Rigid Lenses Research Articles

Design Thinking

In today’s increasingly competitive Higher Education (HE) market, academic jobs are more precarious than ever. The way academics do their day-to-day job is under increasing scrutiny, with their outputs measured through the rigid lens of performativity and financial profit. Professional Learning (PL) is an institutional approach aimed towards achieving and sustaining high quality teaching and innovation among academic staff. The significance of PL to developing academics’ skills and fostering their professional identity has been confirmed by peer reviewed research. However, how to design and deliver PL that is meaningful to academic workforce, while empowering academics and supporting them in finding solutions to their teaching and learning problems, remains up for debate. This paper offers a conceptual way forward; arguing for a complete re-think of the predominant way of doing PL in universities in favour of placing Design Thinking (DT) at the heart of the matter. Grounded within a robust theoretical approach and scaffolded with a practical toolkit, DT can enable a nurturing environment to engage and empower academics, building their confidence and equipping them with a methodology for problem solving into the future.

Case Report: Front surface eccentricity of scleral lens: Its impact on visual quality in eyes with higher-order aberrations induced by refractive surgery

Purpose To report the impact of front surface eccentricity (FSE) of scleral lenses (SCLs) on the visual performance of eyes exhibiting refractive surgery-induced higher-order aberrations (HOAs) Method A female teenager presented to the clinic with blurring of vision and dependency on spectacles even after undergoing Small Incision Lenticule Extraction (SMILE) in both eyes (BE). Her presenting uncorrected high contrast distance visual acuity (HCDVA) was 20/60 in the right eye (RE) and 20/40 in the left eye (LE). On examination, the cornea showed a ring-shaped area of ablation with faint scarring and a well-apposed lenticule-extraction site. Subjective refraction improved the HCDVA to 20/20p in RE and 20/25 in LE but the patient was not happy with the quality of vision. Ocular aberrometry revealed an increase in total HOAs as the underlying cause of unsatisfactory vision. Result A contact lens trial was recommended for BE to enhance visual quality. Rigid corneal lenses (RCLs) were tried, but the patient was intolerant to them. Large diameter SCLs of different FSEs (0, 0.6, and 0.8) were tried to reduce these aberrations. SCL with FSE 0 yielded the most favourable visual outcome, which was confirmed subjectively on ocular aberrometry. Conclusion With this case report, we hypothesize that the eccentricity of SCL can be selected according to the asphericity (at 6 mm) of the posterior corneal surface. This case also re-emphasizes the impact of SCL with varying FSEs on reducing HOAs and enhancing visual quality in eyes where conventional RCLs yield suboptimal results.

Transforming Subdural Hematoma Treatment in the Elderly: Insights from an Endoscopic Case Series.

Subdural hematoma (SDH), a critical brain condition, significantly affects the elderly, making traditional surgeries risky due to their length and potential for blood loss. Endoscope-assisted evacuation offers a safer, less invasive alternative by reducing operation time and minimizing damage, providing an effective solution for older patients. This study evaluated six patients treated with endoscopic evacuation for different stages of SDH from August 2019 to July 2023. Selection criteria were based on altered consciousness, lack of severe brain contusion, SDH thickness over 1 cm, or midline shift over 0.5 cm. The technique used a burr hole and rigid lens endoscope for hematoma removal, focusing on shorter surgery times and better outcomes. Patients aged between 63 to 84 years showed no surgical fatalities, with all recovering well by discharge. Hematoma clearance rates were 76.9% at three days, improving to 96.8% after one month. Endoscope-assisted evacuation is a safe, efficient treatment for elderly patients with various stages of SDH, offering a less invasive option with potential for better outcomes. It supports the trend towards minimally invasive neurosurgery, with further research needed to optimize patient selection and understand long-term benefits.

