Ophthalmic Industry Research Articles

Principles for Management of Extractables and Leachables in Ophthalmic Drug Products.

Ophthalmic solutions and suspensions have long been classified into a high-risk category with respect to concerns over extractables and leachables (E&L), though specific guidance on the management of leachables in these products is generally absent from regulatory authorities or the scientific literature. As a result, ophthalmic drug products (ODPs) were originally included in the scope of the Product Quality Research Institute Leachables and Extractables Working Group for Parenteral and Ophthalmic Drug Products (PQRI-PODP). Relative to other high concern dosage forms such as metered-dose inhalers or injectables, ODPs possess unique challenges with respect to the nature of impactful E&L as well as the safety assessment of leachables. For example, extensive use of semipermeable low-density polyethylene primary packaging for ODPs necessitates a strong focus on E&L from secondary packaging sources. For safety assessment, a key challenge is the lack of a sufficient database developed on all relevant ophthalmic toxicity endpoints. As result, the working group is unable to recommend a safety concern threshold (SCT) for ODPs at this time. Nevertheless, the ophthalmic industry has developed a number of time-tested practices to manage E&L for ODPs. This article describes those science-based practices and key considerations in the analysis, management, and safety assessment of E&L in ODPs.

A comparative analysis of canthal index of ekowe indigenes, bayelsa state

Human body parts are useful in the predictive study of the unknown. The aim of this study is to know the normative values of the canthi of the Ekowe people. Measurements such as inner and outer canthal distances were carried out. The mean value of the innercanthal distance for males and females are 3.55±0.58 and 3.43±0.52. The mean outer canthal distance for male and female is 13.91±0.84 and 13.62±0.76. The canthal index for male and female is 25.59±4.54 and 25.30±4.03. Sexual dimorphism exists and statistical significant difference was noticed in the outer canthal distance between the males and females (P˂0.05). This study has provided us with normative reference values of inner and outer canthal distances and canthal index for the Ekowe Population which is import to the health care givers, Anatomist, ophthalmic industry and anthropologist

Strategies to meet sustainability in the ophthalmic industry

ZusammenfassungEco Mode für Beschichtungen in der OphthalmikKunststoffgläser sind heutzutage der Standard für alle Arten von Brillen. Während der Herstellung von Rezeptgläsern entstehen dabei bis zu 90% Abfall, und die verwendeten Duroplaste können stofflich nicht recycelt werden. Um die Gesamtenergiebilanz der Brillengläser zu verbessern, können beim vorletzten Herstellungsschritt, dem Vakuumbeschichten, unterschiedliche Maßnahmen ergriffen werden. Verkürzung der Prozesszeit, deutlich erhöhte Kratzfestigkeit, Optimierung der Beschichtungsanlagen, die sinnvolle Auswertung der Beschichtungsdaten und das Recyceln des Beschichtungsmaterials tragen dazu bei, Energie und die damit verbundenen Emissionen und Kosten zu sparen.

A review of corneal biomechanics: Mechanisms for measurement and the implications for refractive surgery.

Detailed clinical assessment of corneal biomechanics has the potential to revolutionize the ophthalmic industry through enabling quicker and more proficient diagnosis of corneal disease, safer and more effective surgical treatments, and the provision of customized and optimized care. Despite these wide-ranging benefits, and an outstanding clinical need, the provision of technology capable of the assessment of corneal biomechanics in the clinic is still in its infancy. While laboratory-based technologies have progressed significantly over the past decade, there remain significant gaps in our knowledge regarding corneal biomechanics and how they relate to shape and function, and how they change in disease and after surgical intervention. Here, we discuss the importance, relevance, and challenges associated with the assessment of corneal biomechanics and review the techniques currently available and underdevelopment in both the laboratory and the clinic.

Intraocular Lens Implantation In The Ciliary Sulcus: Challenges And Risks.

