Structural Limits of Orbital Compliance and Treatment Options for Pathologic Orbital Pressure

PURPOSE

The integrity of the orbit has a finite structural limit due to the compliance of its tissue. The authors investigate these limits to quantify them and inform the treatment of heightened ocular and orbital pressure.

METHODS

Cadaveric study with 12 orbits being volumized before randomization of treatment for pathologic levels of ocular and orbital pressure. First-line and second-line treatment was chosen randomly (lateral cantholysis, superior septolysis, inferior septolysis). Prior to treatment, IOP, orbital compartment pressure, and axial globe projection was measured after delivery of each 1cc aliquot and surgical treatment.

RESULTS

Orbital compartment pressure and IOP were well correlated (r = 0.99). The average reduction in IOP after treatment averaged a 56.2 mm Hg reduction in IOP. All treatments were statistically equivalent ( p < 0.01). Loss of compliance (P LOC ) was determined when the mean plus 1 standard deviation of change in IOP/ml volume was achieved with simultaneous change in exophthalmometry of <0.5 mm change/ml added volume, indicating an acceleration in pressure in the face of a steady volume. This criteria was met for 11 of 12 orbits. The 12th orbit missed this threshold by 1 mm Hg in IOP. P LOC occurred at an average IOP of 43.0 mm Hg (±5.8 mm Hg, 90% CI) and after an average injection of 13 ml (±1.4 mm, 90% CI). Additionally, lateral cantholysis, superior septolysis, and inferior septolysis were statistically equivalent in reducing IOP after P LOC .

CONCLUSIONS

IOP and orbital compartment pressure are excellent proxies for each other in the authors' model. Orbital compliance is a mathematic phenomenon that can be quantified, as evident in this investigation. P LOC can inform timing for orbital decompressions in the presence of heightened IOP. Multiple procedures can be used to extinguish dangerously high orbital compartment pressure.

Multi-Frequency RF Combined with Intense Pulsed Light Improves Signs and Symptoms of Dry Eye Disease Due to Meibomian Gland Dysfunction

Purpose

To evaluate the efficacy of multi-frequency RF and IPL + MGX combination for treatment of Meibomian Gland Dysfunction (MGD).

Patients and Methods

Eligible subjects had signs and moderate-to-severe symptoms of DED (Dry Eye Disease) due to MGD. Subjects underwent 4 treatments at 2-week intervals. Each treatment consisted of intense pulsed light (IPL) followed by radiofrequency (RF) on the periocular skin, followed by meibomian gland expression (MGX). The main outcome measure was the quality of meibum in 15 meibomian glands along the lower eyelid, using the modified Meibomian Gland Score (mMGS). The main hypothesis was a reduction of mMGS between the baseline (BL) and the follow-up (FU). Other outcome measures, such as symptoms measured with the OSDI (Ocular Surface Disease Index) questionnaire, meibography, non-invasive tear break-up time (NIBUT), and matrix metallopeptidase 9 (MMP-9) levels in tear samples were evaluated as well.

Results

31 subjects completed the FU. Between BL and FU, mMGS decreased from 30.4 (8.5) to 9.3 (9.5) (-69.3%, 95% CI: -55.6% to -82.9%, p<0.0001); OSDI decreased from 63.6 (17.2) to 25.0 (20.6) (-60.7%, 95% CI: -47.8% to -73.5%, p<0.0001); NIBUT did not change (p=0.92). An adjusted model with a historical control was constructed to allow the comparison of these subjects with those treated similarly with IPL+MGX (but without RF) in a different study. This analysis identified that the change in mMGS was larger when RF was included (-20.9 vs -18.3, adjusted p-value (p_adjusted) <0.05). The difference in OSDI change was not significant (-38.1 vs -25.5, p_adjusted = 0.196).

Conclusion

Combination of multi-frequency RF and IPL+MGX improves signs and symptoms of MGD. In comparison to a historical control, improvements were generally larger. A randomized controlled study comparing the combination of RF and IPL+MGX with IPL+MGX alone is required to further elaborate the relative contribution of RF.

Post-operative vision loss: analysis of 587 patients undergoing endoscopic surgery for pituitary macroadenoma

PURPOSE

Vision loss following surgery for pituitary adenoma is poorly described in the literature and cannot be reliably predicted with current prognostic models. Detailed characterization of this population is warranted to further understand the factors that predispose a minority of patients to post-operative vision loss.

