Lens Removal Research Articles

Corneo-scleral limbal changes following short-term soft contact lens wear.

To assess whether short-term soft contact lens wear alters the anterior eye surface. Twenty-two neophyte subjects wore soft contact lenses for a period of five hours. Topography based corneo-scleral limbal radius estimates were derived from height measurements acquired with a corneo-scleral profilometer. Additionally, central corneal thickness (CCT), anterior chamber depth (ACD), corneal curvature radius (R) and white-to-white (WTW) diameter were acquired with an OCT-assisted biometer. Measurements were obtained without lens wear (baseline), immediately after lens removal following five hours of wear and three hours after lens removal. Short-term soft contact lens wear significantly modifies corneo-scleral limbal radius (mean±SD: 130±74μm, p << 0.001) and the changes are repeatable. In contrast, the WTW diameter and R were not modified. ACD and CCT were significantly affected but no significant correlations were found between the increment of the limbal radius and the decrease in ACD and CCT. Limbal radius increment was reversed three hours after lens removal for 68% of the subjects but the time course of this reversal was not uniform. It is possible to accurately quantify limbal radius changes as a consequence of soft contact lens wear. The increment in the limbal diameter could reach over 0.5mm but that alteration does not correspond to changes in WTW diameter and it was not observable to the examiner using a slit lamp. Assessing topographical limbus after contact lens wear could be a tool to optimize the selection of the contact lens, from the perspective of anterior eye surface changes.

Objective classification of zonular weakness based on lens movement at the start of capsulorhexis.

PurposeTo quantify zonular weakness based on lens movement at the start of continuous curvilinear capsulorhexis (CCC) and establish a classification system for it.SettingKozawa Eye Hospital and Diabetes Center, Mito, Japan.DesignRetrospective interventional case series.MethodsWe examined 402 consecutive eyes of 316 patients who underwent CCC, phacoemulsification and aspiration (PEA), and intraocular lens (IOL) implantation. The movement of the lens capsule was measured using images from video recordings of the CCC procedure. Zonular weakness was classified based on the shifted distance: Grade I, less than 0.20 mm; Grade II, 0.20–0.39 mm; and Grade III, greater than 0.40 mm. For each of these grades, we examined the use of the capsule stabilization device during PEA, the surgical procedure for lens removal, and IOL fixation.ResultsWe classified 276 eyes (68.6%) as Grade I, 102 eyes (25.4%) as Grade II, and 24 eyes (6.0%) as Grade III. As the grade increased, the use of the capsule stabilization device in PEA and scleral suture fixation of IOL increased.ConclusionsZonular weakness was quantified by measuring the movement of the lens capsule. An objective classification of zonular weakness based on lens movement may be useful for selecting the appropriate device and procedure during cataract surgery.

Evaluation of efficacy of lens extraction for intraocular pressure reduction in eyes with primary angle closure glaucoma and primary angle closure

