Cysts and tumours of the iris: Diagnostic tools and key management considerations-A review.

The iris is a unique structure, with exquisite variations in colour and form. Pathological changes, specifically including iris cysts and tumours are relatively uncommon, difficult to diagnose, and yet potentially blinding or life-threatening. Based on a comprehensive literature review, with highly illustrated key case examples, this report aims to guide the clinician in filtering the differential diagnoses of iris cysts and tumours. Evaluation is in the context of key diagnostic clinical tools and management considerations. Diagnostic imaging techniques include serial anterior segment photography, ultrasound, anterior segment optical coherence tomography, and iris fluorescein angiography, however, the roles of computerised topography and magnetic resonance imaging are also considered in this review. Management includes categorisation in terms of solid iris tumours (melanocytic vs. non-melanocytic), or iris cysts (primary vs. secondary) that may be usefully differentiated by clinical assessment, avoiding more invasive interventions. Cystic lesions are generally benign, although implantation cysts in particular cause significant complications and surgical challenges. Most solid tumours are melanocytic and also typically benign. However, in larger lesions, rapid growth, symptoms and complications more likely indicate malignancy, requiring further investigation.

An optimized 3T MRI scan protocol to assess iris melanoma with subsequent histopathological verification - A prospective study.

INTRODUCTION: Magnetic resonance imaging (MRI) has demonstrated high levels of tissue contrast, accuracy and reproducibility in evaluating posterior uveal melanoma. Owing to smaller size, the role of MRI in detecting and characterising iris melanoma has not yet been explored. AIMS: To develop a protocol to image iris melanoma and describe the MRI characteristics of histopathological-confirmed iris melanoma. MATERIALS AND METHODS: An optimised MRI protocol, using a 3T MRI scanner and a 32-channel head coil, was developed to image iris tumours. A prospective, single-centre, 12-month study was conducted on all patients with lesions suspicious for iris melanoma. All patients were offered an MRI scan in addition to the standardised clinical procedures. Image quality comparison was made with existing clinical investigations. Iris melanoma characteristics on MRI are described. RESULTS: A successful optimised MRI scan protocol was developed that was able to detect and characterise iris melanoma. One normal participant and five patients with subsequent histopathological-confirmed iris melanoma (n = 6) were recruited. Four patients completed the full MRI sequence. All iris melanoma were detected on at least one T1- or T2-weighted images. When compared to the vitreous, all iris melanomas demonstrated hyper-intensity on T1-weighted images and hypo-intensity on T2-weighted images. On T1-mapping, T1-values of iris melanoma demonstrated an inverse relationship with the degree of tumour pigmentation. CONCLUSIONS: This study highlights an optimised, easily reproducible MRI scan protocol to image iris melanoma. Numerous MR imaging characteristics of iris melanoma are reported for the first time and a potential non-invasive tumour biomarker is described.

Adult stem cells in the eye: Identification, characterisation, and therapeutic application in ocular regeneration - A review.

Adult stem cells, present in various parts of the human body, are undifferentiated cells that can proliferate and differentiate to replace dying cells within tissues. Stem cells have specifically been identified in the cornea, trabecular meshwork, crystalline lens, iris, ciliary body, retina, choroid, sclera, conjunctiva, eyelid, lacrimal gland, and orbital fat. The identification of ocular stem cells broadens the potential therapeutic strategies for untreatable eye diseases. Currently, stem cell transplantation for corneal and conjunctival diseases remains the most common stem cell-based therapy in ocular clinical management. Lens epithelial stem cells have been applied in the treatment of paediatric cataracts. Several early-phase clinical trials for corneal and retinal regeneration using ocular stem cells are also underway. Extensive preclinical studies using ocular stem cells have been conducted, showing encouraging outcomes. Ocular stem cells currently demonstrate great promise in potential treatments of eye diseases. In this review, we focus on the identification, characterisation, and therapeutic application of adult stem cells in the eye.

Keratoconus Management in the Community: A Survey of Optometrists.

