Applications of contact lens devices in the management of corneal disease

Patient Experiences With Therapeutic Contact Lenses and Dry Eye Disease

OBJECTIVES

To report patient-reported experiences with dry eye disease and therapeutic contact lenses.

METHODS

A survey was distributed to patients with dry eye disease. Demographics, Ocular Surface Disease Index (OSDI), systemic disease, contact lens history, and burden of care information were collected. Descriptive statistics are presented and categorized by nonlens, soft lens, and scleral lens (SL) wearers.

RESULTS

Of 639 respondents, 15% (94/639) were currently using therapeutic soft or SLs (47 soft and 69 SL). Mid-day fogging or clouding of vision was reported by SL (75%, 50/67) and soft lens (62%, 29/47) wearers. Seventy-two percent of SL wearers spent more than 20 min daily on dry eye treatment while 43% of soft lens wearers spent more than 20 min. Median annual expenditure was higher for SL ($1,500, n=63) than nonlens ($500, n=371) or soft lens wearers ($700, n=43). Mean OSDI scores in all groups were in the severe category (51±22 years, n=401 nonlens wearers; mean age; 45±22 years, n=47 soft lens wearers; 60±24 years, n=69 SL wearers).

CONCLUSIONS

Mid-day fogging and blurring of vision was reported by most of the individuals using therapeutic lenses for dry eye disease. SL wearers allocate the most resources for dry eye care.

Determining the information needs of contact lens wearers for better education and more support: a qualitative study

BACKGROUND

Designing educational interventions tailored to the needs of Contact Lens Wearers (CLWs) are important and necessary. The present study aimed to determine the information needs of CLWs to educate and provide information to them to increase their knowledge and reduce complications and non-compliance behaviors.

METHODS

A qualitative approach was applied and semi-structured interviews were conducted in three contact lenses (CL) clinics in Iran among all their practitioners and 24 purposively selected patients. Data were analyzed using the Lundman and Graneheim conventional content analysis.

RESULTS

The qualitative analysis revealed knowledge and skill themes as two main categories. The knowledge category includes five subcategories of basic information for the CLWs, acquaintance with the CL, caring for CL, hygiene and vigilance of CL, and challenges of using CL. The skill category consists of two subcategories, including handling/insertion and removal of the CL, and stabilization of learned information. Moreover, 36 sub-subcategories emerged from these seven subcategories that reflected the information needs of CLWs.

CONCLUSIONS

A clear understanding of CLWs' information needs can help to design and develop appropriate educational approaches to overcome training barriers such as physicians' time constraints and high workload. Moreover, it can help deal with CLWs' insufficient knowledge and provide the required information simply and practically with the possibility of enough repetition.

Polymeric Materials for Eye Surface and Intraocular Applications

Ocular applications of polymeric materials have been widely investigated for medical diagnostics, treatment, and vision improvement. The human eye is a vital organ that connects us to the outside world so when the eye is injured, infected, or impaired, it needs immediate medical treatment to maintain clear vision and quality of life. Moreover, several essential parts of the eye lose their functions upon aging, causing diminished vision. Modern polymer science and polymeric materials offer various alternatives, such as corneal and scleral implants, artificial ocular lenses, and vitreous substitutes, to replace the damaged parts of the eye. In addition to the use of polymers for medical treatment, polymeric contact lenses can provide not only vision correction, but they can also be used as wearable electronics. In this Review, we highlight the evolution of polymeric materials for specific ocular applications such as intraocular lenses and current state-of-the-art polymeric systems with unique properties for contact lens, corneal, scleral, and vitreous body applications. We organize this Review paper by following the path of light as it travels through the eye. Starting from the outside of the eye (contact lenses), we move onto the eye's surface (cornea and sclera) and conclude with intraocular applications (intraocular lens and vitreous body) of mostly synthetic polymers and several biopolymers. Initially, we briefly describe the anatomy and physiology of the eye as a reminder of the eye parts and their functions. The rest of the Review provides an overview of recent advancements in next-generation contact lenses and contact lens sensors, corneal and scleral implants, solid and injectable intraocular lenses, and artificial vitreous body. Current limitations for future improvements are also briefly discussed.

