Lens Removal Research Articles

Grasping Interface With Wet Adhesion and Patterned Morphology: Case of Thin Shell

In this letter, we present an analytical method for studying the role of the micropatterned morphology of soft fingers with wet adhesion in grasping a deformable thin shell. This letter originated from a project on a robotic platform for autonomous attachment and removal of a soft contact lens in a “human eye” under a wet environment. In this scenario, a contact lens (hemispherical thin shell) was gripped by a soft-fingered hand in three conditions: inside/outside a liquid environment and when the contact lens was in contact with a convex curved substrate (as an eye). Two fingertip surfaces were compared: a flat surface, and a micropatterned surface inspired by the adhesion mechanism of a tree-frog's toes. The pattern of the latter comprised 3600 square cells, each of size 85 $\mu$ m × 85 $\mu$ m interspaced by 15 $\mu$ m. A proposed analytical model was utilized to evaluate the grasp forces in both types of fingertip surface. The forces were subsequently verified by application in grasping a contact lens. The experimental results showed good agreement with the analysis as the micropattern pad decreased the preload and deformation of the shell 1.1–2× lower than that of the flat surface. This letter could be extended to model grasping interfaces with deformable curvature objects in wet and high moisture content environments.

English

AIM OF THE STUDY: To clinically analyse visual outcome and intraocular pressure control in surgically treated cases of lens induced glaucoma. MATERIALS AND METHODS: 100 patients with LENS INDUCED GLAUCOMA attending glaucoma services of Regional Institute of Ophthalmology and Government Ophthalmic Hospital were included in the study. Patients with presence of phacolytic, phacomorphic, lens particle, phaco anaphylaxis glaucoma and subluxated or dislocated lens with elevated intraocular pressure were included in the study. Patients with previous history of Primary Open Angle glaucoma and primary angle closure glaucoma, other secondary glaucomas, uncontrolled diabetes and IHD were excluded. All were subjected to detailed anterior segment examination, best corrected visual acuity, intraocular pressure measurement either by Goldmann applanation tonometry or in cases with presence of corneal edema rebound tonometry reading was recorded, fundus examination, gonioscopic examination were done. Surgical procedures like SICS/ECCE or combined surgery in cases with peripheral anterior synechiae or lens removal with secondary iol implantation were done. Surgical complications were analysed in patients undergoing sics/ecce/lens removal with secondary IOL and combined surgery and followed up periodically with visual acuity and intraocular pressure measurements and gonioscopic examination. RESULTS: In our study, 52% cases were in the age group of 56 -60 years, there was a slight male preponderance (59%), 47% presented with an IOP of 28-32mmhg. 60% cases were phacolytic glaucomas, 29% were phacomorphic glaucomas, 10% were lens particle glaucomas, 1% was due to subluxated lens induced glaucoma. 72% cases had PCIOL in other eye, 57% had a visual acuity in 6/36-6/18 range in other eye. At the end of six weeks the visual acuity for maximum number of cases (55%) was in the range 6/36-6/18, 20% cases had vision of range 3/60-6/60, 20% cases had vision of range 6/12-6/9. Hence visual improvement occurred in 95% of cases at the end of sixth post-operative week. 68% of cases had striate keratopathy, Post-operative iritis was present in all cases (100%), zonular dehiscence occurred in 43% cases, 12% cases had posterior capsular rent and 5% cases had vitreous loss. Out of 10 lens particle glaucoma cases, 50% (5 cases) had a good vision of 6/12 when compared to other types of lens induced glaucoma. Intraocular pressure was in the range of 12-14mmhg in 60% cases, 16-18mmhg in 40% cases at the end of six weeks. CONCLUSION: In our study, most of the patients had good vision in fellow eye and PCIOL status. This shows that patients ignored the reduced vision in affected eye due to good vision in fellow eye so their daily life was not affected until they developed symptoms. In lens induced glaucoma, surgery is the main stay of treatment after adequate control of intraocular pressure and inflammation with medications. Following surgery, intraocular pressure reduction occurs in all cases and visual improvement occurs in 95% cases.