INTRODUCTION. The purpose of the study was to evaluate the intraocular pressure (IOP) lowering effect of lens removal in eyes with primary angle closure glaucoma (PACG) and primary angle closure (PAC). MATERIALS AND METHODS. This study was a retrospective analysis of 114 eyes of 97 patients (83 women, 14 men; mean age 69.9 years) with PACG and PAC treated with lens extraction. Outcome measures: age, gender, visual acuity, IOP reduction over time, preoperative and postoperative number of IOP-lowering medications, axial length, intraocular lens (IOL) power, requirement for additional anti-glaucoma operations, and complications. Patients were divided into three groups: 1) patients with PAC (22 eyes) with mean follow-up 12.2 months; 2) patients with PACG with a history of previous acute angle closure (AAC) (39 eyes) with mean follow-up 15.4 months; and 3) patients with PACG without a history of previous AAC (53 eyes), with mean follow-up 13.5 months. Laser iridotomy was performed in all treated eyes prior to the surgery. RESULTS. In the group with PAC mean IOP was reduced from 42.2 ± 15.4 mm Hg (mean ± SD) under 2.6 IOP-lowering medications to 20.2 ± 10.4 mm Hg under 1.1 IOP-lowering medications (mean IOP reduction 52.1%). In the group with PACG with a history of previous AAC mean IOP was reduced from 29.0 ± 15.7 mm Hg under 2.1 IOP-lowering medications to 17.0 ± 7.5 mm Hg under 0.7 IOP-lowering medications (mean IOP reduction 41.3%). In the group with PACG without a history of previous AAC (53 eyes) mean IOP was reduced from 22.8 ± 8.0 mm Hg under 1.75 IOP-lowering medications to 18.8 ± 7.4 mm Hg under 1.5 IOP-lowering medications (mean IOP reduction 17.5%). In all three groups statistically significant improvement of visual acuity as a result of surgery was observed. There were no statistically significant differences between the three groups with regard to AXL or IOL power. Intraoperative complications were noticed in eight cases, and postoperative complications were noticed in four cases. The number of anti-glaucoma medications was reduced, but 17 eyes needed additional anti-glaucoma procedures. CONCLUSIONS. Lens extraction in eyes with PACG and PAC resulted in significant IOP reduction in all groups. The most pronounced IOP reduction was achieved in the group with PAC, where lens extraction was performed up to 60 days from AAC. Visual acuity was significantly improved as a result of surgery in all three study groups.

Influence of aldose reductase on epithelial-to-mesenchymal transition signaling in lens epithelial cells

Cataract is the most frequent cause of blindness worldwide and is treated by surgical removal of the opaque lens to restore the light path to the retina. While cataract surgery is a safe procedure, some patients develop a complication of the surgery involving opacification and wrinkling of the posterior lens capsule. This process, called posterior capsule opacification (PCO), requires a second clinical treatment that can in turn lead to additional complications. Prevention of PCO is a current unmet need in the vision care enterprise. The pathogenesis of PCO involves the transition of lens epithelial cells to a mesenchymal phenotype, designated epithelial-to-mesenchymal transition (EMT). Our previous studies showed that transgenic mice designed for overexpression of human aldose reductase developed lens defects reminiscent of PCO. In the current study, we evaluated the impact of aldose reductase (AR) on expression of expression of EMT markers in the lens. Primary lens epithelial cells from AR-transgenic mice showed downregulated expression of Foxe3 and Pax6 and increased expression of α-SMA, fibronectin and snail, a pattern of gene expression typical of cells undergoing EMT. A role for AR in these changes was further confirmed when we observed that they could be normalized by treatment of cells with Sorbinil, an AR inhibitor. Smad-dependent and Smad-independent pathways are known to contribute to EMT. Interestingly, AR overexpression induced ERK but not Smad-2 activation. These results suggest that elevation of AR may lead to activation of ERK signaling and thus play a role in TGF-β/Smad independent induction of EMT in lens epithelial cells.

The visual outcome after cataract surgery with multifocal intraocular lenses and monofocal intraocular lenses at tertiary care hospital: A prospective observational study

