Outcomes of surgical resection of sphenoid-orbital meningiomas with Sonopet ultrasonic aspirator.

Purpose: Surgical resection is the mainstay of treatment for spheno-orbital meningiomas. The Sonopet® is an ultrasonic aspirator device that provides several advantages over the traditional standard suction techniques and bone drill, including decreased collateral soft tissue damage, more precise bone removal and a clearer operative field. The purpose of the study was to examine the treatment outcomes of Sonopet®-assisted resection of spheno-orbital meningiomas.Methods: A retrospective chart review was conducted in seven patients with spheno-orbital meningioma in a single institution who underwent surgical resection with the Sonopet®. Pre-operative and post-operative data included the assessment of visual acuity, relative afferent pupillary defect (RAPD), Ishihara score, proptosis, fundus examination, computerised visual fields and the presence or absence of diplopia, headache, and other neuro-ophthalmic complications.Results: Nine Sonopet®-assisted procedures were performed on seven patients. Post-operatively, 89% of cases had stabilization or improvement of visual acuity and colour vision, whilst 29% had improved visual fields with the remainder being stable. Proptosis improved in all patients. Five of nine cases (44%) had new post-operative cranial nerve palsies, of which 75% were transient. One patient had tumour recurrence after 14 months, requiring further tumour resection and radiotherapy.Conclusion: Sonopet®-assisted resection of spheno-orbital meningiomas has comparable outcomes of visual improvement and complication rates to traditional resection techniques. Longer periods of post-operative observation and follow-up are recommended to observe long-term benefits.

Safety Profile of Slit-Lamp-Delivered Retinal Laser Photobiomodulation.

Purpose: Photobiomodulation (PBM) refers to therapeutic irradiation of tissue with low-energy, 630- to 1000-nm wavelength light. An increasing body of evidence supports a beneficial effect of PBM in retinal disorders. To date, most studies have utilized light-emitting diode irradiation sources. Slit-lamp-mounted retinal lasers produce a coherent beam that can be delivered with precisely defined dosages and predetermined target area; however, the use of retinal lasers raises safety concerns that warrant investigation prior to clinical application. In this study, we determined safe dosages of laser-delivered PBM to the retina. Methods: A custom-designed, slit-lamp-delivered, 670-nm, red/near-infrared laser was used to administer a range of irradiances to healthy pigmented and non-pigmented rat retinas. The effects of PBM on various functional and structural parameters of the retina were evaluated utilizing a combination of electroretinography, Spectral Domain Optical Coherence (SD-OCT), fluorescein angiography, histology and immunohistochemistry. Results: In non-pigmented rats, no adverse events were identified at any irradiances up to 500 mW/cm2. In pigmented rats, no adverse events were identified at irradiances of 25 or 100 mW/cm2; however, approximately one-third of rats that received 500 mW/cm2 displayed very localized photoreceptor damage in the peripapillary region, typically adjacent to the optic nerve head. Conclusions: A safety threshold exists for laser-delivered PBM in pigmented retinas and was identified as 500 mW/cm2 irradiance; therefore, caution should be exercised in the dosage of laser-delivered PBM administered to pigmented retinas. Translational Relevance: This study provides important data necessary for clinical translation of laser-delivered PBM for retinal diseases.

Preclinical and clinical studies of photobiomodulation therapy for macular oedema.