Risk of cataract removal surgery in Mayak PA workers occupationally exposed to ionizing radiation over prolonged periods.

In this study, the risk of cataract removal surgery was assessed in a cohort of workers occupationally exposed to ionizing radiation over a prolonged period. The study cohort includes 22,377 workers of the Mayak Production Association (about 25% of whom are females) first employed at one of the main facilities in 1948-1982, who were followed up to the end of 2008. Dose estimates used in the study are provided by the Mayak Worker Dosimetry System 2008. The mean cumulative dose from external γ-rays [personal dose equivalent Hp(10)] is 0.54 ± 0.76Sv for males and 0.44 ± 0.65Sv for females. The mean cumulative doses from neutrons (personal dose equivalent Hp(10)n) were 0.034 ± 0.080Sv for males and 0.033 ± 0.092Sv for females. Relative risks and excess relative risks per unit dose were calculated based on maximum likelihood. Among 4,177 workers diagnosed with a verified diagnosis of senile cataract, 701 lens removal surgeries (16.7%) were performed by the end of the follow-up period. The risk of cataract removal surgery was shown to be significantly associated with non-radiation factors such as sex, attained age, smoking, an ocular comorbidity (e.g., glaucoma), and a somatic comorbidity (e.g., diabetes mellitus). There was no significant association of cataract removal surgery with external γ-dose regardless of inclusion of the neutron dose adjustment with either linear or non-linear models. It is concluded that cataract removal surgery rate may not be a highly sensitive and specific indicator that could serve as a surrogate for radiation-related cataracts.

Anterior Corneal Curvature and Aberration Changes After Scleral Lens Wear in Keratoconus Patients With and Without Ring Segments.

To evaluate changes in the anterior corneal curvature and aberrometry after scleral contact lens wear in keratoconus (KC) subjects with and without intracorneal ring segments (ICRS). Twenty-six subjects diagnosed with keratoconus were selected to participate in the study. Subjects were divided into 2 groups, those with ICRS (KC-ICRS group) and those without ICRS (KC group). Subjects were instructed to wear 16.5-mm scleral lenses for 8 hours. Topographic and aberrometric parameters were evaluated before lens wear and immediately after lens removal. Anterior corneal curvature was evaluated at corneal diameters of 2, 4, 6, and 8 mm, and corneal aberrations were measured at 4-, 6-, and 8-mm pupil diameters. The mean age of subjects was 36.95±8.95 years. In KC group, there was a statistically significant flattening of the central corneal curvature, from 6.98 to 7.09 mm (P<0.05). No changes were found in the central corneal curvature in the KC-ICRS group. The KC group showed anterior corneal curvature flattening, mainly in the nasal quadrant. The KC-ICRS group showed flattening primarily in the inferior hemisphere. In the KC group, spherical aberration for 6-mm pupil increased significantly. In the KC-ICRS group, changes in aberrations were significant for high-order root mean square at 4- and 6-mm pupil diameters (P<0.05), for oblique astigmatism for 4 mm and 6 mm, and for vertical coma for 4-mm pupil (P<0.05). Short-term scleral lens wear showed flattening of the anterior corneal surface in all subjects. In the KC group, the flattening was more pronounced in the nasal quadrant while changes were more pronounced inferiorly in KC-ICRS group.

Tolerability and Functionality of a Wireless 24-Hour Ocular Telemetry Sensor in African American Glaucoma Patients.

