Aug 2026· British Journal of Ophthalmology· pp. bjo-2025-327899· 0 citations· 14 references
Medicine
TL;DR
The LAG is a user-friendly, reusable and inexpensive innovation that satisfies a previously unmet need in ophthalmic practice and can have a significant impact on reducing lens damage, increasing procedural safety and increasing clinical efficiency.
Abstract
Background
To create and clinically test the Lens Attachment Guard (LAG), a 3D-printed protective attachment for the prevention of incidental falls and breakage of ophthalmic lenses employed in laser treatments like pan-retinal photocoagulation (PRP).
Methods
The LAG system was designed after several cases of lens damage in a busy clinical practice. It was created with Computer-Aided Design software and produced with thermoplastic polyurethane (TPU) through 3D printing. Iterative prototyping was done to maximise fit, optical compatibility and user-friendliness. The last prototype consisted of three primary elements: a winding clip, thread lock and 3D-printed lens holder.
Results
The LAG system ensured safe lens stabilisation without compromising laser delivery or visualisation. TPU had shock-absorption and was sterilisation compatible. There were no drops of lenses reported when used. Clinician input revealed enhanced procedural confidence and minimal interference with workflow. The system proved versatile for varied lens types and was readily cleaned and could be reused from case to case.
Conclusion
The LAG is a user-friendly, reusable and inexpensive innovation that satisfies a previously unmet need in ophthalmic practice. Its use can have a significant impact on reducing lens damage, increasing procedural safety and increasing clinical efficiency. Multicentre validation and increased lens compatibility testing are ongoing.
The bisecting-angle technique remains clinically useful when anatomical or receptor-placement constraints limit the paralleling technique, but its dependence on operator judgement can produce projection errors and repeated exposures. This pilot study developed a pop-up laser-based cone-alignment accessory and evaluated its initial operator-perceived user experience exclusively in a dental X-ray manikin simulation. The accessory comprised a three-dimensional-printed polyethylene-terephthalate bracket, a 2-rpm DC geared motor, magnetic proximity sensors, one central red cross-line laser, eight perimeter red point lasers, and timer-controlled actuation. The assembled prototype was reported by the authors to have an estimated mass of approximately 500 g; the generic diode modules operated within a documented red-light range of 635-670 nm at <1 mW, although manufacturer and model identifiers were unavailable. Twelve operators (four dental radiographers, four conservative-dentistry residents, and four clinical dental students) completed standardized manikin procedures and the Indonesian User Experience Questionnaire (UEQ). Dewi Kartika distributed and collected the questionnaires but left the room during completion; confidentiality arrangements varied, so strict anonymity cannot be claimed for every response. All six UEQ scales were classified as Excellent, with means of 2.854-2.938 and standard deviations of 0.113-0.225. A separate 50-participant language-validation cohort yielded Cronbach's alpha = 0.850; this coefficient was not recalculated for the 12-operator sample because its item-level matrix was not available. The prototype therefore demonstrated favourable preliminary acceptance under controlled simulation, but neither clinical effectiveness nor patient safety can be inferred. Calibrated mass measurement, model-specific laser verification, physical clearance testing, and controlled patient-based comparison are required.
Dewi Kartika, E. Astuti, Sondang Pintauli et al.· Multidisciplinary Science Jo...· 0 citations
To compare the accuracy of surgical guides manufactured with two different 3D printers, two resins, two different occlusal designs (OS: original shape, and GS: groove sealing), and interactions of these factors were used. Forty surgical guides were printed on a digital light processing (DLP) printer and a Liquid Crystal Display (LCD) printer, with two resin types (SG guide and V-guide) and two occlusal designs. The region where the implant was planned was digitally removed from the cast, allowing passive positioning of the implant through the guide. A scan body was inserted in the implant, and the cast was scanned with an intraoral scanner. The planned implant compared with the actual implant position. Six measurements representing the accuracy of implant placement: (depth, angular, global apical, horizontal apical, global coronal, and horizontal coronal) deviations. Descriptive statistics and a multivariate analysis of variance (MANOVA) were conducted. Printer type had a statistically significant multivariate effect (Wilks’ Lambda = 0.015, p< 0.001, Partial η² = 0.985). The resin type had no multivariate effect on the combined dependent variables, as indicated by Wilks’ Λ = 0.727, p = 0.161. Occlusal shape showed a significant multivariate effect (Wilks’ Lambda = 0.015, p<0.001). The univariate tests revealed that printer type and the shape of the occlusal surface had a statistically significant effect on all six deviation parameters (p < 0.001 for all); however, resin type had a significant effect only on horizontal coronal deviation (p = 0.018). The multivariate analysis using Wilks’ Lambda revealed a significant interaction effect between printer and resin (Wilks’ Λ = 0.593, F (6,27) = 3.094, p = 0.019, Partial η² = 0.407), A significant interaction was also observed between printer and occlusal design (Wilks’ Λ = 0.445, F (6,27) = 5.606, p = 0.001, Partial η² = 0.555) and between printer, resin, and occlusal surface (Wilks’ Λ = 0.414, F (6,27) = 6.380, p < 0.001, Partial η² = 0.586). The DLP printer group and groove sealing group were more accurate than the LCD printer, and occlusal surface group. The accuracy of both SG and V-guide resins was the same.