OBJECTIVES: Defining the patterns of practice and referral criteria of optometrists within New Zealand to investigate the diagnosis and management of keratoconus. METHODS: Optometrists recruited through the New Zealand Association of Optometrists, Cornea and Contact Lens Society of New Zealand, and private practices were invited to complete an anonymous survey. RESULTS: Responses were received from 168 optometrists (representing 20.0% of the optometrist population). Half (48%) of optometrists had ≥15 years of experience, and 22% prescribed soft contact lenses daily, whereas only 6.4% prescribed rigid gas-permeable (RGP) lenses daily. The main barriers to prescribing RGPs were experience with fitting, low market demand, and patient discomfort. When referring to an ophthalmologist, 41% reported referring on progression of corneal parameters, 27% on initial diagnosis, 21% at no set time, and 10% with a reduction in visual acuity. Most optometrists (64%) would refer for possible surgery when visual acuity dropped between 6/9 and 6/12. Optometrists with greater experience were more likely to prescribe RGP lenses and co-manage patients with ophthalmologists. Ownership of a corneal imaging unit suggested an increased likelihood of prescribing RGP lenses but did not alter referral patterns. CONCLUSION: This survey provides an overview of current practice and highlights the importance of optometrists in the diagnosis and management of keratoconus. There was a significant discrepancy in keratoconus management, regarding optical correction modality and referral criteria for ophthalmology review. Further interdisciplinary work is required between optometry and ophthalmology to standardize referral guidelines and enhance visual outcomes.

Tumor Profiles of Late Presentation Uveal Ring Melanoma With Novel Characteristics - A Case Series.

Purpose: The purpose of this study was to investigate the clinical features, tumor characteristics, including histopathology and cytogenetic analysis, and management of patients with uveal ring melanoma in New Zealand. Methods: A retrospective review was conducted on all uveal melanoma cases treated in a single national oncology center in New Zealand. The study period was from January 1, 2013 to December 31, 2022 (10 years). Written consent was obtained from all patients included in this case series. Results: Uveal ring melanoma of ciliary body origin (n = 4) comprised 0.7% of all uveal melanomas (n = 571). Ethnicity distribution was three patients of New Zealand European ancestry and one patient of Chinese/Pasifika ancestry. Three patients (75%) were symptomatic at presentation (spontaneous hyphema, glaucoma, and cataract), whereas one was asymptomatic but subsequently developed painful refractory glaucoma. All eyes underwent enucleation. Three eyes had primary iris biopsies with subsequent enucleation for refractory glaucoma and pain and one eye underwent primary enucleation. All cases demonstrated malignant tumor characteristics including diffuse 270 to 360-degree ciliary body ring growth pattern, epithelioid-cell type and presence of either BAP-1 expression loss or gain of MYC gene. Two cases (50%) developed distant organ metastasis - liver, parotid gland, and breast. Of those, one patient was deceased at the time of follow-up whereas one had completed treatment for metastases. Conclusions: Uveal ring melanoma is a rare tumor that is highly invasive and malignant. When detected, prompt definitive treatment should be advocated, and patient counselling should be given regarding the high risk of developing a painful, blind eye with increased risk of metastasis in the absence of treatment.

The Burden of Histologically Confirmed Uveal Melanoma in Aotearoa-New Zealand: A 21-year Review of the National Cancer Registry.

PURPOSE: The burden of uveal melanoma (UM) in Aotearoa-New Zealand (NZ), a country with the highest global burden of cutaneous melanoma, is unknown. This first, large-scale study of UM in NZ investigates survival and risks of mortality in histologically confirmed UM. METHODS: Deidentified epidemiological data on histologically confirmed UM between January 1, 2000, and December 31, 2020, were extracted from the NZ Cancer Registry. The main outcome measures were patient demographics, tumor characteristics, all-cause versus disease-specific survival, and risks of mortality. RESULTS: Histologically confirmed UM constituted 1.5% (n=703) of all-body site melanomas in NZ (n=47,997). UM predominantly affected Europeans (95%), followed by NZ indigenous Maori (4%), Asians (<1%), and Pacific Peoples (<1%), with no eye or sex predilection. Three hundred eighteen (45%) were deceased at follow-up. Of the deceased, 50% died from UM. The 1-, 5-, and 10-year survival from all-cause mortality was 94%, 68%, and 51%, and disease-specific survival was 97%, 79%, and 71%, respectively. Increasing age at UM diagnosis (>60 y), UM arising from nonspecified sites, and mixed cell UM were associated with an increased risk of disease-specific mortality. No difference in disease-specific mortality was found between sex and ethnicity on multivariate and competing risks analysis. CONCLUSIONS: Despite the government-funded public eye care and increasing research and awareness on UM globally, the burden of UM in the 21st century in NZ remains comparable to global studies. We continue to observe an earlier presentation of UM in non-European cohorts, particularly in our Maori population, and further studies on UM in NZ are warranted.