The purpose of the study was to evaluate the tolerability and functionality of a wireless ocular telemetry sensor in African American patients with glaucoma. In this prospective, observational cohort study, 20 African American patients with primary open angle glaucoma (POAG) were evaluated at the University of Colorado Eye Center. Before lens placement, patients recorded ocular comfort and underwent a baseline eye exam. Following the exam, patients were fitted with a SENSIMED Triggerfish contact lens sensor and data recording device. Patients were sent home and instructed to record their activities in a journal and return in 24 hours. Repeat exams were performed at various time points in clinic before and after lens removal. All 20 patients retained the lens for the 24-hour study period. The patient reported comfort was excellent, with a nadir of mean recorded comfort of 7.05/10. Significant clinical changes were noted in lid/conjunctival erythema, BCVA, refraction, and pachymetry over the course of lens wear. The majority of these changes were improved or resolved by 1 hour after lens removal. Voltage output was significantly greater nocturnally than diurnally (184.79 mV and 71.48 mV, respectively; P<0.0001). There was no significant change in signal variability or slope over the entire duration of the sleep/wake period based on sleep. The wireless ocular sensor is well tolerated over a 24-hour period in African American patients with POAG despite transient changes in visual acuity and conjunctival erythema. Clinically usable 24-hour profiles were generated for all patients, with voltage output increasing significantly during periods of sleep.

PLA-PEG Micelles Loaded with a Classic Vasodilator for Oxidative Cataract Prevention.

The only treatment for cataract in clinic is the clouded lens removal combined with artificial lens implantation. In this study, nifedipine (NFP), a classic vasodilator, was loaded in a U.S. FDA-approved polymer PLA-PEG to form NFP-loaded PLA-PEG micelles as a novel eye drop to prevent oxidative cataract formation and progression at the early stage. The NFP-loaded PLA-PEG micelles not only showed satisfactory biocompatibility and bioavailability, but also efficiently improved the anticataract ability through the inhibition of extracellular calcium ions influx. This study may provide a new insight into the development of cataract treatment.

Frequency and type of macular edema after cataract surgery in patients with glaucoma

Cataract is one of the common causes of reversible vision loss in people older than 50 years. Currently, the only way to treat it effectively is phacoemulsification with simultaneous implantation of an intraocular lens - a method that minimizes the amount of surgical trauma and the number of intra- and postoperative complications. Nevertheless, the problem of prevention and timely diagnosis of pathological changes in the retina, which may develop after extraction of cataracts, and in particular - macular edema, remains relevant. This problem becomes especially important when it comes to patients with concomitant cataract and glaucoma who use local antihypertensive drugs - in particular, prostaglandin analogues - for a long time. Having common properties with inflammatory mediators, in some cases they can cause vasodilation, increase vascular permeability and contribute to the development of exudative processes. Drugs of this group can cause impairment of the hematophthalmic and hematoretinal barriers provoking the development of cystoid macular edema, including in the early postoperative period after cataract extraction. As described by S. Irvine in 1953, macular edema is related to late postoperative complications and remains one of the main causes of visual impairment after lens removal. The review provides information about some studies concerning the effect of prostaglandin derivatives on the postoperative period after phacoemulsification. At this time, there is no consensus on this matter.

Management Strategies of Ocular Abnormalities in Patients with Marfan Syndrome: Current Perspective.

Marfan syndrome is an autosomal dominant genetic connective tissue disorder that results from mutations in the fibrillin-1 gene located on chromosome band 15q15–21. Fibrillin, a glycoprotein, is widely expressed throughout the body and contributes to the elasticity and force-bearing capacity of connective tissue. In the eye, fibrillin is a key constituent of the ciliary zonules, which suspend the crystalline lens in place. The zonular defect leads to ectopia lentis, which is a hallmark of Marfan ocular abnormalities and occurs in 60% to 80% of cases. Other less common ocular features of Marfan syndrome are increased axial length, astigmatism, and flat cornea. Visual function in Marfan syndrome could be affected in several ways: ectopia lentis, refractive error, amblyopia, retinal detachment, cataract, and glaucoma. Management of a subluxated lens starts with the correction of refractive error with eyeglasses in mild cases. In more severe cases, especially when the lens bisects the pupil, complete correction of refractive error is impossible without removing the subluxated lens. The best method for visual rehabilitation after lens extraction is still debated. Aphakic Artisan lens implantation at the time of subluxated lens removal results in good visual outcomes with an acceptable safety profile. Studies with longer term follow-up and larger sample populations are needed to evaluate the safety of this procedure in patients with Marfan syndrome.

