4-factor prothrombin complex concentrate is not inferior to andexanet alfa for the reversal or oral factor Xa inhibitors: An Eastern Association for the Surgery of Trauma multicenter study

BACKGROUND

Andexanet Alfa (AA) is the only FDA approved reversal agent for apixaban and rivaroxaban (DOAC). There are no studies comparing its efficacy with 4-Factor Prothrombin Complex Concentrate (PCC). This study aimed to compare PCC to AA for DOAC reversal, hypothesizing non-inferiority of PCC.

METHODS

We performed a retrospective, non-inferiority multicenter study of adult patients admitted from July 1, 2018 to December 31, 2019 who had taken a DOAC within 12 hours of injury, were transfused red blood cells (RBCs) or had traumatic brain injury, and received AA or PCC. Primary outcome was PRBC unit transfusion. Secondary outcome with ICU length of stay. MICE imputation was used to account for missing data and zero-inflated poisson regression was used to account for an excess of zero units of RBC transfused. 2 Units difference in RBC transfusion was selected as non-inferior.

RESULTS

Results: From 263 patients at 10 centers, 77 (29%) received PCC and 186 (71%) AA. Patients had similar transfusion rates across reversal treatment groups (23.7% AA vs 19.5% PCC) with median transfusion in both groups of 0 RBC. According to the Poisson component, PCC increases the amount of RBC transfusion by 1.02 times (95% CI: 0.79-1.33) compared to AA after adjusting for other covariates. The averaged amount of RBC transfusion (non-zero group) is 6.13. Multiplying this number by the estimated rate ratio, PCC is estimated to have an increase RBC transfusion by 0.123 (95% CI: 0.53-2.02) units compared to AA.

CONCLUSION

PCC appears non-inferior to AA for reversal of DOACs for RBC transfusion in traumatically injured patients. Additional prospective, randomized trials are necessary to compare PCC and AA for the treatment of hemorrhage in injured patients on DOACs.

LEVEL OF EVIDENCE

Therapeutic/Care Management, Level III.

Propensity weighted analysis of chemical venous thromboembolism prophylaxis agents in isolated severe traumatic brain injury: An EAST sponsored multicenter study

BACKGROUND

In patients with severe traumatic brain injury (TBI), clinicians must balance preventing venous thromboembolism (VTE) with the risk of intracranial hemorrhagic expansion (ICHE). We hypothesized that low molecular weight heparin (LMWH) would not increase risk of ICHE or VTE as compared to unfractionated heparin (UH) in patients with severe TBI.

METHODS

Patients ≥ 18 years of age with isolated severe TBI (AIS ≥ 3), admitted to 24 level I and II trauma centers between January 1, 2014 to December 31, 2020 and who received subcutaneous UH and LMWH injections for chemical venous thromboembolism prophylaxis (VTEP) were included. Primary outcomes were VTE and ICHE after VTEP initiation. Secondary outcomes were mortality and neurosurgical interventions. Entropy balancing (EBAL) weighted competing risk or logistic regression models were estimated for all outcomes with chemical VTEP agent as the predictor of interest.

RESULTS

984 patients received chemical VTEP, 482 UH and 502 LMWH. Patients on LMWH more often had pre-existing conditions such as liver disease (UH vs LMWH 1.7 % vs. 4.4 %, p = 0.01), and coagulopathy (UH vs LMWH 0.4 % vs. 4.2 %, p < 0.001). There were no differences in VTE or ICHE after VTEP initiation. There were no differences in neurosurgical interventions performed. There were a total of 29 VTE events (3 %) in the cohort who received VTEP. A Cox proportional hazards model with a random effect for facility demonstrated no statistically significant differences in time to VTE across the two agents (p = 0.44). The LMWH group had a 43 % lower risk of overall ICHE compared to the UH group (HR = 0.57: 95 % CI = 0.32-1.03, p = 0.062), however was not statistically significant.

