The role of topical N-acetylcysteine in ocular therapeutics

N-acetylcysteine (NAC) was first discovered as a mucolytic agent in 1960. We investigate the role of topical NAC in ocular therapeutics, including its mechanism of action, current applications, and adverse effects. A systematic search of peer-reviewed articles identified 106 references including in vitro, in vivo and clinical studies on the use of NAC in the treatment of ocular diseases. NAC can be synthetically manufactured, and its mechanisms of action include mucolysis, scavenging hydroxyl radicals, and modulation of inflammatory cascades. These unique properties contribute to the diverse applications of NAC, including its steroid-sparing potential. NAC has been used topically in the treatment of corneal wounds, chemical injuries, keratitis, dry eye disease and meibomian gland dysfunction. The clinical benefits of NAC are evident over a wide range of concentrations, the most common being 5-10% topical NAC applied four times daily. Adverse effects such as corneal necrosis are rare, but have been reported with higher doses. NAC also has potential applications in laser epithelial keratomileusis, diabetic eye disease, retinitis pigmentosa, senile nuclear cataracts, macular degeneration, and cigarette smoke-induced corneal damage. Recently, chitosan-NAC has been used as a nanocarrier for the topical administration of medications to the ocular surface. Owing to its potent antioxidant, anti-inflammatory and mucolytic properties, topical NAC has had extensive use in the treatment of ocular pathology.

Dysphagia rates in single- and multiple-level anterior cervical discectomy and fusion surgery: a meta-analysis

Background

To conduct a meta-analysis to assess dysphagia complicating single-level and multiple-level (≥2) anterior cervical discectomy and fusion (ACDF) surgery.

Methods

Electronic searches were performed using four electronic databases from their inception to December 2017. Relevant studies reporting the rate of dysphagia as an endpoint for patients undergoing ACDF for degenerative disease, myelopathy, cervical canal stenosis or ossification of the posterior longitudinal ligament were identified according to prior inclusion and exclusion criteria. Statistical analysis was performed using a fixed effect model. P-scores were used to rank the levels of ACDF based on the rate of dysphagia. I² was used to explore heterogeneity.

Results

Ten studies were identified and included in the systematic review and meta-analysis, with a total of 4,018 patients identified; 2,362 patients underwent single-level ACDF, while 1,656 underwent multiple level (≥2 ACDF). The mean age ranged from 49.45 to 57.77 years. Mean follow-up time ranged from 2 days to 27.3 months. Overall, meta-analysis demonstrated a statistically significant higher dysphagia rate for multiple-level ACDF (6.6%) than for single-level ACDF (4%) (P heterogeneity =0.151, OR =1.42, 95% CI: 1.05-1.91, I²=32%).

Conclusions

Dysphagia is a relatively common complication in the early postoperative period following ACDF and may cause patients significant discomfort and distress. This meta-analysis demonstrates a higher rate of dysphagia with multiple-level ACDF than with single-level ACDF at a period of 12-24 months.

Recurrent laryngeal nerve injury following single- and multiple-level anterior cervical discectomy and fusion: a meta-analysis

Background

Recurrent laryngeal nerve (RLN) palsy is a common and potentially debilitating complication of anterior cervical discectomy and fusion (ACDF). The relationship between the risk of RLN palsy and the number of operated levels remains unclear, and no previous studies address potential differences between short- and long-term RLN injury following ACDF.

Methods

Electronic searches of PubMed, Cochrane, ScienceDirect and Google Scholar were performed from database inception to June 2019. Relevant studies reporting the rate of RLN palsy for patients undergoing ACDF for cervical spine pathology were identified according to predetermined inclusion and exclusion criteria. Statistical analysis was performed using fixed effects and random effects modelling. I2 and Q statistics were used to explore heterogeneity.

Results

Five studies with a total of 3,514 patients were included in the meta-analysis. The incidence of RLN palsy was found to be 1.2%. There were no statistically significant differences in the rate of RLN palsy between multiple- and single-level ACDF [odds ratio (OR) 1.04; 95% CI: 0.56-1.95; P=0.891, I2=0%]. There were similarly no statistically significant differences in RLN palsy rates for multiple- and single-level ACDF when patients were stratified based on length of follow-up of less than or greater than 12 months.

