Therapeutic Use of Focus?? Night & Day??? Contact Lenses

Exploring single-cell RNA sequencing as a decision-making tool in the clinical management of Fuchs' endothelial corneal dystrophy

Single-cell RNA sequencing (scRNA-seq) has enabled the identification of novel gene signatures and cell heterogeneity in numerous tissues and diseases. Here we review the use of this technology for Fuchs' Endothelial Corneal Dystrophy (FECD). FECD is the most common indication for corneal endothelial transplantation worldwide. FECD is challenging to manage because it is genetically heterogenous, can be autosomal dominant or sporadic, and progress at different rates. Single-cell RNA sequencing has enabled the discovery of several FECD subtypes, each with associated gene signatures, and cell heterogeneity. Current FECD treatments are mainly surgical, with various Rho kinase (ROCK) inhibitors used to promote endothelial cell metabolism and proliferation following surgery. A range of emerging therapies for FECD including cell therapies, gene therapies, tissue engineered scaffolds, and pharmaceuticals are in preclinical and clinical trials. Unlike conventional disease management methods based on clinical presentations and family history, targeting FECD using scRNA-seq based precision-medicine has the potential to pinpoint the disease subtypes, mechanisms, stages, severities, and help clinicians in making the best decision for surgeries and the applications of therapeutics. In this review, we first discuss the feasibility and potential of using scRNA-seq in clinical diagnostics for FECD, highlight advances from the latest clinical treatments and emerging therapies for FECD, integrate scRNA-seq results and clinical notes from our FECD patients and discuss the potential of applying alternative therapies to manage these cases clinically.

IC3D Classification of Corneal Dystrophies-Edition 3

PURPOSE

The International Committee for the Classification of Corneal Dystrophies (IC3D) was created in 2005 to develop a new classification system integrating current information on phenotype, histopathology, and genetic analysis. This update is the third edition of the IC3D nomenclature.

METHODS

Peer-reviewed publications from 2014 to 2023 were evaluated. The new information was used to update the anatomic classification and each of the 22 standardized templates including the level of evidence for being a corneal dystrophy [from category 1 (most evidence) to category 4 (least evidence)].

RESULTS

Epithelial recurrent erosion dystrophies now include epithelial recurrent erosion dystrophy, category 1 ( COL17A1 mutations, chromosome 10). Signs and symptoms are similar to Franceschetti corneal dystrophy, dystrophia Smolandiensis, and dystrophia Helsinglandica, category 4. Lisch epithelial corneal dystrophy, previously reported as X-linked, has been discovered to be autosomal dominant ( MCOLN1 mutations, chromosome 19). Classic lattice corneal dystrophy (LCD) results from TGFBI R124C mutation. The LCD variant group has over 80 dystrophies with non-R124C TGFBI mutations, amyloid deposition, and often similar phenotypes to classic LCD. We propose a new nomenclature for specific LCD pathogenic variants by appending the mutation using 1-letter amino acid abbreviations to LCD. Pre-Descemet corneal dystrophies include category 1, autosomal dominant, punctiform and polychromatic pre-Descemet corneal dystrophy (PPPCD) ( PRDX3 mutations, chromosome 10). Typically asymptomatic, it can be distinguished phenotypically from pre-Descemet corneal dystrophy, category 4. We include a corneal dystrophy management table.

CONCLUSIONS

The IC3D third edition provides a current summary of corneal dystrophy information. The article is available online at https://corneasociety.org/publications/ic3d .

The efficacy of bandage contact lens in relieving the aggravation of dry eye disease after complicated cataract or/and IOL surgery

PURPOSE

In the present study, we aimed to evaluate the efficacy of the bandage contact lens (BCLs) in the treatment of dry eye disease (DED) after complicated cataract or/and intraocular lens (IOL) surgery.

METHODS

In this retrospective, single-centered, observational study, we collected data from 69 patients who underwent complicated cataract or/and IOL surgery. Of these, 35 cases wore their own BCLs immediately after the operation, while the other 34 cases did not have their own BCLs and were instead covered with gauze. The Ocular Surface Disease Index (OSDI) questionnaire, slit-lamp microscope examination, keratograph analysis, and Schirmer I test were measured at baseline, 1 week and 1 month postoperatively.

