Long-term visual outcomes of children screened for retinopathy of prematurity with telemedicine in New Zealand.

CLINICAL RELEVANCE: Children with a history of regressed retinopathy of prematurity (ROP) are at increased risk of peripheral avascular retina. Wide-field digital retinal imaging and telemedicine is an effective tool for ROP screening. Ophthalmologists and Optometrists should have a high level of clinical suspicion for peripheral retinal changes in children screened for ROP. BACKGROUND: Retinopathy of prematurity, a vaso-proliferative disorder of the pre-term retina, is a preventable cause of childhood visual impairment. The Auckland Regional Telemedicine ROP (ART-ROP) network, established in 2006, utilises wide-field digital imaging and telemedicine to screen at-risk infants for ROP. This prospective observational study reports the long-term ocular outcomes of ART-ROP network infants. METHODS: A comprehensive paediatric eye examination including cycloplegic autorefraction and wide-field retinal imaging was completed on all participants. Participants had been screened for ROP by the ART-ROP network between May 2008 and October 2011. RESULTS: A total of 69 children, with a mean age of 5 to 8 years old were assessed and divided into two groups: those with or without a history of ROP, 44 and 25 children, respectively. Infants with a history of ROP had significantly lower gestational age (26.6 ± 1.9 vs. 29.1 ± 1.6 weeks, p < 0.001) and birth weight (937 ± 237 vs. 1177 ± 311 grams, p = 0.001). No significant differences were detected between the two groups for visual acuity (p = 0.596), stereopsis (p = 0.219), refractive error (p = 0.472), or strabismus. Clinically significant refractive error was noted in 10 participants; none with moderate or high myopia. Retinal imaging exposed asymptomatic, persistent, peripheral avascular retina in four children, all of whom had a history of regressed ROP. CONCLUSION: Visual and ocular outcomes did not vary based on history of ROP, with no participant having reduced vision as a result of undetected or untreated ROP. Further research is required into the long-term implication of persistent avascular retina in regressed ROP.

Prospective one year study of corneal biomechanical changes following high intensity, accelerated cornea cross-linking in patients with keratoconus using a non-contact tonometer.

PURPOSE: To characterize corneal biomechanical properties utilizing a dynamic ultra-high-speed Scheimpflug camera equipped with a non-contact tonometer (CorVis ST, CST) in keratoconic corneas following continuous high intensity, high irradiance corneal cross-linking. DESIGN: Prospective longitudinal single-centre study at a tertiary referral center. METHODS: Corneal biomechanical properties were measured in patients with progressive keratoconus undergoing high intensity (30 mW/cm2), high irradiance (5.4 J/cm2), accelerated corneal cross-linking with continuous exposure to ultraviolet-A for 4 min. CST was used to assess corneal biomechanical properties pre-operatively and at 1, 3, 6 and 12 months post-operatively. CST output videos were further analyzed using several previously reported algorithms. RESULTS: A total of 25 eyes of 25 participants were examined. The mean age of participants was 20.9 ± 5.3 years; 56% were male and 80% were of Maori or Pacific Island origin. Energy absorbed area (mN mm), was the only significantly changed parameter compared to baseline at all time points measuring 3.61 ± 1.19 preoperatively, 2.81 ± 1.15 at 1 month (p = 0.037), 2.79 ± 0.81 (p = 0.033) at 3 months, 2.76 ± 0.95 (p = 0.028) at 6 months and 2.71 ± 1.18 (p = 0.016) at 12 months. CONCLUSIONS: The significant difference between the pre and post-operative energy absorbed area appears to reflect changes in corneal viscous properties that occur following corneal cross-linking.

Peripheral Cornea Crosslinking Before Deep Anterior Lamellar Keratoplasty.

Since Cornea crosslinking (CXL) has been proven to halt progression and biomechanically stabilize keratoconus, we hypothesized that CXL of the corneal periphery 3 months prior to corneal transplantation can reduce the incidence of recurrent ectasia by strengthening the peripheral corneal tissue and causing apoptosis of diseased peripheral host keratocytes. Thus, the aim of this case-report was to propose a novel peripheral CXL technique prior to keratoplasty and evaluate its safety. A 22-year-old woman was admitted with advanced right keratoconus and corrected distance visual acuities of 20/30 in the right eye and 20/200 in the left eye with a manifest refraction of -3.00D/ -8.00D × 36° and -17.00D/ -11.50D × 90°, respectively. The proposed treatment involved crosslinking of peripheral corneal tissue (6.5-9.5mm), sparing the central cornea and limbus, three months prior to corneal transplantation as a means of biomechanically strengthening the peripheral cornea tissue. This procedure was feasible and safe with repopulation of the peripheral cornea with keratocytes, no significant endothelial cell loss and a routine postoperative course following CXL and DALK. This method might reduce or eliminate the need for repeat corneal transplantation in patients with recurrent ectasia. Further studies are needed to confirm the results.