Bandage Contact Lenses versus Deproteinized Calf Blood Extract Eye Gel for Recurrent Corneal Erosion Syndrome: A Case-Control Study

Background

The clinical efficacy of eye drops in the treatment of recurrent corneal erosion syndrome (RCES) is not satisfactory. Many studies have confirmed the positive effect of the bandage contact lens (BCL) in corneal diseases, but not many in patients with RCES. The purpose of this study is to investigate the efficacy of the BCL compared with deproteinized calf blood extract eye gel in the initial treatment of RCES.

Methods

Forty-seven patients with RCES treated in our hospital from September 2010 to September 2018 were retrospectively analyzed, including 24 cases (26 eyes) in the bandage contact lenses (BCLs) group wearing bandage contact lens and 23 cases (24 eyes) in the drug group treated with deproteinized calf blood extract eye gel. The efficacy was evaluated after 3 months of treatment, with a mean follow-up time of 21.15 ± 1.71 months in the BCL group and 20.87 ± 1.89 months in the drug group. Corneal erosion resolution, pain relief, visual acuity recovery time, recurrence and complications were observed.

Results

After 3 months of treatment, 22 eyes (22/26, 84.6%) in the BCLs group achieved complete resolution, compared with 14 eyes (14/24, 58.3%) in the drug group (P <0.05). The corneal healing time in the BCLs group was 4.77 ± 4.51 weeks, which was significantly shorter than that in the drug group (9.83 ± 5.93 weeks (P <0.01)). At 1 and 2 months after treatment, the visual analogue score (VAS) in the BCLs group (3.28 ± 1.15 at 1 month and 1.90 ± 0.77 at 2 months) decreased more significantly than that in the drug group (4.54 ± 0.89 at 1 month and 2.43 ± 0.93 at 2months, P =0.000 at 1 month and P=0.034 at 2 months). At 3 months after treatment, the mean BCVA in the BCL group (logMAR 0.03±0.08) improved more significantly than that in the drug group (logMAR 0.14±0.12,P=0.001). The complete recovery time of visual acuity was 5.46 ± 4.43 weeks in the BCLs group, compared with 10.33 ± 6.12 weeks in the drug group (P =0.003). During further follow-up, recurrence was observed in 2 eyes (2/22, 9.1%) of the BCLs group and 6 eyes (6/14, 42.8%) of the drug group. No patient in both groups developed adverse side effects.

Conclusion

Bandage contact lenses are safe and effective in the initial treatment of RCES. Compared with topical deproteinized calf blood extract eye gel, the use of BCLs can provide a higher cure rate, better pain control, faster visual recovery and lower recurrence rate.

Trial Registration

Chinese Clinical Trial Registry, ChiCTR2000031241. Registered 25 March 2020- Retrospectively registered, http://www.chictr.org.cn/edit.aspx?pid=51309andhtm=4.

Therapeutic HL-Contact Lens versus Standard Bandage Contact Lens for Corneal Edema: A Prospective, Multicenter, Randomized, Crossover Study

Introduction

To compare the safety and efficacy of the Therapeutic Hyper-CL™ lens versus a standard bandage contact lens (PureVision B&L) for chronic corneal edema.

Methods

Prospective, multicenter, randomized, crossover study. Chronic corneal edema patients were randomized to one of two arms. The first arm was fitted with the Therapeutic Hyper-CL™ lens while the second arm was fitted with a standard soft bandage contact lens. Both arms were treated with 5% sodium chloride 6 times a day. After a 7-day treatment period, there was a 7-day washout period, after which the arms were crossed over. Patients were evaluated at days 0 (baseline), 7 (following first treatment allocation), 14 (following washout), and 21 (following second treatment allocation). The primary outcomes were 3 lines of BCVA (best corrected visual acuity) improvement.

Results

In total, 49 patients were enrolled. There was significantly greater BCVA improvement rate >3 lines (30.4% versus 17.4%, P=0.04) in the Therapeutic Hyper-CL™ lens group. The mean change in BCVA lines was significantly greater for the Therapeutic Hyper-CL™ lens (3.4 ± 6.7 versus 0.9 ± 2.3, P=0.02).