Background: The crystalline lens is part of the optical system of the eye that focuses rays of light on the retina. Apart from contributing to the optical power of the eye as a whole, the crystalline lens can dynamically change the optical power of the system by the process of accommodation for younger eyes. During life the ability of the crystalline lens to change in shape decreases, leading to presbyopia. For optimal visual performance, crystalline lens should be transparent. Cataract describes the pathological opacification of the crystalline lens. Removal of the crystalline lens followed by implantation of an artificial intraocular lens (IOL) in the capsular bag of the eye, as practiced in cataract surgery, offers an opportunity to address refractive anomalies in patients who are ametropic due to the removal of cataract. Implantation of an IOL with a fixed focal point (monofocal IOL) will render a patient at best emmetropic for a single fixed working distance only, leading to a postoperative result comparable to presbyopia in an emmetropic subject; pseudoaccommodation can play a role in increasing the depth of field but spectacle independence for a range of working distances is not be expected after implantation of a monofocal IOL. To restore the missing accommodation, we can implant multifocal IOLs. Multifocal IOLs, on the other hand, are designed to have two or more fixed focal points, thus, facilitating a sharp retinal image of objects at multiple working distances resulting in increased spectacle independence, but these lenses can cause a reduction in contrast sensitivity and higher incidence of photic phenomena such as halos, flare, and glare. Aim of The Study: The study was carried out with the aim of comparing the visual outcome after cataract surgery with multifocal IOLs and monofocal IOLs in respect to distant visual acuity, near visual acuity, contrast sensitivity, subjective symptoms, and to assess functional status and quality of life. Materials and Methods: A prospective observational study was conducted in the Department of Ophthalmology, KLES Dr. Prabhakar Kore Hospital and Medical Research Centre, Belagavi on patients undergoing cataract surgery during January 1, 2015–December 31, 2015. The study was approved by the Ethical and Research Committee of Jawaharlal Nehru Medical College, Belagavi. Forty eyes of forty patients who undergone phacoemulsification surgery with IOL implantation under LA. Choice of IOL inserted given according to their desire for spectacle independency. Monofocal group was taken as control. Both groups were evaluated postoperatively after 3 weeks and 6 weeks for distant vision, near vision, contrast sensitivity for distance, subjective satisfaction by standard questionnaire method and subjective symptoms such as glare and halos and difficulty in night driving. Data were analyzed by Chi-square test (P < 0.05%). Results: Distant visual acuity was 6/6–6/9 in 80% and 75% of the patients of multifocal and monofocal groups, respectively, remaining patients had 6/12–6/18 vision. 85% of multifocal group had N6–N8 vision (P < 0.0001). High contrast sensitivity for distance was almost similar in both groups, but low contrast was significantly reduced in multifocal group as compared to monofocal group (P = 0.0023). Fifteen percent of multifocal group had complained of glare and halos compared to monofocal group who never had these visual sensations. About 5% of patients in multifocal group had difficulty with nighttime driving. Nearly, 80% of patients in multifocal group and 40% of patients in monofocal group had become spectacles independent. Interpretation and Conclusion: Multifocal IOL group experienced reduced spectacle dependency for near vision and a high level of patient satisfaction despite some reports of halos, glare, and difficulty in night driving. Monofocal IOL group experienced spectacle dependency for near vision. Overall, multifocal IOLs offer best near vision acuity, good distance visual acuity, less limitation in visual function in selected and motivated individuals.

Der Prophet Borri über die “Restitutio Humorum” und die Linsen-Aspiration im 17. Jahrhundert

The son of a renowned Milan physician, the Italian physician, alchemist, prophet, and founder of a sect, Giuseppe Francesco Borri (1627–1695), was educated by Jesuits in Rome. After experiencing an epiphany of St. Michael he became a prophet and founded a sect. Persecuted by the inquisition and condemned to death, he fled to Strasbourg, later to Amsterdam, Hamburg and Copenhagen. In each place he started with the highest protection but was later expelled. On his last journey from Copenhagen to Istanbul he was taken captive in Austria and extradited by the Emperor to the Pope in Rome, where he died a prisoner. In Amsterdam Borri cut open the eye of a dog, expressed the lens together with the aqueous and vitreous, instilled a liquid and showed that the eye regained its shape and the humors were reformed. He later repeated his experiment in Copenhagen on a goose. Borri’s experiment was widely discussed by the 17th century scientific community, e.g. by Thomas Bartholin, Ole Borch [Olaus Borrichius], Gottfried Wilhelm Leibniz, Johann Daniel Major and Theophile Bonet. In Copenhagen he also claimed that it was possible to aspirate the lens through a cannula, after mashing it up with a brush of metal wires, which was to be inserted into the eye through the cannula. Thus, Borri was one of the first to show that the three humours – aqueous, lens and vitreous – were not needed for seeing. He envisaged the techniques of small incision lens removal after intraocular lens destruction and of lens replacement by surgery, ideas that were realized 300 years later by Charles Kelman and Sir Harold Ridley.

Prevention and management of postoperative endophthalmitis: A case-based approach.