Vision Rehabilitation Using Contact Lenses in Infantile Nystagmus: A Systematic Review

Background and Objectives: Nystagmus has a negative effect on the patient's quality of life (QoL), leading to an increase in their dependence on others and a decrease in self-confidence and social relationships. Therefore, effective treatment and management are crucial in restoring those affected's visual function and social life. To determine whether contact lens (CL) use impairs the vision of infantile nystagmus (IN) patients, this study conducts a systematic review of the relevant literature. Methods: This systematic review adhered to the guidelines of the preferred reporting items for systematic reviews and meta-analyses (PRISMA). We searched databases including PubMed, Scopus, Google Scholar, and the Cochrane Central Register of Controlled Trials for relevant studies published up to May 9, 2022. The search was not limited by study type (except for review articles), publication time, or language. We used medical subject headings (MeSH) and keywords such as “nystagmus,” “CL,” “congenital nystagmus,” “IN,” “rigid gas permeable lenses,” and “soft CLs”. Results: Initially, 102 articles were identified. After removing duplicates, 76 articles remained. Of these, 39 were excluded during screening for irrelevance, and 8 were excluded due to inaccessible abstracts or full texts. Ultimately, 29 articles were included in this review. Conclusion: The majority of studies reviewed reported no significant side effects from using CLs, and most patients achieved similar or improved visual function compared to using glasses. As a result, even if CLs are not superior to glasses, they perform comparably and can be considered a primary treatment option when there are indications for prescribing CLs.

You've got to hide your myopia away: John Lennon's contactlenses.

John Lennon has an enduring, instantly recognisable, iconic, spectacle look. However, prior to 1966, he was rarely seen wearing glasses in public. From ages 7 to 26, he effectively hid his myopia away, including a period of unsuccessful contact lens wear during Beatlemania. This narrative review examines John's experience with contact lenses from 1963 to 1966 when he wore corneal rigid lenses made from polymethylmethacrylate, which regularly fell out. This frequent lens ejection was most likely due to the interaction between his upper eyelid and a spherical back surface rigid lens fitted to his right eye, which had a moderate degree of with-the-rule corneal astigmatism. John's recollection that his contact lenses stayed in place while 'stoned' supports this hypothesis, as a cannabis-induced upper eyelid ptosis would reduce the likelihood of lens ejection.

Triple tunnel and triple intraocular lenses (IOL): Modified scleral fixated IOL in a case of double dislocated IOL

Abstract We present a challenging case of a 60-year-old female who underwent cataract surgery in the right eye (RE) 10 years back. On presentation, visual acuity in RE with aphakic correction was 6/18, and the patient had a superior corneal scar with iris incarceration. Fundus examination revealed an attached retina and healthy optic nerve head with two dislocated rigid intraocular lenses (IOLs). The patient underwent vitrectomy with temporal scleral tunnel for explanting the IOLs. The same tunnel was used for scleral fixation of IOL whose haptics were buried into two opposite-facing scleral partial thickness scleral tunnels made at 12 and 6 o’clock. Thus, we describe a newer technique of sutureless scleral fixated IOL where scleral pockets are used for fixating three-piece IOL without the use of any suture, glue, or specialized IOL.

International trends in rigid contact lens prescribing (2000–2023): An update

PurposeRigid contact lenses have an important role in contact lens practice. The purpose of this work is to update earlier surveys by describing global trends in rigid lens fitting between 2000-2023. MethodAn annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023. Data relating to 342,500 fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of rigid lens fitting, defined as the fitting of any design of a contact lens manufactured in a rigid material. ResultsOverall, rigid lens prescribing increased slightly over time, from 14.2 % of lens fits in 2000 to 15.2 % in 2023 (p < 0.0001). However, post-hoc analysis shows that the change over time is best described as a decline between 2000 and 2012, followed by a steady increase subsequently. There were significant differences in rigid lens prescribing between countries (p < 0.0001). The difference between the percentage of males fitted with rigid lenses, as a proportion of all contact lenses (12.7 %), and females (12.0 %) is significant (p < 0.0001), although not clinically meaningful. Rigid lens wearers are older at fitting than soft lens wearers (38.7 vs 31.3 years, respectively) (p < 0.0001). Analysis of 5,994 rigid lens fits prescribed currently (2019–2023) were categorised as: corneal sphere – 30 %; scleral and corneo-scleral – 28 %; corneal myopia control/orthokeratology – 21 %; and corneal complex (including toric, multifocal and monovision) – 16 %. ConclusionThere has been a slight increase in rigid lens fitting during the second decade of this century. This increase is apparently due to a ‘repurposing’ of rigid lenses, with the growth of scleral/corneo-scleral and myopia control/orthokeratology lens fits essentially replacing conventional spherical corneal lens fits.

