Effects of Sleep Deprivation, Non-Dominant Hand Employment, Caffeine and Alcohol Intake During Surgical Performance: Lessons Learned From the Retina Eyesi Virtual Reality Surgical Simulator

Purpose

Determine whether real-life surgical experience correlates with scores on a retina virtual simulator and the effects of various challenges on surgical performance.

Methods

The study was performed using the Eyesi Surgical Simulator, a virtual reality retina surgical simulator. Residents, fellows, and retina staff were assessed on surgical simulations to determine surgical skills. Participants were assigned baseline scores on speed, efficiency of movement, and ability to avoid retinal damage. After receiving their baseline scores, participants were challenged to use their non-dominant hand or to use the simulator after sleep deprivation or the intake of caffeine or alcohol.

Results

At baseline, junior residents had an average score of 943; senior residents, 1045; retina fellows, 1153; and surgical retina staff, 1161. A 12.5% overall improvement in scores was achieved when comparing baseline 1 to baseline 2; a major improvement was recorded in residents (14.5%) compared with fellows and retina staff (9.97%). A statistically significant difference was observed between residents and fellows (P = 0.027), as well as between residents and retina staff (P = 0.04). A significant decrease in performance (15.7%) was observed when the non-dominant hand was used (P = 0.043). Performance after sleep deprivation and alcohol intake decreased, but not with a statistically significant difference (P = 0.6 and P = 0.5, respectively). A trend toward increasing performance was observed after caffeine intake (6.1%; P = 0.06).

Conclusions

The retina virtual simulator is a novel teaching tool for retinal surgery. A significant association was observed between real surgical experience and the retina surgery virtual simulator results based on surgical experience.

Translational Relevance

An association between real surgical experience and retina surgery virtual simulator results was demonstrated. A complete training program with a cut-off threshold score should be validated for retina training programs.

Cilioretinal artery hypoperfusion and its association with paracentral acute middle maculopathy

BACKGROUND/AIMS

To study the multimodal imaging findings of a large series of eyes with cilioretinal artery obstruction (CILRAO) and describe the systemic associations.

METHODS

Multicentre, retrospective chart review from 12 different retina clinics worldwide of eyes with CILRAO, defined as acute retinal whitening in the distribution of the cilioretinal artery, were identified. The clinical, systemic information and multimodal retinal imaging findings were collected and analysed.

RESULTS

A total of 53 eyes of 53 patients with CILRAO were included in the study. In 100% of eyes, fundus photography illustrated deep retinal whitening corresponding to the course of the cilioretinal artery. Twenty-eight patients (52.8%) presented with isolated CILRAO (baseline best-corrected visual acuity (BCVA) 20/50, final BCVA 20/25) associated with nocturnal hypotension, 23 patients (43.4%) with CILRAO secondary to central retinal vein occlusion (CRVO) (baseline BCVA 20/40, final BCVA 20/20) and two patients with CILRAO due to biopsy-proven giant cell arteritis (GCA) (baseline BCVA 20/175, final BCVA 20/75). With spectral domain optical coherence tomography (SD-OCT), a hyper-reflective band involving the inner nuclear layer (ie, paracentral acute middle maculopathy or PAMM) was noted in 51 eyes (28/28 eyes with isolated CILRAO and 23/23 eyes with CILRAO+CRVO) corresponding to the retinal whitening. In the two eyes with CILRAO+GCA, SD-OCT illustrated hyper-reflective ischaemia of both the middle and inner retina.

CONCLUSIONS

Isolated CILRAO and CILRAO secondary to CRVO are the result of hypoperfusion or insufficiency, rather than occlusion, of the cilioretinal artery and are associated with PAMM or selective infarction of the the inner nuclear layer. With GCA, there is complete occlusion of the cilioretinal artery producing ischaemia involving both the middle and inner retina associated with worse visual outcomes.

Lid splinting eyelid retraction technique: a minimised sterile approach for intravitreal injections

BACKGROUND/AIMS

To describe an alternative technique for avoiding contact with the lids and lashes, without the use of a lid speculum, during intravitreal anti-vascular endothelial growth factor injections.

METHODS

Retrospective case series of all patients undergoing intravitreal injections of bevacizumab and ranibizumab, with the lid splinting retraction technique from January 2010 to December 2015. Injections performed by six vitreoretinal specialists were included. The key preinjection ocular surface preparation includes topical anaesthetic, 5% povidone-iodine and a subconjunctival injection of 2% lidocaine with epinephrine. A second instillation of 5% povidone-iodine is given and the intravitreal injection is then performed. No lid speculum is used. A search of the electronic medical records identified patients diagnosed with postinjection endophthalmitis and charts were reviewed to ensure inclusion criteria were met. The main outcome measure was incidence of postinjection endophthalmitis.