Endophthalmitis following intraocular surgery is a disastrous complication and can lead to poor visual outcomes and loss of globe integrity. It should be differentiated from toxic anterior segment syndrome (TASS) where management differs drastically. This article presents basic knowledge about postoperative endophthalmitis and describes nine different real–world scenarios ranging from TASS to milder forms of endophthalmitis responding to intravitreal antibiotics alone and more complicated forms associated with corneal involvement, fungal endophthalmitis and cases requiring intraocular lens removal, radical vitrectomy with hyaloid peeling, base dissection, and silicone oil. A case-based approach is followed where practical considerations have been adopted with each case such that it facilitates the readers’ ability to apply theoretical knowledge to real-life clinical situations.

Comparison of stability between a modular intraocular lens system and a single-piece hydrophobic acrylic intraocular lens

To compare the movement of a modular intraocular lens (IOL) with that of a standard single-piece hydrophobic acrylic IOL in a human cadaver eye perfusion model. Department of Ophthalmology, University of Colorado, Aurora, Colorado, USA. Experimental study. Eight phakic human donor eyes of 4 patients had standard phacoemulsification with lens removal. One of 2 IOLs was then implanted in the capsular bag: a modular IOL (Harmoni) or a standard single-piece IOL (Acrysof SN60). Each globe was connected to a programmable perfusion pump with an in-line pressure transducer. Ultrasound biomicroscopy (UBM) was used to evaluate the anterior chamber depth (ACD) in each eye, measuring from the posterior cornea to the anterior surface of the optic at an intraocular pressure (IOP) of 5mm Hg, 10mm Hg, 20mm Hg, and 30mm Hg. Five consecutive measurements were recorded for all eyes at each pressure, and the results were averaged. There was significantly less movement in eyes with the modular IOL than in eyes with the single-piece IOL. The mean position of the modular IOL varied from a minimum of 0.03mm to a maximum of 0.07mm, and the mean position of the single-piece IOL varied from a minimum of 0.26mm to a maximum of 0.87mm(P=.002). The modular IOL showed less movement with changes in IOP than a standard single-piece IOL. Improved IOL stability might allow more accuracy in determining the effective lens position and hence improve the predictability of the refractive target. Proprietary or commercial disclosures are listed after the references.

Visual outcomes after lensectomy and iris claw artisan intraocular lens implantation in patients with Marfan syndrome.

To review our experience with crystalline lens extraction and iris claw Artisan IOL implantation in patients with lens subluxation secondary to Marfan syndrome. A retrospective analysis of 12 eyes of 9 patients with lens subluxation due to Marfan syndrome who underwent crystalline lens removal and Artisan IOL (Ophtec, Groningen, Netherlands) implantation. A questionnaire of pre- and post-operative data, including demographics, pre- and postoperative comorbidities and complications was completed. Patients were evaluated for visual outcome and occurrence of complications. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and spherical equivalents (SE) were compared before and after lens extraction and IOL insertion. The mean age of the participants was 30.03±15.02years, and mean post-operative follow-up time was 44.5±16.4months. Mean BCVA also showed a significant improvement from 0.5±0.3 at the baseline to 0.2±0.2 post-operatively (P=0.006). SE changed significantly from -11.38±1.99 preoperatively to -0.45±1.65 post-operatively (P=0.003). All eyes had the IOL implanted at desired position. Post-operative complications were retinal detachment in one case and IOL dislocation in another patient. No other complication such as ocular hypertension, angle abnormalities, clinical cystoids macular edema, and corneal decompensation was observed during the follow-up period. Artisan IOL implantation after lens extraction appears to be an attractive alternative for optical correction in cases of Marfan syndrome with ectopia lentis. It confers a significant improvement in visual acuity with reasonable risk profile.

Use of the phaco tip technique for lens cleavage and removal during cataract surgery.

Use of the phaco tip technique for lens cleavage and removal does not require manual hydrodissection using a syringe and cannula, or cortical removal using an irrigation/aspiration tip. The phaco tip is the only surgical instrument required for this technique. Its advantages include maintaining a stable intraocular pressure during cortical cleaving hydrodissection and lens removal, which includes the cortex.