Assessment of a practitioner's perception of scleral contact lens complications.

The purpose of this survey was to better understand scleral lens (SL) practitioners' fitting preferences and minor SL complications and their subsequent treatments. Practitioners who attended the 2017 Global Specialty Lens Symposium were asked to complete an electronic questionnaire that was created by the investigators, a survey that asked practitioners about their SL fitting experience and preferences, their patients' experience with poor SL wetting, SL fogging, ocular symptoms (redness, pain/discomfort, dryness), and blurred central and side vision, and how the practitioners treated these conditions. This study analyzed data from 164 SL practitioners. The practitioners had been in practice for 16.3 ± 13.4 years, had been fitting SL for 5.5 ± 5.0 years, and fit 7.4 ± 7.1 SL/month. Practitioners preferred a SL with a final central corneal clearance of ∼200 μm and an overall diameter between 15.1 mm to 16.5 mm. Poor SL wetting (90.8% of practitioners documented condition), SL fogging (84.8%), blurred central vision (40.2%), ocular redness (34.8%), ocular dryness (24.4%), ocular pain/discomfort (20.7%), and blurred side vision (12.8%) were encountered by the practitioners. Practitioners preferred treating poor wetting and fogging with lens removal, cleaning, and reapplication, blurred central vision with a lens power change, blurred side (peripheral) vision, ocular redness, and ocular pain with a lens parameter change, and dryness with artificial tears. Most SL practitioners preferred a SL central corneal clearance of ∼200 μm, and they occasionally encountered SL-related complications in their practice, which they treated similarly to corneal gas permeable CLs.

Thickness changes in the corneal epithelium and Bowman\u2019s layer after overnight wear of silicone hydrogel contact lenses

BackgroundTo investigate thickness changes in the corneal epithelium and Bowman’s layer after overnight silicone hydrogel contact lens (CL) wear by using ultra-high resolution optical coherence tomography (UHROCT).MethodsEleven subjects without CL wearing history were recruited for this study. An UHROCT was used to measure the thickness of the epithelium (ET), Bowman’s layer (BT), stroma (ST), and total cornea (CCT) at the center of both eyes. A silicone hydrogel CL was inserted in the right eye of each subject, and the fellow non-CL wearing left eye served as the control. The lens was inserted at 9:30 pm and removed at 8:00 am the next morning. The subjects were evaluated at 9:00 pm (baseline), 9:30 pm (lens insertion), 10:00 pm (before sleep), 7:00 am (waking), 7:30 am, and 8:00 am (lens removal).ResultsCompared to the lens insertion level, the ET of the lens-wearing eye increased by 5.73% at eye opening (P = 0.001). The ET of the non-CL wearing eye and the BT in both eyes did not change after overnight CL wear. Compared to baseline, the CCT of the lens-wearing eye increased by 2.87% upon waking (P = 0.003) and recovered 30 min later (P = 0.555). In contrast, compared to baseline, the CCT of the non-CL wearing eye did not increase upon waking (P = 0.105).ConclusionsBy using UHROCT, we found that overnight CL wear induced different swelling responses in the various sublayers of the cornea.Trial registrationRetrospectively registered. Registration number: ChiCTR1800015115. Registered 07 March 2018.

Scleral asymmetry as a potential predictor for scleral lens compression.

