Evaluating ChatGPT on Orbital and Oculofacial Disorders: Accuracy and Readability Insights.

PURPOSE: To assess the accuracy and readability of responses generated by the artificial intelligence model, ChatGPT (version 4.0), to questions related to 10 essential domains of orbital and oculofacial disease. METHODS: A set of 100 questions related to the diagnosis, treatment, and interpretation of orbital and oculofacial diseases was posed to ChatGPT 4.0. Responses were evaluated by a panel of 7 experts based on appropriateness and accuracy, with performance scores measured on a 7-item Likert scale. Inter-rater reliability was determined via the intraclass correlation coefficient. RESULTS: The artificial intelligence model demonstrated accurate and consistent performance across all 10 domains of orbital and oculofacial disease, with an average appropriateness score of 5.3/6.0 ("mostly appropriate" to "completely appropriate"). Domains of cavernous sinus fistula, retrobulbar hemorrhage, and blepharospasm had the highest domain scores (average scores of 5.5 to 5.6), while the proptosis domain had the lowest (average score of 5.0/6.0). The intraclass correlation coefficient was 0.64 (95% CI: 0.52 to 0.74), reflecting moderate inter-rater reliability. The responses exhibited a high reading-level complexity, representing the comprehension levels of a college or graduate education. CONCLUSIONS: This study demonstrates the potential of ChatGPT 4.0 to provide accurate information in the field of ophthalmology, specifically orbital and oculofacial disease. However, challenges remain in ensuring accurate and comprehensive responses across all disease domains. Future improvements should focus on refining the model's correctness and eventually expanding the scope to visual data interpretation. Our results highlight the vast potential for artificial intelligence in educational and clinical ophthalmology contexts.

Gaining Access to the Superior Ophthalmic Vein for Endovascular Embolization of Indirect Carotid-Cavernous Fistulas.

ABSTRACT: Carotid-cavernous fistulas (CCFs) are abnormal connections between the carotid arterial system and the cavernous sinus. These acquired vascular malformations may result in severe orbital congestion and sight-threatening complications. The authors present their experience in gaining access to the superior ophthalmic vein to embolize indirect CCFs in three different patients. Surgical exposure and cannulation of the SOV were successful in all 3 cases. One patient developed an orbital compartment syndrome towards the end of the embolization process, after the irrigation cannula was inadvertently dislodged from the SOV. He required a lateral canthotomy and inferior cantholysis but did not suffer from any related sequelae. Signs and symptoms resolved gradually in all patients and cosmetic results were excellent. In our experience, the SOV offers a reliable access to indirect CCFs, but patients should be monitored closely during the embolization process to prevent ophthalmic complications.

High risk for obstructive sleep apnea hypopnea syndrome predicts new onset atrial fibrillation after cardiac surgery: a retrospective analysis.

PURPOSE: Obstructive sleep apnea hypopnea syndrome (OSAHS) is highly prevalent in patients undergoing coronary artery bypass surgery (CABG). OSAHS is a risk factor for the development of atrial fibrillation (AF), but the risk of AF in patients who are high risk for OSAHS is unclear. METHODS: A retrospective study was conducted on consecutive patients undergoing CABG from 2013 to 2015 without AF pre-operatively. Patients were categorized as low risk for OSAHS, high risk for OSAHS, or diagnosed OSAHS based on medical records review. All diagnosed OSAHS patients were on active treatment with positive airway pressure. Outcomes assessed were postoperative AF (POAF), postoperative length of stay, re-intubation, in-hospital mortality, and cost of hospitalization. RESULTS: Out of 209 eligible patients, 66.5% were low-risk for OSAHS, 18.7% high-risk for OSAHS, and 14.8% diagnosed/treated for OSAHS. POAF developed in 96 patients (45.9%) with greater frequency in high-risk OSAHS patients (69.2% high risk, 41.9% low risk, 40.3% diagnosed/treated, p = 0.01). In analyses adjusted for age, sex, ethnicity and comorbidities, high risk for OSAHS was associated with 2.9 greater odds (95% CI [1.2, 7.3], p = 0.02) for POAF while diagnosed/treated OSAHS was not associated with elevated risk (OR = 1.4, 95% CI [0.6, 3.6], p = 0.50) compared to patients at low risk for OSAHS. CONCLUSIONS: High risk for OSAHS is an independent predictor for POAF in patients undergoing CABG. In contrast, patients diagnosed and treated for their OSAHS are not at elevated risk of POAF. These findings support evaluation of a standardized OSAHS screening and treatment program as part of the pre-operative evaluation for elective CABG.

