. No other demographic or clinical factors, including the type of procedure or number of initial opioids prescribed, were associated with increased use of postoperative opioids. Of all the opioid prescriptions filled after the initial postoperative prescription, only 9.3% were prescribed by a surgeon’s office.

Conclusions

Patients who undergo thumb basal joint arthroplasty with preoperative opioid use have much greater odds of filling a second opioid prescription and prolonged use after the surgery. Low initial surgeon-provided opioid dosages did not correlate to filling a second prescription, indicating that lower initial doses are feasible. Finally, nearly all opioid-naïve patients who filled a second opioid prescription received them from providers other than a surgeon, indicating the need for greater communication with nonsurgical providers simultaneously caring for patients in the perioperative period.

Type of study/level of evidence

Therapeutic III.

Utility of Perioperative Laboratory Tests in Pediatric Patients Undergoing Spinal Fusion for Scoliosis

STUDY DESIGN

Retrospective comparative study.

OBJECTIVES

We aimed to characterize the frequency of perioperative laboratory tests for posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) and to assess whether test results affected clinical management.

SUMMARY OF BACKGROUND DATA

Perioperative laboratory tests for PSF including complete blood count, coagulation laboratory tests, basic metabolic panels (BMPs), and type and screen, are commonly ordered based on providers' discretion or existing order sets. Studies have shown unnecessary laboratory tests as financially and physically costly in adults; however, no studies have examined the necessity of common perioperative laboratory tests in pediatric spinal deformity surgery.

METHODS

Retrospective review of patients aged 10-18 years who underwent PSF for AIS at our center in the past three years. The clinical utility of perioperative laboratory tests was assessed based on detected incidence of anemia, blood transfusions, hematology/endocrinology/nephrology consultations, insulin administration, and postponed/canceled surgeries.

RESULTS

A total of 234 patients were included (mean age 14.4 ± 1.8 years, 75% female). Of 105 (44.9%) patients with preoperative coagulation laboratory tests, 21 (20%) had abnormal results; however, none had subsequent hematology consultations or canceled/postponed surgeries. Postoperatively, only 5 (2.1%) patients and 30 (12.8%) patients had hemoglobin values less than 8 g/dL on postoperative day (POD) 1 and 2, respectively. Multivariate analysis identified POD1 hemoglobin ≤9.35 g/dL as the only predictor of hemoglobin <8 g/dL on POD2. Overall, there were 8 (3.4%) indicated blood transfusions postoperatively. Costs of unnecessary laboratory tests averaged $95.27 (range $49.72 to $240.27) per patient.

CONCLUSIONS

Many perioperative laboratory orders may be unnecessary in pediatric spinal deformity surgery, subjecting patients to extraneous costs and needlesticks. In particular, preoperative coagulation laboratory tests, perioperative BMPs, and additional postoperative CBCs for those with hemoglobin >9.35 on POD1 may not be warranted.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Pediatric Type II Tibial Spine Fractures: Addressing the Treatment Controversy With a Mixed-Effects Model

Background:

Tibial spine fractures, although relatively rare, account for a substantial proportion of pediatric knee injuries with effusions and can have significant complications. Meyers and McKeever type II fractures are displaced anteriorly with an intact posterior hinge. Whether this subtype of pediatric tibial spine fracture should be treated operatively or nonoperatively remains controversial. Surgical delay is associated with an increased risk of arthrofibrosis; thus, prompt treatment decision making is imperative.

Purpose:

To assess for variability among pediatric orthopaedic surgeons when treating pediatric type II tibial spine fractures.

Study Design:

Cross-sectional study.

Methods:

A discrete choice experiment was conducted to determine the patient and injury attributes that influence the management choice. A convenience sample of 20 pediatric orthopaedic surgeons reviewed 40 case vignettes, including physis-blinded radiographs displaying displaced fractures and a description of the patient’s sex, age, mechanism of injury, and predominant sport. Surgeons were asked whether they would treat the fracture operatively or nonoperatively. A mixed-effects model was then used to determine the patient attributes most likely to influence the surgeon’s decision, as well as surgeon training background, years in practice, and risk-taking behavior.

Results:

The majority of respondents selected operative treatment for 85% of the presented cases. The degree of fracture displacement was the only attribute significantly associated with treatment choice (P < .001). Surgeons were 28% more likely to treat the fracture operatively with each additional millimeter of displacement of fracture fragment. Over 64% of surgeons chose to treat operatively when the fracture fragment was displaced by ≥3.5 mm. Significant variation in surgeon’s propensity for operative treatment of this fracture was observed (P = .01). Surgeon training, years in practice, and risk-taking scores were not associated with the respondent’s preference for surgical treatment.

Conclusion:

There was substantial variation among pediatric orthopaedic surgeons when treating type II tibial spine fractures. The decision to operate was based on the degree of fracture displacement. Identifying current treatment preferences among surgeons given different patient factors can highlight current variation in practice patterns and direct efforts toward promoting the most optimal treatment strategies for controversial type II tibial spine fractures.

Surgeon and Caregiver Agreement on the Goals and Indications for Scoliosis Surgery in Children With Cerebral Palsy

STUDY DESIGN

Prospective multicenter comparative study.

OBJECTIVES

We aimed 1) to survey surgeons and caregivers to rank the surgical indications for spinal fusion of pediatric patients with neuromuscular scoliosis secondary to cerebral palsy in order of importance and 2) to characterize the agreement of surgeons and caregivers on major (top three) indications.

SUMMARY OF BACKGROUND DATA

Surgery for spinal deformity in children with cerebral palsy is a multifaceted and individualized decision that may lead to miscommunication during informed consent. Little data exist on communication effectiveness between surgeon and caregiver during preoperative discussion.

METHODS

This is a multicenter, prospective survey of Harms Study Group patient caregivers and their surgeons. Participants ranked their most important of 15 indications in descending level of importance, where the top 3 selections were considered major indications for surgery for the particular patient in question. Demographic and other perioperative factors were recorded. Surgeon-caregiver agreement on major indications was determined, taking into account preoperative factors and intersurgeon differences.