Conclusions

The Therapeutic Hyper-CL™ lens was associated with a higher chance for significant visual acuity improvement when compared to a standard bandage contact lens combined with 5% sodium chloride. This trial is registered with NCT02660151.

Case Series: Management of Neurotrophic Keratitis from Familial Dysautonomia

SIGNIFICANCE

Familial dysautonomia is a rare genetic disorder that affects the sensory and autonomic nervous systems. Affected individuals have decreased corneal sensation and can develop serious complications from neurotrophic keratitis. Scleral devices are an excellent option for the long-term management of patients with familial dysautonomia and neurotrophic keratitis.

PURPOSE

In this series, we describe three patients with familial dysautonomia and classic ocular complications fit with scleral devices. No identifiable health information is included in this case report.

CASE REPORTS

Case 1: A 35-year-old white male presented with blurred vision without complaint of pain or dryness. He had moderate punctate corneal staining and central stromal corneal scarring in both eyes despite use of artificial tears, punctal plugs, and therapeutic soft lenses. He was fit with 18.2-mm commercial scleral devices, which improved vision and protected the ocular surface. Case 2: A 20-year-old cognitively impaired white female presented with history of frequent eye rubbing and self-mutilation. She had recurrent corneal abrasions with corneal scarring in both eyes and was fit with 16-mm gas-permeable prosthetic replacement of the ocular surface ecosystem devices. Case 3: An 18-year-old white male with history of frequent corneal abrasions and blurred vision was referred by his medical doctor. He and his mother were trained in the safe handling of 16- and 16.5-mm gas-permeable prosthetic replacement of the ocular surface ecosystem devices in the right and left eyes. Corneal epithelial defects healed and vision improved with daily use.

CONCLUSIONS

Individuals with familial dysautonomia present unique clinical challenges owing to severe ocular surface disease and inability to perceive pain. Initial therapy for neurotrophic keratitis includes lubrication, punctal occlusion, and therapeutic lenses. Additional therapies include autologous serum tears, amniotic membrane treatment, scleral devices, and tarsorrhaphy. In this series, scleral devices are an excellent option to protect the ocular surface and prevent common ocular complications.

A new treatment for presumed corneal epithelial inclusion cyst in a shih-tzu dog

An 8-year-old female shih-tzu was assessed for a 3-year history of yellow intrastromal material in the right eye. Slit-lamp biomicroscopy showed a yellow lesion in the upper half of the cornea, superficial corneal neovascularisation and oedema with negative fluorescein staining in the right eye. Ultrasound biomicroscopy revealed a nearly anechoic cystic space surrounded by hyperechoic oedematous cornea separating the stroma at three-quarters of the corneal depth. Two partial-thickness corneal incisions were performed around the lesion under topical anaesthesia. After cytology and culture sampling, intrastromal flushing was performed. A yellow viscous necrotic tissue was identified with no microorganism or evidence of tumour formation. Antibiotics, anti-inflammatories and a bandage contact lens were applied. Ultrasound biomicroscopy confirmed no recurrence 8 days later. Corneal neovascularisation and oedema gradually resolved through a 2-week follow-up. There was no recurrence in the subsequent 8 months.

Prevention of Exposure Keratopathy in Critically Ill Patients: A Single-Center, Randomized, Pilot Trial Comparing Ocular Lubrication With Bandage Contact Lenses and Punctal Plugs

OBJECTIVES

To compare the effectiveness of bandage contact lenses and punctal plugs with ocular lubricants in preventing corneal damage in mechanically ventilated and sedated critically ill patients.

DESIGN

Single-center, prospective, randomized, pilot study.

SETTING

Sixteen-bed, general ICU at a tertiary academic medical center.

PATIENTS

Adults admitted to the ICU and anticipated to require mechanical ventilation and continuous sedation for greater than or equal to 4 days.