CONCLUSION

In this multi-center analysis, patients who received LMWH had a decreased risk of ICHE, with no differences in VTE, ICHE after VTEP initiation and neurosurgical interventions compared to those who received UH. There were no safety concerns when using LMWH compared to UH.

LEVEL OF EVIDENCE

Level III, Therapeutic Care Management.

To close or not to close? Wound management in emergent colorectal surgery, an EAST Multicenter prospective cohort study

BACKGROUND

To determine the clinical impact of wound management technique on surgical site infection (SSI), hospital length of stay (LOS) and mortality in emergent colorectal surgery.

METHODS

A prospective observational study (2021-2023) of urgent or emergent colorectal surgery patients at 15 institutions was conducted. Pediatric patients and traumatic colorectal injuries were excluded. Patients were classified by wound closure technique: skin closed (SC), skin loosely closed (SLC), or skin open (SO). Primary outcomes were SSI, hospital LOS and in-hospital mortality rates. Multivariable regression was used to assess the effect of wound closure on outcomes after controlling for demographics, patient characteristics, ICU admission, vasopressor use, procedure details and wound class. A priori power analysis indicated that 138 patients per group were required to detect a 10% difference in mortality rates.

RESULTS

In total, 557 patients were included (SC n = 262, SLC n = 124, SO n = 171). Statistically significant differences in BMI, race/ethnicity, ASA scores, EBL, ICU admission, vasopressor therapy, procedure details, and wound class were observed across groups (Table 1). Overall, average LOS was 16.9 ± 16.4 days, and rates of in-hospital mortality and SSI were 7.9% and 18.5%, respectively, with the lowest rates observed in the SC group (Table 2). After risk adjustment, SO was associated with increased risk of mortality (OR = 3.003, p = 0.028 in comparison to the SC group. SLC was associated with increased risk of superficial SSI (OR = 3.439, p = 0.014), after risk adjustment.

CONCLUSION

When compared to the SC group, the SO group was associated with mortality, but comparable when considering all other outcomes, while the SLC was associated with increased superficial SSI. Complete skin closure may be a viable wound management technique in emergent colorectal surgery.

STUDY TYPE

Level III Therapeutic/Care Management.

Early VTE Prophylaxis in Severe Traumatic Brain Injury: A Propensity Score Weighted EAST Multi-Center Study

BACKGROUND

Patients with TBI are at high risk of venous thromboembolism events (VTE). We hypothesized that early chemical VTE prophylaxis initiation (≤24 hours of a stable head CT) in severe TBI would reduce VTE without increasing risk of intracranial hemorrhage expansion (ICHE).

METHODS

A retrospective review of adult patients ≥18 years of age with isolated severe TBI (AIS ≥ 3) who were admitted to 24 level 1 and level 2 trauma centers from January 1, 2014 to December 31 2020 was conducted. Patients were divided into those who did not receive any VTE prophylaxis (NO VTEP), who received VTE prophylaxis ≤24 hours after stable head CT (VTEP ≤24) and who received VTE prophylaxis >24 hours after stable head CT (VTEP>24). Primary outcomes were VTE and ICHE. Covariate balancing propensity score weighting was utilized to balance demographic & clinical characteristics across three groups. Weighted univariate logistic regression models were estimated for VTE & ICHE with patient group as predictor of interest.

RESULTS

Of 3,936 patients, 1,784 met inclusion criteria. Incidences of VTE was significantly higher in the VTEP>24 group, with higher incidences of DVT in the group. Higher incidences of ICHE were observed in the VTEP≤24 and VTEP>24 groups. After propensity score weighting, there was a higher risk of VTE in patients in VTEP >24 compared to those in VTEP≤24 ( [OR] = 1.51; [95%CI] = 0.69-3.30; p = 0.307), however was not significant. Although, the No VTEP group had decreased odds of having ICHE compared to VTEP≤24 (OR = 0.75; 95%CI = 0.55-1.02, p = 0.070), the result was not statistically significant.