Pilot Study to Determine the Effect of Lens and Eye Rinsing on Solution-Induced Corneal Staining (SICS).

The main purpose of this study was to determine whether two interventions (rinsing the lens before lens insertion and rinsing the ocular surface post-lens removal) had any impact on solution-induced corneal staining (SICS). In addition, the presence of hyper-reflective epithelial cells in the presence of SICS was investigated. Twenty subjects wore new balafilcon A lenses, which had been soaked overnight in a multipurpose care product containing polyhexamethylene biguanide for 2 hours. The study was conducted across three phases. In phase 1 (investigator and subject masked, randomized eye), one lens was rinsed with nonpreserved saline before lens insertion. In phase 2 (investigator masked, randomized eye), one eye was rinsed with nonpreserved saline after lens removal, before staining assessment. Corneal staining was recorded as the percentage area of the cornea exhibiting superficial punctate staining. In both phases, ocular comfort and presence of specific symptoms were captured. In phase 3, there was no randomized treatment; confocal images of the epithelium were obtained after 2 hours of wear. In phase 1 (lens-rinse), there was no significant difference in staining between the treated and untreated eyes (84 vs. 92%, respectively; p = 0.06). In phase 2 (eye-rinse), there was also no significant difference between the treated and untreated eye (86 vs. 86%, p = 0.92). Most subjects were asymptomatic. In phase 3, images of hyper-reflective cells were captured in 97% of the eyes imaged. The two rinsing procedures did not affect the level of the SICS response. Hyper-reflective epithelial cells were found to be present in a significant number of eyes exhibiting SICS, and their presence warrants further investigation.

Corneal Hydration Control in Fuchs' Endothelial Corneal Dystrophy.

PurposeTo assess corneal hydration control across a range of severity of Fuchs' endothelial corneal dystrophy (FECD) by measuring the percent recovery per hour (PRPH) of central corneal thickness after swelling the cornea and to determine its association with corneal morphologic parameters.MethodsTwenty-three corneas of 23 phakic FECD patients and 8 corneas of 8 healthy control participants devoid of guttae were graded (modified Krachmer scale). Effective endothelial cell density (ECDe) was determined from the area of guttae and local cell density in confocal microscopy images. Steady-state corneal thickness (CTss) and standardized central corneal backscatter were derived from Scheimpflug images. Corneal swelling was induced by wearing a low-oxygen transmissible contact lens for 2 hours in the morning. De-swelling was measured over 5 hours after lens removal or until corneal thickness returned to CTss. Percent recovery per hour was 100 × (1 – e−k), where k was determined from CT(t) = (de−kt) + CTss, and where d was the initial change from CTss.ResultsAfter contact lens wear, corneas swelled by 9% (95% CI 9–10). Percent recovery per hour was 49%/h (95% CI 41–57) in controls and 37%/h in advanced FECD (95% CI 29–43, P = 0.028). Low PRPH was associated with disease severity, low ECDe, and increased anterior and posterior corneal backscatter. Anterior backscatter was associated with PRPH in a multivariable model (R2 = 0.44).ConclusionsCorneal hydration control is impaired in advanced FECD and is inversely related to anterior corneal backscatter. Anterior corneal backscatter might serve as an indicator of impaired endothelium in FECD.

Comparison of bandage contact lens removal on the fourth versus seventh postoperative day after photorefractive keratectomy: A randomized clinical trial