Conjunctival Melanoma in Aotearoa-New Zealand: A 21-Year Analysis of Incidence and Survival.

PURPOSE: Conjunctival melanoma (CM) is a rare and aggressive malignancy. Global studies demonstrate increased burden of disease in countries with high rates of cutaneous melanoma. There are currently no reports on CM incidence, trends, or survival within Aotearoa-New Zealand (NZ), a country with the highest global rates of cutaneous melanoma, which this study aims to address. DESIGN: This was a retrospective review using the national cancer registry. METHODS: Data on histologically confirmed CM diagnosed between January 1, 2000, and December 31, 2020, were obtained from the NZ Cancer Registry. Cases were identified using the International Classification of Disease, 10th edition (ICD-10) codes. Primary outcome measures were age-standardized incidence, trends, and survival. RESULTS: A total of 68 CM cases were identified. There was a preponderance for females (n=40, 58.8%) and CM predominantly affected European patients (n=63, 92.6%). Median follow-up was 5.0 years [interquartile range (IQR)=2.4-9.9 y] and the median age at diagnosis was 68.5 years (IQR=57.0-79.0 y), with non-Europeans presenting at a significantly younger age [-17.3 y (95% CI: -31.3 to -3.2), P =0.019] than Europeans. The annual age-adjusted incidence(±SD) was 0.6±0.2 cases per million population per year with a stable incidence trend over 21 years. All-cause mortality was found in 28 cases (41.2%) and the median time to death was 3.76 years (IQR=2.1-5.7 y). Five-year all-cause survival and disease-specific survival was 69% and 90%, respectively. CONCLUSIONS: This is the first report on CM incidence, trends, and mortality in NZ. The CM burden is in line with European and North American data, despite NZ having the highest rate of cutaneous melanoma. The incidence remained stable over 2 decades.

Repeatability of Scheimpflug based corneal tomography parameters in advanced keratoconus with thin corneas.

OBJECTIVE: To determine the repeatability limits of corneal tomography parameters in patients with advanced and moderately thin keratoconic corneas to assist in planning thickness-based procedural interventions. METHODS: Prospective, single-centre, repeatability study. Three tomography scans using the Pentacam AXL were obtained from patients with keratoconus with thinnest corneal thickness (TCT) ≦400 µm (sub-400 group) and compared to those with TCT = 450-500 µm (450-plus group). Eyes with previous crosslinking, intraocular surgery, or acute corneal hydrops were excluded. Eyes were age and gender-matched. The within-subject standard deviations for flat keratometry (K1), steep keratometry (K2), maximal keratometry (Kmax), astigmatism and TCT were used to calculate respective repeatability limits (r). Intra-class correlation coefficients (ICC) were also analysed. RESULTS: The sub-400 group comprised 114 eyes from 114 participants, and the 450-plus group comprised 114 eyes from 114 participants. In the sub-400 group, TCT was amongst the least repeatable parameters (33.92 µm; ICC 0.96), compared with the 450-plus group (14.32 µm; ICC 0.99, p < 0.01). In the sub-400 group, K1 and K2 of the anterior surface were the most repeatable parameters (r 3.79 and 3.22 respectively; ICC 0.97 and 0.98 respectively) compared with the 450-plus group (r 1.17 and 0.92 respectively; and ICC 0.98 and 0.99 respectively, p < 0.01). CONCLUSIONS: The repeatability of corneal tomography measurements is significantly reduced in sub-400 keratoconic corneas when compared to 450-plus corneas. Repeatability limits should be carefully considered when surgical interventions are planned for such patients.

Progression of keratoconus in children and adolescents.