MATERIALS AND METHODS

The medical records of 587 patients who underwent endoscopic transsphenoidal surgery at the Mount Sinai Medical Centre between January 2013 and August 2018 were reviewed. Patients who experienced post-operative vision deterioration, defined by reduced visual acuity, worsened VFDs, or new onset of blurry vision, were identified and analysed.

RESULTS

Eleven out of 587 patients who received endoscopic surgery for pituitary adenoma exhibited post-operative vision deterioration. All eleven patients presented with preoperative visual impairment (average duration of 13.1 months) and pre-operative optic chiasm compression. Seven patients experienced visual deterioration within 24 h of surgery. The remaining four patients experienced delayed vision loss within one month of surgery. Six patients had complete blindness in at least one eye, one patient had complete bilateral blindness. Four patients had reduced visual acuity compared with preoperative testing, and four patients reported new-onset blurriness that was not present before surgery. High rates of graft placement (10/11 patients) and opening of the diaphragma sellae (9/11 patients) were found in this series. Four patients had hematomas and four patients had another significant post-operative complication.

CONCLUSIONS

While most patients with pituitary adenoma experience favourable ophthalmological outcomes following endoscopic transsphenoidal surgery, a subset of patients exhibit post-operative vision deterioration. The present study reports surgical and disease features of this population to further our understanding of factors that may underlie vision loss following pituitary adenoma surgery. Graft placement and opening of the diaphragma sellae may be important risk factors in vision loss following ETS and should be an area of future investigation.

Portable hardware & software technologies for addressing ophthalmic health disparities: A systematic review

Vision impairment continues to be a major global problem, as the WHO estimates 2.2 billion people struggling with vision loss or blindness. One billion of these cases, however, can be prevented by expanding diagnostic capabilities. Direct global healthcare costs associated with these conditions totaled $255 billion in 2010, with a rapid upward projection to $294 billion in 2020. Accordingly, WHO proposed 2030 targets to enhance integration and patient-centered vision care by expanding refractive error and cataract worldwide coverage. Due to the limitations in cost and portability of adapted vision screening models, there is a clear need for new, more accessible vision testing tools in vision care. This comparative, systematic review highlights the need for new ophthalmic equipment and approaches while looking at existing and emerging technologies that could expand the capacity for disease identification and access to diagnostic tools. Specifically, the review focuses on portable hardware- and software-centered strategies that can be deployed in remote locations for detection of ophthalmic conditions and refractive error. Advancements in portable hardware, automated software screening tools, and big data-centric analytics, including machine learning, may provide an avenue for improving ophthalmic healthcare.

Intra-Arterial Tissue Plasminogen Activator for Central Retinal Artery Occlusion

Purpose

To investigate the benefit of early intra-arterial tissue plasminogen activator (IAT) for treatment of central retinal artery occlusion (CRAO).

Patients and Methods

Fifteen eyes of 15 patients presenting with acute CRAO were included in this retrospective consecutive interventional case series. Patients were excluded if treatment with IAT was not initiated within 12 hours. The diagnosis was confirmed by an ophthalmologist. IAT was performed via a transfemoral arterial approach. Tissue plasminogen activator (tPA) was infused into the ophthalmic artery in aliquots up to 3mg to a maximum of 22mg. Paracentesis was done at the ophthalmologist's discretion. The primary outcome measure was visual acuity after three weeks. Adverse events were recorded during treatment and follow-up visits.

Results

After treatment with IAT, there was a statistically significant improvement in visual acuity, with a mean change of -0.76 (SD 0.91; range -2.4 to 0.85) logMAR (p=0.006). Vision improved by 3 or more lines in 53%, and of these, the mean Snellen visual acuity improvement was >6 lines. Notably, 4 patients (27%) improved from CF or worse to 20/80 or better. The mean dose of tPA used was 17mg and the mean time to treatment was 8.83 hours (range: 5.5 to 12 hours). There were no statistically significant differences based on time to treatment, dose of tPA, or use of a paracentesis. No major adverse events were recorded.