Conclusions

This analysis suggests that there is no statistically significant association between the number of ACDF operative levels and the risk of short- or long-term RLN palsy.

Ventilatory support in Stevens-Johnson syndrome and toxic epidermal necrolysis: a systematic review and meta-analysis

Introduction: Stevens-Johnson syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are blistering cutaneous disorders that often manifest with epidermal and mucosal necrosis. In extreme cases, the upper or bronchial airways are threatened, necessitating intubation and mechanical ventilation. This systematic review and meta-analysis examines the prevalence of mechanical ventilation (MV) in patients with SJS or TENS, despite maximal medical therapy, and additionally aims to identify the risk factors associated with this requirement.Materials and methods: A systematic review of the literature was performed using the PRISMA guidelines and meta-analysis of proportions.Results: Six articles were included, with pooled total of 18648 cases. The weighted prevalence of MV was 27.5% (95%CI 17.8-39.9%). The need for MV was more closely associated with TEN, compared to SJS (OR 4.40, 95%CI 2.73-7.10, I²=48%, p<.00001.) Risk factors associated with the need for MV included bacteremia (OR 5.02, 95%CI 2.87-8.79, I²=0%, p<.00001), shock/organ failure on admission (OR 261.99, 95%CI 21.88-3137, I²=71, p<.0001), total body surface area (TBSA) >30% (OR 4.47, 95%CI 1.41-14.20, I²=71, p=.01.)Conclusion: Limited published evidence with significant heterogeneity exists within the literature regarding the need for MV in SJS and TEN. Greater cutaneous involvement, and more critically unwell patients appear more likely to require MV.

Elective neck dissection versus observation for early-stage oral squamous cell carcinoma: Systematic review and meta-analysis

INTRODUCTION

Oral squamous cell carcinoma (OSCC) is the seventh most common cancer globally, and has been identified as a growing health concern. This study aims to evaluate the current literature comparing elective neck dissection to observation in the treatment of early-stage tongue SCC, focusing on nodal recurrence, overall survival, disease specific survival statistics from randomised controlled trials comparing the two interventions.

METHODS

Systematic review and meta-analysis was conducted according to PRISMA guidelines. The odds ratio (OR) was used as a summary statistic.

RESULTS

From 8 studies, there was a total of 372 cases of recurrence, 98 (15.1%) in END group and 274 (41.5%) in the Observation group. There was a significantly lower rate of recurrence in the END group compared to observation (OR 0.25, 95% CI 0.16-0.39, I² = 54%, P < 0.00001). END was associated with higher overall survival rates when compared with observation (OR 1.95, 95% CI 1.40-2.73, I² = 14%, P < 0.0001). END was also associated with higher disease-specific survival compared with observation (OR 1.88, 95% CI 1.21-2.93), I² = 47%, P = 0.005), with no significant heterogeneity noted.

CONCLUSIONS

END was associated with significantly lower recurrence rates and higher overall and disease-specific survival compared to a conservative observation approach in early-stage oral SCC with clinically N0 neck.

Recurrence rates following surgical excision of periocular basal cell carcinomas: systematic review and meta-analysis

Background: Basal cell carcinomas (BCCs) remain one of the most common non-melanoma skin cancers (NMSCs). Surgical options include primary excision with predetermined margins, frozen section controlled excision, and Mohs micrographic surgery (MMS). There is no randomized study comparing recurrence rates between different surgical techniques for periocular BCCs.Methods: A meta-analysis of proportions was conducted for recurrence rates. Meta-regression was used for subgroup analysis to compare results in those undergoing MMS versus FSE or paraffin controlled sections (WLE).Results: The pooled recurrence rate for periocular BCCs excised via MMS was 2.9% (95% CI 1.9-4.4%) over an average of 48.8 ± 14.9 months. The pooled recurrence rate for FSE was 1.9% (95% CI 1.9-2.4%) over an average of 70.7 ± 48.0 months. By comparison, the pooled recurrence rate following WLE was 5.9% (95% CI 3.9-8.9%) over an average of 49.2 ± 29.3 months. Meta-regression demonstrated that the recurrence rate for WLE was significantly higher compared to MMS and FSE techniques (p<.001) but similar for MMS and FSE (p=.65).Conclusions: Our results highlight the importance of intraoperative margin assessment in the management of BCCs in order to reduce recurrence. These factors should be taken into consideration in the workup and management of patients with periocular BCCs.