CONCLUSIONS

In this large multi-center analysis, there were no significant differences in VTE based on timing of initiation of VTE prophylaxis. Patients who never received VTE prophylaxis had decreased odds of ICHE. Further evaluation of VTE prophylaxis in larger randomized studies will be necessary for definitive conclusions.

LEVEL OF EVIDENCE

level III, Therapeutic Care Management.

Time is domain: factors affecting primary fascial closure after trauma and non-trauma damage control laparotomy (data from the EAST SLEEP-TIME multicenter registry)

PURPOSE

Damage control laparotomy (DCL) is used for both traumatic and non-traumatic indications. Failure to achieve primary fascial closure (PFC) in a timely fashion has been associated with complications including sepsis, fistula, and mortality. We sought to identify factors associated with time to PFC in a multicenter retrospective cohort.

METHODS

We reviewed retrospective data from 15 centers in the EAST SLEEP-TIME registry, including age, comorbidities (Charlson Comorbidity Index [CCI]), small and large bowel resection, bowel discontinuity, vascular procedures, retained packs, number of re-laparotomies, net fluid balance after 24 h, trauma, and time to first takeback in 12-h increments to identify key factors associated with time to PFC.

RESULTS

In total, 368 patients (71.2% trauma, of which 50.6% were penetrating, median ISS 25 [16, 34], with median Apache II score 15 [11, 22] in non-trauma) were in the cohort. Of these, 92.9% of patients achieved PFC at 60.8 ± 72.0 h after 1.6 ± 1.2 re-laparotomies. Each additional re-laparotomy reduced the odds of PFC by 91.5% (95%CI 88.2-93.9%, p < 0.001). Time to first re-laparotomy was highly significant (p < 0.001) in terms of odds of achieving PFC, with no difference between 12 and 24 h to first re-laparotomy (ref), and decreases in odds of PFC of 78.4% (65.8-86.4%, p < 0.001) for first re-laparotomy after 24.1-36 h, 90.8% (84.7-94.4%, p < 0.001) for 36.1-48 h, and 98.1% (96.4-99.0%, p < 0.001) for > 48 h. Trauma patients had increased likelihood of PFC in two separate analyses (p = 0.022 and 0.002).

CONCLUSION

Time to re-laparotomy ≤ 24 h and minimizing number of re-laparotomies are highly predictive of rapid achievement of PFC in patients after trauma- and non-trauma DCL.

LEVEL OF EVIDENCE

2B.

Trauma and nontrauma damage-control laparotomy: The difference is delirium (data from the Eastern Association for the Surgery of Trauma SLEEP-TIME multicenter trial)

BACKGROUND

Damage-control laparotomy (DCL) has been used for traumatic and nontraumatic indications. We studied factors associated with delirium and outcome in this population.

METHODS

We reviewed DCL patients at 15 centers for 2 years, including demographics, Charlson Comorbidity Index (CCI), diagnosis, operations, and outcomes. We compared 30-day mortality; renal failure requiring dialysis; number of takebacks; hospital, ventilator, and intensive care unit (ICU) days; and delirium-free and coma-free proportion of the first 30 ICU days (DF/CF-ICU-30) between trauma (T) and nontrauma (NT) patients. We performed linear regression for DF/CF-ICU-30, including age, sex, CCI, achievement of primary fascial closure (PFC), small and large bowel resection, bowel discontinuity, abdominal vascular procedures, and trauma as covariates. We performed one-way analysis of variance for DF/CF-ICU-30 against traumatic brain injury severity as measured by Abbreviated Injury Scale for the head.