Conclusion

IAT was safe and showed significant visual improvement in this small uncontrolled study. Larger studies and efforts to decrease time to treatment should be initiated to optimize outcomes.

Orbital invasion by Esthesioneuroblastoma: a comparative case series and review of literature

Purpose: To review the current literature on esthesioneuroblastoma (ENB) as it pertains to clinical features, grading systems, treatment options, and survival.Methods: A literature search in PubMed was performed to include all articles published in English with orbit involving ENB. Only articles that included each patient's demographics, tumor stage, treatment, or survival were included. A total of 22 articles with 104 patients were considered for this literature review. We also present five cases of ENB, all encountered in our health system, between 2010 and 2020.Results: The median age of diagnosis of orbit involving ENB was 44.5 years. Males were more likely affected than females at 72.9%. Common presenting ocular symptoms were visual change (38.1%), periorbital pain (33.3%), and diplopia (14.3%). Common clinical exam findings were proptosis (47.6%), extraocular movement deficit (23.8%), and periorbital edema (19.0%). Twenty-seven patients (77.1%) received surgery, 22 patients (62.9%) received chemotherapy, and 30 patients (85.7%) received radiation therapy as part of their treatment. Median duration of survival was 124.0 months and 5-year overall survival (OS) was 67.1%. Hyams, Kadish, and Dulguerov T-staging showed inconsistent survival prognosis while orbital invasion and lymph node metastasis had worse outcomes. Our five cases exhibited the spectrum of disease processes evidenced above, with four involving the orbit.Conclusions: ENB is a rare sinonasal tumor that can invade the orbit. Because of its rarity, no single staging system appears superior. Resection with radiation therapy has superior survival results while the benefits of chemotherapy are currently unknown.

Quantitative assessment of secondary white matter injury in the visual pathway by pituitary adenomas: a multimodal study at 7-Tesla MRI

OBJECTIVE

The objective of this study was to investigate microstructural damage caused by pituitary macroadenomas by performing probabilistic tractography of the optic tracts and radiations using 7-T diffusion-weighted MRI (DWI). These imaging findings were correlated with neuro-ophthalmological results to assess the utility of ultra-high-field MRI for objective evaluation of damage to the anterior and posterior visual pathways.

METHODS

Probabilistic tractography employing 7-T DWI was used to reconstruct the optic tracts and radiations in 18 patients with adenomas and in 16 healthy volunteers. Optic chiasm compression was found in 66.7% of the patients and visual defects in 61.1%. Diffusion indices were calculated along the projections and correlated with tumor volumes and results from neuro-ophthalmological examinations. Primary visual cortical thicknesses were also assessed.

RESULTS

Fractional anisotropy was reduced by 21.9% in the optic tracts (p < 0.001) and 17.7% in the optic radiations (p < 0.001) in patients with adenomas. Patients showed an 8.5% increase in mean diffusivity of optic radiations compared with healthy controls (p < 0.001). Primary visual cortical thickness was reduced in adenoma patients. Diffusion indices of the visual pathway showed significant correlations with neuro-ophthalmological examination findings.

CONCLUSIONS

Imaging-based quantification of secondary neuronal damage from adenomas strongly correlated with neuro-ophthalmological findings. Diffusion characteristics enabled by ultra-high-field DWI may allow preoperative characterization of visual pathway damage in patients with chiasmatic compression and may inform prognosis for vision recoverability.

Variation of the minimally invasive CDCR technique

Purpose: Traditional (tCDCR) and endoscopic conjunctivodacryocystorhinostomy (eCDCR) are challenging surgical techniques requiring general anesthesia, a facial incision, and a large osteotomy and mucosal flap. Minimally invasive CDCR (miCDCR) techniques eliminate the need for some of the steps in t/eCDCR. Introduced here is a variation of the miCDCR technique using a Naugle-Fleming knurled dilator (NKD) to create the osteotomy and instruments within a central line catheter kit to help easily place or replace a Jones' tube into position within a bony conduit.Methods: This IRB-approved retrospective chart review examined all patients who underwent this miCDCR technique performed by two oculoplastic surgeons at Hamilton Eye Institute at the University of Tennessee Health Sciences Center from 2014 to 2016. Inclusion criteria: need for CDCR (either primary or repeat). Exclusion criteria: loss to follow up prior to six months. Primary endpoints: operative time, incidence of tube migration and complications, and cessation of epiphora.Results: Sixteen patients (nine men, seven women) were reviewed, with three undergoing bilateral procedure, totaling 19 cases. Age range: 47.0 to 84.0 years, average of 66.6 years (SD = 11.1). Ten patients had surgery under local/MAC augmented with IV sedation, and six had general anesthesia (38%). Average operative time was 17.4 min (SD = 10.9). One patient (5%) required revision in the six-month immediate post-operative period because of tube migration. All patients had cessation of epiphora.Conclusions: This procedure can be done safely and quickly without general anesthesia, resulting in a satisfactorily lower rate of tube migration and cessation of epiphora rates.