Expression and knockdown of zebrafish folliculin suggests requirement for embryonic brain morphogenesis.

BACKGROUND: Birt-Hogg-Dubé syndrome (BHD) is a dominantly inherited familial cancer syndrome characterised by the development of benign skin fibrofolliculomas, multiple lung and kidney cysts, spontaneous pneumothorax and susceptibility to renal cell carcinoma. BHD is caused by mutations in the gene encoding Folliculin (FLCN). Little is known about what FLCN does in a healthy individual and how best to treat those with BHD. As a first approach to developing a vertebrate model for BHD we aimed to identify the temporal and spatial expression of flcn transcripts in the developing zebrafish embryo. To gain insights into the function of flcn in a whole organism system we generated a loss of function model of flcn by the use of morpholino knockdown in zebrafish. RESULTS: flcn is expressed broadly and upregulated in the fin bud, somites, eye and proliferative regions of the brain of the Long-pec stage zebrafish embryos. Together with knockdown phenotypes, expression analysis suggest involvement of flcn in zebrafish embryonic brain development. We have utilised the zFucci system, an in vivo, whole organism cell cycle assay to study the potential role of flcn in brain development. We found that at the 18 somite stage there was a significant drop in cells in the S-M phase of the cell cycle in flcn morpholino injected embryos with a corresponding increase of cells in the G1 phase. This was particularly evident in the brain, retina and somites of the embryo. Timelapse analysis of the head region of flcn morpholino injected and mismatch control embryos shows the temporal dynamics of cell cycle misregulation during development. CONCLUSIONS: In conclusion we show that zebrafish flcn is expressed in a non-uniform manner and is likely required for the maintenance of correct cell cycle regulation during embryonic development. We demonstrate the utilisation of the zFucci system in testing the role of flcn in cell proliferation and suggest a function for flcn in regulating cell proliferation in vertebrate embryonic brain development.

Eyelid margin basal cell carcinoma managed with full-thickness en-face frozen section histopathology.

PURPOSE: To determine the tumor control rate of basal cell carcinoma (BCC) of the eyelid margin managed by full-thickness eyelid resection with en-face frozen section-controlled margins and primary reconstruction of the defect. METHODS: This is a retrospective, consecutive, noncomparative, longitudinal interventional case series from a single institution. A review of medical records of all patients with BCC involving the eyelid margin treated by full-thickness en-face frozen section histopathology between June 1997 and June 2011 was conducted. All cases were managed with gross full-thickness resection of the eyelid margin tumor with subsequent reconstruction. Intraoperative frozen section histopathology was performed on additional 1-mm thick medial, lateral, and inferior/superior specimens in a full-thickness en-face fashion. The main outcome measure was rate of recurrence over the follow-up period. Additional data collected included patient demographics, lesion site and size, histopathology, reconstructive technique, and postoperative complications. RESULTS: The review resulted in a total of 74 patients with 77 lesions. Of these, 45 lesions had a minimum 5-year follow up. Those cases that involved the lacrimal system were excluded resulting in a total of 43 cases for analysis, which had a mean follow up of 6.4 years (range, 5.0-13.0). Three cases (6.9%) represented a recurrent BCC, while all other cases were primary BCCs. The histopathological subtypes included nodular (65.1%), infiltrative (18.6%), and superficial (16.3%). There were no cases of recurrence (100% cure rate) over the follow-up period. Most defects (88.4%) were reconstructed by direct closure or a temporal rotation flap. The only complication noted was the development of a hypertrophic scar in 1 patient that resolved with conservative management. In the total series of 77 lesions, the mean follow-up period was 4.5 years (range, 0.5-13.0). One recurrence (1.3%) was detected after 1.1 years for an infiltrative BCC measuring 10.0 mm in diameter that involved the lacrimal system. CONCLUSIONS: Eyelid margin BCC can be managed effectively with full-thickness en-face frozen section-controlled excision and primary reconstruction of the defect. The high cure rate compares favorably with other excision techniques such as Mohs micrographic surgery, with the advantages of a single operation and excellent reconstructive result.