RESULTS

Among 554 DCL patients (25.8% NT), NT patients were older (58.9 ± 15.8 vs. 39.7 ± 17.0 years, p < 0.001), more female (45.5% vs. 22.1%, p < 0.001), and had higher CCI (4.7 ± 3.3 vs. 1.1 ± 2.2, p < 0.001). The number of takebacks (1.7 ± 2.6 vs. 1.5 ± 1.2), time to first takeback (32.0 hours), duration of bowel discontinuity (47.0 hours), and time to PFC were similar (63.2 hours, achieved in 73.5%). Nontrauma and T patients had similar ventilator, ICU, and hospital days and mortality (31.0% NT, 29.8% T). Nontrauma patients had higher rates of renal failure requiring dialysis (36.6% vs. 14.1%, p < 0.001) and postoperative abdominal sepsis (40.1% vs. 17.1%, p < 0.001). Trauma and NT patients had similar number of hours of sedative (89.9 vs. 65.5 hours, p = 0.064) and opioid infusions (106.9 vs. 96.7 hours, p = 0.514), but T had lower DF/CF-ICU-30 (51.1% vs. 73.7%, p = 0.029), indicating more delirium. Linear regression analysis indicated that T was associated with a 32.1% decrease (95% CI, 14.6%-49.5%; p < 0.001) in DF/CF-ICU-30, while achieving PFC was associated with a 25.1% increase (95% CI, 10.2%-40.1%; p = 0.001) in DF/CFICU-30. Increasing Abbreviated Injury Scale for the head was associated with decreased DF/CF-ICU-30 by analysis of variance (p < 0.001).

CONCLUSION

Nontrauma patients had higher incidence of postoperative abdominal sepsis and need for dialysis, while T was independently associated with increased delirium, perhaps because of traumatic brain injury.

LEVEL OF EVIDENCE

Therapeutic study, level IV.

Safety and efficacy of thromboelastography guidance of antifibrinolytic therapy in trauma patients: An observational cohort analysis

Background:

Tranexamic acid (TXA) is an antifibrinolytic therapy intended to decrease blood loss and improve hemostasis in traumatic hemorrhage. Viscoelastic assays, such as thromboelastography (TEG), allow for the identification of a patient's specific hemostasis. The purpose of this research study was to explore the safety and efficacy of TEG-guided antifibrinolytic therapy in trauma patients.

Methods:

This study was a retrospective review of trauma patients meeting institution-specific inclusion criteria for TXA. Patients were assigned to fibrinolytic groups per TEG LY30 data. Safety outcomes (24-h mortality, overall in-hospital mortality, and thromboembolic events) were compared between patients who did or did not receive TXA and within fibrinolytic groups. Mortality outcomes were adjusted for baseline Injury Severity Score (ISS). Secondary aims included blood product utilization, length of hospital, and intensive care unit stay.

Results:

Hypofibrinolysis was the most common fibrinolytic phenotype. Adjusting for ISS, there were no significant differences in mortality. A 30.7% thromboembolism incidence was identified in the TXA group compared to 16.6% not receiving TXA (P = 0.26), with 72.7% of these patients experiencing fibrinolytic shutdown.

Conclusions:

There were no differences in 24-h mortality, all-cause mortality, or secondary outcomes. The difference in thromboembolic rates between patients receiving TXA and those who did not, while not statistically significant, poses clinical concern.

Transient CD8-memory contraction: a potential contributor to latent cytomegalovirus reactivation

It is clear that latent CMV can reactivate in immunocompetent individuals, but the mechanism triggering such reactivations remains unclear. Recent clinical data suggest that reactivation can be subverted by CMV-specific T-memory. We therefore monitored CMV-specific T cells in immunocompetent mice with latent mCMV after a known reactivation trigger (LPS). LPS induced transient systemic contraction of mCMV-specific CD8 memory that was followed by transcriptional reactivation. Subsequent recovery of mCMV-specific T cells coincided with resumption of latency. These data suggest that bacterial antigen encounters can induce transient T-memory contraction, allowing viral recrudescence in hosts latently infected with herpes family viruses.