RESULTS

126 surgeon-caregiver pairs responded. The greatest percentage agreement that an indication was major was "to improve sitting" (69.0% major, 0.8% nonmajor), followed by "to prevent pulmonary compromise" (33.3% major, 24.6% nonmajor), "to improve pain" (31.7% major, 20.6% nonmajor), and "to improve head control/position" (20.7% major, 69.0% nonmajor). Preoperative pain showed an association with surgeon-caregiver agreement on pain as a major indication (p=.004), and intersurgeon differences in agreement on gastrointestinal and pain considerations existed (p=.002, p=.007, respectively).

CONCLUSIONS

Surgeon-caregiver agreement is greater where literature support for a particular surgical indication is strong (ie, spinal fusion's known improvement of sitting posture in children with neuromuscular scoliosis). Stronger literature support may bolster surgeons' confidence in recommending a particular procedure, fostering greater communication, understanding, and agreement on surgical necessity between caregivers and surgeons.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Postoperative Pain and Opioid Use in Children with Supracondylar Humeral Fractures: Balancing Analgesia and Opioid Stewardship

BACKGROUND

Effective postoperative analgesia remains a priority in orthopaedic surgery, but concerns with regard to opioid diversion and misuse have brought overdue attention to improving opioid stewardship. Normative data for postoperative pain and opioid use are needed to guide and balance these dual priorities. We aimed to characterize postoperative pain and opioid use for an archetypal pediatric orthopaedic procedure: closed reduction and percutaneous pinning of a supracondylar humeral fracture.

METHODS

Children at a single pediatric trauma center who underwent closed reduction and percutaneous pinning of a supracondylar humeral fracture were enrolled and were prospectively followed. Validated pain scores (Wong-Baker FACES Pain Rating Scale) and opioid utilization data were collected using an automated text message-based protocol on postoperative days 1 to 7, 10, 14, and 21. Data were analyzed with descriptive and univariate statistics.

RESULTS

Eighty-one patients with a mean age (and standard deviation) of 6.1 ± 2.1 years (62% of whom were male) were enrolled, including 53.1% who had Type-II fractures and 46.9% who had Type-III fractures. The mean pain ratings were highest on arrival to the emergency department (3.5 ± 3.5 points) and the morning of postoperative day 1 (3.5 ± 2.4 points). By postoperative day 3, the mean pain rating decreased to <2 (1.8 ± 1.8 points) and the mean opioid doses decreased to <1 dose (0.8 ± 1.2 doses). Postoperative opioid use decreased in parallel to reported pain (r = 0.972; p < 0.001). The interquartile range of opioid use was 1 to 7 doses, and patients used only 24.1% of the prescribed opioids (mean, 4.8 ± 5.6 doses used and 19.8 ± 7.1 doses prescribed). There was no significant difference (p > 0.05) in pain ratings or opioid use by fracture classification, age, or sex.

CONCLUSIONS

Following closed reduction and percutaneous pinning for supracondylar humeral fracture, pain levels and opioid usage decrease to a clinically unimportant level by postoperative day 3. Patients who report pain scores of ≥6 points following discharge are outliers and should be screened for compartment syndrome or ischemia. Patients used <25% of prescribed opioid medication, suggesting the potential for overprescription and opioid diversion. A prescription for 7 opioid doses after discharge should allow adequate postoperative analgesia in the majority of patients while improving narcotic stewardship.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Self-Reported Postoperative Opioid-Prescribing Practices Following Commonly Performed Orthopaedic Hand and Wrist Surgical Procedures: A Nationwide Survey Comparing Attending Surgeons and Trainees

BACKGROUND

Although orthopaedic surgeons have been shown to prescribe excessive amounts of opioid analgesics postoperatively, the degree in which surgical trainees contribute to this trend is unknown. The purpose of this study was to compare self-reported opioid-prescribing behavior, factors influencing this behavior, and perceptions of patient opioid utilization and disposal between hand surgeons and trainees.

METHODS

Attending hand surgeons and trainees in hand, orthopaedic, and plastic surgery programs were invited to participate in a web-based survey including demographic characteristics; self-reported prescribing behavior specific to 4 procedures: open carpal tunnel release, trigger finger release, thumb carpometacarpal arthroplasty, and distal radial fracture open reduction and internal fixation; and perceptions and influencing factors. Analgesic medications were converted to morphine milligram equivalents and were compared across groups of interest using independent t tests or analysis of variance for each procedure.

RESULTS

A total of 1,300 respondents (266 attending surgeons, 98 fellows, 708 orthopaedic residents, and 228 plastic surgery residents) were included. Surgeons reported prescribing fewer total morphine milligram equivalents compared with residents for all 4 procedures. Personal experience was the most influential factor for prescribing behavior by surgeons and fellows. Although residents reported that attending surgeon preference was their greatest influence, most reported no direct opioid-related communication with attending surgeons.

CONCLUSIONS

Residents self-report prescribing significantly higher morphine milligram equivalents for postoperative analgesia following commonly performed hand and wrist surgical procedures than attending surgeons. Poor communication between residents and attending surgeons may contribute to this finding. Residents may benefit from education on opioid prescription, and training programs should encourage direct communication between trainees and attending surgeons.

Short-term Outcomes in Pediatric Patients Managed with Peripheral Nerve Blockade for Arthroscopic Anterior Cruciate Ligament Reconstruction and/or Meniscus Surgeries

Introduction

Peripheral nerve blockade (PNB) can be a useful component of a multimodal analgesia approach in managing pain after knee arthroscopy. However, the impact of PNB and short-term recovery in pediatric patients, particularly adolescents, who underwent knee arthroscopy for anterior cruciate ligament (ACL) reconstruction and/or meniscus surgery (repair or resection) has not been well characterized. This prospective study presents observational data on short-term patient outcomes and side effects for 72 hours following discharging home of pediatric patients who underwent arthroscopic ACL and/or meniscus procedures with PNB.