Precision, agreement and utility of a contemporary non-contact corneal aesthesiometer.

BACKGROUND: The measurement of corneal sensitivity threshold is important for several ocular surface diseases. The current study assesses the precision, agreement and utility of corneal sensitivity threshold measurement using a new, purpose-built non-contact corneal aesthesiometer. METHODS: A new instrument and an established non-contact corneal aesthesiometer device was used to measure the corneal sensitivity threshold on the right eye of 40 healthy human participants. Exclusion criteria included: corneal pathology, previous ocular surgery, ocular trauma, contact lens wear, diabetes or peripheral neuropathy. A forced-response, double-staircase method was used to obtain corneal sensitivity threshold from the mean of three readings per participant, for each non-contact corneal aesthesiometer. Screen demarcations relative to the corneal limbus facilitated alignment with the new device. Repeatability of the new instrument was tested three consecutive times on the same day. Intra-observer and inter-observer reproducibility and agreement were determined using one-way analysis of variance or analysis of variance and Bland-Altman analysis, respectively. RESULTS: Forty eyes of 40 participants were assessed (15:25 M:F, 30.5 ± 11.4 years). The new instrument demonstrated good repeatability (p = 0.47). There was no difference in the mean corneal sensitivity threshold between the new (0.60 ± 0.36 mbar) and established (0.60 ± 0.34 mbar) aesthesiometers (p = 0.92). Utilising the new instrument, inter-observer reproducibility (on a different subset of 10 participants) yielded thresholds of 0.41 ± 0.16 mbar and 0.42 ± 0.13 mbar (p = 0.88) for the two observers. Bland-Altman analysis confirmed good intra and inter-observer agreement. Screen demarcations relative to the limbus, enabled easier corneal alignment. CONCLUSION: The new non-contact corneal aesthesiometer confirmed very good repeatability and reproducibility, as well as good agreement with the long-established instrument. Overall, this contemporary approach enables accurate and precise assessment of corneal sensitivity and thus, corneal nerve function, in normal and diseased cornea.

Improved Refractive Outcomes of Small-Incision Extracapsular Cataract Surgery after Implementation of a Biometry Training Course.

PURPOSE: To determine whether a biometry training course could improve refractive outcomes of patients undergoing manual small-incision extracapsular cataract surgery (SICS). MATERIALS AND METHODS: This was a prospective, interventional, cohort study at the Pacific Eye Institute, Fiji. SICS refractive outcomes were evaluated before and after a structured biometry teaching course. Eyes that underwent evaluation and subsequent SICS with placement of a posterior chamber intraocular lens (IOL) were included. Axial length measurements were obtained using A-scan applanation ultrasound and keratometry with a handheld keratometer. Main outcome measures included mean absolute prediction error of IOL calculations, percentage of eyes within ±0.5 D and ±1.0 D of intended spherical equivalent, and proportion of eyes with ≥6/18 uncorrected visual acuity. RESULTS: A total of 240 eyes were analyzed: 120 eyes before and 120 eyes after the structured biometry training. The mean absolute prediction error was 50% lower following the training (1.13 ± 0.84 D pre vs. 0.56 ± 0.44 D post; P < 0.001). A higher percentage of the eyes had a postoperative spherical equivalent within ±0.5 D (26.7% pre vs. 52.5% post; P < 0.001) and ±1.0 D (55.0% pre vs. 90.0% post; P < 0.001) of the intended target. A higher proportion of the eyes achieved ≥6/18 uncorrected visual acuity (77.5% pre vs. 91.7% post, P = 0.004), while the proportion with ≥6/18 corrected visual acuity was similar (94.4% pre vs. 98.3% post; P = 0.28). CONCLUSIONS: A structured biometry training course may improve the accuracy of preoperative IOL calculations to achieve the postoperative refractive target. Ophthalmology training programs should include structured biometry teaching in their curricula.

In vivo confocal microscopy of the inflamed anterior segment: A review of clinical and research applications.