RESULTS

In the BCL group, the score of the OSDI questionnaire was significantly decreased at 1 week and 1 month postoperatively compared with baseline levels (P = 0.000, collectively). Moreover, the fluorescein staining score of the BCL group was remarkably decreased 1-week and 1-month postoperatively compared with the non-BCL group (P = 0.000 and P = 0.000, respectively). Furthermore, the redness score of the BCL group was also better compared with the non-BCL group at 1 week and 1 month postoperatively (P = 0.014 and P = 0.004, respectively).

CONCLUSIONS

Complicated cataract or/and IOL surgery would intensify the DED. Early application of BCLs postoperatively improved patients' comfort and alleviated dry eye-related symptoms and signs. Furthermore, this mechanism might involve the acceleration of corneal epithelial healing, the alleviation of ocular stress response and the stabilization of the tear film.

TRIAL REGISTRATION

Trial registration ClinicalTrials, NCT04120389. Registered 10 October 2019-retrospectively registered.

Fabrication and Characterization of an Enzyme-Triggered, Therapeutic-Releasing Hydrogel Bandage Contact Lens Material

PURPOSE

The purpose of this study was to develop an enzyme-triggered, therapeutic-releasing bandage contact lens material using a unique gelatin methacrylate formulation (GelMA+).

METHODS

Two GelMA+ formulations, 20% w/v, and 30% w/v concentrations, were prepared through UV polymerization. The physical properties of the material, including porosity, tensile strain, and swelling ratio, were characterized. The enzymatic degradation of the material was assessed in the presence of matrix metalloproteinase-9 (MMP-9) at concentrations ranging from 0 to 300 µg/mL. Cell viability, cell growth, and cytotoxicity on the GelMA+ gels were evaluated using the AlamarBlueTM assay and the LIVE/DEADTM Viability/Cytotoxicity kit staining with immortalized human corneal epithelial cells over 5 days. For drug release analysis, the 30% w/v gels were loaded with 3 µg of bovine lactoferrin (BLF) as a model drug, and its release was examined over 5 days under various MMP-9 concentrations.

RESULTS

The 30% w/v GelMA+ demonstrated higher crosslinking density, increased tensile strength, smaller pore size, and lower swelling ratio (p < 0.05). In contrast, the 20% w/v GelMA+ degraded at a significantly faster rate (p < 0.001), reaching almost complete degradation within 48 h in the presence of 300 µg/mL of MMP-9. No signs of cytotoxic effects were observed in the live/dead staining assay for either concentration after 5 days. However, the 30% w/v GelMA+ exhibited significantly higher cell viability (p < 0.05). The 30% w/v GelMA+ demonstrated sustained release of the BLF over 5 days. The release rate of BLF increased significantly with higher concentrations of MMP-9 (p < 0.001), corresponding to the degradation rate of the gels.

DISCUSSION

The release of BLF from GelMA+ gels was driven by a combination of diffusion and degradation of the material by MMP-9 enzymes. This work demonstrated that a GelMA+-based material that releases a therapeutic agent can be triggered by enzymes found in the tear fluid.

TFOS Lifestyle: Impact of contact lenses on the ocular surface

Several lifestyle choices made by contact lens wearers can have adverse consequences on ocular health. These include being non-adherent to contact lens care, sleeping in lenses, ill-advised purchasing options, not seeing an eyecare professional for regular aftercare visits, wearing lenses when feeling unwell, wearing lenses too soon after various forms of ophthalmic surgery, and wearing lenses when engaged in risky behaviors (e.g., when using tobacco, alcohol or recreational drugs). Those with a pre-existing compromised ocular surface may find that contact lens wear exacerbates ocular disease morbidity. Conversely, contact lenses may have various therapeutic benefits. The coronavirus disease-2019 (COVID-19) pandemic impinged upon the lifestyle of contact lens wearers, introducing challenges such as mask-associated dry eye, contact lens discomfort with increased use of digital devices, inadvertent exposure to hand sanitizers, and reduced use of lenses. Wearing contact lenses in challenging environments, such as in the presence of dust and noxious chemicals, or where there is the possibility of ocular trauma (e.g., sport or working with tools) can be problematic, although in some instances lenses can be protective. Contact lenses can be worn for sport, theatre, at high altitude, driving at night, in the military and in space, and special considerations are required when prescribing in such situations to ensure successful outcomes. A systematic review and meta-analysis, incorporated within the review, identified that the influence of lifestyle factors on soft contact lens dropout remains poorly understood, and is an area in need of further research. Overall, this report investigated lifestyle-related choices made by clinicians and contact lens wearers and discovered that when appropriate lifestyle choices are made, contact lens wear can enhance the quality of life of wearers.