A Computed Tomography Scan Near Miss of an Intraorbital Wooden Foreign Body.

When intraorbital wooden foreign bodies are missed, the consequences can be devastating. While the gold standard diagnostic imaging is computed tomography (CT), it has low sensitivity. We present a 61-year-old man with a bamboo injury to his right eye. He underwent two CT scans that failed to raise the possibility of intraorbital foreign bodies. Upon additional review, a rectangular-shaped pocket of air was identified in the orbit which was most consistent with wooden foreign bodies based on the clinical history. A combined mid-lid approach followed by a transconjunctival and transcaruncular extension were employed to remove several wooden splinters. Postoperatively, due to recurrent orbital compartment syndrome, he required a second decompression with an inferior rim osteotomy. He had good recovery at 3 months follow-up. Overall, intraorbital wooden foreign bodies are challenging to diagnose due to imaging limitations. Providing a clear history and suspected diagnosis to radiology is critical for diagnosis.

Manquer des corps étrangers intraorbitaires en bois peut avoir des conséquences désastreuses. L'imagerie diagnostique de référence est la tomodensitométrie (TDM) mais sa sensibilité est faible. Nous présentons le cas d'un homme de 61 ans ayant une plaie par morceau de bambou dans son œil droit. Il a bénéficié de deux tomodensitométrie qui n'ont pas réussi à donner l'alarme sur la possibilité de corps étrangers intraorbitaires. Lors d'un réexamen supplémentaire, une poche d'air de forme rectangulaire a été identifiée dans l'orbite; cette poche était très compatible avec des corps étrangers en bois, selon l'histoire clinique. Un abord combiné à mi-paupière, suivi d'une extension transconjonctivale et transcaronculaire, a été employé pour retirer plusieurs échardes en bois. En postopératoire, le patient a nécessité une deuxième décompression avec ostéotomie du bord inférieur en raison d'un syndrome du compartiment orbitaire récidivant. La récupération a été bonne au suivi de trois mois. Globalement, les corps étrangers intraorbitaires en bois sont difficiles à diagnostiquer en raison des limites de l'imagerie. Fournir au radiologue une histoire claire et un diagnostic suspecté est essentiel au diagnostic.

Missing Renal Stone Diagnosis in Dementia Patients With Recurrent Urinary Tract Infections: A Case Report and Literature Review.

In older adults, diagnosing, treating, and preventing urinary tract infections (UTIs) can be challenging. This case is of an 82-year-old female of white descent, who was admitted to a post-acute care facility following hospitalization for delirium and a UTI. Hypoactive delirium may be the only clinical manifestation of recurrent UTI. Due to challenges in obtaining a history from this patient with dementia, she had to be admitted multiple times for sepsis. During her final hospitalization, a CT scan of the abdomen and pelvis was ordered, which revealed an obstructed kidney stone as the cause of her recurrent UTIs. Recurrent UTIs especially in patients with dementia should prompt further imaging to look for kidney stones. Factors like dehydration and poor oral intake are risk factors for kidney stones, which patients with dementia are susceptible to.