Methods

This is a single-center, single-surgeon prospective observational study conducted over a three-year period. We characterized 72-hour postoperative outcomes including pain scores, return of sensation to the affected limb, analgesic use [nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids], readmission rate, and activities of daily living (ADL) via telephone survey. In addition, retrospective chart review was conducted to obtain perioperative and anesthesia details. Results for surgery groups were analyzed using descriptive and Pearson correlations using the SPSS version 24 (IBM Corp. Released 2016. IBM SPSS Statistics for Mac, Version 24.0. Armonk, NY, USA).

Results

We collected data on 47 patients undergoing ACL reconstruction with or without meniscus surgery (18/47, 38.3%) or meniscus surgery only (29/47, 61.7%). At 72 hours postsurgery, there were no readmissions or complications related to pain. Median-reported pain scores were 2.5 and 5.0 for the ACL and meniscus groups, respectively. A majority of patients continued to require opioids (45/47, 95.7%) and NSAIDs (46/47, 97.9%) at 72 hours postsurgery, but the number of daily opioid doses taken decreased with each day postoperatively. Over 93% of the patients could ambulate and shower at 72 hours postsurgery.

Conclusions

Regional nerve block appears to be an effective and safe analgesic strategy for pediatric arthroscopic ACL and meniscus procedures, with no short-term complications or readmissions related to pain in our cohort. Future prospective investigation is needed to characterize long-term pain outcomes in this surgical population.

Tibial Spine Fractures in Children: Evaluation, Management, and Future Directions

Fractures of the tibial spine are estimated to occur in 3 per 100,000 children annually, but account for 2 to 5% of pediatric knee injuries with effusion. Although these fractures were historically associated with bicycle accidents, the surge of organized youth sports in recent decades has brought renewed attention to this injury. While minimally displaced fractures can be treated nonoperatively, several techniques have been described for fixation of displaced or comminuted fractures. Sequelae of this injury can include arthrofibrosis, knee instability, and nonunion. Future collaborative endeavors will aim to further identify risk factors for these complications to optimize the treatment of tibial spine fractures in children.

Preoperative Patellofemoral Chondromalacia is Not a Contraindication for Fixed-Bearing Medial Unicompartmental Knee Arthroplasty

BACKGROUND

Patellofemoral chondromalacia (PFCM) has historically been considered a contraindication for unicompartmental knee arthroplasty (UKA), but there is limited data assessing PFCM's impact on the results of fixed-bearing UKA. Our objective was to assess the impact of medial patellar and/or medial trochlear PFCM on overall and patellofemoral-specific 2-year outcomes after fixed-bearing medial UKA.

METHODS

Intraoperative notes defined the presence and location of PFCM during fixed bearing medial UKA. Outcome measures included the New Knee Society Score (NKSS), Kneeling Ability Score (KAS) and Forgotten Joint Score (FJS-12). Thirty-one knees with PFCM (PFCM group), and 52 knees without PFCM (N-PFCM group) were included for analysis. Mann-Whitney U tests assessed the statistical significance of observed differences, and a Bonferroni correction was applied, adjusting threshold for significance to P = .005.

RESULTS

At minimum follow-up of 2 years, no statistical differences were detected between the N-PFCM and PFCM groups in the postoperative NKSS (159 vs 157, P = .731), preoperative to postoperative NKSS change (P = .447), FJS-12 (70.5 vs 67.6, P = .471), or KAS (71% vs 65%, P = .217). Patients with isolated patellar chondromalacia (n = 13) demonstrated trends toward worse outcomes according to NKSS (147, P = .198), FJS-12 (58, P = .094), and KAS (46%, P = .018), but were statistically insignificant. No failures occurred in either group.

CONCLUSION

Functional outcomes of fixed-bearing medial UKA are not adversely impacted by the presence of PFCM involving the medial patellar facet and/or medial or central trochlea. Further follow-up is needed to determine longer-term implications of fixed-bearing medial UKA in patients with PFCM.

Design of a light stimulator for fetal and neonatal magnetoencephalography

The design, safety analysis and performance of a fetal visual stimulation system suitable for fetal and neonatal magnetoencephalography studies are presented. The issue of fetal, neonatal and maternal safety is considered and the maximum permissible exposure is computed for the maternal skin and the adult eye. The risk for neonatal eye exposure is examined. It is demonstrated that the fetus, neonate and mother are not at risk.

Towards optimal filtering of "standard" multifocal electroretinogram (mfERG) recordings: findings in normal and diabetic subjects

AIMS

To study the effects of two commonly used pre-amplifier filtering bandwidths on normal multifocal electroretinogram (mfERG) responses and their comparative abilities to detect retinal disease.

METHODS

103 standard mfERGs were recorded simultaneously in two channels with different pre-amplifier settings (10-100 Hz and 10-300 Hz) from one eye of each of 20 normal subjects, 17 diabetics with non-proliferative diabetic retinopathy (NPDR), and 12 diabetics without retinopathy. Signal to noise ratios (SNR) of the normal subjects' first order mfERGs were compared between channels. All subjects' amplitudes and implicit times were derived using a "template stretching" method. For comparison, implicit time was also measured using a "template sliding" method. mfERG amplitudes and implicit times were compared between the channels and among subject groups.

RESULTS

Normal mean amplitudes and implicit times were similar for the two channels. However, normal 10-100 Hz recordings had significantly higher SNR and lower intersubject variability than 10-300 Hz recordings. In NPDR, the 10-100 Hz channel identified significantly more implicit time and amplitude abnormalities. In the diabetics without retinopathy, 10-100 Hz filtering identified significantly more implicit time abnormalities than 10-300 Hz filtering. For both filter settings, diabetic implicit times were more often abnormal than amplitudes. The 10-100 Hz channel was superior for both implicit time measurements.

CONCLUSION

Standard mfERGs recorded from normal eyes and filtered 10-100 Hz contain less noise, higher SNR, and less intersubject variability than those filtered at 10-300 Hz. This underlies the finding that the 10-100 Hz filter setting identifies more retinal dysfunction than the 10-300 Hz setting.