Role of therapeutic contact lens following Descemet's stripping automated endothelial keratoplasty: A randomized control trial

Purpose

Therapeutic contact lenses (TCL) are known to help in epithelial healing and decreasing pain after various corneal surgeries. However, literature lacks any data describing their use following Descemet's stripping automated endothelial keratoplasty (DSAEK) where intraoperative epithelial debridement is commonly performed. Here we study the efficacy and safety of TCL in patients undergoing DSAEK.

Methods

In this prospective, randomized, controlled clinical trial. 40 eyes of 40 patients of pseudophakic bullous keratopathy undergoing DSAEK were enrolled and randomized into two groups, control (no TCL) and test (TCL). Primary outcome was time taken for epithelial healing and secondary outcomes were postoperative pain score, graft attachment, best spectacle-corrected visual acuity, and endothelial cell loss at 3 months.

Results

Average time taken for epithelial healing was 3.35 ± 0.49 days in the test group and 4.95 ± 1.05 days in the control group (P < 0.001). Average pain scores in first operative week were significantly lower in the test group as compared to control (P < 0.001). Graft detachment occurred in eight patients in control group and two in test group (P = 0.03). Both rebubbling rates and average endothelial cell loss at 3 months were higher in the control group with P = 0.07 and 0.06 respectively. No contact lens-related adverse effects were noted during the study period.

Conclusion

Use of TCL in DSAEK leads to faster epithelial healing and lesser postoperative pain. In addition, it may also contribute to lower rebubbling rates and endothelial cell loss.

CLEAR - Medical use of contact lenses

The medical use of contact lenses is a solution for many complex ocular conditions, including high refractive error, irregular astigmatism, primary and secondary corneal ectasia, disfiguring disease, and ocular surface disease. The development of highly oxygen permeable soft and rigid materials has extended the suitability of contact lenses for such applications. There is consistent evidence that bandage soft contact lenses, particularly silicone hydrogel lenses, improve epithelial healing and reduce pain in persistent epithelial defects, after trauma or surgery, and in corneal dystrophies. Drug delivery applications of contact lens hold promise for improving topical therapy. Modern scleral lens practice has achieved great success for both visual rehabilitation and therapeutic applications, including those requiring retention of a tear reservoir or protection from an adverse environment. This report offers a practical and relevant summary of the current evidence for the medical use of contact lenses for all eye care professionals including optometrists, ophthalmologists, opticians, and orthoptists. Topics covered include indications for use in both acute and chronic conditions, lens selection, patient selection, wear and care regimens, and recommended aftercare schedules. Prevention, presentation, and management of complications of medical use are reviewed.

Evaluation of the safety and efficacy of therapeutic bandage contact lenses on post-cataract surgery patients

AIM

To evaluate the safety of therapeutic bandage contact lens for post-cataract surgery patients and to illustrate its efficacy on post-operative comfort and tear-film stability.

METHODS

A total of 40 participants were recruited and randomly divided into two groups. Group one was instructed to wear bandage contact lenses for a week and use antibiotic eye drops for a month since the first day after surgery. Group two received sub-conjunctival injection of tobramycin and was asked to wear eye pads on the first day after surgery and then were instructed to use antibiotic eye drops as the first group did. Ocular surface disease index (OSDI) questionnaire, slit-lamp microscope examination of tear break-up time (TBUT), corneal fluorescein score (CFS), tear meniscus height (TMH) together with anterior segment optical coherence tomography (AS-OCT) and corneal topography were evaluated preoperatively and postoperatively.

RESULTS

The subjective feeling (P=0.004), TBUT (P<0.001) and TMH (P=0.02) post-surgery had improved in patients who used bandage contact lenses compared with those who did not at 1wk post-surgery. Until three month postoperatively, the comfort degree (P=0.004) and TMH (P=0.01) of group two were still worse than group one. Moreover, TBUT (P<0.001) and CFS (P=0.004) of the group with eye pads got worse than the results before, whereas the group with bandage contact lenses recovered to normal. None of these patients had infections or other complications.

CONCLUSION

Wearing therapeutic bandage contact lens after cataract surgery, compared with traditional eye-pads, is a safe method to improve tear-film stability and reduce post-operative discomfort without hindering corneal incision recovery.

Coenzyme Q10 in the Treatment of Corneal Edema in Kearns-Sayre: Is There an Application in Fuchs Endothelial Corneal Dystrophy?

