Economic and Environmental Impact of Single-use Plastics at a Large Ophthalmology Outpatient Service.

PRéCIS:: The use of disposable tonometer prisms and gonioscopy lenses at a large ophthalmology outpatient service incurs significant financial and environmental waste that may not be justified given the limited data surrounding arguments for their use. PURPOSE: To quantify the economic and environmental burden of single-use plastics from an ophthalmology outpatient service at a large tertiary hospital and describe the relative value and evidence for the safety of disposable versus nondisposable tonometer prisms and gonioscopy lenses. METHODS: The total number of single-use applanation tonometer prisms and gonioscopy lenses used per year at Boston Medical Center (BMC) was estimated, and the average dollars spent and plastic waste generated in kilograms per year were then determined. These values were compared with the total spending and waste that would be produced if the clinic were to use nondisposable tonometer prisms and gonioscopy lenses exclusively. RESULTS: Single-use tonometer prisms cost an average of $70,282 per year and produce ~100.8 kg of plastic waste per year at BMC. Single-use gonioscopy lenses cost ~$9,040 per year and produce 8.8 kg of plastic waste per year at BMC. An excess of $65,185 and 109.6 kg of plastic waste could be avoided each year by only using nondisposable tonometer prisms and gonioscopy lenses at the BMC ophthalmology outpatient service. CONCLUSIONS: Single-use plastics in ophthalmology outpatient services generate significant environmental waste and financial cost compared with nondisposable instruments. This cost may outweigh the benefits of these instruments given the limited data surrounding arguments for their use.

Laser-induced Damage to Disposable Single-mirror Trabeculoplasty Lens During Selective Laser Trabeculoplasty.

PURPOSE: To demonstrate disposable trabeculoplasty lens damage after routine selective laser trabeculoplasty (SLT) for primary open-angle glaucoma. METHODS: Disposable single-mirror laser lenses were used to perform SLT in 2 patients with primary open-angle glaucoma. Images of the single-use mirrors were taken before and after treatment. RESULTS: One lens showed heavy focal loss of reflectivity of its mirror with SLT settings of 0.8 to 0.9 mJ × 97 shots on a patient with a lightly pigmented angle. Aiming beam splashing or loss was noted after most shots. The second lens showed much less damage with 0.6 mJ × 90 shots in a heavily pigmented angle. CONCLUSION: Although single-use Gonio lenses have gained popularity for their role in infection control and elimination of wear and tear of reusable lenses, our cases show that damage occurs to the silver mirror because of high laser fluence, interfering with proper aiming and possibly diminishing delivered energy and treatment efficacy.

Automated anterior chamber angle pigmentation analyses using 360° gonioscopy.

PURPOSE: To assess the pigmentation distribution in the iridocorneal angle using an established algorithm with gonioscopically obtained images. METHODS: Manual and automatically modified Scheie's pigmentation grading (ie, 0/I=0, II=1 and III/IV=2) of trabecular meshwork was performed using an established algorithm on the 75 open-angle eyes of 75 subjects obtained by automated gonioscopy. All images were collected at the Matsue Red Cross Hospital in 2016. The differences in the pigmentation density were compared statistically between the automated and manual techniques and among the four sectors (ie, inferior, superior, temporal and nasal) and the four quadrants. RESULTS: There was substantial agreement between both grading methods (kappa value=0.70). There was no significant difference between the automated and manual grading in any sectors except for the superior (p=0.0004). The automated pigmentation grade was significantly (p<0.05) higher in the inferior sector (mean grade, 1.43) than in the others (mean grade, 0.48~0.76), and it was also significantly (p<0.05) higher in the inferior quadrant (mean grade, 3.56) than in the others (mean grade, 1.64~2.24). The findings were similar for manual grading. CONCLUSIONS: The entire distribution of the pigmentation in the anterior chamber angle was classified successfully using the algorithm, and the automated versus manual grading comparison showed good agreement. The automated pigmentation grading scores in the inferior sector and inferior quadrant were significantly higher than in the others as previously reported. Similar findings also were seen for manual grading.

Smartphone-based Gonio-Imaging: A Novel Addition to Glaucoma Screening Tools.

Gonioscopy is one of the most difficult skill acquired by ophthalmologists. It is one of the key components of glaucoma diagnosis and management. Smartphone based imaging solutions have revolutionised the imaging in ophthalmology by virtue of their ease of use and portability. Authors hereby describe a smartphone based gonioimaging technique with a 4-mirror goniolens, which can detect the gross findings in anterior chamber angle, and thus can be utilised as screening tool for glaucoma.