RESULTS

A total of 78 009 consecutive intravitreal injections were performed, of which 22 207 were bevacizumab and 55 802 were ranibizumab. In this cohort of patients (n=6320), 12 cases of endophthalmitis developed, corresponding to a rate of 0.015%.

CONCLUSIONS

The technique of eyelid retraction for intravitreal injection has a low rate of endophthalmitis, similar to the reported rates using a metal lid speculum. This is beneficial for both the physician and the patient as it minimises patient discomfort as well as the duration of the procedure. To our knowledge, this is one of the largest studies performed to date evaluating intravitreal injection-related endophthalmitis.

Documenting the subjective patient experience of first versus second cataract surgery

PURPOSE

To examine the subjective patient experience after cataract surgery.

SETTING

Single multisurgeon cataract facility.

DESIGN

Prospective intraindividual observational study.

METHODS

Patients completed a questionnaire immediately after cataract extraction performed in their second eye. All patients had second-eye surgery within 6 months of first-eye surgery. Cases longer than 30 minutes were excluded.

RESULTS

Of the 292 patients who completed the questionnaire, 12 were excluded based on surgical time. The response rate varied per question. The surgery was rated as taking longer or being more painful in the second eye by 127 patients (45.4%) and in the first eye by 38 patients (13.5%) (P < .05); 115 patients (41.1%) reported no difference. Patients (47.83%) who rated the second eye as the generally more negative experience thought their vision would be better and 3.48% worse (P < .05); 48.70% thought it would be the same. No difference was noted in length of surgery (P = .3) or sedation used (P = .96).

CONCLUSIONS

Of 125 patients who rated second-eye surgery as the generally more unpleasant procedure, 90 (72.0%) were similarly or more relaxed during the second procedure. Second-eye cataract surgery was perceived as being a longer and/or more painful procedure by a significant number of patients (45.4%), and only 3.48% thought that vision in the second eye would be worse. These results can help surgeons when counseling patients regarding expectations for second surgery.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Pediatric orbital cellulitis in the Haemophilus influenzae vaccine era

PURPOSE

To evaluate the microbiology of pediatric orbital cellulitis in blood cultures and abscess drainage cultures following the introduction of the Haemophilus influenzae serotype b (Hib) vaccine.

METHODS

The medical records of all pediatrics patients (aged <18 years) at a tertiary pediatric hospital during the period January 2000 to July 2011 with a computed tomography orbital imaging querying "orbital cellulitis," "periorbital cellulitis," "preseptal cellulitis," or "post-septal cellulitis" were retrospectively reviewed. The records, microbiology, and radiology of these patients were reviewed to assess the rates and complications of H. influenzae orbital cellulitis, including bacteremia and meningitis.

RESULTS

A total of 149 patients were diagnosed with preseptal or orbital cellulitis, of whom 101 (mean age, 7.2 ± 4.0) had true orbital cellulitis. No patients grew H. influenzae from blood cultures. Of the 101 patients, 30 (29.7%) required surgical drainage and had abscess drainage fluid sent for microbiology. Of these, 18 (64.3%) had a positive culture: 4 (13.3%) grew H. influenzae from their abscess drainage fluid samples; 1 grew H. influenzae alone; and 3 had mixed growth that included H. influenzae. The patients positive for H. influenzae were significantly older and had significantly larger abscesses.

CONCLUSIONS

Although there were no cases of H. influenzae bacteremia or meningitis in our cases of orbital cellulitis, abscess drainage fluid microbiology indicated that H. influenzae remains a cause of orbital cellulitis. H. influenzae abscess volume was significantly larger than other bacterial abscesses and was associated with abscesses of mixed bacterial growth in older children.

The effect of adding orbital computed tomography findings to the Chandler criteria for classifying pediatric orbital cellulitis in predicting which patients will require surgical intervention

PURPOSE

To assess the effect of adding orbital computerized tomography (CT) findings to the Chandler criteria for classifying pediatric orbital cellulitis in predicting which patients will require surgical intervention.

METHODS

The medical records of patients with orbital CT at a tertiary pediatric hospital from January 2000 to March 2011 were reviewed retrospectively. CT images of cases with radiology report of postseptal orbital involvement were further reviewed by a neuroradiologist.

RESULTS

Of 101 cases of orbital cellulitis, 71 (mean age, 7.1 ± 4.0) were successfully managed with systemic antibiotics alone; 30 patients (mean age, 7.2 ± 4.3) required surgical intervention. Bony destruction on CT was significantly associated with surgical intervention (P = 0.02), and the size of the subperiosteal abscess (SPA) was significantly correlated with management outcome. Patients who were managed with systemic antibiotics alone had a mean SPA volume of 2.1 ± 2.4 mL; those who had undergone surgical intervention had a mean SPA volume of 14.3 mL ± 16.8 mL (P < 0.0001). If SPA volume is <3.8 mL, then the probability of surgery is 12%; if SPA is >3.8 mL, the probability of surgery is 71% (P < 0.0001).