The fast oscillation of the electrooculogram reveals sensitivity of the human outer retina/retinal pigment epithelium to glucose level

The effect of acute blood glucose elevations on human outer retinal function was examined. Electrooculograms were recorded as the background light cycled on/off with a 2-min period, eliciting rapid changes in the corneo-retinal standing potential known as the fast-oscillation of the electrooculogram. Recordings were made while subjects fasted and after they consumed 100 g of D-glucose. In all subjects, blood glucose levels strongly affected fast oscillation amplitude, which reflects photoreceptor-driven changes in RPE cell chloride concentration. The sensitivity of RPE metabolism to glucose fluctuations may relate to changes in the blood-retinal barrier that are known to occur in diabetes (e.g. macular edema).

Multifocal electroretinogram delays reveal local retinal dysfunction in early diabetic retinopathy

PURPOSE

To identify local retinal abnormalities in diabetic patients with and without retinopathy, by using the multifocal electroretinogram (M-ERG).

METHODS

Electroretinograms were recorded at 103 discrete retinal locations in each eye of eight persons with nonproliferative diabetic retinopathy (NPDR) and eight diabetic persons without retinopathy, using VERIS (EDI, San Mateo, CA). The amplitude and implicit time of each local (first-order) retinal response were derived and compared with normal values obtained from 16 age-matched, nondiabetic subjects. Maps of local response amplitude and implicit time were compared with fundus photographs taken at the time of testing.

RESULTS

In eyes with NPDR, the implicit times of responses from retinal sites manifesting clinical pathologic fundus lesions (e.g., microaneurysms and focal edema), were markedly delayed (e.g., up to 7 msec from normal). Responses from adjacent retinal sites that were more normal in clinical appearance were also delayed, but to a lesser extent (e.g., 2-5 msec). Smaller, yet significant local response delays were also found in eyes without retinopathy. By contrast, local response amplitudes bore no consistent relationship to fundus abnormalities in eyes with retinopathy, and amplitudes were typically normal in eyes without retinopathy.

CONCLUSIONS

The M-ERG reveals local retinal dysfunction in diabetic eyes even before retinopathy. The magnitude of delay of local ERG implicit time reflects the degree of local clinical abnormality in eyes with retinopathy. Local response delays found in some eyes without retinopathy suggest that the M-ERG detects subclinical local retinal dysfunction in diabetes. Analysis of M-ERG implicit time, independent of amplitude, improves the sensitivity of detection of local retinal dysfunction in diabetes.

Positive selection as a developmental progression initiated by alpha beta TCR signals that fix TCR specificity prior to lineage commitment

During positive selection, immature thymocytes commit to either the CD4+ or CD8+ T cell lineage ("commitment") and convert from short-lived thymocytes into long-lived T cells ("rescue"). By formal precursor-progeny analysis, we now identify what is likely to be the initial positive selection step signaled by alpha beta TCR, which we have termed "induction". During induction, RAG mRNA expression is downregulated, but lineage commitment does not occur. Rather, lineage commitment (which depends upon the MHC class specificity of the alpha beta TCR) only occurs after downregulation of RAG expression and the consequent fixation of alpha beta TCR specificity. We propose that positive selection can be viewed as a sequence of increasingly selective developmental steps (induction-->commitment-->rescue) that are signaled by alpha beta TCR engagements of intrathymic ligands.

Flow cytometric analysis of lymphocyte subsets in migraine patients during and outside of an acute headache attack

We have conducted flow cytometric studies of two subsets of lymphocyte markers in groups of migraineurs during (n = 12; group B) and outside (n = 10; group C) of a migraine without aura attack (total n = 22; group A), including a group of patients tested in both of these phases (n = 5; group D), and compared these results with those obtained from a population of age-comparable, sex- and race-matched healthy volunteers (n = 12; group E). Comparison of the first set of lymphocytes (CD3+CD16 + 56+, CD3-CD16 + 56+, CD3-CD19+, CD3+CD19+, and CD3+HLA - DR+) between the patients in group A and the controls (group E) showed differences, reflecting greater group A percentages of CD3+CD16 + CD56+ and CD3-CD19+ lymphocytes. Furthermore, these differences reached statistical significance only for the CD3+CD16 + CD56+ lymphocytes, and then solely for the patients in group C (Scheffe's test, p < 0.05). Paired analysis of the above lymphocyte markers for subjects in group D failed to show significant differences between patients when they were having and not having a migraine attack, raising the possibility that results from a larger study could show meaningful increases in percentages of CD3+CD16 + CD56+ lymphocytes as one of the immune parameters useful for differentiating migraineurs from controls. Comparison of a second set of lymphocyte markers (CD19+CD5+, CD20+CD72-, CD20-CD72+, CD20+CD72+) among either the different groups of patients or between the patients and controls failed, however, to show statistically significant differences, emphasizing the apparent specificity of the findings described above for CD3+CD16 + CD56+ lymphocytes. Our results, albeit of a preliminary nature, suggest the occurrence of significant, differential changes in lymphocyte subset immunophenotyping between groups of pain-free migraineurs and patients during an acute migraine episode or controls. Corroboration of these findings may prove useful in clinical laboratory practice to identify changes in immunological parameters specifically associated with migraineurs, and help towards a better understanding of the etiology and pathophysiology of this condition.

Optical and structural development of the crystalline lens in childhood

PURPOSE

To document the development of key optical and structural parameters of the crystalline lens throughout childhood and examine possible mechanisms by which lens power remains coordinated with the growth of the eye to maintain emmetropia.

METHODS

Using cycloplegic autorefraction, video-based phakometry, and ultrasonography, the authors measured refractive error and crystalline lens parameters in 994 children in the first through eighth grades, who participated in the Orinda Longitudinal Study of Myopia, between one and five times from 1989 through 1993. Polynomial growth curves were fit to the data by maximum likelihood estimation. The average annual rates of change in each parameter from each subject's longitudinal data were also estimated.