Effect of Corneal and Lens Eccentricity Difference on Rigid Corneal Lens Treatment in Patients With Keratoconus.

To evaluate the effects of rigid corneal lenses (RCL) in patients with keratoconus, based on eccentricity. Eighty-four eyes from 84 patients were included in this retrospective comparative study. Based on the median value of eccentricity difference between the cornea and back surface of the RCL, the patients were divided into groups 1 (<0.08) and 2 (≥0.08). Visual acuity, refractive index, and corneal topography indices were compared before and three months after lens use. Visual acuity, astigmatism, refractive error, corneal curvature, and corneal thickness improved significantly in both groups. Apical power and anterior elevation improved significantly in group 1, with small differences in eccentricity, but not in group 2. Changes in apical power before and after lens use were significantly different between the two groups. The RCL was effective for the cornea of keratoconus, especially when the prescription was made with a small difference in eccentricity.

Applying individual rigid scleral contact lenses in visual rehabilitation of patients with an irregular corneal surface. Clinical cases

Scleral rigid contact lenses efficiently correct the vision of patients with irregular corneas. Purpose. To study the features of contact correction and visual rehabilitation of patients with irregular corneal surface using individual scleral rigid contact lenses. Results. Three clinical cases of successfully selected rigid individual scleral lenses for patients with an irregular corneal surface that appeared after a penetrating keratoplasty, implantation of intrastromal corneal segments, and eye injury. The expected refractive result was achieved; high tolerance and good adaptation to lenses was revealed. Conclusion. Scleral RCL can be successfully used in patients with irregular cornea to improve visual acuity, reduce the number of aberrations, restore binocular vision and social adaptation.

Corneal Rigid Gas Permeable Contact Lens in Corneal Scarring: a Case Report

Introduction : Corneal scarring is part of corneal wound healing response to injury, surgery, or infection to the cornea. Corneal scarring causes significant visual reduction. This case report highlights visual acuity (VA) improvement in patient with corneal scarring following rigid glass permeable contact lens (RGP-CL)&#x0D; Case Illustration : A 25 year-old male presented blurry vision in right eye (RE) due to trauma. His VA was 3/60 on RE and 6/6 on left eye (LE). The best corrected visual acuity (BCVA) of RE was 6/45 (S-1.25 C-5.00 X 180°). Slit lamp examination of RE showed corneal scarring in central area and deep neovascularization. Keratometry readings obtained 39.50D (8.48mm) at 170 degree and vertical curvature of 44.00D (7.68mm) at 80 degree, with markedly irregular mires of RE. A trial fitting was performed for RE by using tisilfocon A lens with base curve of 8.30 mm, power S-4.00D and diameter 9.20 mm. The over-refraction with trial lens obtained a total refractive error of S-6.00 with cylindrical correction neutralize with RGP. The achieved BCVA by over-refraction was 6/45 with comfortable fit.&#x0D; Discussion : Rigid permeable lens (RGP) is an option in dealing with irregular astigmatism due to corneal scarring. The RGP fitting works best especially when the corneal scarring is not in the center of visual pathway. Rigid lens works by providing tear-lens power and creating smooth surface to neutralize the irregular cornea. Good RGP-CL fitting could help patient with corneal carring gain better VA.&#x0D; Conclusion : Good rigid permeable contact lens fitting could help patients with corneal scarring gain better VA.

Change in Corneal Astigmatism After Phacoemulsification with Rigid Intraocular Lens Implantation