Total intravenous versus inhalational anesthesia in endoscopic sinus surgery: A meta-analysis

OBJECTIVE

Achieving optimal intraoperative surgical field visibility and minimizing blood loss are two important parameters in endoscopic sinus surgery (ESS). The aim of this meta-analysis was to compare two total intravenous anesthesia (TIVA) and inhalational anesthesia (IA) to determine if either conferred superior outcomes of these and other parameters based on randomized control trials (RCTs) only.

METHODS

The recommended Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines were followed, and searches of electronic databases from inception to September 2018 identified 157 articles for screening. Data were extracted and analyzed using meta-analysis of proportions.

RESULTS

In total, we identified 15 RCTs that satisfied our selection criteria. There were 828 ESS cases described, with 391 (47%) and 437 (53%) being managed by TIVA and IA, respectively. Pooled analysis demonstrated significantly superior visibility scores for TIVA compared to IA based on 10-point grading scores (P = 0.049, visual analog scale; P = 0.009, Wormald scale) and 5-point grading scores (P = 0.002, Boezaart scale). Blood loss was significantly less following TIVA (P = 0.003), with no significant difference in intraoperative heart rate (P = 0.70) or mean arterial pressure (P = 0.96). Additionally, duration of surgery (P = 0.16) and anesthesia (P = 0.39) were comparable between the two approaches.

CONCLUSION

This meta-analysis indicates that TIVA has the potential to confer superior surgical field visibility and reduce intraoperative blood loss compared to IA in ESS. Currently, there are significant heterogeneity concerns in this meta-analysis, which temper any expectations that either approach is absolutely superior to the other. Caution should be exercised when interpreting these results until further validation can be achieved.

LEVEL OF EVIDENCE

1A Laryngoscope, 130:575-583, 2020.

Changing biological disease modifying treatment for paediatric uveitis in the real world

IMPORTANCE

Paediatric uveitis is a severe sight-threatening uveitis due to disease progression and treatment failure. Biological agents are a promising new treatment. This study provides real-world data on their use from Sydney, Australia.

BACKGROUND

Traditionally corticosteroids and non-biological immunosuppressive agents were used to treat paediatric uveitis, often with poor outcomes.

DESIGN

Retrospective, chart review over an 8-year period at a tertiary referral eye hospital.

PARTICIPANTS

A total of 27 paediatric uveitis patients treated with biological agents.

METHODS

Chart review of demographic data and treatment outcomes.

MAIN OUTCOME MEASURES

Treatment efficacy (corticosteroid-sparing effect, topical steroid cessation/reduction, reduction in systemic-steroid sparing agents, change in intraocular inflammation, visual acuity and central macular thickness); treatment failure; and adverse events. Data were collected at biological initiation, 6 weeks, 6 months and 12 months.

RESULTS

Biological therapy over 1 year was effective with prednisolone dose reduced to <5 mg/day in five of six patients (83%), number of systemic steroid-sparing agents was reduced to ≤1 in two of four patients (50%) and cessation of topical steroid achieved in 12/41 of eyes (29%). Improvement of anterior chamber cells by two grades occurred in 20/25 eyes (80%), improvement of logMAR to ≤0.3 occurred in 12/18 eyes (67%) and macular oedema decreased in 4/5 eyes (80%). Treatment failure occurred in six eyes (13.01%) and five patients (18.5%) developed an adverse reaction.

CONCLUSIONS AND RELEVANCE

Biological therapy was effective in paediatric patients with uveitis. Intraocular inflammation improved with maintained visual acuity, systemic corticosteroid dose decreased and there was a low frequency of adverse events.