RESULTS

The lens radii of curvature flattened throughout childhood, yet decreases in lens equivalent power stopped after 10 years of age. This indicates that the refractive index of the lens increased during later childhood. Lens thinning in early childhood also ceased after 10 years of age. The spherical volume of the lens showed no appreciable net increase, but the axial length of the eye continued to grow throughout childhood. The prevalence of myopia in our data increased sharply at age 10 years, reaching 21.3% by the age of 14 years.

CONCLUSIONS

Concurrent thinning and flattening of the crystalline lens imply that the lens is mechanically stretched by the equatorial growth of the eye during childhood. Changes in the patterns of lens development near the age of 10 years, concurrent with the onset of myopia, suggest that forces arise which interfere with equatorial growth. Such forces might diminish the decreases in lens power and amplify axial elongation to promote myopia.

Temporal response characteristics of the spatiochromatic visual evoked potential: nonlinearities and departures from psychophysics

Although the visual evoked potential (VEP) for isoluminant stimuli has been characterized in terms of spatiochromatic parameters, temporal tuning along various chromatic directions has received less systematic attention. Additionally, there has been little categorical comparison of psychophysical appearance with VEP responses obtained for temporal variation of these patterns. At appropriate contrasts the VEP's for color axes (LM, S) show a robust and contrast-sensitive temporal tuning peak at 4 Hz. Contrast response functions at 4 Hz for the LM color axis are markedly nonmonotonic. However, there is a clear monotonicity with contrast for VEP latencies along these color axes. The anomalous behavior does not appear to be due to interactions between chromatic signals, to luminance artifact, or to rod intrusion. These anomalies in the temporal characteristics of the chromatic VEP may reflect interactions between chromatic responses and inherent cortical responsivity not linked to psychophysical behavior.

Acute effects of blood glucose on chromatic visually evoked potentials in persons with diabetes and in normal persons

PURPOSE

To determine whether specific chromatic pathways are selectively affected by short-term variations in blood glucose levels in observers with and without diabetes.

METHODS

Ten subjects with diabetes, all with type 1 diabetes and no retinopathy, and eight age-similar normal subjects were tested. Cortical visually evoked potentials (VEPs) in response to stimuli designed to selectively activate the short-wavelength-sensitive (S) or long- and middle-wavelength-sensitive (LM) chromatic (isoluminant) pathways or the achromatic pathway were recorded over a period of several hours. Capillary blood glucose also was measured repeatedly over the same period. The relation between VEP latency and blood glucose was determined.

RESULTS

The S-pathway VEP latency was correlated significantly with blood glucose in a slight majority (6/10) of persons with diabetes; S-pathway latency was longer at higher blood glucose levels. This association between S-pathway latency and blood glucose was not dependent on the pattern of blood glucose variation over time (i.e., significant correlations between blood glucose and latency were observed in persons for whom blood glucose increased, decreased, or rose and then fell over time). No dependence on blood glucose was observed for LM- or achromatic-pathway VEP latency in subjects with diabetes.

CONCLUSIONS

Acute variations in blood glucose of subjects with diabetes over hours selectively affect the function of the short-wavelength-sensitive chromatic pathway. The findings are discussed within the context of known mechanisms by which elevated glucose affects cellular metabolism with a time course consistent with the transient nature of the effect observed.

Optimum parameters for short-wavelength automated perimetry

PURPOSE

To determine the optimum parameters for short-wavelength automated perimetry (SWAP) and to recommend these for standardization of the procedure.

METHODS

We used a variety of stimulus and background configurations to determine the optimum background spectral distribution and luminance, and the optimum target spectral distribution, maximum luminance, and duration. We measured threshold versus intensity curves to determine which combination provided (a) the greatest isolation of the short-wavelength sensitive mechanisms and (b) the largest dynamic range for perimetry. We also evaluated the effect of lens absorption and cataract on these two factors.

RESULTS

A broad-band yellow background at 100 candela/m2 with a narrow-band 440-nm (27-nm half-bandwidth), 1.8 degrees diameter (Goldmann size V) stimulus presented for 200 ms was optimum at all retinal eccentricities. Specific recommendations for how to modify existing perimeters are given.

CONCLUSION

Agreement regarding the optimum parameters for SWAP should lead to standardization of the test that will facilitate comparison of results from different centers. Normative data can be collected at several sites and incorporated into statistical analysis packages currently available with various perimeters. This will greatly improve the clinical utility of this test.

Longitudinal evidence of crystalline lens thinning in children

PURPOSE

Most earlier studies indicated that the eye's crystalline lens grows continually throughout life, but cross-sectional results of crystalline lens thinning during childhood have been reported. The authors investigated crystalline lens thickness in childhood using cross-sectional and longitudinal data.

METHODS

The Orinda Longitudinal Study of Myopia is a community-based study of normal eye growth and myopia development in school-age children. During a 1-to 3-year period, A-scan ultrasonographic lens thickness measurements of 869 children 6 through 14 years of age were analyzed.

RESULTS

On average, between the ages of 6 and 10 years, the crystalline lens thins in its axial dimension by almost 0.2 mm. This thinning can be depicted by a cubic model. In this sample, the children with myopia had thinner crystalline lenses than the children with emmetropia of the same age.

CONCLUSIONS

This article provides the first longitudinal evidence that the crystalline lens thins during the period of coordinated ocular growth between the ages of 6 and 10 years. Further, it shows that lens thickness is associated with refractive error. Thinner crystalline lenses in children with myopia may result from one of two underlying mechanisms: Either the crystalline lens exhausts its ability to compensate for axial elongation after undergoing accelerated lens thinning before the onset of myopia, or the crystalline lens in the myopic eye may be thinner throughout childhood, during which it thins at a rate consistent with other refractive errors. If mechanical forces link eye growth to crystalline lens compensation, more complex, visually guided feedback loops may not be needed to explain the normal eye growth that results in emmetropization.