Assistant Independent Self-retaining Truncated Gonioscopy Contact Lens for Minimally Invasive Glaucoma Surgery.

A new assistant independent self-retaining surgical goniolens provide panoramic view of angle during ocular surgery by means of new optical system that consists of 2 fused elements. First element comprises of a concave lens that mirror corneal curvature with 3 stabilizing feet for retention and stability on corneal surface during surgery. Second element comprise of a fused biconvex lens with prism that direct images of the angle through prism into surgical microscope. This surgical lens can be used for visualization of angle during all glaucoma procedures and especially helpful for performing minimally invasive glaucoma surgery.

Bubble-free Gonioscopy.

PURPOSE: Accurate gonioscopy is necessary for the diagnosis and the treatment of glaucoma. The "gold standard" for indirect gonioscopy has been the Goldmann 3-mirror lens, requires an optical coupling agent (methylcellulose) between the cornea and under the surface of the goniolens. The design of an ideal lens would not only eliminate the need for gel, but could at the same time solve the problems associated with the trapping of an air bubble under the lens. MATERIALS AND METHODS: This investigation involved a prototype 2-mirror goniolens with a radius of curvature of 8.4 mm and a 16 mm diameter area of corneal contact. A total of, 69 consecutive patients had bilateral keratometer measurements made. The prototype 2-mirror lens was applied to the anesthetized eye. The results of this examination were tabulated by one of the authors (F.M.K.); A=good fit without trapping of air, B=good fit but trapped bubble of air which could be expelled by the patient turning their eye towards the bubble, and C=total failure to expel the trapped bubble of air. Finally, if there were wrinkles in Descemet's membrane, this was recorded. RESULTS: A total of 64 patients were evaluated with a prototype 2-mirror lens. In total, 54/64 (84.38%) of eyes were successfully evaluated without trapping of an air bubble. CONCLUSION: Our stated goal of eliminating the need for gel as a coupling agent without trapping of an air bubble was successful in 54/64 eyes (84.38%). Our findings could spur development of newer bubble-free goniolenses for procedures such as laser trabeculoplasty.

An investigation into the bacterial contamination of goniolenses in use in clinical practice.

Objectives To report the incidence and evaluate the clinical significance of goniolens bacterial contamination in clinical use in dogs with three different usage protocols and one with an added cleaning protocol. Animals Studied and Methods Three groups of twenty dogs undergoing gonioscopy at a private practice in the UK had the goniolenses swabbed for bacteriology culture and identification prior to placement on the cornea. Three protocols of lens use, with 2 different types of goniolens, were studied. One protocol was then repeated with 21 dogs with a lens cleaning protocol prior to storage. Results Low levels of bacterial contamination were found in all 3 initial groups (10-15%). No correlation was found between usage protocol used and rate of contamination and no correlation was found between length of storage between use and contamination. All bacteria cultured were considered naturally occurring commensals for the canine eye and environment. The group with a cleaning protocol had a 4.7% contamination rate. This was not statistically different from the non-cleaning groups. Conclusions The rate of bacterial contamination of goniolenses in clinical practice is low and the bacterial contaminants consist of commensal bacteria, unlikely to be of detriment to the eye. Minimal contamination of the goniolenses was found and this did not appear to be of clinical significance. The introduction of a simple cleaning protocol did not produce a statistically significant reduction in bacterial contamination.

Are Disposable and Standard Gonioscopy Lenses Comparable?