AIMS: To evaluate the rates of keratoconus progression and associated factors in eyes of children and adolescents. METHODS: Retrospective, cohort study of individuals ≤18 years old at the time of keratoconus diagnosis and with at least 6 months of follow-up. Corneal tomography was performed using an Orbscan tomographer (Bausch & Lomb, Rochester, New York, USA) to determine whether progression occurred. Tomographic progression of keratoconus was defined as a change in any of the investigated parameters (keratometry values, KMAX, maximum anterior or posterior elevation, central pachymetry, thinnest pachymetry) beyond the limits of repeatability. RESULTS: 148 eyes of 106 patients with a mean age of 15.2±2.5 years were studied over a mean follow-up period of 2.9±2.2 years. The overall rate of tomographic progression was 77.0% (114/148 eyes). Eyes that progressed had more advanced disease at presentation with higher anterior curvature (KMAX55.4±6.3 vs 52.2±5.4 dioptres; p<0.01), posterior elevation (108.2±40.9 vs 86.3±35.6 µm; p<0.01) and lower central pachymetry measurements (442.1±56.7 vs 454.4±47.5 µm; p=0.01). Age at presentation, gender, atopy, documented eye rubbing, ethnicity and duration of follow-up were not significantly associated with progression in the multivariate analyses. There was a higher rate of bilateral progression if at least one eye had severe keratoconus (73.9%) compared with no severe keratoconus in either eye (36.8%; p=0.03). CONCLUSIONS: A high rate of progression was identified in keratoconic eyes of children and adolescents. More advanced disease at initial presentation may increase the risk of further keratoconus progression.

Iris melanocytic tumours in New Zealand/Aotearoa: presentation, management and outcome in a high UV exposure environment.

BACKGROUND/OBJECTIVES: Iris melanoma, a rare intraocular malignancy, represents the smallest subgroup of uveal melanoma. This first, comprehensive study of iris melanocytic lesions in the high ultraviolet environment in New Zealand/ Aotearoa (NZ) examines diagnosis, management and outcomes. SUBJECTS/METHODS: Retrospective study of iris melanocytic tumours referred to tertiary referral centres in Auckland, NZ, over 20 years (1999-2018). Data analysed include demographics, tumour characteristics, histology, genetic analyses, treatment modalities, recurrence, metastasis, 5-year and overall survival. RESULTS: Cohort (N = 51) was predominantly NZ European (98.0%) with no indigenous Maori, or Pasifika. Median age at presentation was 58 years. Tumours involved a median of two clock hours of iris. The posterior tumour margin extended to the anterior chamber angle in 22 patients (45.8%). Management included initial observation 54.9%, iridectomy/excision biopsy 29.4%, irido-cyclectomy 7.8%, plaque radiotherapy 7.8%, proton beam radiotherapy 7.8%, and ultimately enucleation 17.6%. Histology was performed in 19 cases (37%) with 16 confirmed melanomas (84%). Mean follow-up 4.2 years with median visual acuity of 6/7.5 two years post intervention. Melanoma-related metastasis and mortality occurred in two cases with five-year melanoma-related mortality of 2.0%. CONCLUSION: In a climate with high ultraviolet exposure iris melanocytic tumours occurred almost exclusively in NZ Europeans, however, the majority of cases were category T1, possibly reflecting early diagnosis in the NZ health system. Nonetheless, >50% underwent surgery or radiotherapy, often utilising more than one modality. A high index of suspicion and early referral of iris melanocytic lesions should be considered in regions with high UV exposure.

Corneal Nerve Changes Observed by In Vivo Confocal Microscopy in Patients Receiving Oxaliplatin for Colorectal Cancer: The COCO Study.