To identify the position and magnitude of lens compression due to short-term miniscleral contact lens wear, as well as evaluating the usefulness of scleral asymmetry as a predictor for scleral lens decentered compression. Fourteen healthy subjects (mean±S.D.: 29.2±6.0years) wore a highly gas-permeable spherical haptic miniscleral contact lens during a 5-h period. Corneo-scleral height Fourier profilometry was captured using an Eye Surface Profiler (www.eaglet-eye.com) before and immediately after lens removal. Scleral asymmetry, lens compression location and magnitude were processed using custom-made algorithms, both globally and for scleral quadrants. Miniscleral contact lenses do not set uniformly on the ocular surface, with the largest decentration seen along the horizontal meridian. The greatest flexural stress exerted by the lens on the ocular surface occurs at the point coinciding with the inner diameter landing point of the lens and not with its overall diameter. Scleral asymmetry was significantly correlated with compression location (R=0.71, p=0.002) and compression magnitude (R=0.81, p<0.001), showing its potential as compression predictor. Larger amounts of scleral asymmetry will lead to more decentration of spherical haptic scleral lenses. Objective and accurate methods, like the one presented here, could help the practitioner prevent cases of scleral blanching or discomfort due to an excessive compression by the lens.

The efficacy of surgery for removal of intraocular lens which prolapsed into vitreous

Objective To evaluate the surgical efficacy of surgery for removal of posterior chamber intraocular lens which prolapsed into the vitreous. Methods From Oct. 2012 to Oct. 2017, the data of 16 eyes of 16 patients with intraocular lens prolapsed into vitreous were analyzed restropectively. The cause was ocular contusion in 11 eyes, after cataract surgery without history of trauma in 5 eyes. The best corrected visual acuity before operation was CF-0.1. Vitrectomy was performed via the standard pars plana closed incision. The perfluorocarbon liquid of 0.5-3.5 ml was injected during operation, and intraocular lens was removed through the tunnel of the corneal limbus. All cases received IOL suture fixation in the ciliary sulcus.The postoperative visual acuity, intraocular pressure, intraocular lens position and complications were observed. Results The intraocular lens were successfully removed in 16 eyes. Thirteen eyes received the posterior chamber intraocular lens with ciliary sulcus suture fixation in one stage, and the visual acuity was improved. The best corrected visual acuity was 0.1-0.5. Postoperatively hypotony occurred in 1 eye, hypertension occurred in 3 eyes, and the intraocular pressure returned to normal after drug treatment. No complication such as intraocular lens decentration or dislocation, suture knot exposure or vitreous hemorrhage occurred. Conclusion Vitrectomy combined with intraocular lens removal and ciliary sulcus stature fixation for the treatment of the intraocular lens prolapsed into the vitreous can obviously improve visual acuity and prevent complications. Key words: Dislocation, lens, intraocular; Removal, lens, intraocular; Suture fixation; Ciliary groove

Electroencephalogram alertness responses to blue light stimulus in elderly people with cataract

Daytime blue light exposure can reduce fatigue and increase alertness in young healthy adults. Little is known of the daytime blue light influence on alertness in elders. A prospective with-in subject study was carried out in Peking University Third Hospital to evaluate the impact of cataract surgery on visual functions and the electroencephalogram alertness response to blue light stimulus before and after surgery. 14 participants diagnosed with age-related cataract were scheduled for monocular cataract surgery with ultraviolet-filtering intraocular lens (IOL) implantation. Best corrected visual acuity (BCVA), color discrimination and electroencephalogram results were measured before and after surgery. Exposure to blue light resulted in decreased delta (0.25–3.00 Hz) activity and increased beta (13.25–30.00 Hz) activity both before and after cataract surgery. Significant improvements in the BCVA and Farnsworth-Munsell-100-hue total error scores were found after cataract surgery. The partial error scores in the red-yellow, green blue-blue, and blue purple-purple red bands also showed significant differences, with the green blue-blue band showing the most obvious improvement. Day-time blue light stimulus can increase alertness in elderly people with significant cataracts. Cataract surgery with ultraviolet-filtering IOL implantation can increase light, particularly blue light transmittance. Opaque lens removal does not increase the alertness responses to blue light 1 day after surgery. Nevertheless, the increase in light especially blue light perception can be beneficial for the health of elder people in the long run.