Comparing the outcomes of severe versus mild/moderate ptosis using closed posterior levator advancement

Traditionally, posterior eyelid surgical approaches such as Müller's muscle-conjunctival resection (MMCR) have been utilised with great success for mild cases of ptosis, with external levator approaches having been used for more severe cases of ptosis. We present a new technique which we label closed posterior levator advancement (CPLA) for the correction of all grades of ptosis. This article is a retrospective cohort study reviewing patients with mild, moderate, and severe ptosis over a 6-year period, treated by a single surgeon using CPLA. Minimum follow-up was 3 months. Patients with good levator function (levator palpebrae superioris (LPS) function >10 mm) without concomitant procedures were subdivided based on margin-to-reflex-distance-1 (MRD1) into mild-to-moderate ptosis (MRD1 > 1.5 mm) and severe ptosis (MRD1 ≤ 1.5 mm) cohorts. The outcome measures were preoperative and postoperative MRD1, lid contour, intereye symmetry, complications, and revision rates. 393 eyes of 313 patients were identified. 91 eyes in the mild-to-moderate cohort had a preoperative MRD1 of 2.38 mm, and 302 eyes in the severe cohort had a preoperative MRD1 of 0.27 mm. Postoperatively, MRD1 was 3.86 mm and 3.49 mm, respectively. There were no significant complications in both cohorts, and revision rates were 3.3% (3 of 91 eyes) in the mild-to-moderate and 2% (6 of 302 eyes) in the severe cohorts. Upper-eyelid contour was satisfactory in 98.2% of eyes, and 97.5% intereye symmetry within 1 mm was observed. Our results show an effective correction of all ptosis grades with satisfactory cosmetic outcomes and low complication and revision rates.

Orbital Cellulitis and Secondary Angle Closure: A Rare Presentation of Choroidal Melanoma

We describe a case of choroidal melanoma initially presenting with orbital cellulitis, fulminant conjunctival swelling, and secondary angle closure. Despite treatment with intravenous antibiotics, the patient's condition did not improve. With further investigations including ultrasound scan and magnetic resonance imaging, a high-density lesion was found within the globe. Characteristic imaging findings suggested a malignant origin and the lesion was found to be a melanoma on histopathological analysis.

Full blood count as an ancillary test to support the diagnosis of giant cell arteritis

BACKGROUND

Temporal artery biopsy is considered the investigation of choice to diagnose definitively giant cell arteritis (GCA) in patients with compatible symptoms. However it is invasive and not completely sensitive. Serum markers, particularly erythrocyte sedimentation rate (ESR), can be supportive, but are not definitive in individual cases.

AIMS

To investigate whether indices derived from the full blood count, including neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were associated with a positive biopsy in patients with suspected GCA.

METHODS

The clinical and pathological details of 537 patients undergoing temporal artery biopsy at our institution from 1992 to 2015 were reviewed.

RESULTS

In univariate analysis high platelets (odds ratio (OR) 4.44, P < 0.001), NLR (OR 1.81, P = 0.02), PLR (OR 3.25, P < 0.001), C-reactive protein (CRP) (OR 3.00, P < 0.001), ESR (OR 3.62, P < 0.001) and increased age (OR 1.03, P = 0.006) were strongly associated with a positive biopsy. In multivariate modelling only high platelets (P < 0.001) and ESR (P = 0.049) maintained significance.

CONCLUSIONS

We conclude that the presence of thrombocytosis and high NLR, PLR, ESR and CRP can all be used clinically to support the diagnosis of GCA prior to biopsy. Of particular note, in multivariate modelling the presence of thrombocytosis is a stronger predictor of a positive temporal artery biopsy than ESR. Therefore, careful consideration of the findings in a full blood count can be used to predict the likelihood of a positive temporal artery biopsy in patients with suspected GCA.

Outcomes of Primary Total Knee Arthroplasty in Patients With Parkinson's Disease

BACKGROUND

Parkinson's disease is a degenerative disorder causing rigidity, bradykinesia, and tremor of the motor system. There is significant paucity of evidence regarding whether total knee arthroplasty (TKA) is of benefit in patients with both Parkinson's disease and osteoarthritis. We aimed to compare outcomes and complications of TKA between patients with Parkinson's disease and those without.