In vivo confocal microscopy (IVCM) allows non-invasive imaging of the living human cornea, specifically enabling the detection of immune cells in the healthy and diseased ocular anterior segment. Studies using IVCM have provided insight into the effects of contact lens wear on corneal Langerhans cell density and morphology, and the effects of eye drops on conjunctiva-associated lymphoid tissue. IVCM has also been shown to be a useful adjunctive diagnostic tool in distinguishing infective and non-infective uveitis and in diagnosing atypical infective keratitis. In the research setting, this technology has enhanced our understanding of the role of inflammatory cells in corneal neuropathy and angiogenesis. In vivo-ex vivo correlation using animal models has helped overcome some of the difficulties in identifying cell type on IVCM images. As highlighted in this review, currently there are multiple established, and emerging, clinical and research applications for IVCM in the inflamed anterior segment.

Cystoid macular oedema following cataract surgery: A review.

Pseudophakic cystoid macular oedema (PCMO) remains a significant cause of compromised postoperative vision in contemporary cataract surgery. Well-established risk factors include intraoperative complications such as posterior capsule rupture and preoperative factors including: diabetes mellitus, uveitis, retinal vein occlusion, epiretinal membrane. The role of topical glaucoma medications in PCMO continues to be debated. Current treatment strategies largely target suppression of inflammation. Topical NSAIDs remain the mainstay in prophylaxis and treatment of PCMO. Topical corticosteroids are commonly used as monotherapy or in combination with NSAIDs. Unfortunately, high-quality trials are notably lacking for other PCMO treatment modalities such as: periocular corticosteroids, orbital floor triamcinolone, intravitreal triamcinolone, corticosteroid implants, intravitreal bevacizumab and pars-plana vitrectomy. A lack of consistency in defining PCMO and resolution of PCMO explains why even large systematic reviews may come to contradictory conclusions. This review explores the varied contemporary evidence-base in relation to the aetiology, diagnosis, prophylaxis and treatment of PCMO.

Clinical applicability of the Saccadic Vector Optokinetic Perimeter in children with and without visual impairment.

BACKGROUND: Common paediatric perimetry techniques require central fixation and subjective responses, which may be challenging for young or cognitively impaired children. The Saccadic Vector Optokinetic Perimeter (SVOP) was designed to overcome these challenges by using infra-red eye tracking to assess the visual field. This study assessed the clinical feasibility of SVOP in children without visual impairment, comparing it to current paediatric techniques, and in children with visual impairment. METHODS: Participants were recruited into two cohorts: children without visual impairment (visual acuity ≥ 6/7.5) and children with visual impairment (visual acuity ≤ 6/18). Children without visual impairment attempted the Goldmann perimeter, confrontation method, and SVOP. Children with visual impairment attempted SVOP, when clinically indicated, as part of a full ophthalmic assessment. Visual field results and test length were recorded. RESULTS: Twenty-three children without visual impairment (4-14 years old) attempted all three visual field assessments. Full results were recorded for 91 per cent of children with SVOP, 87 per cent with Goldmann, and 100 per cent with confrontation SVOP was significantly faster than Goldmann (p < 0.001) and confrontation (p = 0.003). Thirty-five children with visual impairment (3-19 years old) with visual acuity ranging from 6/9.5 to worse than 6/360 (mean of 0.8 ± 0.4 logMAR) attempted SVOP, with 26 children able to complete SVOP. DISCUSSION: This is the largest study to date of the clinical applicability of SVOP in children without visual impairment, as well as assessing the utility of SVOP in children with visual impairment. Further research is needed to assess the accuracy of SVOP in a range of paediatric ocular disorders. SVOP may potentially offer a visual field assessment method for children previously unable to complete current paediatric perimetry techniques.

Mortality after endophthalmitis following contemporary phacoemulsification cataract surgery.

IMPORTANCE: To determine if endophthalmitis following cataract surgery is linked to increased mortality. BACKGROUND: Increased mortality has been linked to patients with cataract and cataract surgery. We tested the hypothesis that post-cataract endophthalmitis has a greater risk of death than pseudophakes who do not develop this complication. DESIGN: Case-control study conducted in a tertiary public hospital. PARTICIPANTS: The study group comprised 50 consecutive patients with post-cataract endophthalmitis, and these were matched with selected controls. METHODS: Patients with endophthalmitis following cataract surgery were identified from a prospective electronic surgical database. Subsequently, it was determined if the patient was deceased at the time of sequestration (September 2015), and the date of death was recorded. A previously described population who had undergone cataract surgery in the same facility was selected as a control group, and the population was case-matched in terms age, gender, presence or absence of diabetes and/or hypertension. MAIN OUTCOME MEASURES: The median survival rates were determined for the control group and the patients with post-cataract endophthalmitis. RESULTS: Fifty patients were identified as undergoing endophthalmitis post-cataract surgery, and 48 (n = 48) met inclusion criteria (mean age 72 years ±12 SD with 30:18 F:M); 17% were diabetic, and 50% had systemic hypertension. No statistically significant difference in median survival between the study and control cases was identified (100 months (95% confidence interval 86-114) vs. 106 months (95% confidence interval 66-146), respectively, P = 0.756). CONCLUSIONS AND RELEVANCE: Post-cataract endophthalmitis was not associated with an increased rate of mortality in this study.