Development of CD8 T-memory inflation after cytomegalovirus infection determined by initial viral burden (39.28)

Both mice and humans can develop large “inflated” populations of CD8 effector memory T-cells after cytomegalovirus (CMV) infection, and such memory inflation has been associated with immune senescence. Not all humans develop CD8 memory inflation after CMV infection, so we hypothesized that memory inflation might be predicated by the initial viral burden. Because it is impossible to know an individuals CMV inoculum during natural infection, we infected mice with murine CMV (MCMV) titers ranging from 102 to 106 PFU. After infection, peripheral blood was evaluated monthly for MCMV-specific CD8 T-cells and antibody. Using MCMV-specific MHC class I tetramers we confirm that high titer infections induce inflationary T-memory responses. In contrast, low titer infections induce significantly less inflation over time. Serum ELISA for MCMV-antibody responses showed a similar pattern. DNA from lung tissues evaluated 16 weeks after infection confirmed successful infection in all mice. Quantitative PCR showed that latent viral load in lungs correlated well with eventual lung resident T-memory responses (R2=0.96). We therefore conclude that an individual’s initial infectious burden determines their latent viral load and eventual development of memory inflation after cytomegalovirus infection, possibly explaining the wide variability in T-cell responses to CMV observed in humans.

Effects of serotonin reuptake inhibitors on aggressive behavior in psychiatrically hospitalized adolescents: results of an open trial

Low concentrations of the neurotransmitter serotonin and its 5-hydroxyindoleacetic acid metabolite in the central nervous system have been associated with increased aggressive behavior in animals and humans. Controlled clinical trials of serotonin agonists in depressed adults have suggested that aggressive behavior is less likely during treatment with these medications than with placebo, but there have been no previous studies of selective serotonin reuptake inhibitors (SSRIs) and aggression in children. We prospectively followed the course of aggressive behavior in 19 psychiatrically hospitalized adolescents (not selected for aggressiveness) who received open clinical trials of fluoxetine, paroxetine, or sertraline. The patients received standard doses (equivalent to fluoxetine 10-40 mg daily) for a minimum of 5 weeks. The starting dose was 15 +/- 5 mg, and dosages were raised at a mean rate of 5 mg every 4 days up to a mean dose of 25 +/- 10 mg daily. Results from trials of the three SSRIs were clustered because the sample sizes were not sufficient for separate analyses. Overall, there were no statistically meaningful improvements in the level of aggressive behavior, as measured on a modified version of the Overt Aggression Scale, over the course of these patients' SSRI trials. Symptoms of physical aggression toward others or self were manifest in 12 of the 19 patients while on SSRIs. Of the 19 patients, 13 were assessed both on and off SSRIs: verbal aggression (p = 0.04), physical aggression toward objects (p = 0.05), and physical aggression toward self (p < 0.02) occurred significantly more frequently on SSRIs than off; no increase was observed in physical aggression toward others. Patients with the highest baseline aggressivity scores did not show greater improvement during SSRI treatment. Further research is warranted, particularly to explore whether SSRIs may have therapeutic effects on aggression at higher (or lower) doses than were administered in this open trial.

Aminoglycoside levels in the rabbit vitreous cavity after intravenous administration

PURPOSE

To determine the penetration of gentamicin and amikacin into the rabbit vitreous cavity after their intravenous administration.

METHODS

Gentamicin (1.6 mg/kg every 8 hours) and amikacin (6 mg/kg every 12 hours) were administered intravenously to 25 rabbits that had previously had the lens and vitreous removed from 43 eyes. For each drug, ocular inflammation was induced in one group of eyes by injection of heat-killed Staphylococcus epidermidis, while the other group was maintained as a control. Samples from the vitreous cavity were taken at regular intervals for 72 hours after beginning the intravenous medications and were analyzed for drug concentrations.

RESULTS

The maximum intravitreal concentration +/- SD achieved for gentamicin was 1.8 +/- 0.5 microgram/ml. The maximum intravitreal concentration for amikacin was 8.5 +/- 3.2 micrograms/ml. Inflamed eyes demonstrated higher concentrations than did those without inflammation.

CONCLUSIONS

In a rabbit model with conditions optimized to enhance penetration of antimicrobials into the vitreous cavity after intravenous administration, neither gentamicin nor amikacin penetrated sufficiently to reach potentially therapeutic concentrations consistently for either Pseudomonas or S epidermidis organisms.