I. Hasan, R. H. Hasan· Dentistry 3000· 0 citations
To evaluate the early clinical outcomes and surgical feasibility of a trans-ocular threading technique for four-point flanged scleral fixation of intraocular lenses (IOLs).
This retrospective case series included 12 eyes of 12 patients who underwent four-point flanged scleral fixation using a trans-ocular threading technique with a preloaded four closed-loop haptic intraocular lens (Artis PE, Cristalens, France). A bent 25-mm long 30-gauge needle was introduced 2.5 mm posterior to the limbus and passed across the anterior chamber to a contralateral corneal incision. During IOL delivery, the needle was threaded through the haptic loops, allowing extraocular suture externalization without intraocular suture handling. A 6 − 0 polypropylene suture (Prolene, Ethicon, USA) was secured using a flanged technique with low-temperature cautery. The anterior chamber was maintained with viscoelastic without an infusion system. Clinical outcomes, including corrected distance visual acuity (CDVA), intraocular pressure (IOP), corneal endothelial cell density (ECD), IOL centration, and postoperative complications, were evaluated at a mean follow-up of 3.2 ± 1.1 months (range, 2–5 months).
At a mean follow-up of 3.2 months (range, 2–5 months), corrected distance visual acuity (CDVA) improved in 10 of 12 eyes (83.3%), with a mean improvement from 0.86 ± 0.72 to 0.38 ± 0.51 logMAR. After suture revision in one eye with early postoperative IOL subluxation due to insufficient suture tension, all IOLs were well-centered at the final follow-up. Mean preoperative and postoperative IOP did not differ significantly (14.9 ± 2.4 vs. 14.1 ± 2.8 mmHg;
P
= 0.43). Mean corneal endothelial cell density (ECD) was preserved at final follow-up (2205 ± 907 vs. 2146 ± 926 cells/mm²;
P
= 0.61). Postoperative IOL decentration assessed by anterior segment optical coherence tomography (AS-OCT) was 0.31 ± 0.13 mm (range, 0.04–0.46 mm), with all 12 eyes below the 0.5 mm threshold for clinical significance. One eye developed transient hyphema that resolved spontaneously within one week. No cases of cystoid macular edema, hypotony, or significant intraocular inflammation were observed.
The trans-ocular threading technique for four-point flanged scleral fixation demonstrated favorable early clinical outcomes with minimal complications. This approach may reduce intraocular manipulation and maintain anterior chamber stability without the need for an infusion system.
J. Park, Woong-Joo Whang, Jae-Jung Kim et al.· BMC Ophthalmology· 0 citations
Contact lenses have been the most outstanding innovation in non-medical or non-surgical aspects of vision care in recent years. Progress has been steady and rapid over the past four decades in both the science and art of contact lens fitting. But have not our successes in this area led us to neglect the less spectacular procedures at our disposal?
For example, has the trend to simplify fitting procedures, to make the fitting less tiresome, less time-consuming for both patient and practitioner really resulted in improved quality of service? Has this trend improved the main objective, the end result of fitting - namely, an optical device to correct a specific visual problem?
Optometry earned its reputation because of its expertise in doing skillful and accurate eye examinations and by prescribing a variety of aids capable of satisfying the vocational and avocational needs of their patients. Contact lenses have limited abilities to satisfy the multifarious demands of our modern society and industry. Practitioners, perhaps because of the popularity of contact lenses and for fear of being considered old-fashioned, may not discuss openly the very limited optical performance of contact lenses when compared with conventional ophthalmic lenses. Could we not be doing a disservice to the patient and the profession?