Long-Term Changes in Straylight Induced by Overnight Orthokeratology: An Objective Measure Using the Double-Pass System

ABSTRACTPurpose: To map the time course of changes in intraocular straylight of the human eye 1 year after initial lens wearing for orthokeratology treatment using the objective double-pass technique.Materials and Methods: A total of 35 subjects (19 males and 16 females) completed the study. The mean age was 11.46 ± 2.33 years (range, 8–16 years). All subjects were fitted with spherical four-zone orthokeratology lenses following the procedures recommended by the lens manufacturer. The subjects were required to wear the lens for at least eight consecutive hours at night. After lens removal during the daytime, objective scattering index (OSI) was evaluated using the double-pass technique (OQAS-II, Visiometrics, Terrassa, Spain) prior to lens dispatch (baseline), followed by evaluations at 1 week, 1 month, 6 months, and 12 months after the initial lens wearing. Longitudinal changes were fitted to a model containing both an impairing and recovery component, and the results were based on an extrapolation between the visits.Results: OSI rose quickly following lens wearing, reaching its highest level (double that of baseline values) by approximately 1.47 months. However, the recovery phase was slow and modest. One year after the initial lens wearing, OSI exhibited a 20% recovery from the peak level, but remained 63% higher than the baseline level.Conclusions: Intraocular straylight immediately increased flowing lens wearing, and this change reaches maximal level around 1 month after lens wearing. Slow but significant recoveries of optical quality subsequently followed.

Intraocular robotic interventional surgical system (IRISS): Semi-automated OCT-guided cataract removal.

With the development of laser-assisted platforms, the outcomes of cataract surgery have been improved by automating several procedures. The cataract-extraction step continues to be manually performed, but due to deficiencies in sensing capabilities, surgical complications such as posterior capsule rupture and incomplete cataract removal remain. An optical coherence tomography (OCT) system is integrated into our intraocular robotic interventional surgical system (IRISS) robot. The OCT images are used for preoperative planning and intraoperative intervention in a series of automated procedures. Real-time intervention allows surgeons to evaluate the progress and override the operation. The developed system was validated by performing lens extraction on 30 postmortem pig eyes. Complete lens extraction was achieved on 25 eyes, and "almost complete" extraction was achieved on the remainder due to an inability to image small lens particles behind the iris. No capsule rupture was found. The IRISS successfully demonstrated semiautomated OCT-guided lens removal with real-time supervision and intervention.

Reduced posterior capsular rupture rate observed among trainee surgeons utilizing a disposable silicone-tipped irrigation and aspiration handpiece for soft lens removal

ABSTRACTBackground: To determine if there is an association between lower posterior capsule rupture (PCR) rates among trainees using silicone-tipped handpieces compared with trainees using conventional instrumentation.Methods: In a retrospective audit, anonymized data was extracted for two groups of supervised deanery trainees. Group one operated with conventional IA handpieces. Group two utilized silicone-tipped IA handpieces. Risk factors found to increase the likelihood for intraoperative PCR were included in the analysis. Statistical significance was tested using a parametric test of two proportions.Results: Group one performed 782 surgeries and had a PCR rate of 3.6% vs 1.6% from 933 surgeries in group two. Following adjustment for risk factors, the p-value was 0.057. Group two had no IA-related PCR complications vs 12% in group one. Both groups demonstrated highest rates of PCR during phacoemulsification, 48% and 57%, respectively.Conclusion: Group two had lower than expected complication rates compared to the published literature. Trainees utilizing a 45-degree silicone-tipped IA handpiece had a lower rate of PCR and vitreous loss compared to group one and experienced no complications during IA. This suggests silicone-tipped IA handpieces may be safer for soft lens extraction compared to conventional instrumentation.

Uncommon complication following uneventful Nd:YAG capsulotomy

This article reports the development of low grade endophthalmitis following Nd:YAG laser posterior capsulotomy. The patient previously underwent uncomplicated extracapsular cataract extraction with intraocular lens (IOL) insertion and was free of inflammation prior to laser capsulotomy. Anterior vitrectomy with partial capsular bag removal and anterior chamber washout were performed. Samples for cultures were taken and intravitreal antibiotics injected. The patient was managed with topical and systemic antibiotics and steroids. Complete resolution of the inflammation with return of vision to 20/25 was achieved without removal of the intraocular lens or lenticular remnants. The endophthalmitis was responsive to a minimally invasive intervention as well as medicinal therapy including antibiotic agents, and it resolved without any invasive surgical intervention, such as total capsulectomy, IOL exchange or removal and posterior vitrectomy.