INTERVENTIONS

Patients were randomized to receive eye care with ocular lubricants (n = 38), bandage contact lenses (n = 33), or punctal plugs (n = 33). The bandage contact lenses were changed every 4 days, whereas the punctal plugs remained in situ for the entire study.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the presence or absence of corneal damage as assessed by the grade of keratopathy. Patients were examined by an ophthalmologist blinded to the study group every 4 days and at the time of withdrawal from the study, due to cessation of sedation, discharge from the ICU, or death. The mean duration of the study was 8.6 ± 6.2 days. The grade of keratopathy in the ocular lubricant group increased significantly in both eyes (p = 0.01 for both eyes) while no worsening was noted in either the lens or punctal plugs groups. In a post hoc analysis of patients with an initially abnormal ophthalmic examination, significant healing of keratopathy was noted in the lens group (p = 0.02 and 0.018 for left and right eyes, respectively) and in the right eye of the plugs group (p = 0.005); no improvement was noted in the ocular lubricant group.

CONCLUSIONS

Compared with ocular lubrication, bandage contact lenses and punctal plugs were more effective in limiting keratopathy, and their use, particularly of bandage contact lenses, was associated with significant healing of existing lesions.

Glycoproteins functionalized natural and synthetic polymers for prospective biomedical applications: A review

Glycoproteins have multidimensional properties such as biodegradability, biocompatibility, non-toxicity, antimicrobial and adsorption properties; therefore, they have wide range of applications. They are blended with different polymers such as chitosan, carboxymethyl cellulose (CMC), polyvinyl pyrrolidone (PVP), polycaprolactone (PCL), heparin, polystyrene fluorescent nanoparticles (PS-NPs) and carboxyl pullulan (PC) to improve their properties like thermal stability, mechanical properties, resistance to pH, chemical stability and toughness. Considering the versatile charateristics of glycoprotein based polymers, this review sheds light on synthesis and characterization of blends and composites of glycoproteins, with natural and synthetic polymers and their potential applications in biomedical field such as drug delivery system, insulin delivery, antimicrobial wound dressing uses, targeting of cancer cells, development of anticancer vaccines, development of new biopolymers, glycoproteome research, food product and detection of dengue glycoproteins. All the technical scientific issues have been addressed; highlighting the recent advancement.

Effect of bandage contact lens wear and postoperative medical therapies on corneal healing rate after diamond burr debridement in dogs

PURPOSE

To determine the effect of bandage contact lens wear and type of post-operative medical treatment on corneal healing rates in dogs after diamond burr debridement.

ANIMALS STUDIED

237 client-owned dogs.

PROCEDURES

Canine patients having undergone diamond burr debridement (DBD) for treatment of spontaneous chronic corneal epithelial defects (SCCEDs) were included. Patients were put into 1 of 12 different groups based on type of postoperative medical regimen and whether a bandage contact lens (BCL) was utilized. Each dog was examined on a routine basis until the cornea was fluorescein negative. Data points collected included age, sex, breed, diabetic status, eye affected, Schirmer tear test 1, rebound tonometry, type and frequency of topical antibiotic, use of topical sodium chloride, use and retention of BCL, and days until healed.

RESULTS

A total of 237 dogs, each contributing one eye to the study, underwent DBD for SCCEDs. All eyes treated had estimated median ± standard error (SE) days to heal of 9.37 ± 0.42 days. When sodium chloride and BCL were utilized, ofloxacin had a significantly shorter median healing time when compared to oxytetracycline (adjusted P = 0.0158) and tobramycin (adjusted P = 0.0261). BCL use significantly improved healing times (P = 0.0002). Overall BCL retention rate was 62.02% (80 of 129). PureVision lenses were retained more often compared to Acrivet lenses (P < 0.0001). Overall, BCL retention significantly improved healing rates (P = <0.0001).

CONCLUSIONS

Postdebridement antibiotic type or use of sodium chloride ointment had minor effects on healing rates. Bandage contact lens use and retention significantly improves healing times.

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.