AIMS/HYPOTHESIS: Diabetic macular oedema (DME) is the leading cause of visual impairment in people with diabetes. Intravitreal injections of vascular endothelial growth factor inhibitors or corticosteroids prevent loss of vision by reducing DME, but the injections must be given frequently and usually for years. Here we report laboratory and clinical studies on the safety and efficacy of 670 nm photobiomodulation (PBM) for treatment of centre-involving DME. METHODS: The therapeutic effect of PBM delivered via a light-emitting diode (LED) device was tested in transgenic mice in which induced Müller cell disruption led to photoreceptor degeneration and retinal vascular leakage. We also developed a purpose-built 670 nm retinal laser for PBM to treat DME in humans. The effect of laser-delivered PBM on improving mitochondrial function and protecting against oxidative stress was studied in cultured rat Müller cells and its safety was studied in pigmented and non-pigmented rat eyes. We then used the retinal laser to perform PBM in an open-label, dose-escalation Phase IIa clinical trial involving 21 patients with centre-involving DME. Patients received 12 sessions of PBM over 5 weeks for 90 s per treatment at a setting of 25, 100 or 200 mW/cm2 for the three sequential cohorts of 6-8 patients each. Patients were recruited from the Sydney Eye Hospital, over the age of 18 and had centre-involving DME with central macular thickness (CMT) of >300 µm with visual acuity of 75-35 Log minimum angle of resolution (logMAR) letters (Snellen visual acuity equivalent of 20/30-20/200). The objective of this trial was to assess the safety and efficacy of laser-delivered PBM at 2 and 6 months. The primary efficacy outcome was change in CMT at 2 and 6 months. RESULTS: LED-delivered PBM enhanced photoreceptor mitochondrial membrane potential, protected Müller cells and photoreceptors from damage and reduced retinal vascular leakage resulting from induced Müller cell disruption in transgenic mice. PBM delivered via the retinal laser enhanced mitochondrial function and protected against oxidative stress in cultured Müller cells. Laser-delivered PBM did not damage the retina in pigmented rat eyes at 100 mW/cm2. The completed clinical trial found a significant reduction in CMT at 2 months by 59 ± 46 µm (p = 0.03 at 200 mW/cm2) and significant reduction at all three settings at 6 months (25 mW/cm2: 53 ± 24 µm, p = 0.04; 100 mW/cm2: 129 ± 51 µm, p < 0.01; 200 mW/cm2: 114 ± 60 µm, p < 0.01). Laser-delivered PBM was well tolerated in humans at settings up to 200 mW/cm2 with no significant side effects. CONCLUSIONS/INTERPRETATION: PBM results in anatomical improvement of DME over 6 months and may represent a safe and non-invasive treatment. Further testing is warranted in randomised clinical trials. TRIAL REGISTRATION: ClinicalTrials.gov NCT02181400 Graphical abstract.

Spatio-temporal characterization of S- and M/L-cone degeneration in the Rd1 mouse model of retinitis pigmentosa.

BACKGROUND: The Pde6brd1 (Rd1) mouse is widely used as a murine model for human retinitis pigmentosa. Understanding the spatio-temporal patterns of cone degeneration is important for evaluating potential treatments. In the present study we performed a systematic characterization of the spatio-temporal patterns of S- and M/L-opsin+ cone outer segment and cell body degeneration in Rd1 mice, described the distribution and proportion of dual cones in Rd1 retinas, and examined the kinetics of microglial activation during the period of cone degeneration. RESULTS: Outer segments of S- and M/L-cones degenerated far more rapidly than their somas. Loss of both S- and M/L-opsin+ outer segments was fundamentally complete by P21 in the central retina, and 90% complete by P45 in the peripheral retina. In comparison, degeneration of S- and M/L-opsin+ cell bodies proceeded at a slower rate. There was a marked hemispheric asymmetry in the rate of S-opsin+ and M/L-opsin+ cell body degeneration. M/L-opsin+ cones were more resilient to degeneration in the superior retina, whilst S-opsin+ cones were relatively preserved in the inferior retina. In addition, cone outer segment and cell body degeneration occurred far more rapidly in the central than the peripheral retina. At P14, the superior retina comprised a minority of genuine S-cones with a much greater complement of genuine M/L-opsin cones and dual cones, whilst the other three retinal quadrants had broadly similar numbers of genuine S-cones, genuine M/L-cones and dual cones. At P60, approximately 50% of surviving cones in the superior, nasal and temporal quadrants were dual cones. In contrast, the inferior peripheral retina at P60 contained almost exclusively genuine S-cones with a tiny minority of dual cones. Microglial number and activity were stimulated during rod breakdown, remained relatively high during cone outer segment degeneration and loss of cone somas in the central retina, and decreased thereafter in the period coincident with slow degeneration of cone cell bodies in the peripheral retina. CONCLUSION: The results of the present study provide valuable insights into cone degeneration in the Rd1 mouse, substantiating and extending conclusions drawn from earlier studies.