PurposeTo compare the outcomes of bandage contact lens (BCL) removal on the fourth versus seventh post-operative day following photorefractive keratectomy (PRK). MethodsThis study recruited eyes of patients who underwent PRK surgery. The patients were randomly assigned to 2 groups. In Group 1 BCL was removed on the 4th postoperative day, while in Group 2, BCL was removed on the 7th postoperative day. After BCL removal, patients were asked to express their pain score and eye discomfort. At one and three months follow-up examinations, visual acuity scale was assessed. Slit-lamp examination was performed in all visits to evaluate complications. Results260 eyes of 130 patients underwent PRK. The age and sex ratio were not significantly different between the two groups. One month after the surgery, the logMAR uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were significantly lower in Group 2 (P value = 0.016, 0.001 respectively), however, the UDVA and CDVA were not significantly different after 3 months (P > 0.05). In Group 1, filamentary keratitis (FK) was observed in 10 (7.6%) eyes, 6 (4.61%) eyes were diagnosed with recurrent corneal erosion (RCE) and corneal haze was detected in 3 (2.3%) eyes. However, in Group 2, RCE was observed in 4 (2.3%) and FK was noted in 4 (3.07%) eyes. No haze was seen in Group 2. The difference in rate of complications was statistically significant (14.6% and 6.1% in Groups 1 and 2, respectively, P = 0.02). Pain and eye discomfort scores were not significantly different (P > 0.05). There was no major complications including infectious keratitis in either groups. ConclusionFollowing PRK surgery, BCL removal on the seventh postoperative day yields faster visual rehabilitation and lower rate of postoperative complications with no increase in eye pain, discomfort or infection.

Chondro‐keratoprosthesis: an alternative to OOKP?

PurposeTo evaluate the use of cartilage as a potential graft material in order to explore a new approach toward osteo‐odontal tissue replacement in keratoprosthesis surgeryMethodsWe describe a modification of the osteo‐odonto‐keratoprosthesis that involves the use of autogenous auricular conchal cartilage graft (ACCG) in 2 patients. In stage 1, ACCG was harvested via a posterior approach. Then, an optical polymethyl‐methacrylate cylinder was embedded into a double‐layered fragment of the conchal cartilage and secured by cyanoacrylate glue. The optical cylinder and cartilage complex were then implanted into the cheek. The stage 2, performed 2–4 months later, involved retrieval of the complex and implantation into the cornea, after reflection of the buccal mucosal flap, corneal trephination, iris and lens removal, and anterior vitrectomy. Cartilage specimens were then processed for histological evaluation after retrieval.ResultsWe report 2 cases of chondro‐keratoprosthesis (CKPRO) who underwent surgery with a 9 months follow‐up following a bilateral limbal stem cell deficiency associated with severe corneal changes. On patient 1, vision was improved to 20/100 J6 during the follow‐up. On patient 2, postoperative visual acuity stay limited to LP related to preoperative retinal lesions. During the follow‐up, any postoperative complication as extrusion, epithelial downgrowth, retrocorneal membrane or endophtalmia was observed.ConclusionsACCG could be a good alternative to replace osteo‐odontal graft in keratoprosthesis surgery especially in young patients with healthy teeth. ACCG has already been widely used for reconstructive surgery and provides safe and stable support to the optical cylinder. However, further comprehensive studies with larger sample size and longer follow‐up are required.

Lanosterol reversal of protein aggregation in cataract

SummaryThe human lens is comprised largely of crystalline proteins assembled into a highly ordered, interactive macro‐structure essential for lens transparency. Any disruption of protein interactions will alter this delicate structure, with consequent protein aggregation and cataract formation. Cataracts are the most common cause of blindness, and currently the only treatment is surgical removal of cataractous lenses. The precise mechanisms by which lens proteins prevent aggregation and maintain lens transparency are largely unknown. Lanosterol is an amphipathic molecule enriched in the lens. It is synthesized by lanosterol synthase (LSS) in a key cyclization reaction of a cholesterol synthesis pathway. Here we identify two distinct homozygous LSS missense mutations in two families with extensive congenital cataracts. Both of these mutations affect highly conserved amino acid residues and impair key catalytic functions of LSS. Treatment by lanosterol, but not cholesterol, significantly decreased preformed protein aggregates both in vitro and in cell‐transfection experiments. Our study identifies lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment.

Diurnal Variation in Comfort in Contact Lens and Non-contact Lens Wearers.