Phacoemulsification with lens implant is the preferred method of cataract extraction nowadays. In resource-deficient settings, rigid polymethyl methacrylate (PMMA) lenses are implanted which require enlargement of corneal incision to 5.5mm. Objectives: We conducted this study to evaluate the effect of corneal incisions secured with a single suture on corneal astigmatism after routine cataract surgery. Methods: It was a quasi-experimental study conducted at tertiary care hospitals. Sixty patients were studied and preoperative visual acuity and keratometry readings were noted. After standard phacoemulsification, a 5.5mm rigid PMMA lens was implanted in the bag, and the corneal incision was sutured using a single central 10/0 nylon suture. Visual acuity and keratometry readings were noted on 1st postoperative day, 1-week postoperatively, and 6-weeks postoperatively and compared with pre-operative values. Results: The mean age was 59.27 ± 10.72 (range: 46 – 78) years. There were 32 (53.3%) males and 28(46.7%) females in the study. The mean preoperative keratometry reading was 0.89 ± 0.70 D, and the mean first-day postoperative cylinder was 1.94 ± 0.98 D (p &lt; 0.05). The mean astigmatism at the 6th week postoperatively was 0.96 ± 0.65 D, and its comparison with the pre-operative astigmatism was statistically not significant (p &gt; 0.05). Surgically induced astigmatism was found to be 0.07 diopters. Almost 60% of the patients achieved uncorrected 6/7.5 or better visual acuity, and more than one-third of patients achieved 6/6 best corrected visual acuity six weeks after the cataract surgery using the described technique. Conclusions: Phacoemulsification with 5.5mm PMMA IOL with a central single suture is an effective procedure for postoperative astigmatism and visual outcome.

Fitting RPG Progressive Bitoric Lenses after Bilateral Glaucoma Surgery

Glaucoma is a group of eye diseases which result in damage to the optic nerve and vision loss. Glaucoma can be divided in two groups’ open-angle and closed-angle. The importance in glaucoma disease is to treat it early because vision loss from this pathology, once it has occurred, is permanent. The main risk of factors for glaucoma includes increased pressure in the eye, a family history of the condition and high blood pressure . Generally, it is possible to treat glaucoma with laser and this treatment may be affective in both open-angle and closed-angle. A number of types of glaucoma surgeries may be used in people who do not sufficiently respond to other measure and treatment of closed-angle glaucoma is a medical emergency. After the laser treatment, if the ophthalmologist gives permission, it is possible to fit contact lenses to achieve better vision or correct patients with spectacles. This case report shows the fitting of rigid gas permeable progressive bitoric lenses after laser treatment because visual acuity achieved with spectacles was not good. Due to the intervention and patient needs, it was not possible to fit a scleral or hybrid lens.

Prevalence of contact lens complications among rigid lens wearers in specialty contact lens clinic in Delhi, India

Prevalence of contact lens complications among rigid lens wearers in specialty contact lens clinic in Delhi, India

Comparison of optical aberrations in keratoconus with scleral versus rigid gas permeable lenses.

to assess optical aberrations under scleral (SL) versus rigid gas permeable (RGP) lenses in patients with keratoconus. A prospective study including 25 eyes of 14 patients. The best-corrected visual acuity (BCVA) with corrective glasses, RGP and SL, stage of keratoconus (Amsler-Krumeich classification), minimum pachymetry, maximum keratometry, and corneal higher-order aberrations (i.e, total HOAs, coma, and trefoil) with RGP and with SL were collected. Aberrometry was performed using iTrace® aberrometer (Tracey Technologies, USA). 80% of the included keratoconus patients were stage 4, with a mean age of 34.3 years (±8.8). There were no significant differences in mean BCVA (logMAR) between SL and RGP. The mean BCVAs were significantly better both with SL (p < 0.0001) and RGP (p < 0.0001) compared with corrective glasses. Total HOAs (p = 0.01), coma (p = 0.003) and trefoil (p = 0.008) were significantly lower with SL compared with RGP. The BCVA decreased with the stage of keratoconus in SL (p = 0.01) and RGP (p = 0.02). The BCVA decreased with decreasing minimum pachymetry in SL (p = 0.02) and RGP (p = 0.002), and with increasing maximum keratometry in SL (p = 0.02) and RGP (p = 0.01). Significant correlations were found between BCVA, total HOAs (p = 0.008), and coma (p = 0.02) in SL. For the same keratoconus patients, total higher order, coma and trefoil optical aberrations were reduced with scleral lenses compared to rigid gas permeable lenses.

Development of a bio-inspired optical system that mimics accommodation and lighting regulation like the human eye.

Bio-inspired optical systems have recently been developed using polarizers and liquid or rigid lenses. In this work, we propose a bio-inspired opto-mechatronic system that imitates the accommodation and regulation of light intensity as the human eye does. The system uses a polymeric lens as a cornea, an adjustable diaphragm as an iris, a tunable solid elastic lens as a crystalline lens, and a commercial sensor as a retina. We also present the development of the electronic control system to accommodate and regulate the amount of light that enters the system, for which two stepper motors, an Arduino control system, and light and movement sensors are used. The characterization of the system is presented together with the results obtained, where it can be seen that the system works in an acceptable range as the human eye does.