A well-fitted contact lens must meet at least two criteria: it must cause no insult to the cornea and its physiology, and it must provide as accurate a refractive result as would a conventional spectacle lens. If we are interested in meeting vocational and avocational needs, we should ask ourselves whether even the well-fitted contact lens satisfies these needs. The answer would be in the affirmative for the majority of pre-presbyopes, but as age increases, the number of successful patients falls drastically. This is a challenge for the profession and the industry. Will contact lens designs ever be as numerous and complete as those available with spectacle lenses in order to meet al/ vision demands?
Optometrists should not forget that the contact lens is but one of the many devices and procedures available in the performance of their duty as vision care professionals. There is a "glamour" of a sort in contact lenses, but optometrical vision care is much more than the fitting of contact lenses.
Although the human visual system has a certain flexibility and can tolerate other than the optimum refractive correction, it is this writer's opinion that the fitting of soft contact lenses has tended to produce sloppy retraction. A spectacle lens in error by 0.50D sphere, or even 0.25 cylinder would likely be rejected and sent back to the laboratory for correction. Are we as prompt to reject a contact lens when over-retraction reveals that it is not the proper correction? What happens to this incorrect lens? Is it destroyed? Will the laboratory accept its return, or is it simply one more "slightly used" lens in an ever growing inventory?
Why should such an attitude prevail when one considers the tremendous amounts of money and effort expended on research?
It would seem that the answer to the preceding question is simply that clinicians and researchers have overlooked the primary objective of any lens -namely that it is a refractive device intended to compensate an optical or muscular defect of the human eye.
Researchers have done an outstanding job in helping to explain corneal physiology, in the development of materials more compatible with the requirements of corneal physiology, in the production of all necessary solutions. But have our efforts to improve the contact lens as a refractive device been on a par with our efforts to understand corneal physiology? Bifocal and toric lenses do exist, but fitting is still very much a hit and miss affair despite the improvements realized in the design of toric lenses. There is still a long way to go, particularly in providing a wider range of cylindrical powers and axis orientations, not to mention design parameters. Can we look forward to the day when soft lenses will permit, as is possible with rigid lenses, the practitioner to calculate the results of his/her prescription when placed on the eye? This is not beyond the realm of possibility, but our understanding of the performance and flexure of soft lenses, the nature and physical properties of present day materials, appears to be inadequate at the moment.
Will bifocal contact lenses ever become truly versatile and practical devices, a worthy competitor to the present array of multifocus spectacle lenses? Limitations of existing designs are barriers to the desire to continue with contact lenses when presbyopia is reached. The potential for future growth seems restricted by the limits of present designs: poorer acuity than with SV lenses, small near point fields, discomfort and lack of variation in near point powers.
What clinical procedures are available to better evaluate refractive results? Is the contrast sensitivity technique the ultimate, or are attempts yet being made to find "the ultimate", a simple, inexpensive test which all practitioners can readily integrate into their office routine?
Have we abandoned our efforts to provide the practitioner with an accurate tool to check all soft lens parameters? All offices have a vertometer of sorts to verify spectacle lenses, even though the laboratories have these instruments as well. It would appear logical that practitioners should be as well equipped to verify soft lens parameters as they do with rigid lenses, and regular spectacle lenses. Practitioners' confidence would be enhanced because they would know exactly with what they are working.
Improvement in contact lenses as optical corrections will not be achieved by any reduction in available lens parameters whatever the reason: to enhance production capabilities, to simplify fitting, or to reduce costs. Single base curve series, single diameters fitted to different corneae of different dimensions may not cause damage to the corneae, but what kind of refractive result ensues? Why do contact lens manufacturers and designers try to evade the basic rules of optics? It takes specific curves to produce specific powers for the materials involved. Is lens flexure adequate justification for the scrapping of scientific parameters? Why do clinicians let themselves be swayed by manufacturers? Why do clinicians not boycott firms who refuse to provide lenses with all the required parameters?