Self-Healing Supramolecular Hydrogels Based on Reversible Physical Interactions

Dynamic and reversible polymer networks capable of self-healing, i.e., restoring their mechanical properties after deformation and failure, are gaining increasing research interest, as there is a continuous need towards extending the lifetime and improving the safety and performance of materials particularly in biomedical applications. Hydrogels are versatile materials that may allow self-healing through a variety of covalent and non-covalent bonding strategies. The structural recovery of physical gels has long been a topic of interest in soft materials physics and various supramolecular interactions can induce this kind of recovery. This review highlights the non-covalent strategies of building self-repairing hydrogels and the characterization of their mechanical properties. Potential applications and future prospects of these materials are also discussed.

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.

Dexamethasone diffusion across contact lenses is inhibited by Staphylococcus epidermidis biofilms in vitro

PURPOSE

This study was designed to measure the impact of bacterial biofilms on diffusion of an ocular therapeutic through silicone hydrogel bandage lenses in vitro.

METHODS

An assay was designed to study the passage of a commonly used steroid, dexamethasone, through silicone hydrogel soft contact lenses. Diffused dexamethasone was measured using a spectrophotometer over a period of 18 hours and quantified using a standard curve. This assay was performed with control and Staphylococcus epidermidis biofilm-coated contact lenses comprised of lotrafilcon A and methafilcon. Biofilms were formed in brain heart infusion broth supplemented with D-glucose.

RESULTS

The presented data validate a simple in vitro model that can be used to measure the penetration of a topical therapeutic through silicone hydrogel soft contact lenses. Using this model, we measured a reduction in dexamethasone diffusion up to 88% through S. epidermidis biofilm-coated silicone hydrogel lenses compared with control lenses.

CONCLUSIONS

The results of this in vitro study demonstrate that bacterial biofilms impede dexamethasone diffusion through silicone hydrogel contact lenses and warrant future studies regarding the clinical benefit of using ocular therapeutics in the setting of bandage contact lens use for corneal epithelial defects.

Scleral Lenses

OBJECTIVE

To present a comprehensive review of current and historical literature on scleral lenses.

METHODS

A comprehensive search of several databases from each database's earliest inception to May 23, 2014 was conducted by an experienced librarian with input from the author to locate articles related to scleral lens design, fabrication, prescription, and management.

RESULTS

A total of 899 references were identified, 184 of which were directly related to scleral lenses. References of interest were organized by date, topic, and study design. Most of articles published before 1983 presented lens design and fabrication techniques or indications for scleral lens therapy. Case reviews published after 1983 identified major indications for scleral lenses (corneal ectasia, ocular surface disease, and refractive error) and visual and functional outcomes of scleral lens wear. Statistically significant improvements in visual acuity, vision-related quality of life, and ocular surface integrity were reported. Reviews of ocular and systemic conditions suggested that comprehensive management strategies for these conditions could include scleral lenses. Early work investigating scleral lens fitting characteristics, optical qualities, and potential physiological impact on anterior ocular structures have been published in the past 5 years.

CONCLUSIONS

Indications for scleral lens wear are well-established. Developing areas of research on the physiologic impact of scleral lens wear on the ocular surface, the use of technology to improve scleral lens vision and fit, and the impact of these devices on the quality of life should further enhance our understanding of scleral lenses in the future.

Use of therapeutic non-refractive contact lenses to improve visual outcome after repair of traumatic corneal wounds

BACKGROUND

The purpose of this study was to evaluate the effect of use of contact lenses to improve visual outcome after repair of traumatic corneal wounds.

METHODS

Two groups of patients (n=30 each) with traumatic full thickness corneal wounds were entered into this study. All cases were caused by sharp objects such as a knife or piece of glass that produced a corneal full thickness wound without any other associated ocular injuries. One group was repaired and received medical treatment (non-contact lens group) and the other group was repaired and a soft contact lens was fitted over the cornea, then medically treated (contact lens group). Each patient was followed up until complete healing, the sutures were removed after about 6 weeks, and the patients were followed up for a further 6 weeks, for a complete follow-up period of 3 months, after which postoperative refraction, manifest refractive spherical equivalent, uncorrected visual acuity, and best-corrected visual acuity were measured and compared between the two groups.