PURPOSE

Corneal involvement in mitochondrial disease is seldom described. Kearns-Sayre syndrome (KSS) is a mitochondrial disorder characterized by retinitis pigmentosa, external ophthalmoplegia, and heart block. We report 2 patients with KSS with corneal lesions involving the endothelium, which improved with Coenzyme Q10 (CoQ10). Based on recent research regarding the role of dysfunctional oxidative metabolism in Fuchs Endothelial Corneal Dystrophy (FECD), we propose that mitochondrial diseases and FECD share a final pathway.

METHODS

A chart review was performed and a review of the literature was completed with a PubMed search using the terms "Kearns-Sayre Syndrome", "mitochondria", "endothelium", "Fuchs endothelial corneal dystrophy", and "cornea".

RESULTS

There are 19 reports of corneal involvement in clinical phenotypes of mitochondrial disease. Nine of these 19 cases had findings consistent with KSS. Our patients with KSS had microcystic changes throughout the cornea and excrescences on the endothelial surface seen with ultrasound biomicroscopy, similar to the clinical findings in FECD. CoQ10 improved corneal disease in both children. CoQ10 deficiency has been reported in a variety of mitochondrial diseases, and efficacy of supplementation has been demonstrated. It may be beneficial in these patients because of its antioxidant properties and role in oxidative phosphorylation.

CONCLUSIONS

The common deletion found in patients with KSS has recently been implicated in FECD, which has recently been shown to be a disease related to dysfunctional oxidative metabolism. Future research should explore the use of antioxidants, such as CoQ10 in patients with FECD.

Diffusion of Antimicrobials Across Silicone Hydrogel Contact Lenses

OBJECTIVES

To measure the diffusion of topical preparations of moxifloxacin, amphotericin B (AmB), and polyhexamethylene biguanide (PHMB) through silicone hydrogel (SH) contact lenses (CLs) in vitro.

METHODS

Using an in vitro model, the diffusion of three antimicrobials through SH CLs was measured. Diffused compounds were measured using a spectrophotometer at set time points over a period of 4 hr. The amount of each diffused antimicrobial was determined by comparing the experimental value with a standard curve. A biological assay was performed to validate the CL diffusion assay by testing antimicrobial activity of diffused material against lawns of susceptible bacteria (Staphylococcus epidermidis) and yeast (Saccharomyces cerevisiae). Experiments were repeated at least two times with a total of at least four independent replicates.

RESULTS

Our data show detectable moxifloxacin and PHMB diffusion through SH CLs at 30 min, whereas AmB diffusion remained below the limit of detection within the 4-hr experimental period. In the biological assay, diffused moxifloxacin demonstrated microbial killing starting at 20 min on bacterial lawns, whereas PHMB and AmB failed to demonstrate killing on microbial lawns over the course of the 60-min experiment.

CONCLUSIONS

In vitro diffusion assays demonstrate limited penetration of certain anti-infective agents through SH CLs. Further studies regarding the clinical benefit of using these agents along with bandage CL for corneal pathologic condition are warranted.

Persistent corneal epithelial defect responding to rebamipide ophthalmic solution in a patient with diabetes

Objective

Rebamipide ophthalmic suspension was developed for the treatment of dry eyes and for other corneal diseases, promoting the secretion of both mucin in tear fluid and membrane-associated mucin, increasing the number of goblet cells, and restoring the barrier function of the corneal epithelium. We report a case of a persistent corneal epithelial defect in a patient with diabetes treated with topical application of rebamipide ophthalmic suspension.

Case presentation

A 73-year-old woman had a history of type 2 diabetes for 35 years and nonproliferative diabetic retinopathy for 23 years. She presented to our department with discharge and ophthalmalgia in the left eye. A corneal ulcer was detected, and culture of corneal scrapings was performed, with Staphylococcus aureus and Streptococcus canis being isolated. The infection was treated with levofloxacin eye drops and ofloxacin ophthalmic ointment based on the sensitivity profile of the isolate. However, a corneal epithelial defect persisted for approximately 2 months despite continuing treatment with 0.1% hyaluronic acid ophthalmic suspension and 0.3% ofloxacin eye ointment. Her hemoglobin A1c was 7.3%. The persistent corneal epithelial defect showed improvement at 2 weeks after treatment with rebamipide unit dose 2% ophthalmic suspension, and it did not recur even when vitrectomy was subsequently performed for vitreous hemorrhage due to progression of diabetic retinopathy.