PurposeThis article reviews the current literature on the risks and challenges associated with intraocular lens (IOL) implantation in the ciliary sulcus.Recent findingsThe development of IOLs designed specifically for placement in the ciliary sulcus continues to be an area of interest for the ophthalmic industry. Currently the one-piece PMMA (polymethylmethacrylate) lens or a three-piece IOL are the best available options for IOL placement in the ciliary sulcus space. Single piece acrylic (SPA) IOLs are not designed for sulcus placement and there is growing evidence of chronic complications related to their use in the ciliary sulcus. Many of these eyes ultimately require surgical intervention, including lens exchange. Endoscopic imaging and ultrasound biomicroscopy (UBM) have enabled a better understanding of ciliary sulcus anatomy and measurements in the living eye.SummaryWhen the capsular bag is compromised, IOL placement in the ciliary sulcus is a reasonable option. In these circumstances, appropriate choice of IOL, knowledge of the sulcus anatomy, and correct technique can improve results and reduce postoperative complications.

Ophthalmic community perception of new medication needs

To survey ophthalmologists (who have participated previously in clinical research) and ophthalmic industry professionals (who have been involved in ocular research and development) to indicate perceived needs for new pharmaceuticals in various ophthalmic subspecialties. A prospective, industry-based survey was sent to ophthalmologists and ophthalmic industry professionals about the perceived needs for new pharmaceutical products. This survey was sent to 559 ophthalmic pharma professionals and ophthalmologists. We received 82 (15%) responses. The results showed that the most commonly perceived need for new pharmaceuticals were dry and wet age-related macular degeneration, glaucoma, diabetic macular edema and dry eye. There was a statistical difference found between response groups (P<0.0001). Respondents indicated they would express their commitment to a new product they perceived as needed by recommending to colleagues (63%), prescribing (60%), participating as principle investigator in a related clinical trial (52%), advising the company (52%), lecturing on behalf of the product (43%), investing in the product (38%), taking no action (7%) or obtain a position in the company (1%). Ophthalmic pharma professionals and ophthalmologists perceive the greatest need for new medicines in ophthalmology to be in dry and wet age-related macular degeneration, glaucoma, diabetic macular edema and dry eye.

Periorbital Soft Tissue Anthropometric Analysis of Young Adults.

The authors aim to determine the periorbital soft tissue anthropometric norms for Turkish young adults for right and left eyes using a noninvasive two-dimensional photogrammetric analysis. Anthropometric measurements of the periorbital soft tissue were taken from 172 female and 56 male Turkish adults aged between 18 and 24 years. The periorbital soft tissue profiles (ocular and palpebral) for males and females were digitally analyzed using linear measurements made with standardized photographic records, taken in a natural head position. Statistically significant differences were found for ocular soft tissue measurements according to gender except inner intercanthal distance (P = 0.125) and right horizontal palpebral aperture (P = 0.240). Statistically significant differences were found for palpebral soft tissue measurements according to gender except right pretarsal skin height (P = 0.112) and left pretarsal skin height (P = 0.056). Results were compared with other ethnic groups. Normal periorbital soft tissue measurements are fundamental anatomical parameters utilized in ophthalmology, optometry, ophthalmic industry, oculoplastic surgery, clinical genetics, dermatocosmetology. Further, normal anthropometric measurements generate reference data for studies in craniofacial dysmorphology, oculoplastic surgery, dermatocosmetology, and comparative physical anthropology.

Dr. S. Donald (Don) Stookey (1915–2014): Pioneering Researcher and Adventurer

Don Stookey was a special person by any measure: an unassuming optimist, eminent scientist and inventor, adventurer, and a beloved family man. Don Stookey, the father of glass-ceramics, was a pioneer in inducing and understanding internal nucleation phenomena in glass. His early work on dense opal glasses and photosensitive precipitation of gold and silver in glass led to an amazing series of inventions: Fotalite®, a photosensitive opal, chemically machined Fotoform® and Fotoceram®, and TiO2-nucleated Pyroceram™ products including missile nosecones and oven-proof cookware. He received a basic patent on glass-ceramics which was contested and affirmed in court. Don was able to demonstrate a clear photochromic glass that showed reversible darkening for thousands of cycles. This material became a fixture in the ophthalmic industry. He went on to invent a full-color polychromatic glass capable of yielding a permanent patterned and monolithic stained glass. In his life outside science, Don chaired an interfaith group that founded a home for the elderly in Corning. He was also a wilderness enthusiast, surviving a plane crash in the Arctic and two boat capsizings. Even In his later years, he continued fishing off the coast of Florida and on Lake Ontario, and went solo on a trip to the Patagonian Andes.