Unveiling a Neurological Enigma: Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL) Presenting With Facial Palsy.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an uncommon genetic disorder that affects small blood vessels in the brain. It leads to neurological symptoms, disability-adjusted life years, and difficult emotional and physical situations for patients and their families. As unusual brain symptoms appear, it becomes important to understand the different clinical manifestations of CADASIL. Our case report and review examine several cases to demonstrate different presentations and management strategies of CADASIL. A 52-year-old male with a family history of strokes at a young age from his father and paternal grandfather presented to a neurology clinic for left facial droop and drooling. Brain magnetic resonance imaging showed extensive periventricular and subcortical white matter disease, including the external capsule and subcortical white matter of the temporal lobe. Findings were suggestive of small vessel vasculopathy. A cerebral angiogram showed that all large extra- and intracranial vessels were patent without evidence of aneurysm formation. There was no obvious evidence of beading of the distal intracranial vessels. Cerebrospinal fluid studies were normal. The NOTCH3 mutation was sent to test for CADASIL, which came back positive. The patient was started on aspirin (81 mg) and atorvastatin (20 mg) daily. The patient was counseled on the possibility of having an ischemic or hemorrhagic stroke. Aspirin and atorvastatin were continued, a neuropsychological evaluation was ordered, and CADASIL genetic counseling and testing were offered to him and his children. Over several years, patients developed several strokes and seizures due to infarcts. He also developed intraparenchymal hemorrhage complicated by dysphagia, requiring a feeding tube. Due to his severe physical debility, he was discharged to a nursing home for rehabilitation, where he did not improve with therapy and remained bedbound. He was discharged and sent home with his family. CADASIL can present as a diagnostic challenge due to its common presentation with migraines, transient ischemic attacks, and strokes, with or without risk factors. This unique presentation of CADASIL with facial palsy highlights the importance of emerging atypical presentations and the need for a detailed history of neuroimaging, family history, and personal history of neurovascular events. By accurately diagnosing the condition, patients and families can be counseled on the disease course and genetics. Management requires a multidisciplinary approach with neurology, genetic counseling, physical therapy, psychology, and psychiatry if depression or anxiety is present, with the aim of improving the patient's quality of life.

Mucosa-Associated Lymphoid Tissue Surgeries as a Possible Risk for Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

Background: Inflammatory bowel disease (IBD) is a group of chronic inflammatory gastrointestinal disorders that are caused by genetic susceptibility and environmental factors and affects a significant portion of the global population. The gut-associated lymphoid tissue (GALT) is known to play a crucial role in immune modulation and maintaining gut microbiota balance. Dysbiosis in the latter has a known link to IBD. Therefore, the increasing prevalence of adenoidectomy in children should be explored for its potential association with IBD. The objective of this paper was to assess the association between adenoid tissue removal and the risk of developing Crohn's disease (CD) and ulcerative colitis (UC). Methods: We conducted a pooled meta-analysis to evaluate the extended clinical outcomes in patients who underwent appendicectomy and tonsillectomy compared to those who did not. Our approach involved systematically searching the PubMed database for relevant observational studies written in English. We followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines to collect data from various time periods, and to address the diversity in study results; we employed a random-effects analysis that considered heterogeneity. For outcomes, odds ratios (ORs) were pooled using a random-effects model. Results: Seven studies, out of a total of 114,537, met our inclusion criteria. Our meta-analysis revealed a significant association between appendicectomy and CD (OR: 1.57; 95% confidence interval (CI): 1.01 - 2.43; heterogeneity I2 = 93%). Similarly, we found a significant association between tonsillectomy and CD (OR: 1.93; 95% CI: 0.96 - 3.89; I2 = 62%). However, no significant association was observed between appendicectomy and UC (OR: 0.60; 95% CI: 0.24 - 1.47; I2 = 96%), while a modest association was found between tonsillectomy and UC (OR: 1.24; 95% CI: 1.18 - 1.30; I2 = 0%). Conclusions: In summary, we found that the trend of appendicectomy is linked to higher odds of CD, and tonsillectomy is more likely associated with increased odds for both CD and UC, with a risk of bias present.

Clinical features and management of keratoconjunctivitis associated with inadequate tear drainage.