Conclusion

This is the first report about efficacy of rebamipide unit dose 2% ophthalmic suspension for presenting persistent corneal epithelial defect in a patient with diabetes. In the present case, the suggested mechanisms are the following: improving the corneal barrier function, stabilization of mucin on the keratoconjunctival epithelium, and improving the wettability and stability of the tear film, which resulted in the promotion of healing of the corneal epithelial defect in a short time period.

Objective and subjective evaluation of the performance of medical contact lenses fitted using a contact lens selection algorithm

PURPOSE

To evaluate the performance of medical contact lenses (CLs) for a wide range of clinical indications.

DESIGN

Prospective cross-sectional study.

METHODS

A total of 281 eyes were evaluated in 281 consecutive patients (≥18 years of age; CL use ≥3 months) who visited the contact lens service in a tertiary academic clinic for a scheduled follow-up visit. The main outcome measured were clinical indications for CL wear; CL type; change in corrected distance visual acuity (CDVA) with CL use; CL wearing duration; CL wearing time; subjective performance measured using a visual analog scale (VAS) questionnaire (score range: 0-100); and effectiveness of the lens-selection algorithm.

RESULTS

Wearing CLs significantly improved CDVA compared to wearing spectacles (median change: -0.15 logMAR, range: 1.00 to -2.10; P<.001). Daily-wear CLs were worn by 77% of patients for a median of 15h/day (range: 5-18h/day), median 7 days/week (range: 1-7 days/week). High subjective scores were measured, with similar results obtained between the scleral lens and soft lens groups. The medical CL fitting was found to be generally effective (the overall satisfaction rating was ≥70 for 81% of patients).

CONCLUSIONS

Fitting CLs based on the lens-selection algorithm yielded positive clinical results, including improved visual acuity, satisfactory wearing time, and high overall subjective performance. Moreover, subjective performance was similar between users of scleral lenses and users of soft lenses. These results underscore the importance of prescribing scleral lenses and the need for tertiary eye clinics to offer patients a variety of CL types.

Bandage Soft Contact Lenses for Ocular Graft-versus-Host Disease

To examine safety and efficacy of bandage soft contact lenses (BSCLs) for ocular chronic graft-versus host disease (GVHD), we conducted a phase II clinical trial. Extended-wear BSCLs were applied under daily topical antibiotic prophylaxis. Patients completed standardized symptom questionnaires at enrollment and at 2 weeks, 4 weeks, and 3 months afterward. Ophthalmologic assessment was performed at enrollment, at 2 weeks, and afterward as medically needed. Assessments at follow-up were compared with baseline by paired t-test. Nineteen patients with ocular GVHD who remained symptomatic despite conventional treatments were studied. The mean Lee eye subscale score was 75.4 at enrollment and improved significantly to 63.2 at 2 weeks (P = .01), to 61.8 at 4 weeks (P = .005), and to 56.3 at 3 months (P = .02). The ocular surface disease index score and 11-point eye symptom ratings also improved significantly. According to the Lee eye subscale, clinically meaningful improvement was observed in 9 patients (47%) at 2 weeks, in 11 patients (58%) at 4 weeks, and in 9 patients (47%) at 3 months. Visual acuity improved significantly at 2 weeks compared with enrollment values. Based on slit lamp exam at 2 weeks, punctate epithelial erosions improved in 58% of the patients, showed stability in 16%, and worsened in 5%. No corneal ulceration or ocular infection occurred. BSCLs are a widely available, safe, and effective treatment option that improves manifestations of ocular GVHD in approximately 50% of patients. This study was registered at www.clinicaltrials.gov as NCT01616056.

Simplified technique for sealing corneal perforations using a fibrin glue-assisted amniotic membrane transplant-plug

Purpose. To describe a surgical technique using amniotic membrane transplant (AMT) with fibrin glue (FG) for treating smaller corneal perforations more practically and appropriately filling the defect. Method. A patient with noninfectious central corneal perforation, in 1 mm in diameter, was treated with FG-assisted AMT-plug. An AMT was folded in on itself twice by using FG then a small piece of this FG-AMT mixture was cut to maintain an appropriate plug for the site of the corneal perforation. The FG-assisted AMT-plug was placed in the perforation area by using FG. An amniotic membrane patch was placed over the plug, which was then secured by a bandage contact lens. Result. Surgery to restore corneal stromal thickness without recurrence of perforation. Conclusion. The FG-assisted AMT-plug allowed a successful repair of 1 mm in diameter corneal perforation. This technique was easily performed, thus seeming to be a good alternative to treat corneal perforations with restoring corneal thickness.