METHODS

A cohort of 43 knees from 35 patients with Parkinson's disease who received a primary TKA between January 2004 and December 2015 were retrospectively extracted from a private clinical database held by 2 surgeons and compared to an age and gender-matched control group of 50 knees from 41 patients. TKAs were performed by 2 surgeons at 1 tertiary private hospital.The indication for TKA in both groups was osteoarthritis. Difference between preoperative and 1-year range of movement (ROM) and 12-point Oxford Knee Score (OKS) was assessed using Student's unpaired t-test. Postoperative complications and revision procedures were also recorded during the follow-up period. The minimal clinically important difference for OKS at 1-year follow-up, defined as improvement of ≥6, was also assessed.

RESULTS

In the Parkinson's group, mean ROM improvement was 14° (100° preoperatively to 114° at 12 months), compared to 12° in the control group (102°-114°, respectively). Mean OKS improvement was 15 in the Parkinson's group (23 preoperatively to 38 at 12 months) compared to 17 in the control group (23 and 40, respectively.) No significant difference was identified between the 2 groups for either ROM (P = .96) or OKS (P = .45.) All Parkinson's patients achieved the minimal clinically important difference at 1-year follow-up. There were no mortalities during the study follow-up period and no significant difference in complication rates between the 2 groups (P = .41).

CONCLUSION

Parkinson's disease was not associated with poorer functional outcomes or increased complications compared to controls in our study. We suggest that Parkinson's disease is not an absolute contraindication to TKA.

Anti-vascular endothelial growth factor for neovascular age-related macular degeneration: a meta-analysis of randomized controlled trials

BACKGROUND

To evaluate the relative efficacy and safety of anti-vascular endothelial growth factor (anti-VEGF) agents for the treatment of neovascular age-related macular degeneration (AMD).

METHODS

Systematic literature review identifying RCTs comparing anti-VEGF agents to another treatment published before June 2016. Efficacy assessed by mean change in best corrected visual acuity (BCVA) and central macular thickness (CMT) from baseline at up to 2 years followup. Safety assessed by proportions of patients with death, arteriothrombotic and venous thrombotic events, and at least one serious systemic adverse event at up to 2 years of followup.

RESULTS

Fifteen RCTs selected for meta-analysis (8320 patients). Two trials compared pegaptanib, and three trials compared ranibizumab versus control. Eight trials compared bevacizumab with ranibizumab. Two trials compared aflibercept with ranibizumab. There were no significant differences between bevacizumab and ranibizumab for BCVA at 1 or 2 years (weighted mean difference = - 0.57, 95% CI - 1.55 to 0.41, P = 0.25 and weighted mean difference = - 0.76, 95% CI - 2.25 to 0.73, P = 0.32, respectively). Ranibizumab was more effective in reducing CMT at 1 year (weighted mean difference = 4.49, 95% CI 1.13 to 7.84, P = 0.009). Risk ratios comparing rates of serious systemic adverse events at 1 and 2 years were slightly out of favour for bevacizumab. Aflibercept compared with ranibizumab demonstrated similar mean change in BCVA, reduction in CMT, and safety at 1 year.

CONCLUSIONS

Bevacizumab and ranibizumab had equivalent efficacy for BCVA, while ranibizumab had greater reduction in CMT and less rate of serious systemic adverse events. Aflibercept and ranibizumab had comparable efficacy for BCVA and CMT. This provides information to balance comparable effects on vision and risk of adverse events between anti-VEGF agents.

Prospective study of Centurion® versus Infiniti® phacoemulsification systems: surgical and visual outcomes

AIM

To evaluate surgical outcomes (SOs) and visual outcomes (VOs) in cataract surgery comparing the Centurion^® phacoemulsification system (CPS) with the Infiniti^® phacoemulsification system (IPS).

METHODS

Prospective, consecutive study in a single-site private practice. Totally 412 patients undergoing cataract surgery with either the CPS using the 30-degree balanced^® tip (n=207) or the IPS using the 30-degree Kelman^® tip (n=205). Intraoperative and postoperative outcomes were documented prospectively up to one month follow-up. Nuclear sclerosis (NS) grade, cumulated dissipated energy (CDE), preoperative corrected distance visual acuity (CDVA), and CDVA at one month were recorded.