The purpose of this investigation was to evaluate the diurnal variation in symptoms associated with ocular discomfort in contact lens (CL) wearers and non-CL wearers. The study population comprised 604 individuals attending pre-screening visits at the OTG-i research clinic; 60% were current soft CL wearers (hydrogel and silicone hydrogel) and 40% were non-CL wearers. Symptomatology status was determined by the OSDI questionnaire (58% asymptomatic, 42% symptomatic). Participants were asked to grade their comfort, vision, and other symptoms during the day and in the evening (before lens removal for CL wearers) on 0 to 100 visual analogue scales. Diurnal decrease in comfort was significantly greater for CL wearers (-16.0 vs. -6.3, p < 0.001) and symptomatic participants (p = 0.015). Diurnal decrease in subjective vision was also significantly greater for CL wearers (-10.4 vs. -6.9, p = 0.005) and symptomatic participants (p = 0.001), and the interaction between these factors was also significant (p = 0.019). Dryness, grittiness, and irritation increased significantly more for CL wearers (p < 0.001, p = 0.012, and p = 0.004, respectively) and grittiness, irritation, and stinging for symptomatic participants (p = 0.016, p < 0.001, and p < 0.001, respectively). For the CL wearers, there was a significant interaction between dryness and age (p = 0.026) with the diurnal increase in dryness being greater in those under 40 (+15.6 vs. +10.0). The diurnal decrease in comfort and subjective vision, and the diurnal increase in dryness, grittiness, and irritation, were significantly more marked for CL wearers than non-CL wearers. Diurnal changes in comfort, grittiness, stinging, irritation, and vision were influenced by the subject's overall symptomatology as assessed by the OSDI questionnaire. For dryness symptoms, the diurnal decrease was most marked in young CL wearers. For the symptoms of stinging and vision, the diurnal changes were most pronounced in the symptomatic groups.

Eye rubbing type and prevalence including contact lens ‘removal‐relief’ rubbing

BackgroundEye rubbing is commonly associated with keratoconus and may contribute to disease onset and progression. Verbal counselling to avoid rubbing may not be successful and adverse consequences of rubbing, which occurs on contact lens removal may be more serious. This study examines the prevalence of ‘removal‐relief’ rubbing and its potential consequences.MethodsRubbing histories were recorded for contact lens wearing normal and keratoconic patients as well as for normal non‐contact lens wearers. Analogue scaled responses were used to identify and compare abnormal rubbing habits.ResultsContact lens wearing patients (both with and without keratoconus) reported significantly more rubbing before contact lens insertion (p < 0.05) compared to non‐contact lens wearers. Eye rubbing after contact lens removal (‘removal‐relief’ rubbing) was found to be significantly more prevalent among contact lens‐wearing keratoconic patients compared to contact lens‐wearing non‐keratoconic patients (p < 0.001 in both cases).ConclusionsRubbing‐related trauma occurring before contact lens insertion may predispose the cornea to wound healing activities and greater levels of adverse response to contact lens wear. Such adverse responses could predispose the cornea to greater trauma, which occurs in response to rubbing on removal of contact lenses. Strong counselling to avoid eye rubbing is often not an adequate form of management for a significant number of patients with keratoconus. Evidence of relapses indicates the need for better methods of counselling and for them to be repeated regularly. Apart from keratoconus, any other keratectasia, corneal disease or wound healing (including post‐surgical) may increase susceptibility to corneal rubbing trauma. Such cases also appear to warrant counselling on avoidance of rubbing.

Changes in Tear Cytokine Concentrations Following Discontinuation of Soft Contact Lenses-A Pilot Study.