Primary visual cortical thickness in correlation with visual field defects in patients with pituitary macroadenomas: a structural 7-Tesla retinotopic analysis

OBJECTIVE

Vision loss remains a debilitating complication of pituitary adenomas, although there is considerable variability in visual impairment before and after decompression surgery. Growing evidence suggests secondary damage to remote visual structures may contribute to vision loss in patients with chiasmatic compression. The present study leverages ultrahigh field 7-T MRI to study the retinotopic organization of the primary visual cortex (V1), and correlates visual defects with cortical thinning in V1 to characterize consequences of pituitary adenomas on the posterior visual system.

METHODS

Eight patients (4 males and 4 females, mean age 44.3 years) with pituitary adenomas who exhibited chiasmatic compression and visual field defects, as well as 8 matched healthy controls (4 males and 4 females, mean age 43.3 years), were scanned at 7-T MRI for this prospective study. Whole-brain cortical thickness was calculated using an automated algorithm. A previously published surface-based algorithm was applied to associate the eccentricity and polar angle with each position in V1. Cortical thickness was calculated at each point in the retinotopic organization, and a cortical thickness ratio was generated against matched controls for each point in the visual fields. Patients with adenoma additionally underwent neuroophthalmological examination including 24-2 Humphrey automated visual field perimetry. Pattern deviation (PD) of each point in the visual field, i.e., the deviation in point detection compared with neurologically healthy controls, was correlated with cortical thickness at corresponding polar and eccentricity angles in V1.

RESULTS

Whole-brain cortical thickness was successfully derived for all patients and controls. The mean tumor volume was 19.4 cm3. The median global thickness of V1 did not differ between patients (mean ± SD 2.21 ± 0.12 cm), compared with controls (2.06 ± 0.13 cm, p > 0.05). Surface morphometry-based retinotopic maps revealed that all 8 patients with adenoma showed a significant positive correlation between PD and V1 thickness ratios (r values ranged from 0.31 to 0.53, p < 0.05). Mixed-procedure analysis revealed that PD = -8.0719 + 5.5873*[Median V1 Thickness Ratio].

CONCLUSIONS

All 8 patients showed significant positive correlations between V1 thickness and visual defect. These findings provide retinotopic maps of localized V1 cortical neurodegeneration spatially corresponding to impairments in the visual field. These results further characterize changes in the posterior visual pathway associated with chiasmatic compression, and may prove useful in the neuroophthalmological workup for patients with pituitary macroadenoma.

Measuring degeneration of the lateral geniculate nuclei from pituitary adenoma compression detected by 7T ultra-high field MRI: a method for predicting vision recovery following surgical decompression of the optic chiasm

OBJECTIVE

Predicting vision recovery following surgical decompression of the optic chiasm in pituitary adenoma patients remains a clinical challenge, as there is significant variability in postoperative visual function that remains unreliably explained by current prognostic factors. Available literature inadequately characterizes alterations in adenoma patients involving the lateral geniculate nucleus (LGN). This study examined the association of LGN degeneration with chiasmatic compression as well as with the retinal nerve fiber layer (RNFL), pattern standard deviation (PSD), mean deviation (MD), and postoperative vision recovery. PSD is the degree of difference between the measured visual field pattern and the normal pattern ("hill") of vision, and MD is the average of the difference from the age-adjusted normal value.