RESULTS

CDE was 13.50% less in the whole CPS compared with the whole IPS subcohort. In eyes with NS grade III or greater, CDE was 28.87% less with CPS (n=70) compared with IPS (n=44) (P=0.010). Surgical complications were not statistically different between the two subcohorts (P=0.083), but in the one case of vitreous loss using the CPS, CDVA of 6/4 was achieved at one month. The mean CDVAs (VOs) at one month for NS grade III and above cataracts were -0.17 logMAR (6/4.5) in the CPS and -0.15 logMAR (6/4.5) in the IPS subcohort respectively (P=0.033).

CONCLUSION

CDE is 28.87% less, and VOs are significantly improved, in denser cataracts in the CPS compared with the IPS. The authors recommend the CPS for cases with denser nuclei.

Adult Degenerative Lumbar Scoliosis

Adult degenerative lumbar scoliosis is a 3-dimensional deformity defined as a coronal deviation of greater than 10°. It causes significant pain and disability in the elderly. With the aging of the population, the incidence of adult degenerative lumbar scoliosis will continue to increase. During the past decade, advancements in surgical techniques and instrumentation have changed the management of adult spinal deformity and led to improved long-term outcomes. In this article, the authors provide a comprehensive review of the pathophysiology, diagnosis, and management of adult degenerative lumbar scoliosis. [Orthopedics. 2017; 40(6):e930-e939.].

Value of temporal artery biopsy length in diagnosing giant cell arteritis

BACKGROUND

Giant cell arteritis (GCA) is considered an ophthalmological emergency with severe sight and life-threatening sequelae. Temporal artery biopsy (TAB) is the current gold standard for the diagnosis of GCA; however, the required length of biopsy remains an issue of contention in the literature.

METHODS

Retrospective case-control study of a consecutive cohort of 545 patients who had undergone TABs across five hospitals between 1 January 1992 and 1 January 2016. In patients with either positive or negative TABs, we collected age, sex, biopsy length and erythrocyte sedimentation rate (ESR).

RESULTS

A total of 538 patients were included in the final analysis. Of these, 23.4% of TABs were positive, with the average length being 17.6 mm. There was a significant difference in means for positive (19.9 mm) and negative (16.8 mm) biopsies (P = 0.0009). Each millimetre increase in TAB length increased the odds of a positive TAB by 3.4% (P = 0.024). A cut-off point of ≥15 mm increased the odds of a positive TAB by 2.25 compared with a TAB <15 mm (P = 0.003). We also found that ESR ≥50 mm/h was a very strong predictor for a positive TAB result (P < 0.0001).

CONCLUSION

Biopsy length and ESR were significant predictors of a pathological diagnosis of GCA. We also found that the optimal length threshold predictive for GCA was 15 mm in order to avoid a false-negative GCA diagnosis. Although TAB remains the gold standard for diagnosis, clinicians should refer to both clinical and pathological data to guide their management.

Transneuronal degeneration of thalamic neurons following deafferentation: quantitative studies using [3H]thymidine autoradiography

Transneuronal degeneration of thalamic neurons following partial deafferentation was studied using [3H]thymidine autoradiography. Timed-pregnant female Sprague-Dawley rats received systemic injections of [3H]thymidine on embryonic day (E) 13, 14 and/or 15. On the day of birth, pups were anesthetized by hypothermia and subjected to unilateral enucleation, unilateral removal of the inferior colliculus or sham lesion. Animals were sacrificed on postnatal day 10 or 30 and the brains processed for autoradiography. Material from sham-lesioned animals demonstrates that neurons destined for the dorsal lateral geniculate nucleus (LGd) undergo final mitoses on E13, 14 and 15. Neurons in the ventral medial geniculate nucleus (MGv) undergo final mitoses on E13 and 14. Thirty days following neonatal unilateral eye removal, the contralateral LGd displays a loss of approximately 30-35% of [3H]thymidine labeled neurons. Neonatal unilateral removal of the inferior colliculus results in a loss of approximately 30-40% of labeled neurons in MGv. For both LGd and MGv, shorter survival times reveal less severe cell loss. Late generated (E15) LGd neurons show less severe loss following enucleation than do earlier generated neurons. These results document the degree of cell loss in sensory thalamic nuclei following deafferentation and demonstrate that [3H]thymidine autoradiography provides a useful quantitative method for assessing anterograde transneuronal cell loss in targeted populations of neurons in the developing central nervous system.