PURPOSE: Gonioscopy is important in the evaluation and treatment of glaucoma. With increased scrutiny of acceptable sterilization processes for health care instruments, disposable gonioscopy lenses have recently been introduced. Single-time use lenses are theorized to decrease infection risk and eliminate the issue of wear and tear seen on standard, reusable lenses. However, patient care would be compromised if the quality of images produced by the disposable lens were inferior to those produced by the reusable lens. The purpose of this study was to compare the quality of images produced by disposable versus standard gonioscopy lenses. MATERIALS AND METHODS: A disposable single mirror lens (Sensor Medical Technology) and a standard Volk G-1 gonioscopy lens were used to image 21 volunteers who were prospectively recruited for the study. Images of the inferior and temporal angles of each subject's left eye were acquired using a slit-lamp camera through the disposable and standard gonioscopy lens. In total, 74 images were graded using the Spaeth gonioscopic system and for clarity and quality. Clarity was scored as 1 or 2 and defined as either (1) all structures perceived or (2) all structures not perceived. Quality was scored as 1, 2, or 3, and defined as (1) all angle landmarks clear and well focused, (2) some angle landmarks clear, others blurred, or (3) angle landmarks could not be ascertained. The 74 images were divided into images taken with the disposable single mirror lens and images taken with the standard Volk G-1 gonioscopy lens. The clarity and quality scores for each of these 2 image groups were averaged and P-values were calculated. RESULTS: Average quality of images produced with the standard lens was 1.46±0.56 compared with 1.54±0.61 for those produced with the disposable lens (P=0.55). Average clarity of images produced with the standard lens was 1.47±0.51 compared with 1.49±0.51 (P=0.90) with the disposable lens. CONCLUSIONS: We conclude that there is no significant difference in quality of images produced with standard versus disposable gonioscopy lenses. Disposable gonioscopy lenses may be an acceptable alternative to standard reusable lenses, especially in conditions where sterilization is difficult.

[Gonioscopy - How, Why, What for?] / Gonioskopie ­ wozu, weshalb, warum?

Aim Gonioscopy is used to exam the anterior chamber angle and the neighbouring structures. Gonioscopy can be performed using a contact lens, with the patient sitting at the slit lamp or in a supine position. Due to the total inner reflection of the cornea, the anterior chamber angle would otherwise be invisible in a healthy eye. During normal daily clinical routine, gonioscopy is often omitted, due to lack of time, although additional information could be gained. Materials and Methods The aim is to give a summary of the diagnostic possibilities using gonioscopy and to emphasise the importance of this relatively easy clinical method. Results The development of gonioscopy, the appropriate tools, proper procedure at the slit lamp and the most popular grading systems are described. In addition, an overview of detectable pathological changes in the anterior chamber angle is given and future prospects about developments in gonioscopy. Conclusion Gonioscopy can provide additional information otherwise missed by slit lamp examination or ophthalmoscopy alone. Up to now, no (semi-)automatic devices have been developed which could completely replace gonioscopy. Therefore gonioscopy remains an important part of a complete ophthalmological examination and should be learned, mastered and performed regularly by every ophthalmologist.

Differential Canalograms Detect Outflow Changes from Trabecular Micro-Bypass Stents and Ab Interno Trabeculectomy.

Recently introduced microincisional glaucoma surgeries that enhance conventional outflow offer a favorable risk profile over traditional surgeries, but can be unpredictable. Two paramount challenges are the lack of an adequate training model for angle surgeries and the absence of an intraoperative quantification of surgical success. To address both, we developed an ex vivo training system and a differential, quantitative canalography method that uses slope-adjusted fluorescence intensities of two different chromophores to avoid quenching. We assessed outflow enhancement by trabecular micro-bypass (TMB) implantation or by ab interno trabeculectomy (AIT). In this porcine model, TMB resulted in an insignificant (p > 0.05) outflow increase of 13 ± 5%, 14 ± 8%, 9 ± 3%, and 24 ± 9% in the inferonasal, superonasal, superotemporal, and inferotemporal quadrant, respectively. AIT caused a 100 ± 50% (p = 0.002), 75 ± 28% (p = 0.002), 19 ± 8%, and 40 ± 21% increase in those quadrants. The direct gonioscopy and tactile feedback provided a surgical experience that was very similar to that in human patients. Despite the more narrow and discontinuous circumferential drainage elements in the pig with potential for underperformance or partial stent obstruction, unequivocal patterns of focal outflow enhancement by TMB were seen in this training model. AIT achieved extensive access to outflow pathways beyond the surgical site itself.

High resolution iridocorneal angle imaging system by axicon lens assisted gonioscopy.

Direct visualization and assessment of the iridocorneal angle (ICA) region with high resolution is important for the clinical evaluation of glaucoma. However, the current clinical imaging systems for ICA do not provide sufficient structural details due to their poor resolution. The key challenges in achieving high quality ICA imaging are its location in the anterior region of the eye and the occurrence of total internal reflection due to refractive index difference between cornea and air. Here, we report an indirect axicon assisted gonioscopy imaging probe with white light illumination. The illustrated results with this probe shows significantly improved visualization of structures in the ICA including TM region, compared to the current available tools. It could reveal critical details of ICA and expected to aid management by providing information that is complementary to angle photography and gonioscopy.