RESULTS

After repair and follow-up, uncorrected visual acuity ≥0.3 (decimal system) was achieved in 19 cases (63%) in the contact lens group and in only 14 cases (47%) in the non-contact lens group (P=0.018). Best-corrected visual acuity ≥0.6 was achieved in 26 cases (87%) in the contact lens group and in only 17 cases (57%) in the control group (P=0.012).

CONCLUSION

Soft contact lenses can be used after repair of traumatic corneal wounds to improve visual outcome.

Prescribing prophylactic antibiotics to users of therapeutic contact lenses

BACKGROUND

To describe the benefits and optimum use of prophylactic antibiotics in users of therapeutic contact lenses (TCL).

METHODS

A microbiological study was carried out on samples from 33 patients who continuously wore TCL. The resistance to antibiotics of bacteria isolated in our health region was also reviewed. An assessment was also made on whether there were microorganisms of a higher pathogenic potential in TCL than conventional contact lenses, as reported in the literature.

RESULTS

No bacteria were isolated from 17 (52%) of the 33 lenses studied. From the 16 (48%) remaining lenses, coagulase negative Staphylococci were isolated from 10 (62%), Propionibacterium acnes from 4 (25%), and Corynebacterium from 2 (13%).

CONCLUSIONS

The high number of negative cultures and the presence of saprophytic bacteria indicate that prophylactic antibiotic treatment is not precise. The most frequent pathogenic bacteria found in contact lenses are strongly resistant to the current commercially available antibiotics.

Recurrent erosion syndrome--the patient's perspective

AIM

The purpose of this study was to investigate the symptomatic effect of bandage contact lens (BCL) wear along with regular lubrication for the treatment of recurrent erosion syndrome (RES) resistant to simple measures alone (lubrication, artificial tears, or ointment). A patient satisfaction questionnaire assessed the longer term impact on RES symptoms and recurrence rate following the period of BCL wear.

METHOD

A retrospective case note review of all patients presenting with RES to a regional Ophthalmology department and referred for therapeutic BCL fitting over a one year period. An audit of 50 clinical records was performed and a patient satisfaction questionnaire survey completed before, during and following treatment.

RESULT

Thirty four patients responded to a satisfaction questionnaire which was sent to the fifty patients identified with RES. These patients were identified over a one-year period and all had been treated with BCLs. The predominant RES symptoms were pain (n=31), photosensitivity (n=5) and reduced vision (n=4). The majority of patients (n=30) felt that RES significantly affected their professional or social life. The average duration of BCL wear for RES was 6 months (range 2-15 months). On completion of treatment 79% (27/34) of patients felt that overall there had been some improvement in their RES symptoms, and 13 of these patients defined this improvement as being "cured".

CONCLUSION

Overall we found that RES patients were satisfied that BCL wear was beneficial in relieving their RES symptoms. The predominant symptom of RES was ocular pain. No patient developed a sight threatening complication secondary to BCL wear.

Spectral optical coherence tomography: a new imaging technique in contact lens practice

PURPOSE

Spectral optical coherence tomography (SOCT) is a new non-invasive, non-contact, high-resolution technique, which provides cross-sectional images of objects that weakly absorb and scatter light. The aim of this article is to demonstrate the application of SOCT to imaging of eyes fitted with contact lenses.

METHODS

Nine eyes of six different subjects fitted with various contact lenses have been examined with a slit-lamp and a prototype SOCT instrument.

RESULTS

Our SOCT system provides high-resolution (4-6 mum longitudinal, 10 mum transversal) tomograms composed of 3000-5000 A-scans with acquisition time of 100-250 ms. The quality of the images is adequate for detailed evaluation of contact lens fit. Design, shape and lens edge position were assessed, and complications of contact lens wear could be visualized. Thickness of the lens, corneal epithelium and stroma as well as the space between the lens and the eye surface have been measured.

CONCLUSIONS

SOCT allows high-resolution, cross-sectional visualization of the eye fitted with a contact lens. The ability to carry out a detailed evaluation of the fitting relationship between the lens and the ocular surface might be useful in research and optometric practice. SOCT can also be helpful in diagnosis, evaluation and documentation of contact lens complications.