Intra-ocular pressure variation associated with the wear of scleral lenses of different diameters.

To evaluate the variation of intra-ocular pressure during scleral lens wear, and the influence of the lens diameter on the results. This is a prospective, randomized study performed on Caucasian subjects (16 F; 5 M), aged 24.7 + 4.1 y.o. A diurnal variation pattern (IOPg) was established, then, transpalpebral IOP (IOPt) was taken before and during SL wear. One eye, randomly fitted with a 15.8 diameter SL (L1), was compared to the fellow eye, fitted with an 18 mm SL of the same design, thickness and material (L2). Anterior segment tomography was taken pre-and after lens removal. Baseline IOPg (L1:15.2 + 3.1 mm HG; L2: 15.1 +/- 2.8 mm) did not reveal significant diurnal variations. Wearing L1, IOPt rose from 10.1 + 1.9 mm HG to 14.4 + 5.5 mm HG after 4.5 + 0.3 hrs, while with L2, it rose from 9.2 + 2.1 mm HG to 14.4 + 4.8 mm Hg. This difference is statistically significant based on time but not on lenses. Anterior segment parameters did not vary except for the anterior chamber volume (L1: -1.53 + 7.61 mm3; L2: -3.47 + 6.4 mm3), and for the corneal thickness (+2.1% with L1 and L2). These results suggest that, as evaluated with a non-standard transpalpebral methodology, IOP during scleral lens wear may be increased in average by 5 mm Hg, regardless of the lens diameter. More work is needed to confirm if practitioners should be warned when using SL on populations at risk for glaucoma.

Anterior eye surface changes following miniscleral contact lens wear.

To quantify the effect of short-term miniscleral contact lens wear on the anterior eye surface of healthy eyes, including cornea, corneo-scleral junction and sclero-conjuctival area. Twelve healthy subjects (29.9 ± 5.7 years) wore a highly gas-permeable miniscleral contact lens of 16.5 mm diameter during a 5-hour period. Corneo-scleral height profilometry was captured before, immediately following lens removal and 3 h after lens removal. Topography based corneo-scleral limbal radius estimates were derived from height measurements. In addition, elevation differences in corneal and scleral region were calculated with custom-written software. Sclero-conjuctival flattening within different sectors was analysed. Short-term miniscleral lens wear significantly modifies the anterior eye surface. Significant limbal radius increment (mean ± standard deviation) of 146 ± 80 μm, (p = 0.004) and flattening of -122 ± 90 μm in the sclero-conjuctival area, (p << 0.001) were observed immediately following lens removal. These changes did not recede to baseline levels 3 h after lens removal. The greatest anterior eye surface flattening was observed in the superior sector. No statistically significant corneal shape change was observed immediately following lens removal or during the recovery period. Short-term miniscleral contact lens wear in healthy eyes does not produce significant corneal shape changes measured with profilometry but alters sclero-conjuctival topography. In addition, sclero-conjuctival flattening was not uniformly distributed across the anterior eye.

Methods for Examining Lens Regeneration in Xenopus.

Some vertebrates are able to regenerate the lens following its removal. This includes species in the genus Xenopus (i.e., X. laevis, X. tropicalis, and X. borealis), the only anurans known to undergo lens regeneration. In Xenopus the regenerated lens is derived de novo from cells located within the basal-most layer of the larval corneal epithelium, and is triggered by factors provided by the neural retina. In larval frogs the corneal epithelium is underlain by an endothelium separated from the corneal epithelium except for a small central attachment (i.e., the "stromal-attracting center"). This connection grows larger as the stroma forms and the frogs approach metamorphosis. Here we provide instructions for performing lentectomies (removal of the original lens) to study lens regeneration.