The equivalent refractive index of the crystalline lens in childhood

Despite the importance of crystalline lens power in ocular development, schematic refractive index values used to calculate lens power have been validated for children. We measured refractive error and ocular component dimensions in 519 schoolchildren, calculating lens power using phakometrically measured lens radii and three different refractive index profiles: (1) Gullstrand-Emsley schematic indices [Gullstrand-Emsley lens power (GELP)]; (2) a 10-shell gradient index model [gradient index lens power (GILP)]; and (3) the equivalent refractive index (IND) needed to bring calculated and measured refractive error into agreement [calculated lens power (CLP)]. GELP was significantly lower than either GILP or CLP, indicating the Gullstrand-Emsley refractive index of 1.416 is too low for use in children. Variation in IND cannot be explained by measurement error alone. GILP and CLP also differed as a function of lens shape, with GILP greater than CLP at steeper external curvatures and less than CLP at flatter external curvatures. Variation in equatorial gradient index profile as a function of lens shape is proposed as an explanation for this bias. Equivalent index appears to be a useful tool for encompassing individual variation in lens gradient profiles as well as for assessing the relative role of lens surface curvature and refractive index changes during lens power development in childhood.

Short-wavelength automated perimetry in low-, medium-, and high-risk ocular hypertensive eyes. Initial baseline results

OBJECTIVE

To examine the relationship between the prevalence of short-wavelength sensitivity losses in the central 30 degrees visual field and risk factors for development of glaucomatous visual field loss in ocular hypertension.

DESIGN

A modified Humphrey Field Analyzer was used to perform standard automated perimetry and short-wavelength automated perimetry (SWAP), which is a technique that isolates the activity of short-wavelength-sensitive ("blue") mechanisms. In addition, an assessment of the risk of developing glaucomatous visual field loss was determined, based on a validated model that utilized intraocular pressure, a family history of glaucoma, age, and the vertical cup-to-disc ratio.

PATIENTS

Both eyes of 232 ocular hypertensive patients were examined and compared with results from an age-matched control group of normal subjects. Both ocular hypertensive patients and normal subjects had to have normal visual fields on standard automated perimetry, good visual acuity, and no evidence of other ocular or neurologic disease or surgery. Intraocular pressure in the ocular hypertensive patients was 21 mm Hg or greater OU (without medication), and it was less than 20 mm Hg OU in normal control subjects.

RESULTS

Less than 10% of the low-risk ocular hypertensive eyes had a SWAP deficit, as compared with 20% of the moderate-risk and 33% of the high-risk ocular hypertensive eyes. Intraocular pressure and a family history of glaucoma showed no meaningful relationship with the prevalence of SWAP deficits, but both age and the vertical cup-to-disc ratio demonstrated a strong association with the SWAP abnormalities.

CONCLUSIONS

The SWAP results that were found in the ocular hypertensive eyes were associated with other risk factors that have been reported to be predictive of the development of glaucomatous visual field loss, especially the vertical cup-to-disc ratio and age. These findings support the notion that the SWAP deficits represent early glaucomatous damage and may be related to early changes that occur at the optic nerve head.

Visual evoked potentials in three-dimensional color space: correlates of spatio-chromatic processing

Visual evoked potentials (VEPs) were measured for sinusoidal gratings with spatio-chromatic modulation defined in a three-dimensional color space. The spatio-chromatic modulation of the gratings can be decomposed into contributions from an achromatic luminance varying component, an isoluminant component which modulates only the activities of L cones and M cones, and an isoluminant component corresponding to modulation of only S-cone activity. The emphasis of this report is the nature of VEPs resulting from isoluminant spatio-chromatic modulation. The VEP response was characterized along a number of spatial, temporal, and chromatic stimulus dimensions: contrast, spatial frequency, chromaticity in the isoluminant plane, chrominance/luminance ratio, orientation, and temporal frequency. Isoluminant VEPs resulting from stimuli modulating L and M cones are compared with those from S-cone modulation. When appropriate spatiotemporal conditions are employed, both types produce robust VEPs; however, the S-pathway VEPs show considerably longer latencies than do those from LM-pathway activation. The VEP results are compared to psychophysical and single unit electrophysiological observations. VEP latencies exhibit the lowpass character of psychophysical chromatic contrast sensitivity functions but VEP amplitudes show bandpass tuning along both the S and LM axes. An oblique effect, i.e. shorter latencies for horizontal and vertical gratings than for diagonal, is observed in the isoluminant VEP. S-pathway VEPs are used to demonstrate an electophysiological correlate of transient tritanopia. Normative amplitude and latency data for VEPs from selectivity stimulated chromatic mechanisms provide a baseline for clinical electrodiagnostic applications.

The effect of parental history of myopia on children's eye size

OBJECTIVE

To evaluate whether eye size and shape are different in children based on their parental history of myopia.

DESIGN

A community-based cohort study of schoolchildren (aged 6 to 14 years), the Orinda (Calif) Longitudinal Study of Myopia.

SETTING

Four campuses of the Orinda Union School District, a predominantly white, high socioeconomic status community.

PARTICIPANTS

A cross-sectional volunteer sample of 716 children (662 non-myopic) in the first, third, and sixth grades in 1989, 1990, and 1991. All children in those grades were eligible for inclusion in the study.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURES

Refractive error (measured by autorefraction), corneal curvature (measured by photokeratoscopy), crystalline lens power (measured by video phakometry), and axial ocular dimensions (measured by ultrasonography).

RESULTS

With prevalent cases of myopia excluded and grade in school and "near work" controlled for, children with two myopic parents had longer eyes and less hyperopic refractive error (analysis of covariance, P < or = .01) than children with only one myopic parent or no myopic parents. A model incorporating parental history is only improved by the addition of near work for the prediction of refractive error.

CONCLUSIONS

Even before the onset of juvenile myopia, children of myopic parents have longer eyes. These results suggest that the premyopic eye in children with a family history of myopia already resembles the elongated eye present in myopia.

Diabetic short-wavelength sensitivity: variations with induced changes in blood glucose level

PURPOSE

To investigate variations in diabetic short-wavelength sensitivity with acute, induced changes in blood glucose level.

METHODS

Increment threshold measures were obtained for short-wavelength-sensitive and middle/long-wavelength-sensitive cone pathways after an induced, acute change in blood glucose level in diabetic observers.