METHODS

A prospective study of 27 pituitary adenoma patients and 27 matched healthy controls was conducted. Participants were scanned on a 7T ultra-high field MRI scanner, and 3 independent readers measured the LGN at its maximum cross-sectional area on coronal T1-weighted MPRAGE imaging. Readers were blinded to diagnosis and to each other's measurements. Neuro-ophthalmological data, including RNFL thickness, MD, and PSD, were acquired for 12 patients, and postoperative visual function data were collected on patients who underwent surgical chiasmal decompression. LGN areas were compared using two-tailed t-tests.

RESULTS

The average LGN cross-sectional area of adenoma patients was significantly smaller than that of controls (13.8 vs 19.2 mm2, p < 0.0001). The average LGN cross-sectional area correlated with MD (r = 0.67, p = 0.04), PSD (r = -0.62, p = 0.02), and RNFL thickness (r = 0.75, p = 0.02). The LGN cross-sectional area in adenoma patients with chiasm compression was 26.6% smaller than in patients without compression (p = 0.009). The average tumor volume was 7902.7 mm3. Patients with preoperative vision impairment showed 29.4% smaller LGN cross-sectional areas than patients without deficits (p = 0.003). Patients who experienced improved postoperative vision had LGN cross-sectional areas that were 40.8% larger than those of patients without postoperative improvement (p = 0.007).

CONCLUSIONS

The authors demonstrate novel in vivo evidence of LGN volume loss in pituitary adenoma patients and correlate imaging results with neuro-ophthalmology findings and postoperative vision recovery. Morphometric changes to the LGN may reflect anterograde transsynaptic degeneration. These findings indicate that LGN degeneration may be a marker of optic apparatus injury from chiasm compression, and measurement of LGN volume loss may be useful in predicting vision recovery following adenoma resection.

Central retinal artery occlusion secondary to Barlow's disease

PURPOSE

To report a rare case of isolated, unilateral CRAO in a young patient with mitral valve prolapse secondary to Barlow's disease.

OBSERVATIONS

A 29-year-old woman with history of premature ventricular contractions and cardiac ablation presented to the emergency room after sudden onset painless visual loss in her left eye (OS). Her vision was 20/20 in her right eye and hand motion in the left. Fundus exam demonstrated a central retinal artery occlusion (CRAO) OS. Computerized tomography of head and neck were unremarkable. She underwent cerebral angiogram and local intra-arterial thrombolysis. Her vision remained stable post-procedure, with marked APD and stable fundus examination. Her cardiac work-up revealed a left atrial mass with calcified mitral valve, and small atrial septal defect. Rheumatologic, hematologic, and auto-immune work-up were unremarkable. She underwent resection of the mass with repair of mitral valve and ASD closure. Surgical pathology was compatible with diagnosis of Barlow's disease, a cause of mitral valve prolapse. The patient underwent intravitreal injection of anti-VEGF therapy at one month follow-up, with vision stable at hand motion and without neovascularization on subsequent evaluation.

CONCLUSIONS

In young patients presenting with CRAO, aggressive work-up for systemic disease or embolic source must be undertaken to avoid future sequelae.

Immunoglobulin G4-related sclerosing disease with orbital inflammation in a 12-year-old girl

Immunoglobulin G4-related sclerosing disease is a rare but potentially debilitating cause of orbital inflammation, with a predilection for older males. We report the case of a 12-year-old African girl with immunoglobulin G4-related sclerosing disease, including possible extraorbital involvement. Because of an escalating severity of illness leading to oculomotor nerve palsy and cavernous sinus thrombosis that was resistant to steroids, systemic immunosuppressive therapy with rituximab was used to achieve disease remission. The diagnosis was histologically confirmed with a tissue biopsy.

Bruton's tyrosine kinase is essential for human B cell tolerance

Most polyreactive and antinuclear antibodies are removed from the human antibody repertoire during B cell development. To elucidate how B cell receptor (BCR) signaling may regulate human B cell tolerance, we tested the specificity of recombinant antibodies from single peripheral B cells isolated from patients suffering from X-linked agammaglobulinemia (XLA). These patients carry mutations in the Bruton's tyrosine kinase (BTK) gene that encode an essential BCR signaling component. We find that in the absence of Btk, peripheral B cells show a distinct antibody repertoire consistent with extensive secondary V(D)J recombination. Nevertheless, XLA B cells are enriched in autoreactive clones. Our results demonstrate that Btk is essential in regulating thresholds for human B cell tolerance.