Применение склеральных линз для коррекции посткератопластической аметропии

Purpose. Analysis of clinical and functional results of correction of postkeratoplastic ametropia with rigid gas-permeable scleral lenses. Material and methods. Clinical and functional results of the correction of postkeratoplastic ametropia (PA) with rigid gas-permeable scleral lenses (RGSL) were analyzed based on a comprehensive examination of 25 eyes (25 patients). Of these, there were 16 men and 9 women. The mean age of the patients was 40±9 years. Uncorrected visual acuity (UCVA) was 0.14±0.16, best corrected visual acuity (BCVA) with glasses was 0.44±0.25, the spherical refractive component was 1.37±2.58 D, the cylindrical refractive component was –4,75±1.68 D. The follow-up period was about 5 years. Results. After application of RGSL, all patients noted a significant improvement in visual acuity due to the correction of PA and an increase in the regularity of the corneal graft. There was a statistically significant increase in BCVA in RGSL up to 0.66±0.13 (p=0.0022), which remained stable throughout the entire observation period. BCVA in RGSL 0.5 and above was noted in 93% of the eyes. In all patients, after the selection of RGSL, a significant decrease in total corneal aberrations, including higher order ones, was noted. When calculating the cell density of the epithelium of the corneal graft on HRT III Cornea after 5 years of wearing RGSL, a decrease in the cell density of all layers of the epithelium was noted. The absence of endothelial cell density loss, clinically significant corneal graft edema, and reduction in the biomechanical properties of the corneal graft indicate the safety of long-term use of RGSL in patients after keratoplasty. Conclusion. Clinical and functional analysis of the correction of postkeratoplastic ametropia with rigid gas-permeable scleral lenses during 5 years of observation showed: higher rates of best corrected visual acuity compared to spectacle correction by an average of 0.22±0.05, a significant decrease in corneal aberrations, a decrease in the density of cells of all corneal graft epithelium layers, high optical efficiency, and safety of their use during the entire observation period. Key words: postkeratoplastic ametropia, rigid gas-permeable scleral lens, corneal graft

Comparative analysis of the correction of irregular postkeratoplastic astigmatism with scleral lenses and intrastromal ring implantation

Background. Many patients after penetrating keratoplasty (PK) experience induced postkeratoplastic astigmatism, which is often irregular and causes an increase in corneal aberrations that reduce visual acuity and quality. The aim of the study. To conduct a comparative analysis of the effect of rigid gas permeable scleral lenses and the MyoRing implantation method on clinical and functional parameters in patients with IPA. Material and methods. The clinical study included 60 patients (60 eyes). The age of patients with IPA was from 25 to 42 years. All patients underwent penetrating keratoplasty. All patients were divided into two groups depending on the method for irregular postkeratoplastic astigmatism correction. Group I included 30 patients (30 eyes) who were fitted with rigid gas permeable scleral lenses. Group II consisted of 30 patients (30 eyes) who underwent implantation of the MyoRing into a penetrating corneal graft. The observation period was 1 year. Results. After 12 months of observation, there was a greater increase in uncorrected visual acuity by an average of 3 lines, in corrected visual acuity – by 2 lines; a greater decrease in corneal aberrations in photo- (root mean square (RMS) of total aberrations (RMS total) by 0.30 ± 0.08 µm, RMS of higher order aberrations (RMS HOA) – by 1.01 ± 0.24 μm) and mesopic conditions (RMS total – by 0.33 ± 0.09 μm, RMS HOA – by 0.08 ± 0.03 μm) in patients wearing rigid gas permeable scleral lenses compared with patients after MyoRing implantation into a penetrating corneal graft. Conclusion. Patients of group I, wearing rigid gas permeable scleral lenses, showed a greater improvement in visual acuity and a decrease in corneal aberrations in photo- and mesopic conditions compared to the patients of group II (after MyoRing implantation) at a follow-up period of 12 months.

High Astigmatism Secondary to Peripheral Ectasia Recurrence in Postpenetrating Keratoplasty Eyes Managed With Miniscleral Contact Lenses.