CONCLUSIONS

Adding radiological characteristics such as presence of bony destruction on CT and size of SPA to the Chandler orbital cellulitis classification scheme increases the ability to more accurately predict which patients will require surgical intervention.

Surgical macular decompression for macular edema in retinal vein occlusion

BACKGROUND

Recently, a number of surgical and laser approaches have been used to improve visual outcome in cases of central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). Intravitreal steroid injection alone appears to offer only temporary improvement at best. Radial optic neurotomy for CRVO and arteriovenous adventitial sheathotomy for BRVO are the most frequently utilized surgical procedures for these conditions, but evidence regarding efficacy is still lacking. We have suggested that macular decompression by internal limiting membrane (ILM) peeling may reduce macular edema and hemorrhage and improve visual acuity by relieving elevated intraretinal tissue pressure and facilitating egress of blood and extracellular fluid out of inner retinal layers into the vitrectomized vitreous cavity.

METHODS

50 cases of severe visual loss due to macular edema caused by CRVO or BRVO, not eligible for laser photocoagulation, underwent pars plana vitrectomy with removal of preretinal hyaloid, peeling of the ILM stained with indocyanine green dye, air-fluid exchange, and postoperative prone positioning.

RESULTS

In all cases, intraretinal blood and retinal thickening diminished within 6 weeks of surgery. Visual acuity improved in 87% of CRVO cases and 68% of BRVO cases. Vision improved and stabilized at 39 days after surgery. Average improvement was 2.6 lines with a 6-line improvement in 1 case. There was no difference in outcome between cases with ischemic or nonischemic features on fluorescein angiography.

INTERPRETATION

Macular decompression using vitrectomy and ILM peeling is effective in the treatment of severe visual loss due to macular edema in CRVO and in those BRVO cases that do not qualify for laser photocoagulation.

Chronic open-angle glaucoma. Review for primary care physicians

INTRODUCTION

Chronic open-angle glaucoma (COAG) is a leading cause of irreversible blindness worldwide, including in Canada. It presents a challenge in diagnosis, as disease often progresses without symptoms; an estimated 50% of cases are undetected.

SOURCES OF INFORMATION

MEDLINE searches, reference lists of articles, and expert knowledge from one of the authors (K.F.D.), a glaucoma specialist, were used.

MAIN MESSAGE

A casefinding approach using early referral to optometrists and ophthalmologists for early detection of COAG is helpful for patients with risk factors such as age above 50, a positive family history, black race, and myopia. Moderate evidence for referral also exists for the following risk factors: hypertension, type 2 diabetes mellitus, hypothyroidism, and sleep apnea. Treatment with intraocular pressure-lowering medication can arrest or slow the course of the disease, permitting patients to retain good visual function. Family physicians should be aware that some intraocular pressure-lowering medications, particularly topical beta-blockers, can pose iatrogenic harm to patients and result in or exacerbate such conditions as asthma, cardiovascular disturbances, depression, and sexual dysfunction.

CONCLUSION

Appropriate referral patterns and an understanding of common as well as serious side effects of glaucoma medications are important in optimizing management of patients at risk of developing, or who have, COAG.

Correlation between corneal sensitivity, subjective dry eye symptoms and corneal staining in Sjögren's syndrome

BACKGROUND

Previous studies have shown a poor correlation between dry eye symptoms and objective clinical signs in patients with Sjögren's syndrome. We examined the hypothesis that reduced corneal sensitivity is associated with increased ocular surface disease and reduced symptoms in patients with Sjögren's syndrome.

METHODS

Eighteen subjects with a diagnosis of Sjögren's syndrome attending a Sjögren's clinic participated in the study. All participants completed the Ocular Surface Disease Index (OSDI) and the Symptom Severity of Discomfort (SSD) scale and answered a question regarding overall severity of dry eye symptoms. The subjects underwent measurement of best-corrected Snellen visual acuity, corneal sensitivity testing with the Cochet-Bonnet esthesiometer, fluorescein and lissamine green staining of the cornea, Schirmer's test I and determination of the tear film break-up time. The results were analysed using Pearson correlational analysis.

RESULTS

Both fluorescein and lissamine green staining of the cornea correlated negatively with central corneal sensation (r = -0.3542, p = 0.034, and r = -0.3748, p = 0.029 respectively), indicating that corneal sensation was reduced with increased ocular surface disease. The overall symptom severity correlated negatively with lissamine green staining of the cornea (r = -0.4310, p = 0.011), suggesting reduced symptoms with increased corneal disease.