Symptom stability in geriatric chronic schizophrenic inpatients: a one-year follow-up study

The results of previous studies of symptom stability in schizophrenia suggest that negative symptoms manifest traitlike characteristics while positive symptoms fluctuate over time. Various prospective studies of chronic schizophrenic patients have found consistent results, regardless of the follow-up period, yet there is little research addressing symptomatology in geriatric schizophrenic patients. Since these patients have a very poor outcome and more severe negative symptoms, their symptoms might differ from younger patients. This study examined the course of symptomatology in 178 geriatric schizophrenic inpatients who were assessed twice at a 1-year interval with the Positive and Negative Syndrome Scale (PANSS). Intraclass correlations revealed that the distribution of negative symptoms was considerably more stable than that of positive symptoms over the interval, and subtypes based on negative symptoms were the only ones that manifested consistent stability over time. There was also a significant increase in negative symptom severity for the sample, with a slight decrease in positive symptom severity. Thus, even in chronic inpatients, with a very extended illness, positive symptom severity is not particularly stable within patients. These data indicate that the characteristics of negative and positive schizophrenic symptoms are similar in younger and geriatric schizophrenic patients, suggesting a continuity of the illness process. Tentative evidence for increasing severity of negative symptoms over a brief follow-up period suggests the possibility of a steady worsening of clinical state in very elderly patients who remained hospitalized.

Vancomycin levels in the vitreous cavity after intravenous administration

PURPOSE

We studied the effects of inflammation, repeated antibiotic doses, and the surgical status of the eye on penetration of vancomycin hydrochloride into the rabbit vitreous cavity after intravenous administration.

METHODS

We studied three anatomic states (phakic, aphakic, and aphakic, vitrectomy-treated eyes) subdividing each into inflamed and noninflamed groups. Intravenous vancomycin hydrochloride (15 mg/kg of body weight) was administered every 12 hours for 48 hours. Eyes were harvested for the assay of vitreous cavity antibiotic levels at various intervals from one to 49 hours. We determined concentrations and calculated mean values and S.E.M.

RESULTS

Therapeutic levels were not established in the vitreous cavity at any time period in the two phakic groups. At 25 hours, the inflamed aphakic eyes had concentrations of 5.05 +/- 1.9 micrograms/ml and the control noninflamed aphakic eyes 4.5 +/- 1.23 micrograms/ml; slight increases were found by 49 hours. Concentrations tested in the aphakic, vitrectomy-treated eyes at two, 13, 25, and 49 hours demonstrated progressive increases both in the inflamed eyes (5.4 +/- 2.4 micrograms/ml, 9.64 +/- 4.25 micrograms/ml, 9.2 +/- 3.96 micrograms/ml, 10.34 +/- 4.49 micrograms/ml) and noninflamed eyes (3.52 +/- 2.1 micrograms/ml, 5.4 +/- 1.96 micrograms/ml, 6.8 +/- 2.53 micrograms/ml, 8.7 +/- 5.44 micrograms/ml).

CONCLUSIONS

Vitreous vancomycin concentrations in aphakic and aphakic, vitrectomy-treated eyes after intravenous administration exceed the minimal inhibitory concentrations for the usual gram-positive pathogens that create endophthalmitis, suggesting a role for intravenous vancomycin in the treatment of bacterial endophthalmitis.

Vitreous cavity penetration of ceftazidime after intravenous administration

PURPOSE

Penetration of ceftazidime, a third generation cephalosporin, into the vitreous cavity after intravenous administration was investigated.

METHODS

Because antimicrobial penetration varies with surgical status of the eye and with inflammation, studies were conducted in phakic, aphakic, and aphakic, vitrectomized eyes in both normal and inflamed conditions. Ceftazidime 50 mg/kg was administered every 8 hours and vitreous cavity concentrations were tested at intervals from 2 to 72 hours after the initial dose.