Anterior Chamber Angle and Anterior Chamber Volume in a 40- to 64-Year-Old Population.

PURPOSE: To determine the distribution of the anterior chamber angle (ACA) and anterior chamber volume (ACV) in an Iranian population of 40- to 64-year-old people using the Pentacam. METHODS: In this cross-sectional study, multistage sampling was used to select 300 clusters, including 6,311 individuals from the city of Shahroud. All selected participants underwent examinations in one place. Optometric examinations, including measurement of visual acuity and refraction, and ophthalmologic examinations, including slit-lamp examination, were performed for all participants. Moreover, all patients underwent imaging with the Pentacam. RESULTS: The mean ACA and ACV was 34.3° (95% confidence interval [CI]: 34.1°-34.5°) and 139 µL (95% CI: 137.7-140.3), respectively. In a multiple linear regression model, the ACA was inversely correlated with age (coefficient=-0.08), lens thickness (coefficient=-1.38), corneal diameter (coefficient=-0.36), and corneal curvature (coefficient=-1.43), and directly correlated with the anterior chamber depth (ACD) (coefficient=6.59). In another model, ACV was inversely correlated with age (coefficient=-0.37), central corneal thickness (coefficient=-0.04), and spherical equivalent (coefficient=-1.15), and directly correlated with the ACD (coefficient=85.67), lens thickness (coefficient=14.15), corneal diameter (coefficient=4.80), corneal curvature (coefficient=18.43), ACA (coefficient=0.65), and intraocular pressure (coefficient=0.23). CONCLUSION: The findings of this study could be used as a reference for diagnosis and treatment in Iran and the Middle East region. Increase in age and decrease in the ACD were important factors associated with decreased ACA and ACV, although the correlation of other biometric components was also evaluated. Some of these components, such as the corneal curvature and lens thickness, had a significant relationship with these two variables.

¿Sirve para algo la lente de Goldman en el glaucoma por cierre angular? / Is the Goldman lens any good in angle-closure glaucoma?

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Coloboma de cristalino / Crystalline coloboma

CASO CLÍNICO: Paciente mujer de 73 años diagnosticada de coloboma de cristalino tras ser derivada a consulta para cirugía de catarata. DISCUSIÓN: La incidencia de coloboma en España por cada 10.000 nacimientos es de 0,5, en Francia de 1,4, en Estados Unidos de 2,6 y en China de 7,5. El diagnóstico es clínico mediante visualización directa. El pronóstico visual depende de la extensión y gravedad del defecto. El tratamiento de la catarata se realizó mediante la técnica convencional de facoemulsificación más lente intraocular de cápsula posterior (FACO + LIO CP) con ayuda de anillo de tensión capsular

CASE REPORT: We present a seventy-three year-old female diagnosed with lens coloboma when she was going to be operated on for cataracts. DISCUSSION: The incidence of congenital coloboma of the eye is estimated to be 0.5 per 10000 newborns in Spain, 1.4 in France, 2.6 in United States, and 7.5 in China. The diagnosis is clinical by observing the defect. The visual prognosis depends on the extent and severity of the coloboma. The treatment of the cataract was by phacoemulsification with an intraocular lens using a capsular tension ring

[Screening method for angle closure and angle closure glaucoma using scanning laser polarimeter GDxVCC and photodynamic gonioscopy in a darkened room. One-year outcomes of systematic peripheral iridotomy]. / Méthode de dépistage du glaucome chronique par fermeture de l'angle basée sur l'utilisation systématique du GDxVCC et de la gonioscopie photodynamique. Résultats à un an d'une iridotomie systématique.