INTERPRETATION

Reduced corneal sensation correlated with increased ocular surface disease. Ocular surface disease similarly demonstrated a reciprocal relation with patients' dry eye symptoms. Consequently, we found that patients with Sjogren's syndrome with advanced corneal staining tended to have fewer dry eye symptoms than patients with less corneal staining.

Cellular specificity of proexendin-4 processing in mammalian cells in vitro and in vivo

Glucagon-like peptide-1 (GLP-1) is a potent stimulator of glucose-dependent insulin secretion. Exendin-4(1-39) (Ex-4), isolated from Gila monster venom, is a highly specific GLP-1 receptor agonist that exhibits a prolonged duration of action in vivo. Although the processing mechanisms underlying liberation of GLP-1 from its prohormone have been elucidated, those for Ex-4 remain unknown. To examine the requirements for proEx-4 processing in mammalian cells, BHK fibroblasts, InR1-G9 islet A cells, and AtT-20 corticotropes, which express different prohormone convertases (furin, prohormone convertase 2, and prohormone convertase 1, respectively) were transfected with full-length lizard proEx-4, and the processing of proexendin was examined by HPLC and RIA (n = 3). All of the transfected cell lines exhibited Ex-4-like immunoreactivity in the media, and Ex-4-like immunoreactivity was detected in extracts of InR1-G9 and AtT-20 cells. However, only media and extracts from AtT-20 cells (not InR1-G9 and BHK cells) contained a single peak by HPLC corresponding to synthetic Ex-4. To establish whether proEx-4 can be processed to Ex-4 in nonimmortalized mammalian cells in vivo, the molecular forms of exendin-4 were examined in mice expressing a metallothionein-proEx-4 transgene (n = 3-6 for both males and females). ProEx4 mRNA transcripts were detected by RT-PCR in a broad range of both endocrine and nonendocrine tissues. Ex-4-like immunoreactivity was detected in pituitary, fat, adrenals, and testes; however HPLC analyses demonstrated that processed Ex-4 was found only in adrenals and testes. These results indicate that lizard proEx-4 is processed to mature bioactive Ex-4 in both rodent endocrine and nonendocrine mammalian cell types in vitro and in murine tissues in vivo. These findings may be useful for engineering cells that express a lizard pro-Ex4 transgene for the treatment of type 2 diabetes.

Nerve-derived trophic factors and DNA elements controlling expression of genes encoding synaptic proteins in skeletal muscle fibers

The neuromuscular junction represents an excellent model system for studying various critical issues in neurobiology at the molecular, cellular, and physiological levels. Our understanding of the basic events underlying synpase formation, maintenance, and plasticity has progressed considerably over the last few years primarily because of the numerous studies that have focused on this synapse and used sophisticated recombinant DNA technology. Recent data indicate that myonuclei located in the vicinity of the postsynaptic membrane are in a differential state of transcription compared to nuclei of the extrasynaptic sarcoplasm. Thus, renewal of postsynaptic membrane proteins appears to occur via a mechanism involving the local transcriptional activation of genes encoding these specialized proteins and extracellular cues originating from motoneurons. Such interaction between presynaptic nerve terminals and the postsynaptic sarcoplasm indicates that the entire signal transduction pathway is compartmentalized at the level of the neuromuscular junction. Expression of these genes appears less coregulated than originally anticipated, indicating that maintenance of the postsynaptic membrane requires the contribution of multiple extracellular signals, which ultimately urge target transcription factors to distinct DNA regulatory elements via various second messenger systems.

Increased expression of acetylcholinesterase T and R transcripts during hematopoietic differentiation is accompanied by parallel elevations in the levels of their respective molecular forms

Differentiation of hematopoietic cells is known to be accompanied by profound changes in acetylcholinesterase (AChE) enzyme activity, yet the basic mechanisms underlying this developmental regulation remain unknown. We initiated a series of experiments to examine the molecular mechanisms involved in regulating AChE expression during hematopoiesis. Differentiation of murine erythroleukemia (MEL) cells using dimethyl sulfoxide resulted in a 5- and 10-fold increase in intracellular and secreted AChE enzyme activity, respectively. Interestingly, these increases resulted from a preferential induction of the globular molecular form G1 and a slight increase in G4 instead of an increase in the levels of the G2 membrane-bound form, a molecular form expressed in mature erythrocytes. Concomitantly, expression of the two predominant AChE transcripts (R and T, for read-through and tail, respectively) in MEL cells was induced to a similar extent with differentiation. Nuclear run-on assays performed with nuclei isolated from induced versus uninduced MEL cells revealed that in contrast to the large increases seen in the transcription of the beta-globin gene, the transcriptional activity of the AChE gene remained largely unaffected after differentiation. Determination of the half-lives of the R and T transcripts demonstrated that they both exhibited an increase in stability in induced MEL cells. Taken together, results from these studies indicate that post-transcriptional regulatory mechanisms account for the increased expression of AChE in differentiated hematopoietic cells.