An objective method of early identification of people at risk of chemotherapy-induced peripheral neuropathy is needed to minimize long-term toxicity and maximize dose intensity. The aims of the study were to observe corneal nerve microstructure and corneal sensitivity changes and peripheral neuropathy in patients receiving oxaliplatin, and to determine its association with corneal parameters at different stages of treatment and assess utility as non-invasive markers to detect and monitor peripheral neuropathy. Twenty-three patients scheduled to receive oxaliplatin chemotherapy with intravenous 5-FU for gastro-intestinal cancer were recruited and followed up with for 12 months. Ocular examinations including corneal and retinal evaluations, alongside peripheral neuropathy assessment, were performed. The corneal nerve density did not show significant change after chemotherapy when measured with a widely used semi-automated program or an automated analysis technique. Macula and optic nerve function did not change during or after oxaliplatin chemotherapy. However, the corneal nerve density modestly correlated with clinical peripheral neuropathy after 20 weeks of chemotherapy (r = 0.61, p = 0.01) when peripheral neuropathy is typical most profound, and corneal nerve sensitivity correlated with neuropathy at 12 (r = 0.55, p = 0.01) and 20 weeks (r = 0.64, p = 0.006). In conclusion, corneal changes detected on confocal microscopy show moderate association with peripheral neuropathy, indicating their potential to identify the development of oxaliplatin-induced peripheral neuropathy. However, further studies are required to confirm these findings.

Endocapsular artificial iris implantation for iris defects: Reducing symptoms, restoring visual function and improving cosmesis.

BACKGROUND: To investigate repair of iris defects by endocapsular implantation of an artificial iris, in relation to visual outcomes, safety profile and patient satisfaction. METHODS: Retrospective, consecutive case series from Greenlane tertiary teaching hospital and Eye Institute, Auckland, New Zealand. Medical records of patients implanted with an endocapsular artificial iris were reviewed and followed for minimum 3 months. Patient characteristics, surgical management, clinical outcomes and subjective responses were recorded. RESULTS: Nineteen artificial irises were implanted in 18 patients. Etiologies were iris melanotic lesion excision (73.7%), trauma (10.5%), congenital aniridia (10.5%) and Urrets-Zavalia syndrome (5.3%). During postoperative follow-up [14.1 ± 12.4 months (range: 3 to 59 months)], best corrected visual acuity (BCVA) and intraocular pressure (IOP) did not change significantly [BCVA, 0.23 logarithm of the minimum angle of resolution (logMAR) (20/32 Snellen) preoperatively vs. 0.18 logMAR postoperatively (20/25 Snellen) (Z = -0.222, p = 0.824); IOP, 15 mmHg preoperatively vs. 17 mmHg postoperatively (Z = 1.377, p = 0.1447)]. Mild or self-limiting complications included: elevated IOP (42.1%), cystoid macular oedema (15.8%); persisting postoperative uveitis (15.8%) and minor vaulting of the prosthesis (15.7%). Moderate or severe complications included significant vaulting of prosthesis requiring surgical revision (5.3%) and a single eye (5.3%) with trabeculectomy and corneal graft failure. 94.4% of patients were very satisfied with the cosmesis and would be highly likely to have the procedure again. CONCLUSIONS: This study confirms that endocapsular insertion of an artificial iris is typically associated with good functional and cosmetic results and a relatively low risk of significant complications.

Corneal Confocal Microscopy in Type 1 Diabetes Mellitus: A Six-Year Longitudinal Study.

Purpose: The current study describes corneal nerve morphology using in vivo confocal microscopy (IVCM) in patients with type 1 diabetes (T1D) who were followed up for 6 years, and it examines the relationship between corneal parameters and metabolic control of glucose and peripheral neuropathy. Methods: Sixty-two participants (37 with T1D and 25 control participants) were assessed in 2011 and 2017. Participants with bilateral cataract surgery or controls who developed diabetes were excluded. All underwent HbA1c, IVCM, and central corneal sensitivity measurements at both time points in the eye previously examined. A modified total neuropathy score was obtained. Results: Participants were age and sex matched. The mean duration of diabetes was 32.1 ± 12.0 years at the follow-up visit. The sub-basal nerve density in participants with T1D was lower than that of the controls and did not change (mean ± SD, 11.07 ± 4.0 to 11.41 ± 4.1 mm/mm2; P = 0.71), but it showed a marginal change in controls (19.5 ± 3.7 to 21.63 ± 4.03 mm/mm2; P = 0.06). The corneal sensitivity in T1D did not change (1.3 ± 1.5 to 1.4 ± 1.0 mbar; P = 0.8), and it declined in the controls (0.2 ± 0.3 to 0.6 ± 0.3 mbar; P < 0.001). There were no significant changes in HbA1c (60.5 ± 12.5 to 61.6 ± 13.7 mmol/mol) or in modified total neuropathy scores (2.4 ± 3.2 to 3.4 ± 3.8; P = 0.2). Conclusions: The corneal nerve damage and poorer corneal sensitivity reported in the patients with T1D did not change and displayed improvement with good glycemic control. Translational Relevance: The corneal nerve changes may be of more value in those with a shorter duration of diabetes for the timely prediction of at-risk individuals likely to develop peripheral neuropathy, particularly in type 1 diabetes.