Interpupillary Distance Measurements among Students in the Kumasi Metropolis

Objective: The aim was to obtain interpupillary distance (IPD) measurements of students in the Kumasi Metropolis. The study will provide a database for manufacturers of spectacle frames and optical equipment with Ghana as the target population. The IPD is a crucial measure that needs to be considered before frames can be selected for patients who have been prescribed with spectacle corrections. IPD data from other populations are unsuitable due to variations with age, sex and race. Method: A cross-sectional study involving 500 students, aged 10 to 20 years and selected from Junior and Senior High Schools in the Kumasi Metropolis, was carried out. Interpupillary distances were measured using the pupillometer and the PD rule. Results: Out of the 500 students, 290 (58%) were males. The study revealed that the distance and near IPD measured with pupillometer in students was 65.53 ± 3.348 mm and 61.60 ± 3.054 mm respectively. Furthermore, the IPD was 64.48 ± 3.429 mm and 62.01 ± 3.464 mm for distance and near, respectively, when measured with a PD rule. Conclusion: IPD is affected by age, ethnicity and gender variations. The study will provide normal reference values of interpupillary distance in the Ghanaian population which will be useful to anthropometry, medicine, ophthalmic industry and primary eye care.

A drug-eluting contact lens to treat glaucoma

Purpose: To investigate the uptake and release of a novel antibiotic-steroid solution from three commercial contact lenses. Method:A0.3%ciprofloxacin(CF)and0.1%dexamethasone23phosphate (DXP) solution was prepared in acetate buffer using cyclodextrins to prevent precipitation. Concentrations of both drugs were simultaneously determined using a combination of fluorescence spectrophotometry and UV absorbance. Three commercially available contact lenses, balafilcon A, etafilcon A and lotrafilcon B were placed in 2mL of the CF-DXP solution and soaked at room temperature for 24hours. The lenses were then removed and placed in 2mL of phosphate buffered saline, and the release of CF and DXP into solution was monitored over 24hours. Results: All lens types were able to release significant amounts of CF and DXP (p 0.05). The absolute amount of CF and DXP being released was less than when the species were loaded into the lenses individually compared to previous studies, suggesting a possible interaction effect. The majority of the drug was released within the first three hours, suggesting that specifically tailored and designed lenses are needed if these drug delivery lenses are to be useful. Conclusions: Antibiotic steroid combination drops are one of the most commonly prescribed agents in the ophthalmic industry, thus theyareanatural target for those interested indevelopingcontact lens drug delivery devices. Further study is required to tailor the release rates and amounts to be clinically relevant.

Astigmatism management at the time of cataract surgery

Patients expect their vision to improve after cataract surgery and, increasingly, they expect to be free of the encumbrance of glasses and contact lenses. These expectations are driven by technological advancements throughout the ophthalmic industry and the experiences of family and friends. To meet or exceed patient expectations, cataract surgeons must pay increasing attention to the management of pre-existing corneal astigmatism at the time of cataract surgery. Pre-existing corneal astigmatism is a significant component of preoperative ametropia. To achieve satisfactory postoperative refractive results, it is important to correct pre-existing spherical errors by accurate biometry and intraocular lens (IOL) power calculation, and to manage preoperative corneal cylinder errors by a suitable method. Guided by preoperative corneal topography, patients with varying degrees of corneal astigmatism can be placed into a variety of dioptric categories. These categories dictate a systematic ‘stepladder’ approach to guide the optimum approach to surgical correction. For patients with less than 1 D of corneal astigmatism, the preferred approach is to place the phacoemulsification incision on the steep corneal meridian. For 1–3 D of corneal astigmatism, single or paired peripheral corneal-relaxing incisions may be used. Alternately, for astigmatic errors of 1–4 D, toric IOLs can be implanted. Astigmatism of 4.5–7 D may be addressed using a combined approach of toric IOL implantation and peripheral corneal relaxing incision placement in the steep meridian of corneal cylinder. Moreover, high-powered toric IOLs, currently available in select European and Asian markets and not currently approved by the US FDA, may be implanted in the USA if an ophthalmologist obtains a compassionate use exemption from the FDA and local Institutional Review Board approval. If visually significant refractive errors are present after cataract surgery, surgical management options include piggyback IOL implantation, IOL exchange, toric IOL rotation, photorefractive keratectomy and laser-assisted in situ keratomileusis. Of these options, photorefractive keratectomy and laser-assisted in situ keratomileusis usually provide the most simple solution to manage suboptimal refractive outcomes. This simple stepladder approach to astigmatism management, which is based on preoperative corneal topography, enables cataract surgeons to achieve excellent unaided visual acuity in the absence of vision-limiting ocular comorbidities.