After penetrating keratoplasty (PK) for keratoconus, vision can be impaired by high-degree astigmatism, particularly in those patients with recurrent peripheral ectasia. Scleral contact lenses (CLs) have long been used in the management of keratoconus both in treatment-naive corneas and those postcorneal transplants. We report the use of miniscleral CLs and their related visual and clinical outcomes in a series of patients with post-PK peripheral rim ectasia. In this retrospective case series, 5 patients (7 eyes) presented because of reduced visual acuity with their spectacles/CLs and/or reduced comfort with their existing rigid gas-permeable lenses. All patients in this series underwent PK more than two decades ago for keratoconus (mean 28.7 years±7.2). All patients demonstrated characteristic thinning at the graft-host junction, with anterior chamber deepening. Central corneas had remained clear in all patients inferring high visual potential. Contact lenses used were No 7 Comfort 15 miniscleral and the Onefit MED scleral with 14.5 mm and 15.6 mm diameters, respectively. All eyes achieved a best-corrected visual acuity of 6/9 or greater. One case had difficulty with insertion and removal and has since discontinued wearing lens at this time. All others are successfully wearing the lenses regularly. Despite advances in CL design, surgical management is still required in some patients. Miniscleral CLs are effective in the refractive management of peripheral ectasia in keratoconic post-PK eyes and should be considered in such eyes before proceeding with repeat surgical intervention.

High myopia control is comparable between multifocal rigid gas-permeable lenses and spectacles.

Ocular pathology may be reduced by slowing myopia progression. The purpose of this study was to evaluate the potential of a novel custom-designed rigid gas permeable (RGP) contact lens to control high myopia by comparing the efficacy of multifocal RGP lenses and single-vision spectacles for high myopia control. The medical records of children fitted with spectacles or multifocal rigid gas-permeable lenses between January 2018 and May 2020 were retrospectively reviewed. Children (5-17 years) with non-cycloplegic spherical equivalent refraction of ≤ -6.00 D or spherical equivalent refraction > - 6.00 D with baseline axial length ≥ 26.5 mm, and astigmatism of ≥ -2.00 D were included. Axial length and refraction were measured at baseline, before fitting the participants with multifocal rigid gas-permeable lenses or spectacles, and at 1- and 2-year follow-up visits. Changes in axial length were compared between the groups. Among the 77 children with 1-year follow-up data, the mean axial elongation was 0.20 ± 0.17 mm and 0.21 ± 0.14 mm in the multifocal rigid gas-permeable and control groups, respectively, without significant differences between groups (F = 0.004, p = 0.835). Among the 41 patients who completed 2 years of follow-up, the mean axial elongation values in the multifocal rigid gas-permeable and control groups were 0.21 ± 0.15 mm and 0.24 ± 0.13 mm, respectively, at the 1-year follow-up, and 0.37 ± 0.27 mm and 0.43 ± 0.23 mm, respectively, at the 2-year follow-up, without significant between-group differences at either time point (p = 0.224). Axial length increased at a similar rate in both the control (spectacles) and multifocal rigid gas-permeable lens groups, suggesting that multifocal rigid gas-permeable lenses have no significant impact on controlling high myopia progression compared with spectacles.

Evaluation of Rinsing Options for Rigid Gas Permeable Contact Lenses.

This study assessed the efficacy of various saline solutions as alternative methods to rinsing rigid gas permeable (RGP) lenses with tap water. The exiting fluid pressure of five commercially available saline solutions was measured using a venous pressure transducer system. Rigid gas permeable lenses were cleaned with one of two commercially available cleaners and then rinsed with one of five saline solutions or with tap water. High-resolution imaging was performed after each rinse, and light transmission through the lens surface was determined by measuring the mean pixel count within a 1 mm by 1 mm square. The mean pixels/mm 2 and the rinsing method were correlated (Spearman rank order correlation, P <0.0001), that is, high pixel counts represented more lens surface deposits and residue, and as fluid pressure of the rinsing methods increased, mean pixels/mm 2 decreased. Measured fluid pressure relates to lens surface opacity suggesting that some products leave less residue than others. In addition, tap water, with its high exiting fluid pressure, seems to be the most effective option for removal of RGP cleaners from the contact lens surface. Despite these findings, tap water rinse is not encouraged because of its potential to lead to corneal inflammation and infection; therefore, the development of alternative procedures and products is needed.