RESULTS

Diabetic observers showed an increase in short-wavelength sensitivity, but no change in middle/long-wavelength sensitivity, with a rapid drop in blood glucose level.

CONCLUSIONS

Experimentally induced changes in diabetic blood glucose levels can directly affect diabetic short-wavelength sensitivity.

The effect of cycloplegia on measurement of the ocular components

PURPOSE

The purpose of this study was to examine the effect of cycloplegic agent on the measurement of refractive error and the ocular components.

METHODS

We compared two commonly used topical cycloplegic agents, 1% tropicamide and 1% cyclopentolate, for their effect on the measurement of refractive error (by Canon R-1 autorefraction), accommodative response (by Canon R-1 autorefraction and by the conventional, subjective "pushup" method), crystalline lens power (by video phakometry and by calculation), and axial ocular dimensions (by A-scan ultrasonography) in 20 emmetropic to moderately hyperopic children.

RESULTS

Comparison of refractive error at each drug's reported time of maximum cycloplegia (30 minutes for tropicamide and 60 minutes for cyclopentolate) showed that distance autorefraction in the vertical meridian differed by +0.20 +/- 0.30 diopters (D) (P = 0.008). The average difference was +0.07 +/- 0.10 mm for anterior chamber depth (P = 0.004), -0.03 +/- 0.05 mm for crystalline lens thickness (P = 0.025), -0.65 +/- 0.69 D for phakometrically measured crystalline lens power (P < 0.001), +0.03 +/- 1.55 D for calculated crystalline lens power (P = 0.94), and -0.09 +/- 0.19 mm for vitreous chamber depth (P = 0.062, all paired t tests; positive signs denote greater values with cyclopentolate). Residual accommodation was 0.47 and 0.67 D greater with tropicamide when measured by autorefraction and the pushup method (P = 0.013 and 0.08 respectively, paired t test). All significant differences were consistently in the direction of poorer cycloplegia with tropicamide.

CONCLUSIONS

Although tropicamide, as expected, showed poorer cycloplegia compared to cyclopentolate, the degree of difference appeared to be small, with minimal effect on the measurement of distance refractive error and the ocular optical components.

Comparison of cyclopentolate versus tropicamide cycloplegia in children

This double masked study compares the cycloplegic effects of tropicamide 1% and cyclopentolate 1% in 20 nonstrabismic, nonamblyopic, hyperopic 6- to 12-year-old children with a mean refractive error = +1.48 +/- 1.10 diopters (D). Unlike previous studies which used only amplitude of accommodation to measure the depth of cycloplegia, this study compares refractive error as determined by retinoscopy, distance subjective refraction, and distance autorefraction (Canon R-1). In addition, we compare the amplitude of accommodation as measured by subjective push-up and objective autorefraction methods. There is no statistically significant difference between cyclopentolate and tropicamide for either cycloplegic retinoscopy or distance subjective refraction. Autorefraction measurement of refractive error shows a statistically significant but clinically unimportant bias (0.14 +/- 0.30 D) toward more hyperopia with cyclopentolate. Both drops reveal latent hyperopia, and the mean latencies are not statistically different between the two cycloplegic agents. Latent hyperopia is not systematically related to the degree of hyperopia after tropicamide, but this relation is significant after cyclopentolate. No differences were found between refractive results with either agent at 30 min compared to 60 min after drop instillation. When measured objectively with the autorefractor, accommodation is inhibited more effectively by cyclopentolate than by tropicamide. Our results suggest that although tropicamide is not as effective as cyclopentolate in inhibiting accommodation it is, nevertheless, a useful cycloplegic agent for measuring distance refractive error of low to moderate hyperopia in school-aged children.

Initial cross-sectional results from the Orinda Longitudinal Study of Myopia

BACKGROUND

Although investigations of human refractive error development and normal ocular growth have been conducted for the last 50 years, no previous study of refractive error and the ocular components has measured all the ocular components.

METHODS

The Orinda Longitudinal Study of Myopia was initiated to characterize the development of refractive error and normal eye growth in a sample of predominantly Caucasian children ages 6 to 14 years.

RESULTS

Cross-sectional results from 530 children ages 5 to 12 years in the 1st, 3rd, and 6th grades are presented.

CONCLUSIONS

This sample's refractive error decreased toward emmetropia with age from an average of +0.73 D at age 6 years to an average of +0.50 D by age 12 years. Between the ages of 6 and 12 years, the vitreous chamber elongated (by 0.52 mm) and the crystalline lens power decreased (by 1.35 D); surprisingly, the crystalline lens thinned by 0.14 mm during this same time period.

Application of the spatiochromatic visual evoked potential to detection of congenital and acquired color-vision deficiencies

Visual evoked potentials were recorded in response to spatiochromatic stimuli modulated in different directions in cone-activation color space from subjects with congenital and acquired color defects. This technique was effective for detection and classification of both mild and severe forms of congenital deficits. Results suggest that the visual evoked potential is useful for early identification of color abnormalities in acquired deficits such as diabetes and that it is sensitive enough to detect regional retinal losses of sensitivity (e.g., as in central serous choroidopathy). The spatiochromatic visual evoked potential provides a systematic and sensitive indication of different color-vision anomalies.

Size induction transcends the cardinal directions of color space

Certain psychophysical phenomena occur separately for color and for luminance stimulation. Separate psychophysical effects have also been elicited along different directions in equiluminant colour space. Whereas in most studies in which separate luminance and color effects have been reported the authors have used successive-adaptation approaches, less is known about the separateness of color and luminance processing under simultaneous conditions. A study is reported in which simultaneous size induction was examined for several different color directions thought to be 'cardinal' for early stages of processing. The perceived size of a test object was influenced by the size of the surrounding objects regardless of the color direction of the test and induction objects. The results indicate that simultaneous size induction occurs at a level of processing at which information conveyed by color and by luminance mechanisms is compared and contrasted to influence visual perception.