Microscratch resistance of ophthalmic coatings on organic lenses

The mechanical properties, the scratch resistance and the surface damage mechanisms of organic lenses and transparent anti-scratch and antireflective coatings, commonly used in ophthalmic industry, have been studied by means of instrumented nanoindentation and microscratch testing. The effect of the tip microscratch velocity on the mechanical response of a polymeric commercial lens has been qualitatively explained in terms of Eyring's formalism. The analysis of the mean residual scratch depth is proposed as a powerful characterization technique to foresee the Bayer abrasion resistance of ophthalmic coatings.

The Impact of Contact Angle on the Biocompatibility of Biomaterials

Biomaterials may be defined as artificial materials that can mimic, store, or come into close contact with living biological cells or fluids and are becoming increasingly popular in the medical, biomedical, optometric, dental, and pharmaceutical industries. Within the ophthalmic industry, the best example of a biomaterial is a contact lens, which is worn by approximately 125 million people worldwide. For biomaterials to be biocompatible, they cannot illicit any type of unfavorable response when exposed to the tissue they contact. A characteristic that significantly influences this response is that related to surface wettability, which is often determined by measuring the contact angle of the material. This article reviews the impact of contact angle on the biocompatibility of tissue engineering substrates, blood-contacting devices, dental implants, intraocular lenses, and contact lens materials.

Complications of sulcus placement of single-piece acrylic intraocular lenses: Recommendations for backup IOL implantation following posterior capsule rupture

To describe complications arising from sulcus placement of single-piece acrylic (SPA) intraocular lenses (IOLs), evaluate IOL options for eyes that lack adequate capsule support, and examine the appropriateness of various IOL designs for sulcus placement. University and private anterior segment surgery practices. Patients referred for complications of SPA IOLs in the ciliary sulcus from 2006 and 2008 were identified. Demographic information, examination findings, and complications of the initial surgery were recorded. Details of surgical interventions and the most recent corrected distance visual acuity (CDVA) were noted. A thorough review of the literature was undertaken to analyze options for IOL placement. Complications of sulcus SPA IOLs included pigment dispersion, iris transillumination defects, dysphotopsia, elevated intraocular pressure, intraocular hemorrhage, and cystoid macular edema. Two patients in the series of 30 patients experienced 1 complication; 8 experienced 2 complications; 13 experienced 3 complications; 4 experienced 4 complications; and 2 experienced 5 complications. Twenty-eight eyes (93%) required surgical intervention; IOL exchange was performed in 25 (83%). Postoperatively, the mean CDVA improved, with most eyes attaining 20/20. Intraocular lenses designed solely for the capsular bag should not be placed in the ciliary sulcus. Backup IOLs in appropriate powers, sizes, and designs should be available for every cataract procedure. The development, investigation, and supply of IOLs specifically designed for placement in eyes that lack adequate capsule support represent clinically important endeavors for ophthalmology and the ophthalmic industry.