OBJECTIVE: To describe clinical features and management of toxic keratoconjunctivitis associated with punctal and (or) canaliculus stenosis (toxic soup syndrome). DESIGN: Retrospective observational case series. METHODS: Electronic medical record database search for the keywords "toxic soup syndrome" and retrospective chart review were performed. Thirty-five eyes of 25 patients were seen at a tertiary cornea clinic between January 2017 and December 2021. Sex, age, distance-corrected visual acuity, topical medications, symptoms, clinical signs, and outcomes after medical and surgical interventions were analyzed. The main outcome measured was improvement in ocular surface signs and symptoms after interventions. RESULTS: Overall, 35 eyes of 25 patients with a mean age of 66.8 ± 12.8 years, of which 72% were female, were included. The primary complaint was hyperemia and epiphora in all patients. Rosacea or meibomian gland disease were present in all patients, 7 (28%) had glaucoma, and 7 (28%) developed limbal stem cell deficiency. Twenty-two patients (88%) were using topical medications on presentation. All eyes had either punctal plugs, cauterized puncta, or punctal and (or) canaliculus stenosis. Management of all patients consisted of suspension of all preserved topical medications and institution of some type of anti-inflammatory therapy. Nineteen patients (76%) improved after improvement of lacrimal drainage. One patient with severe resistance in the canaliculus required ongoing preservative-free topical steroids. CONCLUSIONS: Chronic drug-induced or pooled inflammatory mediators causing toxic conjunctivitis may be aggravated by punctal and (or) canaliculus stenosis, leading to toxic soup syndrome. Clearance of punctal obstruction leads to improvement in most patients.

Long-term efficacy of botulinum a toxin for blepharospasm and hemifacial spasm.

OBJECTIVE: To determine whether the duration of relief from symptoms in patients with essential blepharospasm (EB) or hemifacial spasm (HFS) who receive serial treatments with botulinum toxin type A (BtA) changes over the long-term. METHODS: Retrospective longitudinal comparative analysis. The main outcome measure is the mean duration of relief from symptoms after an injection with BtA. Participants included 34 patients who received 30 or more serial BtA treatments for facial dyskinesia (EB or HFS). Repeated measures and linear regression analyses were used to determine trends and the mean duration of relief from symptoms was compared between early (first ten effective treatments) and late (last ten treatments) sessions in each group. RESULTS: In the EB group (18 patients), the mean duration of relief was 13.5 weeks for the early and 11.4 weeks for the late sessions (P = 0.04). In the HFS group (16 patients) the mean duration of relief was 12.4 weeks in both treatment periods (P = 0.91). The duration of relief had a small negative correlation with mean late session BtA dose in the EB group (P = 0.03) but no correlation in the HFS group (P = 0.12). CONCLUSIONS: There was a trend towards a decreased duration of relief from symptoms in patients with EB over the long-term, but no changes for HFS. The treatment remains effective in relieving symptoms and signs for both conditions.

Guidelines for vismodegib in the management of periocular basal cell carcinoma.

OBJECTIVE: The management of advanced basal cell carcinoma (BCC) in the periocular region remains a clinical challenge. Vismodegib (ErivedgeTM) has been approved in 2013 by Health Canada for adult patients with "histologically confirmed metastatic BCC or locally advanced BCC inappropriate for surgery or radiation." An expert consensus was sought to create a standardised approach in the use of this novel treatment. METHODS: Fourteen practicing oculoplastic surgeons across Canada were involved in formulating and reviewing guidelines until consensus was reached. A consultancy meeting was followed by further ratification of guidelines over email. Two voting surveys were performed of the group to objectively assess agreement over each statement within the guidelines. Ratification continued until at least two-thirds of the group agreed on every guideline statement. RESULTS: The guidelines summarize 21 statements in a major and minor criteria format. A multidisciplinary team review is suggested for each patient with the involvement of recommended specialists. The internal survey revealed 100% agreement over 9 statements, 91.7% agreement over 8 statements, 83.3% agreement over 4 statements, and 2 statements had 66.7% and 58.7% agreement each. All statements with less than 91.7% agreement were surveyed again, and they were kept, modified, or removed on the basis of a consensus of over 66.7%. CONCLUSIONS: These guidelines serve to act as a framework for physicians considering vismodegib for the medical management of patients with advanced or metastatic periocular BCC. Future applications, including neoadjuvant uses of the drug, may become apparent through further research.