This study investigated changes in selected tear cytokine concentrations (IL-1β, IL-1Ra, IL-6, IL-10, IL-12 (p70), and TNF-α) after a 1-week washout from soft contact lens wear (CLW), and the repeatability of cytokine measurements using custom multiplex assays. A total of 10 subjects completed this 6-visit (immediately following contact lens removal, and after 1, 2, 3, 4, and 7 [±1] days without CLW) pilot study. Approximately 20 to 30 μL of pooled basal tears were collected from both eyes at each visit. Two custom multiplex assays were used by two operators to quantify the concentration of tear cytokines. Tear samples from subjects 1 to 6 were analyzed using the first kit by operator 1. Tear samples from subject 7 to 10 plus additional tear samples from subjects 1 to 5, which were used to determine the between-kit per operator repeatability, were analyzed using the second kit by operator 2. Linear mixed models were used to determine changes in tear cytokine concentrations over time. Between-kit per operator and within-kit per operator repeatabilities were assessed using the Bland and Altman analysis. There were no significant changes in tear cytokine concentrations over a 1-week washout of CLW. More than 99% of the tear samples had detectable levels of cytokines using custom multiplex assays. Within-kit per operator repeatability was good, but between-kit per operator repeatability was poor; likely due to protein degradation, differences in operator experience, and operating procedures. A washout period may not be necessary when evaluating changes in tear cytokines with new contact lenses or lens care products. A well-trained operator using standardized operating procedures can produce repeatable measurements using custom multiplex assays.

Morphologic changes in the anterior segment using ultrasound biomicroscopy after cataract surgery and intraocular lens implantation.

To evaluate morphologic changes in the anterior segment using ultrasound biomicroscopic imaging (UBM) after phacoemulsification and foldable intraocular lens implantation (IOL). Thirty-six patients with a mean age of 68.68 ± 8.44 years (range 51-89) who had phacoemulsification and foldable IOL implantation were included in this prospective study. Several anterior segment parameters including aqueous depth (AQD), trabecular meshwork-iris angle (TIA), ciliary body thickness (CBT), sclera thickness (ST), trabecular meshwork-ciliary process distance (T-CPD), iris-ciliary processes distance (I-CPD), and iris thickness (IT) were measured using UBM preoperatively and at postoperative month 2. There was a significant increase in AQD (p&lt;0.001) and TIA (p&lt;0.001) at postoperative month 2. However, CBT, ST, T-CPD, I-CPD, and IT did not significantly change (p&gt;0.05) during the study period. Removal of the crystalline lens results in change in the anterior segment parameters. Our results confirmed that UBM is a helpful option for the analysis of anterior segment structures both qualitatively and quantitatively.

Novel roles for the lens in preserving overall ocular health

Outside the traditional roles of the lens as an important refractive element and a UV filter, it was David Beebe’s group that first demonstrated that the lens acts an oxygen sink that protects the tissues of the anterior segment of the eye from oxygen or oxygen metabolites. In this review, we follow on from this work, and present new evidence from our laboratory to demonstrate that the lens serves as a reservoir for the release of the antioxidant glutathione (GSH) into the aqueous humor to provide a source of GSH and/or its precursor amino acids to nearby tissues that interface with the aqueous humor, or to remove toxic metabolites from the eye via the aqueous outflow pathway. In addition to GSH release, our laboratory and others have shown that ATP is released from the lens under hyposmotic conditions to activate purinergic signalling pathways in an autocrine manner to alter lens function. In this review, we raise the idea that ATP and/or its subsequent degradation product adenosine may exert a paracrine function and influence purinergic signalling systems in other tissues to alter aqueous humor outflow. These new secondary roles indicate that the lens is not just a passive optical element, but a highly dynamic and active tissue that interacts with its neighbouring tissues, through modifying the environments in which these tissues function. We believe that the lens actively contributes to the ocular environment and as a consequence, removal of the lens would alter the functionality of neighbouring tissues. We speculate that a long term effect of lens removal may be to inadvertently increase the exposure of anterior tissues of the eye to oxidative stress due to elevated oxygen levels and a reduction in the availability of GSH and purinergic signalling molecules in the aqueous humor. Since cataract surgery is now being performed on younger patients due to our increasing diabetic population, over time, we predict these changes may increase the susceptibility of these tissues to oxidative stress and the incidence of subsequent ocular pathologies. If our view of the lens is correct, the actual loss of the biological lens may have longer term consequences for overall ocular health than currently appreciated.