The rising tide of Acanthamoeba keratitis in Auckland, New Zealand: a 7-year review of presentation, diagnosis and outcomes (2009-2016).

IMPORTANCE: Acanthamoeba is an increasingly prevalent cause of vision-threatening microbial keratitis. BACKGROUND: To assess the incidence, clinical presentation, diagnosis and outcomes of patients with Acanthamoeba keratitis (AK) in Auckland, New Zealand over a 7-year period. DESIGN: Retrospective observational consecutive case series. PARTICIPANTS: Fifty-eight eyes of 52 patients diagnosed with AK. METHODS: All cases of AK were identified using a cross-referenced search of clinical, laboratory and pharmacy records from March 2009 to May 2016. MAIN OUTCOME MEASURES: Demographic and clinical data were collected including age, gender, risk factors, clinical manifestations, initial diagnosis, diagnostic investigations, treatment, presenting and final visual acuity and surgical interventions. RESULTS: Contact lens (CL) use was noted in 96% of unilateral and 100% of bilateral cases. The mean duration of symptoms at presentation was 21 days and the mean duration from presentation to definitive diagnosis was 14 days. Initial diagnosis was recorded as CL-related keratitis in 70.6%, viral keratitis in 15.5% and AK in 12.0%. The diagnosis was confirmed with In vivo confocal microscopy (IVCM) in 67.2%, corneal scrape in 22.4%, corneal biopsy in 1.7% and clinically in 8.6%. IVCM sensitivity was 83.0%. Surgical intervention was required in four patients, all with delayed diagnosis (range 63-125 days). The incidence of AK has more than doubled when compared with the preceding 7-year period. CONCLUSIONS AND RELEVANCE: AK is a rare vision-threatening protozoal infection with rapidly-increasing incidence in New Zealand, predominantly affecting CL users. Diagnosis is often challenging and when delayed is associated with worse outcomes. IVCM offers rapid diagnosis with high sensitivity.

Auckland cataract study 2: clinical outcomes of phacoemulsification cataract surgery in a public teaching hospital.

IMPORTANCE: A contemporary benchmark for the most common ophthalmic surgery. BACKGROUND: To assess patient characteristics and outcomes of contemporary phacoemulsification cataract surgery in a New Zealand public teaching hospital setting. DESIGN: Prospective observational study. PARTICIPANTS: Consecutive cases (n = 500) of phacoemulsification surgery between April and June 2015. METHODS: An independent observer assessed clinical and surgical data preoperatively and 4-6 weeks postoperatively. MAIN OUTCOME MEASURES: Visual acuity, intraoperative and postoperative complications. RESULTS: Mean age was 72.3 ± 11.9 years and 57% female. Mean preoperative best-measured visual acuity was 6/30. Ocular comorbidity was present in 45.8% of eyes, most commonly glaucoma (10%), age-related macular degeneration (8%) and diabetic retinopathy (8%). Systemically, hypertension (59%) and diabetes mellitus (31%) were prevalent. Mean contralateral best-measured visual acuity was 6/12 (n = 495) with 62% being phakic. The rate of posterior capsular tear was 2.6% and cystoid macular oedema 3.5%. Intraoperative complication rates were not significantly different between surgeon levels (P = 0.234). However, registrars had fewer postoperative complications than fellows (2.2% vs. 11.9%, P = 0.012). Postoperatively, mean unaided and best-measured visual acuity were 6/12 and 6/9. CONCLUSIONS AND RELEVANCE: This study reports current phacoemulsification surgery outcomes in a major public teaching institution. A large proportion of patients exhibited systemic and ocular comorbidities, relatively dense cataracts and poor presenting visual acuity. However, visual outcomes and intraoperative complication rates were not statistically different between trainees and senior surgeons. Generally, outcomes reflect international standards and have improved since the last comparable study in this region.