Changing Trends in Corneal Transplantation in Aotearoa/New Zealand, 1991 to 2020: Effects of Population Growth, Cataract Surgery, Endothelial Keratoplasty, and Corneal Cross-Linking for Keratoconus.

PURPOSE: The purpose of this study was to identify trends in the primary indication for keratoplasty in New Zealand/Aotearoa (NZ) after significant population growth, increase in the number of cataract surgeries per population, widespread adoption of endothelial keratoplasty, and introduction of corneal cross-linking for keratoconus. METHODS: Statistical analysis of the New Zealand National Eye Bank's prospective database of all keratoplasties was performed between January 1991 and January 2020. Indications for keratoplasty were isolated for the primary diagnosis. RESULTS: In total, 6840 corneas were transplanted with mean 236 ± 57.5 transplants/year, increasing from 2.55 to 6.06 per 100,000 NZ population/year. Over the past decade, the number of transplant recipients aged 60 years or older has increased and recipients aged 20 to 39 years have plateaued. In 2019, for the first time, regraft became the most common indication (30.9%), followed by keratoconus (27.9%) and corneal dystrophy (18.8%), with a steady decline in bullous keratopathy. Proportions of the keratoplasty technique changed dramatically: penetrating keratoplasty fell from 91.4% in 2006 to 55.0% in 2019, Descemet's stripping endothelial keratoplasty increased from 0% to 29.5%, anterior lamellar keratoplasty increased from 2.5% to 5.7%, and Descemet membrane endothelial keratoplasty increased from 0% to 9.1%. CONCLUSIONS: Keratoplasty trends in Aotearoa/NZ have changed considerably because of the evolution of phacoemulsification and keratoplasty techniques. Unlike proportions observed overseas, NZ still performs penetrating keratoplasties in over half of all transplants. Corneal cross-linking may be having an early effect of reducing keratoplasty rates for keratoconus.

Case Series: Different Presentations of Iris Melanoma-Potential Masquerade of Benign and Malignant.

SIGNIFICANCE: Iris melanoma and iris nevi can be challenging to distinguish clinically. This case series provides unique insight into the rare condition and variable clinical presentations of iris melanoma. PURPOSE: This study aimed to highlight the varying clinical presentations of iris melanoma and to demonstrate the overlapping features of melanoma and nevi. CASE REPORTS: This case series includes five patients of varying age and sex who presented to clinic with pigmented iris lesions. These five patients have differing timeline to presentation and very different clinical presentations of their lesions. Clinical evaluation was based around the established "ABDCEF" guide for the assessment of malignant risk in iris lesions. The presentation of each lesion is discussed in relation to this guide and the experienced clinician's clinical suspicion of malignancy. When comparing the clinical suspicion with histological analysis, after biopsy, the result may be unexpected. Notably, initially benign nevi may transform into melanoma over time. These five cases were managed on an individual basis because the management and prognosis of iris melanomas vary significantly. Importantly, iris melanotic lesions have variable metastatic risk based on cytology and genetic predisposition. Informed consent was obtained from all the patients, institutional approval was obtained, and no identifiable health information is included in this case series. CONCLUSIONS: When presented with a pigmented iris lesion, clinicians must be vigilant with regular monitoring and have a low threshold for biopsy in pigmented lesions of high clinical suspicion.

The Enigma of Environmental Factors in Keratoconus.