Soft contact lenses for controlled ocular delivery: 50 years in the making

The use of contact lenses as ocular bandages for drug delivery was envisioned nearly 50 years ago by Wichterle and co-workers. Despite the therapeutic advantages that can be obtained, this application has to face up to the poor affinity shown by commercially available contact lenses for most ophthalmic drugs, resulting in small amounts of drug being loaded and short time of therapeutic levels in the eye structures. Novel strategies that appeared in the beginning of 21st century, for example coating lenses with vitamin E, incorporation of drug nanocarriers or application of molecular imprinting technology, are becoming relevant tools for development of true drug/contact lens combination products that may be available for ocular therapy in the foreseeable future.

"Swiss roll" amniotic membrane technique for the management of corneal perforations

PURPOSE

To describe a novel technique for using amniotic membrane in the management of corneal perforations.

METHODS

Interrupted 10-0 nylon sutures are passed across the perforation site. A roll of amniotic membrane is then placed across the row of preplaced sutures, and the sutures are tied to secure the membrane. An amniotic membrane patch is placed over the graft, which is then protected by a bandage contact lens.

RESULTS

We illustrate the results of our 2 most recent patients.

CONCLUSIONS

Amniotic membrane has been widely used in ocular surgery. We recommend the "Swiss roll" amniotic membrane graft technique in cases of severe corneal thinning or localized perforations.

Multilayered Gore-Tex patch for temporary coverage of deep noninfectious corneal defects: surgical procedure and clinical experience

PURPOSE

To evaluate the multilayer Gore-Tex patch as temporary coverage of deep, noninfectious corneal defects.

DESIGN

Retrospective, interventional case series.

METHODS

SETTING

University Medical Center Schleswig-Holstein, Kiel, Germany.

PATIENT POPULATION

Thirty-nine eyes of 38 patients with noninfectious, deep corneal defects. Underlying disorders included neurotrophic or immunologic ulcers in 37 eyes (94.9%) and traumatic defects in 2 eyes (5.1%). Intervention procedures: Corneal defects were covered with multiple Gore-Tex layers, of which the uppermost was sutured to the cornea. The Gore-Tex patch was kept in place until an appropriate corneal transplant was obtained and effective systemic immunosuppression was initiated.

MAIN OUTCOME MEASURES

Long-term preservation of the eye, frequency of resuturing of the Gore-Tex patch, and best-corrected visual acuity.

RESULTS

In 38 cases, the eye could be preserved. In 10 eyes, additional sutures were required. Before surgery, the mean best-corrected visual acuity (logMAR) was 1.14 ± 0.45 (20/250), and that at final follow-up was 1.13 ± 0.41 (20/250). The Gore-Tex patch remained in place 4 days to 32 months (mean, 6.4 ± 8.3 months) until corneal transplantation (27 eyes) or until an alternative way of defect coverage could be performed. Three eyes did not require further coverage after explantation of the Gore-Tex patch. In 6 eyes, either the Gore-Tex patch was kept in place or the patients died.

CONCLUSIONS

Temporary coverage of deep corneal defects with multilayer Gore-Tex patches allows time until an appropriate corneal transplant is obtained. The technique is particularly useful in patients with underlying autoimmune disorders, because an effective systemic immunosuppression can be initiated before corneal transplantation.

New insights into the diagnosis and treatment of neurotrophic keratopathy

Abnormalities of the ocular surface can be acquired or inherited disorders of the central nervous system. Loss of neural stimulation from the sensory division of the trigeminal nerve or from the autonomic nervous system can have devastating consequences on corneal epithelial wound healing and the precorneal tear film, leading to decreased vision. The pathogenesis of neurotrophic keratopathy is reviewed, and treatment modalities are recommended.

Variations in the corneal surface temperature with contact lens wear

This paper presents the two-dimensional simulation of heat propagation in the human eye model during contact lens wear with finite element analysis. Three types of contact lens are studied: Lotrafilcon A, Balafilcon A, and Etafilcon A. The models are solved for both steady and transient solutions. The corneal surface temperature during contact lens wear is found to decrease (average, 0.52 ± 0.05°C compared with a bare cornea for all lens types). A contact lens with a higher water content has a lower steady state temperature than a contact lens with a lower water content does. Various initial temperatures for the contact lens are found to affect the first 400 s of the temperature variation. When the initial temperature is lower than the corneal temperature, a reduction in temperature is observed during contact lens insertion while the opposite is observed when the initial temperature is higher than the corneal temperature. The increase in evaporation rate when a contact lens is worn increases the cooling effect on the ocular surface. This is suggested to be the cause of lower corneal surface temperature when wearing a contact lens.