Surgical Sparing and Pairing Endovascular Interventions for Carotid-Cavernous Fistula: Case Series and Review of the Literature.

BACKGROUND: Carotid-cavernous fistulas (CCFs) are abnormal communications between the arterial and venous circulation within the cavernous sinus, manifesting in myriad neurological and ophthalmological sequalae. In rare circumstances patients' unique vascular anatomies preclude standard endovascular treatment for this pathology, warranting combined surgical and endovascular approaches wherein the cavernous sinus is accessed via superior ophthalmic vein (SOV) exposure, cutdown, and cannulation. CASE DESCRIPTION: We describe 3 cases of CCF treated at our quaternary neurovascular referral center between 2017 and 2019. The first is a 35-year-old man with symptomatic, traumatic, right-sided CCF, treated with endovascular therapy (transarterial detachable balloon placement). The other cases were treated with contrasting surgical and endovascular combined approaches because of unique vascular challenges. The second is a 71-year-old woman with spontaneous right-sided CCF whose carotid sinus was accessed and embolized through a transpalpebral cutdown of the SOV. The third case is a 70-year-old man with symptomatic, spontaneous bilateral CCF. After unsuccessful transarterial and transvenous endovascular approaches, transorbital (intracranial) SOV cutdown and cannulation were performed to embolize the shunting fistula. CONCLUSIONS: Endovascular approaches are well described as the mainstay of treatment for CCF but are not possible for all patients. In circumstances where individual vascular anatomy is not amenable to transarterial or transvenous access or embolization, a combined surgical and endovascular approach may be appropriate. We describe 3 cases that illustrate the spectrum of interventions for CCF, as well as the technical aspects of treatment for 2 patients with complex, direct CCF, using an embolization approach reliant on SOV cutdown and cannulation.

Effective control of SARS-CoV-2 transmission between healthcare workers during a period of diminished community prevalence of COVID-19.

Previously, we showed that 3% (31/1032)of asymptomatic healthcare workers (HCWs) from a large teaching hospital in Cambridge, UK, tested positive for SARS-CoV-2 in April 2020. About 15% (26/169) HCWs with symptoms of coronavirus disease 2019 (COVID-19) also tested positive for SARS-CoV-2 (Rivett et al., 2020). Here, we show that the proportion of both asymptomatic and symptomatic HCWs testing positive for SARS-CoV-2 rapidly declined to near-zero between 25th April and 24th May 2020, corresponding to a decline in patient admissions with COVID-19 during the ongoing UK 'lockdown'. These data demonstrate how infection prevention and control measures including staff testing may help prevent hospitals from becoming independent 'hubs' of SARS-CoV-2 transmission, and illustrate how, with appropriate precautions, organizations in other sectors may be able to resume on-site work safely.

A screening strategy for the detection of sickle cell retinopathy in pediatric patients.

BACKGROUND: Children with sickle cell hemoglobinopathy are referred routinely to detect retinopathy and thereby prevent vision-threatening complications. This study aimed to determine the prevalence and age of onset of clinically significant retinopathy in such patients, and to recommend a screening strategy for ophthalmologists. METHODS: Two hundred sixty-three pediatric sickle cell patients to a maximum age of 18 years during the period of observation were reviewed for the onset of retinopathy, considering the influence of hemoglobin genotype, gender, and the presence of systemic manifestations. RESULTS: Proliferative retinopathy (PR) was rare. Six cases (8.2%) of PR were seen in the SC genotype, 1 case (0.6%) in the SS genotype, and no cases in the SB-Thalassemia genotype. The age of onset of PR was a mean of 13.7 years (median 13, range 9-18) in the SC genotype and 16 years in the SS genotype. Neither gender nor the presence of systemic manifestations was predictive for the prevalence or age of onset of retinopathy. INTERPRETATION: Screening for retinopathy may begin at age 9 years for SC genotype patients and at age 13 years for SS and SB-Thalassemia genotype patients. Serial examinations may be done biennially for eyes with normal findings. Patients with an abnormal examination should undergo fluorescein angiography and be followed as necessary.