Certain host-donor strain combinations do not reject brain allografts after systemic sensitization

To investigate the factors related to allogenic brain graft rejection, rat cortex from either LEW-RT1l or BN-RT1n rats was transplanted into brains of several isogenic and allogenic inbred strains: F344-RT1l, LEW-RT1l, BN-RT1n, AO-RT1u, PVG-RT1c, PVG-RT1u, and PVG-RT1l. Each donor and host combination was subsequently subdivided into two subgroups. One group was systematically sensitized twice with donor skin tissue and another group served as a sham-sensitization control. Four weeks after the second sensitization, host brains were examined histologically, and the percentage volume of each graft that showed increased cellularity was estimated. Expression of major histocompatibility complex (MHC) and T cell antigens was also studied immunocytochemically. Almost all grafts in sham-sensitized animals from all groups were accepted with minimal or no reaction. However, two strains (AO-RT1u and F344-RT1l) showed considerable cell infiltration and expression of MHC antigens even without sensitization. After sensitization, almost all allogenic strain combinations showed greater signs of rejection-related responses. The severity of the tissue reaction, however, varied considerably between groups. All grafts from BN-RT1n donors were rejected severely in all host strains. For LEW-RT1l donors, grafts survived well in some host strains (BN-RT1n, AO-RT1u, PVG-RT1c, and PVG-RT1u), even with MHC + non-MHC disparity. Curiously, F344-RT1l hosts rejected LEW-RT1l grafts even though the two strains have the same MHC loci, but different minor histocompatibility (mH) loci. For both donor strains, experimental autoimmune encephalomyelitis-susceptible hosts tended to show more vigorous rejection responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Automated perimetry and short wavelength sensitivity in patients with asymmetric intraocular pressures

Automated visual field testing [white-on-white (W-on-W) perimetry] and perimetry of short wavelength sensitive mechanisms [blue-on-yellow (B-on-Y) perimetry] were conducted in both eyes of patients with large asymmetries in intraocular pressure (IOP) between eyes (average difference = 19.9 mm Hg). Overall visual field sensitivity was significantly (P < 0.05) depressed in the eyes with higher IOP by an average of 2.33 dB, in spite of the fact that all but two of the eyes with higher IOP demonstrated visual field sensitivities that were within normal limits. None of the eyes with lower IOP were outside of normal sensitivity limits. B-on-Y perimetry revealed similar findings, except that three of the fellow eyes with relatively lower IOP also demonstrated abnormalities. Our results are consistent with the hypothesis that the diffuse loss in visual field sensitivity in glaucoma is related to IOP. In addition, it appears that short wavelength sensitive mechanism may reveal early glaucomatous losses in patients with elevated IOP.

Blue-on-yellow perimetry can predict the development of glaucomatous visual field loss

OBJECTIVE

The purpose of this investigation was to determine whether blue-on-yellow (B/Y) perimetry is capable of predicting the onset and location of impending glaucomatous visual field loss in patients with ocular hypertension.

DESIGN

A Humphrey Field Analyzer (Humphrey Instruments, San Leandro, Calif) was modified to perform B/Y perimetry to isolate and measure the sensitivity of short-wavelength-sensitive mechanisms. Participants were tested annually with standard white-on-white (W/W) and B/Y automated perimetry for a period of 5 years.

PATIENTS

The study population consisted of 38 patients with ocular hypertension and 62 age-matched normal control subjects.

RESULTS

Initially, all 76 ocular hypertensive eyes had normal W/W automated perimetry results, with 67 eyes having normal and nine eyes having abnormal B/Y test results. Five years later, five of the nine ocular hypertensive eyes with initial B/Y abnormal results developed glaucomatous visual field loss measured by standard W/W automated perimetry, while none of the 67 ocular hypertensive eyes with initially normal B/Y results developed abnormal W/W perimetry results.

CONCLUSIONS

Blue-on-yellow perimetry deficits are an early indicator of glaucomatous damage and are predictive of impending glaucomatous visual field loss for standard W/W automated perimetry. To our knowledge, this is the first prospective, long-term longitudinal study that demonstrates the ability to predict the onset of glaucomatous visual field loss in patients with ocular hypertension on the basis of psychophysical testing.

Progression of early glaucomatous visual field loss as detected by blue-on-yellow and standard white-on-white automated perimetry

OBJECTIVE

To determine whether blue-on-yellow perimetry reveals progression of glaucomatous damage before it is evident with standard white-on-white perimetry.

DESIGN

A Humphrey field analyzer (Humphrey Instruments, San Leandro, Calif) was modified to perform blue-on-yellow perimetry to isolate and measure the sensitivity of short wavelength-sensitive mechanisms. Participants were tested annually with standard white-on-white automated perimetry and blue-on-yellow automated perimetry for 5 years.

PATIENTS

Sixteen patients with early glaucomatous visual field loss in one or both eyes and 62 age-matched normal control subjects.

RESULTS

At baseline, 25 (78.1%) of the 32 eyes exhibited larger deficits with blue-on-yellow perimetry, five (15.6%) had equivalent loss with both tests, and two (6.3%) had larger deficits with standard white-on-white perimetry. Seven (21.9%) of the 32 eyes demonstrated evidence of progressive visual field loss with standard white-on-white perimetry in 5 years, while the other 25 eyes (78.1%) were relatively stable. Deficits with blue-on-yellow perimetry were twice as large as deficits with white-on-white perimetry in the stable group and were three to four times as large in the group with progressive field loss.

CONCLUSIONS

Blue-on-yellow perimetry is effective in predicting which patients with early glaucomatous visual field loss are most likely to have progressive loss. The rate of progressive loss is greater with blue-on-yellow perimetry than with standard white-on-white perimetry.

Impact of new and emerging instrumentation in optometry

Traditional tests of vision emphasize visual acuity, visual fields, and testing for hereditary color vision defects. New instrumentation for testing vision has proliferated due to advances in our knowledge of the visual system, the availability of new technologies, the introduction of computers into practice, and the expanded scope of optometric practice. Each is discussed in relation to the subsequent symposium papers by other authors.