Extended-Wear Silicone Hydrogel Soft Contact Lenses in the Management of Moderate to Severe Dry Eye Signs and Symptoms Secondary to Graft-Versus-Host Disease

PURPOSE

To determine the safety and efficacy of the Focus NIGHT & DAY (CIBA Vision, Duluth, GA) silicone hydrogel contact lens in the management of refractory, moderate to severe dry eye signs and symptoms secondary to graft-versus-host disease (GVHD).

METHODS

Seven patients with GVHD and moderate to severe dry eye disease as determined by the Ocular Surface Disease Index (OSDI) questionnaire were fitted with a near plano Focus NIGHT & DAY soft contact lens (SCL) used on a 7-night continuous-wear basis. Visual acuity, objective measures of dry eye disease (i.e., Schirmer I, tear breakup time, and corneal fluorescein staining), and OSDI scores were compared before SCL wear and after 1 week and 1 month of SCL wear.

RESULTS

There was significant improvement in subjective assessment of dry eye symptoms (initial vs. 1-month OSDI score, 76.8 +/- 13.6 vs. 31.2 +/- 17.8, P<0.0005, paired t test). In addition, patients had significant improvement in best-corrected visual acuity after 1 month of SCL wear (initial vs. 1-month logMAR visual acuity for the right eye, 0.23 +/- 0.050 vs. 0.04 +/- 0.027, P<0.007; initial vs. 1-month logMAR visual acuity for the left eye, 0.22 +/- 0.049 vs. 0.04 +/- 0.020, P<0.007, analysis of variance, Dunnett post hoc). There were no significant changes in results of Schirmer I testing, corneal fluorescein staining, or tear breakup time. No adverse events or complications of SCL wear were observed.

CONCLUSIONS

The Focus NIGHT & DAY contact lens can improve subjective dry eye symptoms and visual acuity in patients with refractory dry eye disease secondary to GVHD.

Science and Strategy for Preventing and Managing Corneal Ulceration

ABSTRACT Corneal ulcers can cause significant loss of vision from scarring and astigmatism, but rapid management can limit the destruction and improve outcomes. Infectious ulcers usually resolve with antimicrobial treatment. Noninfectious ulcers, however, present a diagnostic and therapeutic challenge. They can often be resolved by eliminating toxic medications and providing surface support with lubrication and collagenase inhibitors, but resistant ulcers may need more aggressive therapy with bandage contact lenses, tarsorrhaphy, or autologous serum. Ulcers impending perforation require urgent surgical management (e.g., tissue glue, conjunctival flaps, or keratoplasty). Topical steroids are useful when the ulceration is secondary to inflammatory mediators, but they are contraindicated in corneal melts with minimal inflammation, such as those associated with Sjogren syndrome. Systemic immunomodulation is required in addition to topical therapy in the presence of autoimmune disease. Understanding of the pathological processes that occur in different types of corneal ulcers is essential to formulation of a logical and effective treatment plan. Newer, more targeted treatment modalities may offer treatment options that have greater efficacy and fewer adverse effects.

Comparison of Conventional and Silicone Hydrogel Contact Lenses for Bullous Keratoplasty

PURPOSE

To compare the efficacy and safety of conventional lenses and silicone hydrogel lenses in the treatment of bullous keratopathy. The silicone hydrogel bandage contact lenses used were Focus NIGHT & DAY and PureVision. The conventional lens used was Sauflon 85%.

METHODS

This was a prospective, comparative study of 22 patients with painful bullous keratopathy in one eye. Patients visited a specialty contact lens department and were fitted with all three different lens types in their affected eye for 1 month each, for a total duration of 3 months. The main outcome measures were comfort and pain relief, which patients scored on a scale that ranged from 1 to 5, with 1 being very poor and 5 being excellent. Doctors assessed the fit of the lens, its movement, and any deposit buildup. The statistical tests applied were the Kruskal-Wallis test and the Mann-Whitney test.