Effectiveness of endoscopic versus external surgical approaches in the treatment of orbital complications of rhinosinusitis: a systematic review protocol.

OBJECTIVE: This review aims to investigate and compare the effectiveness of endoscopic drainage techniques against external drainage techniques for the treatment of orbital and subperiosteal abscesses as a complication of rhinosinusitis. INTRODUCTION: Transnasal endoscopic drainage and external drainage techniques have been used in the management of subperiosteal orbital abscesses secondary to rhinosinusitis. Each of these approaches has its own advantages and disadvantages, with extensive literature describing each technique separately. However, there is a lack of guidance in the studies on assessing and comparing the safety, effectiveness and suitability of these techniques. This review aims to compare the effectiveness of these techniques based on measuring outcomes in the literature such as: length of postoperative hospital stay, rate of revision surgery and complication rates. INCLUSION CRITERIA: Eligible studies will include people of all ages diagnosed with subperiosteal abscess, orbital abscess or cavernous sinus thrombosis (Chandler stages III-V) secondary to rhinosinusitis disease, who have also undergone drainage via either an endoscopic approach, external approach or combined surgical approach. METHODS: A comprehensive search of both published and unpublished literature will be performed to uncover studies meeting the inclusion criteria. Reference lists of studies included in final analyses will also be manually searched and subject matter experts contacted to investigate other sources of literature. Two reviewers will screen studies and a third reviewer will resolve disagreements. Studies will, where possible, be pooled in statistical meta-analysis with heterogeneity of data being assessed using the standard Chi-squared and I tests.

PRIMARY LASER PHOTOCOAGULATION FOR THE TREATMENT OF GIANT RETINAL TEARS.

PURPOSE: Laser photocoagulation has typically been used as an adjunctive treatment to pars planar vitrectomy in achieving retinopexy in the treatment of giant retinal tears. We describe three cases where the giant retinal tear was treated with laser photocoagulation alone. METHODS: A retrospective case report of three patients with giant retinal tears who underwent primary laser photocoagulation. RESULTS: Fundus examination up to 18 months after primary laser photocoagulation of all 3 patients revealed a flat attached retina and no significant complications. CONCLUSION: Laser photocoagulation alone is a viable alternative treatment for giant retinal tears in the absence of significant subretinal fluid.

Retinal pigment epithelium in the pathogenesis of age-related macular degeneration and photobiomodulation as a potential therapy?

The retinal pigment epithelium (RPE) comprises a monolayer of cells located between the neuroretina and the choriocapillaries. The RPE serves several important functions in the eye: formation of the blood-retinal barrier, protection of the retina from oxidative stress, nutrient delivery and waste disposal, ionic homeostasis, phagocytosis of photoreceptor outer segments, synthesis and release of growth factors, reisomerization of all-trans-retinal during the visual cycle, and establishment of ocular immune privilege. Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. Dysfunction of the RPE has been associated with the pathogenesis of AMD in relation to increased oxidative stress, mitochondrial destabilization and complement dysregulation. Photobiomodulation or near infrared light therapy which refers to non-invasive irradiation of tissue with light in the far-red to near-infrared light spectrum (630-1000 nm), is an intervention that specifically targets key mechanisms of RPE dysfunction that are implicated in AMD pathogenesis. The current evidence for the efficacy of photobiomodulation in AMD is poor but its safety profile and proposed mechanisms of action motivate further research as a novel therapy for AMD.

Review of the ophthalmic manifestations of gout and uric acid crystal deposition.

Gout is a clinical disorder that is characterized by the deposition of monosodium urate crystals (MSU) in joints and tendons, usually in the presence of prolonged hyperuricaemia. Following an asymptomatic phase of hyperuricaemia, gout usually presents as acute monoarthritis followed by periods of remission and exacerbation. Conjunctival hyperaemia and subconjunctival haemorrhage exacerbated by purine intake are two of the more common manifestations that may go unrecognized. Other ocular and adnexal structures can be affected by urate crystal deposition and associated inflammation, with potentially vision-threatening consequences; however, ocular manifestations of gout are rare and may have been over-reported in the older literature, but our understanding of the clinic-pathological features of ocular urate deposits remains limited.