INTRODUCTION: Angle closure glaucoma, a recognized major world health issue disproportionately affecting women and Asians, is not often considered in our European populations, normotensive subjects, myopic patients, or subjects with a deep anterior chamber. Early diagnosis is worthwhile, as laser peripheral iridotomy (LPI) is an effective one-step treatment of the causal mechanism. PATIENTS AND METHODS: We have performed a retrospective study of patients who underwent an LPI, the indication for which was based on "photodynamic" gonioscopy in a darkened room showing iridotrabecular contact in darkness. Such photodynamic gonioscopy was motivated by the presence of even minute defects in the nerve fiber layer as seen on the GDxVCC or the presence of a Van Herick sign (narrow limbal anterior chamber depth). RESULTS: One hundred and three eyes of 103 patients underwent LPI and a minimum 1-year follow-up (mean follow-up almost 2 years). Mean age was 63.7±11.8 years, and women accounted for 63.1% of cases. The vast majority (78.6%) of patients had neither glaucoma nor ocular hypertension. There were 60.1% hyperopes and 39.9% myopes. Over half (57%) had a deep or a very deep anterior chamber. After LPI, there was immediate deepening of the limbal depth of the anterior chamber in 100% of cases. The aqueous humor that flowed forward was almost always viscous-looking. After 1 year, the IOP was 1.3mm Hg±2.4 lower (P<.001) (t test). All patients who had experienced morning headaches (44% of patients) were relieved of this symptom. GDxVCC after 1 year was clearly improved in 18% of cases, slightly improved in 20%, stable in 50%, slightly worse in 11% of cases, and clearly worse in 1%. Cases treated at an earlier stage had a better improvement in GDxVCC. DISCUSSION: Our study shows frequent chronic angle closure in our European population even with deep anterior chambers. Absence of a Van Herick sign does not rule out angle closure at night. A photodynamic gonioscopy with the Goldmann three-lens mirror (to avoid unintentional indentation with the small diameter lenses in these normotensive eyes) should be performed in a darkened room. LPI is an effective one-step treatment of the underlying cause, that is particularly beneficial if performed early.

Retcam fluorescein gonioangiography: a new modality for early detection of angle neovascularization in diabetic retinopathy.

PURPOSE: To evaluate the role of Retcam fluorescein gonioangiography in detecting neovascularization of the angle and correlate the same with gonioscopy in diabetic retinopathy. METHODS: One hundred and fifty eyes of 150 patients (25 each of mild, moderate, severe, very severe nonproliferative diabetic retinopathy (NPDR) proliferative diabetic retinopathy (PDR); and PDR with high-risk characteristics) were recruited. They underwent complete ocular examination including applanation tonometry, gonioscopy, Retcam fluorescein gonioangiography, and fundus fluorescein angiography. RESULTS: Using Retcam fluorescein gonioangiography, of 150 eyes neovascularization of the angle was detected in 37 eyes (24.66%) compared with 22 eyes (14.66%) on gonioscopy (P = 0.04). Small newly formed vessels were evident only with Retcam fluorescein gonioangiography. In 10 of 50 patients (20%) with severe/very severe NPDR, angle neovascularization was appreciable on Retcam fluorescein angiography compared with 5 patients (10%) on gonioscopy. Similarly, 25 of 50 patients (50%) with PDR/PDR with high-risk characteristics had neovascularization of the angle on Retcam gonioangiography compared with 17 (34%) on gonioscopy. CONCLUSION: Retcam fluorescein gonioangiography is a novel technique for early detection of angle neovascularization in diabetic retinopathy and hence preventing progression to neovascular glaucoma. The objective nature of this test helps in precise decision making compared with gonioscopy for early intervention especially in cases of pre-PDR.

Hong's grading for evaluating anterior chamber angle width.

PURPOSE: To compare Hong's grading method with anterior segment optical coherence tomography (AS-OCT), gonioscopy, and the dark-room prone-position test (DRPT) for evaluating anterior chamber width. METHODS: The anterior chamber angle was graded using Hong's grading method, and Hong's angle width was calculated from the arctangent of Hong's grades. The correlation between Hong's angle width and AS-OCT parameters was analyzed. The area under the receiver operating characteristic curve (AUC) for Hong's grading method when discriminating between narrow and open angles as determined by gonioscopy was calculated. Correlation analysis was performed between Hong's angle width and intraocular pressure (IOP) changes determined by DRPT. RESULTS: A total of 60 subjects were enrolled. Of these subjects, 53.5 % had a narrow angle. Hong's angle width correlated significantly with the AS-OCT parameters (r = 0.562-0.719, P < 0.01). A Bland-Altman plot showed relatively good agreement between Hong's angle width and the angle width obtained by AS-OCT. The ability of Hong's grading method to discriminate between open and narrow angles was good (AUC = 0.868, 95 % CI 0.756-0.942). A significant linear correlation was found between Hong's angle width and IOP change determined by DRPT (r = -0.761, P < 0.01). CONCLUSIONS: Hong's grading method is useful for detecting narrow angles. Hong's grading correlated well with AS-OCT parameters and DRPT.