Keratoconus is an ectatic disorder with highly complex and varied causes including genetic variations and environmental factors. Its prevalence varies widely between regions and countries. Many environmental factors have been proposed to be associated with keratoconus, but the interpretation of their individual contributions is difficult due to the presence of many confounding variables. The current literature was reviewed to evaluate the strength of the associations and the causative effects of environmental factors on keratoconus. Ethnicity and consanguinity have been revealed as important determinants for geographical variations in keratoconus prevalence. Eye rubbing, atopy, floppy eyelid syndrome, contact lens wear, pregnancy, and thyroid hormone disturbances are likely associated with keratoconus. The first 4 factors can induce ocular surface inflammation, matrix metalloproteinase release, and keratocyte apoptosis, consistent with the postulated etiology of keratoconus. The associations of keratoconus with UV exposure, cigarette smoking, personality, and sex were less convincing once confounding factors were considered. Future studies powered for multivariate analysis of factors discussed will hopefully shed light on what is truly important in the development and progression of keratoconus.

Microdroplet and spatter contamination during phacoemulsification cataract surgery in the era of COVID-19.

IMPORTANCE: Determine phacoemulsification cataract surgery risk in a Covid-19 era. BACKGROUND: SARS-CoV-2 (Covid-19) transmission via microdroplet and aerosol-generating procedures presents risk to medical professionals. As the most common elective surgical procedure performed globally; determining contamination risk from phacoemulsification cataract surgery may guide personal protection equipment use. DESIGN: Pilot study involving phacoemulsification cataract surgery on enucleated porcine eyes by experienced ophthalmologists in an ophthalmic operating theatre. PARTICIPANTS: Two ophthalmic surgical teams. METHODS: Standardized phacoemulsification of porcine eyes by two ophthalmologists accompanied by an assistant. Fluorescein incorporated into phacoemulsification irrigation fluid identifying microdroplets and spatter. Contamination documented using a single-lens reflex camera with a 532 nm narrow bandpass (fluorescein) filter, in-conjunction with a wide-field blue light and flat horizontal laser beam (wavelength 532 nm). Quantitative image analysis using Image-J software. MAIN OUTCOME MEASURES: Microdroplet and spatter contamination from cataract phacoemulsification. RESULTS: With phacoemulsification instruments fully within the eye, spatter contamination was limited to <10 cm. Insertion and removal of the phacoemulsification needle and bimanual irrigation/aspiration, with irrigation active generated spatter on the surgeons' gloves and gown extending to >16 cm below the neckline in surgeon 1 and > 5.5 cm below the neckline of surgeon 2. A small tear in the phacoemulsification irrigation sleeve, presented a worse-case scenario the greatest spatter. No contamination above the surgeons' neckline nor contamination of assistant occurred. CONCLUSIONS AND RELEVANCE: Cataract phacoemulsification generates microdroplets and spatter. Until further studies on SARS-CoV-2 transmission via microdroplets or aerosolisation of ocular fluid are reported, this pilot study only supports standard personal protective equipment.

Characteristics of Platelet Lysate Compared to Autologous and Allogeneic Serum Eye Drops.

Purpose: Platelet lysate produced from platelet apheresis components has been proposed as an alternative to serum eye drops in the treatment of ocular surface disease. This study compared the effects of platelet lysate and serum on growth factor, cytokine and nanoparticle concentrations, and corneal epithelial cell proliferation. Methods: The concentration of growth factors, cytokines, and nanoparticles in platelet lysates manufactured from either fresh or expired platelet apheresis concentrations collected with Trima or Haemonetics technology was characterized and compared with those of allogeneic, autologous, and fetal calf serum. The ability to promote corneal epithelial cell proliferation and wound healing was tested in vitro. Results: Platelet lysate enriched the amount of transforming growth factor ß1, platelet-derived growth factor -AB and -BB, fibroblast growth factor, and epidermal growth factor compared with the two sera groups. The concentrations of insulin-like growth factor 1, hepatocyte growth factor, and fibronectin were significantly lower than in sera. There were no differences in nanoparticle concentrations. There was no significant difference in corneal epithelial cell proliferation. Platelet lysates were comparable to fetal calf serum in accelerating corneal epithelial wound healing in vitro. Conclusions: Fresh and expired platelet lysates from the Trima and Haemonetics systems had higher growth factor concentrations than sera. The ability of platelet lysates to promote corneal epithelial cell proliferation and wound healing was equivalent to sera. Translational Relevance: Platelet lysates may serve as an efficient and reliable source of human growth factors for the treatment of ocular surface diseases.