RESULTS

No penetration was found into control phakic and aphakic eyes, but drug concentrations were detected in inflamed eyes at 24 hours. Vitreous concentrations of ceftazidime in aphakic, vitrectomized eyes reached levels well above the minimal inhibitory concentration (MIC) for Pseudomonas organisms within 2 hours of intravenous administration in control eyes (8.5 micrograms/ml) and inflamed eyes (35.4 micrograms/ml). Inflammation and removal of the lens and vitreous significantly enhanced ceftazidime penetration at all time periods tested.

CONCLUSION

Ceftazidime penetrates into the vitreous cavity of inflamed eyes after intravenous administration and achieves concentrations above the MIC for Pseudomonas organisms. Penetration is greatest in aphakic, vitrectomized eyes.

The pattern ERG in man following surgical resection of the optic nerve

Pattern electroretinogram (PERG) results recorded in different laboratories from patients with unilateral traumatic transections of the optic nerve have led investigators to opposite conclusions about the sources of this response. There was no absolute demonstration of complete transection in any of these studies. In the present study, PERGs and flash ERGs were recorded from a patient who, 30 months earlier, had undergone surgical resection of the right optic nerve to remove a glioma. The histological section of the biopsied nerve confirmed complete optic nerve transection. Ophthalmoscopically and angiographically, the right eye was normal except for marked optic atrophy. PERGs were produced by 10 Hz reversal of high contrast checks with check widths from 13 deg 30 min to 12 min arc. Field size was 27 deg X 21 deg and space-averaged screen luminance was 110 cd/m2. Smaller checks (3 deg 23 min to 12 min) produced responses in both eyes, but the responses in the right eye were much smaller than those in the left eye. Large checks and diffuse flashes produced approximately equal responses in the two eyes. The implicit times of the PERGs produced by stimulation of the right eye with smaller checks were shorter than those of the left eye. The authors conclude that, in humans, there is a contribution to the high contrast pattern reversal ERG from cells which are not dependent upon the integrity of the ganglion cell layer. These cells and cells dependent upon ganglion cells may both contribute to the high contrast PERG in the normal human eye.

Retinal fluorograms using oral fluorescein

Sodium fluorescein may be safely administered orally. The resulting angiograms serve to document the presence or absence of dye leakage in the same manner as venous injection. The oral route of administration is of particular benefit for use in children, patients with inaccessible veins, and patients participating in studies of late retinal vascular leakage, such as postoperative cystoid macular edema. Serum concentrations of the dye plateau between thirty minutes and one hour, at levels approximating those obtained by intravenous injection.

Presumed ocular histoplasmosis syndrome. A clinicopathologic correlation of a treated case

A patient with bilateral presumed ocular histoplasmosis had been successfully treated in his symptomatic right eye with laser photocoagulation for subretinal neovascularization in two areas of the macula. The left eye also showed neovascularization clinically and histopathologically but was not treated because there was no detectable leakage and the vision was not affected. There was no change in the left eye over a two-year period. Clinicopathologic correlation of the treated and untreated macular lesions and the peripapillary and peripheral lesions is presented.

Retinal fluorography using oral fluorescein

Fluorescein sodium can be administered safely by mouth. The resulting fluorograms are useful in demonstrating many retinal conditions characterized by bright late leakage, such as cystoid macular edema. Oral administration of fluorescein may be preferred in studies of children, patients with difficult veins, and in some surveys of large patient populations.

Laser scotometry in drusen and pits of the optic nerve head

Laser scotometry is an accurate means of detecting dense blind spots. A small low-energy spot is guided across the fundus from nonseeing to seeing areas. Patient responses are recorded on fundus photographys, allowing direct correlation with fundus pathology. Accuracy to less than 1 degree is feasible. All typical optic nerve drusen tested with this technique had field defects. In cases of optic nerve pits, dense scotomas correlated with the shape of visible nerve fiber defects rather than with the shape of serous retinal detachments.