Antireflection coatings on plastics deposited by plasma polymerization process

Antireflection coatings (ARCs) are deposited on the surfaces of optical elements like spectacle lenses to increase light transmission and improve their performance. In the ophthalmic industry, plastic lenses are rapidly displacing glass lenses due to several advantageous features. However, the deposition of ARCs on plastic lenses is a challenging task, because the plastic surface needs treatment for adhesion improvement and surface hardening before depositing the ARC. This surface treatment is usually done in a multi-stage process—exposure to energetic radiations, followed by deposition of a carbonyl hard coating by spin or dip coating processes, UV curing, etc. However, this treatment can also be done by plasma processes. Moreover, the plasma polymerization process allows deposition of optical films at room temperature, essential for plastics. The energetic ions in plasma processes provide similar effects as in ion assisted physical deposition processes to produce hard coatings, without requiring sophisticated ion sources. The plasma polymerization process is more economical than ion-assisted physical vapour deposition processes as regards equipment and source materials and is more cost-effective, enabling the surface treatment and deposition of the ARC in the same deposition system in a single run by varying the system parameters at each step. Since published results of the plasma polymerization processes developed abroad are rather sketchy and the techniques are mostly veiled in commercial secrecy, innovative and indigenous plasma-based techniques have been developed in this work for depositing the complete ARCs on plastic substrates.

Longitudinal analysis of precorneal tear film rupture patterns.

The precorneal tear film is a complex structure that has attracted much attention over the years, especially in relation to dry eyes and contact lens (CL) wear. A healthy and stable tear film is essential for comfortable vision and successful CL wear.1 With an estimated 40% of the North American population suffering from dry eyes2 and some 60 million CL wearers worldwide,3 the need for simple, accurate, and cost-effective tests of tear stability has spawned much research both in the ophthalmic industry and in clinical practice.

Low energy photon attenuation measurements of hydrophilic materials for tissue equivalent phantoms

The object of the study was to measure the linear attenuation coefficients of hydrophilic materials with the aim of investigating their suitability as tissue equivalent materials. Hydrophilic materials are used in the ophthalmic industry for the manufacture of soft contact lenses. Hydrophilic materials have the trade name “Biogel” and are commonly known as hydrogels. Two types of hydrophilic material were tested, ED4C (72% water uptake by weight) and EDIS (60% water uptake by weight). The measurements were obtained using γ-ray photons of energy 59.5 keV, and x-ray photons of energies 44.23 and 17.44 keV. Measurements were made for material types ED4C and ED IS in both the dry and fully hydrated state. Measurements were also made on powdered samples of ED4C at different hydration levels using a photon energy of 17.44 keV and powdered samples of ED IS at different hydration levels using a photon energy of 59.5 keV. The precision of the measurements was approx. 1%. It was found that material ED4C has linear attenuation coefficients that closely match those of the calculated values for soft tissue across the range of energies used.

Image Evaluation of Ophthalmic Devices

Methods used in the ophthalmic industry to evaluate the optical image quality of correcting lenses have remained the same over many years. This is especially true for single-vision ophthalmic lenses. With the development of new optical designs and materials for correcting refractive errors and presbyopia, new procedures for evaluating lens performance are being explored. One such method is the measurement of the modulation transfer function. Over the last 2 years, we have been measuring modulation transfer functions on a variety of single-vision and bifocal contact lenses, progressive addition spectacle lenses, holographic-diffractive lenses, and intraocular lenses. In this article, the modulation transfer function procedure and its application and results from one study on safety goggles will be presented and discussed.

Strategic regulatory entry deterrence An empirical test in the ophthalmic market

This paper provides an empirical test of the theory of strategic regulatory entry deterrence – the theory that subgroups of firms within an industry will use the regulatory process to increase rival's costs and thereby deter rivals' entry. The results suggest that the commercial practice restrictions present in the ophthalmic industry deterred chain optical firms' entry into the market. This result in combination with earlier findings that the restrictions increase optometrists' prices suggests that cost-raising strategies can be used to disadvantage rivals or drive them out of the market without the need to lower price.

4. Remarks on the teaching of geometrical optics to elementary students

It is suggested that the teaching of the earlier stages of geometrical optics from the experimental point of view, the introduction of mathematics being postponed until later, would benefit larger numbers of students and at the same time provide those who are to pass on to more advanced work with a useful practical groundwork. In deciding upon a system of nomenclature and conventions, consideration should again be given to non-mathematical students and to the conventions established in the ophthalmic industry.