What effect on acuity, accommodation, binocular relationships, aniseikonia and stereopsis results from the single base curve series? Has anyone ever taken th.e time to investigate the variations in resulting refractions for a series of eyes all having the same degree of optical error, but with different corneal diameters and curvatures? Will a lens with specifications 8.4/-3.00/13.5 properly correct patients with keratometer readings of 400, 420, 440, 460, 480, all of whom are -3.00 diopter myopes? What happens with corneal diameters of 10.5, 11.0, 11.5? How many of these will give piano overrefraction? Plano over-refraction may be achieved by changing lens powers, but this may involve the introduction of variable and unwanted cylindrical effects. Certainly it involves a considerable inventory, which is contrary to the goal of reducing costs. Moreover, can the practitioner afford a significant inventory of several makes of lenses?
Speaking of inventory raises the question of the dubious merit of fitting from inventory. What technical advantage, other than patient convenience, is to be realized from fitting from inventory? The patient loses any assurance that he or she will obtain a new and unused lens, free from aging deterioration. What happens to a lens found to be unsatisfactory after a few days, or even a few weeks? Does it go back into inventory as a "new, unused lens"? Is there any possibility that such a lens was not properly asepticised and disinfected, thus presenting some risk for future patients? Can the practitioner afford to discard the lens? If it could be done, would it?
There follows then a serious economic consideration. Professional fees should take into account the possibility of having to refit or exchange lenses, as well as to build and maintain an adequate inventory for trial purposes. Are such fees realistic considering the existence of price cutting outlets with slogans such as "Satisfaction guaranteed or money refunded"?
Does not the fierce competition between corporations and the offering of lenses at lower and lower cost reduce the sources of funds available for research and development? Do discounts for volume purchase serve only to encourage the price cutters to enter the field?
In the rush by multinational corporations to corner the market, to mass produce lenses, one must seek their true motivation - quality vision care, or profits. Cannot the trend to reduce parameters more honestly be interpreted as profit based, rather than aimed at improving care? The clinicians must bear some responsibility also. One would have to look long and hard. through the I iteratu re to find any objections being raised by optometrists. Is the reduction in parameters the first step in the production of over the counter "throwaway" lenses, a feeling out of the market, of acceptability to the public and the professionals? Could not this lead to a situation similar to that of the "glazed goods" sold over the counter in department stores and other retail stores?
Would this be in the patient's best interest? Would not this approach involve risk that the patient would judge a symptom to be, instead, a dirty lens and simply exchange it for one at hand?
Among the many solutions available to practitioners and patients are decongestants. We question the indiscriminate use of such solutions by patients, but some optometrists tolerate their use, and even recommend them. A red eye is a warning, a symptom that something is
G. M. Belanger· Canadian journal of optometr...· 0 citations
This review paper provides an overview of contemporary research areas in the field of contact lenses, recent progress and outstanding questions. Beyond the introduction of silicone hydrogel materials and current widespread use of daily disposable soft lenses, material and design innovations over the past decade have expanded the scope of contact lens applications to include preventative strategies for myopia, drug delivery, biosensing, theranostic (diagnostic sensing and delivery of therapy in response), visual augmentation and communication. Material and nanotechnology innovations have supported drug loading and controlled drug release from contact lenses, using molecular imprinting, layer-by-layer assembly and the incorporation of colloidal and polymeric nanoparticles. Other than many optical interventions for myopia control, most applications are either in pre-clinical or clinical testing. Drug delivery and theranostic applications are likely to be advanced with standardisation of protocols and agreed outcome measures in clinical trials to support comparisons between studies and regulatory approval pathways. Development of visual augmentation, sensing and communication applications will depend on demonstration of clear benefits, affordability, comfort and wearer acceptance. While innovations beyond myopia control are largely not commercially available, the next decade is likely to translate these new technologies into broader use.
With the growing prevalence of myopia, traditional lens design and fabrication methods can no longer meet the increasing demand for personalization and precision. This study proposes a novel approach integrating Zemax optical simulation with 3D printing technology for automated myopic lens design and manufacturing. By connecting Python to the Zemax API, an automated system was developed that allows users to input optical parameters, enabling the system to generate optimized lens designs and corresponding 3D models automatically. The lenses fabricated via photopolymerization 3D printing were characterized for optical, mechanical, and refractive properties. Results showed a strong linear correlation between theoretical and measured refractive powers, with minimal deviation. Drop simulations in ANSYS Workbench confirmed that the maximum deformation and stress levels were well within safety limits, ensuring adequate impact resistance. Overall, this method offers an efficient, precise solution for personalized lens fabrication and expands the application potential of additive manufacturing in optical engineering.