Transpupillary thermotherapy in the management of juxtapapillary and parafoveal circumscribed choroidal hemangioma.

BACKGROUND: Circumscribed choroidal hemangioma (CCH) is a rare, vascular tumor that may be associated with formation of subretinal fluid, cystic retinal de-generation, and serous retinal detachment. Studies have suggested that proximity of this tumor to the fovea or optic nerve precludes the use of trans-pupillary thermotherapy (TTT) for treatment. We report our experience using TTT in managing patients with juxtapapillary and parafoveal CCH. METHODS: We reviewed the records of consecutive patients with CCH treated by TTT at Princess Margaret Hospital, Toronto, between November 1999 and March 2003. This resulted in 11 eyes of 11 patients with juxtapapillary or parafoveal tumors. Treatment was delivered via slit lamp using an 810 nm diode laser with 350 to 800 mW, a 3.0 mm spot, and duration range from 5 s to 90 s. Outcome measures were reduction in tumor thickness, resolution of serous fluid, tumor control, visual acuity, and complications of treatment. RESULTS: Mean age of patients was 47.6 years. Symptoms included blurred vision, metamorphopsia, light flashes, and floaters. Macular and optic disk edema, field defect, presence of subretinal fluid, and retinal detachment were noted. At presentation, Snellen visual acuity ranged from 20/70 to hand motions. Mean tumor base diameter was 6.0 mm and tumor thickness at baseline was 3.0 mm. Mean follow-up was 18.0 months. Post-TTT, mean tumor thickness was 2.8 mm. Macular and optic disk edema resolved in the majority of patients. Partial regression of the tumor was noted in 4 cases (36%) and good tumor control in 9 cases (82%). Visual acuity improved in 6 patients (55%). INTERPRETATION: TTT can be effective for treating juxtapapillary and para-foveal CCH. Proximity to the fovea and optic nerve may not be predictive of poor post-treatment visual acuity, although statistical analysis with a larger sample size would more clearly demonstrate a clear advantage.

Effects of sleep-wake state on the genioglossus vs.diaphragm muscle response to CO(2) in rats.

The effects of sleep on the ventilatory responses to hypercapnia have been well described in animals and in humans. In contrast, there is little information for genioglossus (GG) responses to a range of CO(2) stimuli across all sleep-wake states. Given the notion that sleep, especially rapid eye movement (REM) sleep, may cause greater suppression of muscles with both respiratory and nonrespiratory functions, this study tests the hypothesis that GG activity will be differentially affected by sleep-wake states with major suppression in REM sleep despite excitation by CO(2). Seven rats were chronically implanted with electroencephalogram, neck, GG, and diaphragm electrodes, and responses to 0, 1, 3, 5, 7, and 9% CO(2) were recorded. Diaphragm activity and respiratory rate increased with CO(2) (P < 0.001) across sleep-wake states with significant increases at 3-5% CO(2) compared with 0% CO(2) controls (P < 0.05). Phasic GG activity also increased in hypercapnia but required higher CO(2) (7-9%) for significant activation (P < 0.05). Further studies in 15 urethane-anesthetized rats with the vagi intact (n = 6) and cut (n = 9) showed that intact vagi delayed GG recruitment with hypercapnia but did not affect diaphragm responses. In the naturally sleeping rats, we also showed that GG activity was significantly reduced in non-REM and REM sleep (P < 0.04) and was almost abolished in REM even with stimulation by 9% CO(2) (decrease = 80.4% vs. wakefulness). Such major suppression of GG activity in REM, even with significant respiratory stimulation, may explain why obstructive apneas are more common in REM sleep.