RESULTS

Sixteen of the 22 patients (24 eyes) successfully completed 1 month's wear of all three bandage contact lenses. The median comfort score was 3.9 for PureVision, 3.8 for Focus NIGHT & DAY, and 2.8 for Sauflon 85%; there was a statistical significance among the three groups (P=0.031). Silicone hydrogel lenses performed better than conventional lenses for comfort. The Mann-Whitney test showed that there was no statistically significant difference for comfort scores of Focus NIGHT & DAY versus PureVision (P<0.782) or of Focus NIGHT & DAY versus Sauflon 85% (P<0.073). However, there was a statistically significant difference for comfort scores of PureVision versus Sauflon 85% (P<0.0136). The median pain relief score was 3.8 for PureVision, 3.7 for Focus NIGHT & DAY, and 3.2 for Sauflon 85%. There was no significant difference among the three lenses for pain relief score. All three lens types were similarly good with regard to contact lens fit, movement, and deposit buildup.

CONCLUSIONS

The use of silicone hydrogel lenses are a safe and effective alternative to conventional contact lenses for the treatment of bullous keratopathy.

Therapeutic Use of Silicone Hydrogel Contact Lenses in Children

PURPOSE

To evaluate the safety and efficacy of silicone hydrogel extended-wear contact lenses when used for therapeutic purposes for children.

METHODS

This was a prospective open-ended nonrandomized study. Twenty-nine consecutive pediatric patients at the Eye Clinic of Kaunas University of Medicine in Lithuania requiring therapeutic contact lens wear for anterior segment disorders were enrolled. In all cases, Focus NIGHT & DAY (CIBA Vision, Duluth, GA) contact lenses were used. Success or failure of specific treatment and the presence of ocular or lens-related complications were noted in each case.

RESULTS

Twenty-nine eyes were fitted with Focus NIGHT & DAY contact lenses. The average age at the time of presentation was 9 years (range, 2 months to 17 years). The conditions treated were burn (seven eyes), corneal erosion (three eyes), neurotrophic keratitis (four eyes), descemetocele (one eye), corneal ulcer (one eye), keratouveitis (one eye), exposure keratitis (one eye), vernal keratoconjunctivitis (one eye), herpetic keratitis (one eye), corneal perforation (two eyes), and corneal injury (seven eyes). The mean duration of continuous contact lens wear was 17.8 days (range, 1-131 days). Dry eye was the cause of contact lens loss in one eye. Total bandage contact lens wear was effective in 27 (93%) eyes. Complications related to contact lens wear were limited to one case (increased signs of inflammation in the case of herpetic keratitis) requiring cessation of therapeutic lens wear after 24 hours.

CONCLUSIONS

Focus NIGHT & DAY silicone hydrogel contact lenses were found to be safe and efficacious for continuous-wear therapeutic use for children.

The effect of contact lens wear on dynamic ocular surface temperature

AIM

To determine the dynamic emitted temperature changes of the anterior eye during and immediately after wearing different materials and modalities of soft contact lenses.

METHOD

A dynamic, non-contact infrared camera (Thermo-Tracer TH7102MX, NEC San-ei) was used to record the ocular surface temperature (OST) in 48 subjects (mean age 21.7 +/- 1.9 years) wearing: lotrafilcon-A contact lenses on a daily wear (LDW; n=8) or continuous wear (LCW; n=8) basis; balafilcon-A contact lenses on a daily wear (BDW; n=8) or continuous wear (BCW; n=8) basis; etafilcon-A contact lenses on a daily disposable regimen (EDW; n=8); and no lenses (controls; n=8). OST was measured continuously five times, for 8s after a blink, following a minimum of 2h wear and immediately following lens removal. Absolute temperature, changes in temperature post-blink and the dynamics of temperature changes were calculated.

RESULTS

OST immediately following contact lens wear was significantly greater compared to non-lens wearers (37.1 +/- 1.7 degrees C versus 35.0 +/- 1.1 degrees C; p < 0.005), predominantly in the LCW group (38.6 +/- 1.0 degrees C; p < 0.0001). Lens surface temperature was highly correlated (r=0.97) to, but lower than OST (by -0.62 +/- 0.3 degrees C). There was no difference with modality of wear (DW 37.5 +/- 1.6 degrees C versus CW 37.8+/-1.9 degrees C; p=0.63), but significant differences were found between etafilcon A and silicone hydrogel lens materials (35.3 +/- 1.1 degrees C versus 37.5 +/- 1.5 degrees C; p < 0.0005). Ocular surface cooling following a blink was not significantly affected by contact lens wear with (p=0.07) or without (p=0.47) lenses in situ.

CONCLUSIONS

Ocular surface temperature is greater with hydrogel and greater still with silicone hydrogel contact lenses in situ, regardless of modality of wear. The effect is likely to be due to the thermal transmission properties of a contact lens.