Management of Post-LASiK Keratoectasia with a Piggyback Contact Lens System

This case report highlights the clinical challenges involved in managing a patient with post-LASiK keratoectasia. A single case is presented with a focus on contact lens fitting and concurrent ocular surface disease. A review of the literature indicates that current screening methods prior to refractive surgery have made improvements for detecting patients at higher risk of serious complications. Possible treatment options for iatrogenic keratoconus include contact lenses, intrastromal corneal ring segments, corneal cross linking, and keratoplasty. This report demonstrates that post-LASiK keratoectasia with concurrent ocular surface disease can be successfully managed with a piggyback contact lens system

Case study: Use of contact lenses to manage complications following combined corneal cross-linking and topography-guided photorefractive keratectomy for pellucid marginal degeneration

This case report describes two significant long-term complications experienced by a patient following treatment for pellucid marginal degeneration (PMD). Two years after undergoing a combination of topography-guided photorefractive keratectomy (T-PRK) and corneal collagen cross-linking (CXL) procedures, the patient continued to experience glare and dryness associated with persistent stromal haze and dry eye. These procedures resulted in dissatisfaction with the final outcome, which led the patient to seek contact lens correction. Management of the symptomatic ocular sequelae with specialty soft toric contact lenses designed for irregular corneas supported her visual rehabilitation

Mid-peripheral corneal steepening after orthokeratology

Purpose: The purpose of this study was to retrospectively examine data from patients who had undergone orthokeratology (OK) to quantify the amount of mid-perpheral steeping in tangential curvature (MP-TC) and total refractive power (TRP) changes. Methods: Charts were reviewed from participants and data from the Pentacam instrument were collected prior to OK and after the final visit. Variables included central flattening (C-TC), the e-value, the mid-peripheral tangential curvatures (MP-TC), total corneal refractive power (TRP), the initial Rx (sphere) and initial corneal curvature (flat K). The group was further subdivided into high and low myopia for comparison. All participants were fitted with the Paragon CRT lenses. Data analysis was conducted to analyse the effects of lenses on TC and TRP. Results: A total of 40 patients (80 eyes) age13.95±6.80, 34 M and 46 F, were successfully fitted with CRT lenses. The average sphere was -4.23±0.90D for Group 1 and -1.89±0.62D for Group 2 The changes in TC and TRP from baseline were significant (both P<0.0001). The difference between the amount of C-TC and the maximum area of MPTC was ≈4.00D in the horizontal meridian and ≈3.00 in the veritcal meridian. The amount of MP-TC change from baseline was ≈2.00D in both meridians. There was a similar change in TRP: the distance from the centre to mid-periphery ≈2.50D. For C-TC, C-TRP, MP-TC, MP-TRP there was no significant difference between the 2 groups, overall (P=0.541 (TC) and P=0.321(TRP)). Conclusion: Results from this study should provide valuable insights into the topographic and refractive changes occurring with orthokeratology

Étude de cas : Utilisation de lentilles de contact pour la prise en charge des complications suite à une intervention combinant réticulation cornéenne et kératectomie photoréfractive guidée par topographie pour la dégénérescence pellucide marginale

Ce cas décrit deux complications à long terme importantes rencontrées par une patiente après le traitement de la dégénérescence pellucide marginale (DPM). Deux ans après avoir subi une kératectomie photoréfractive guidée par topographie (T-PRK) combinée à une procédure de réticulation du collagène cornéen (CXL), la patiente continuait à éprouver des éblouissements et une sécheresse associés à une opacité stromale persistante et à un œil sec. Ces procédures ont causé une insatisfaction avec le résultat final, ce qui a conduit la patiente à utiliser des lentilles de contact pour corriger sa vision. La prise en charge des séquelles oculaires symptomatiques avec des lentilles de contact toriques souples spécialement conçues pour les cornées irrégulières a favorisé sa rééducation visuelle

Impact of contact lens wear on epithelial alterations in keratoconus

Purpose The purpose of this study was to characterize the central epithelial thickness (CET) of penetrating keratoplasty corneal specimens obtained from patients with keratoconus (KC) and correlate the histological patterns with their clinical history.Methods Ex vivo histological imaging was performed to measure CET and total corneal thickness (TCT) in 56 patients with KC. Microscopic slides from penetrating keratoplasty corneal specimens, stained with hematoxylin and eosin were evaluated using bright field microscopy. CET and TCT were measured, and morphological features were studied. Clinical history regarding duration of KC prior to surgery and length of and tolerance to contact lens wear were compared and analyzed. Results The microscopic slides of all patients available for follow up (n = 48) were analyzed and CET and TCT were measured. The histological evaluation revealed 3 distinctive epithelial patterns. Pattern 1 with central hypertrophic and hydropic changes (n = 19) measured 70.89 ± 25.88 μm in CET and 308.63 ± 100.74 μm in TCT; Pattern 2 (n = 14) had not changed, similar to normal epithelium CET and TCT measuring 36.5 ± 7.02 μm and 260.14 ± 87.93 μm respectively. Pattern 3 (n = 15) demonstrated thinner central epithelium characterized by atrophy and focal hydropic changes measuring 19.93 ± 4.60 μm and 268.00 ± 79.39 μm in CET and TCT respectively (all p < 0.0001). The presence of Pattern 2 characterized by similar to normal CET was correlated with the duration of the condition (R = 0.600, p = 0.030). There was a significant difference in the length of CL wear comparing those with patterns 1 and 2 versus 3 (least no. of CL years) (p = 0.05 and p = 0.33 respectivelly). Conclusions Patients with advanced disease have various central corneal epithelial changes detected with histology. Although each central epithelial pattern type was distinctive comparing the 3 patterns, there was no correlation with years of CL wear but only with the duration of the condition.Office of Research of the University of Waterlo

Clinical and Epidemiologic Research Case-Control Pilot Study of Soft Contact Lens Wearers With Corneal Infiltrative Events and Healthy Controls

PURPOSE. The purpose of this study was to assess risk factors associated with soft contact lens (SCL)-related corneal infiltrative events (CIEs). METHODS. This was a single-visit, case-control study conducted at five academic centers in North America. Cases were defined as current SCL wearers with a symptomatic CIE. For each case, three age-and sex-matched controls were enrolled. Subjects completed the Contact Lens Risk Survey (CLRS), a standardized scripted medical interview, supplied a recent health history, and underwent an ocular examination. Microbial culturing of the ocular surface, SCL, and lens storage case was conducted for all cases and one of the three matched controls. Univariate and multivariate logistic regression modeling were used to assess the risk of developing a CIE. RESULTS. Thirty cases and 90 controls 13 to 31 years of age completed the study. Corneal infiltrative event diagnosis included contact lens-associated red eye, infiltrative keratitis, and contact lens peripheral ulcer. Subjects with symptomatic CIEs were more likely to harbor substantial levels of gram-negative bioburden on the ocular surface and contact lens. Significant risk factors for developing a CIE were overnight wear of SCLs, use of multipurpose solution, rinsing SCLs with water, lens storage case older than 6 months, previous &apos;&apos;red eye&apos;&apos; event, use of ocular drops in the past week, and illness during the past week. CONCLUSIONS. This pilot study demonstrated feasibility of enrolling a representative pool of SCL wearers with an untreated, symptomatic CIE and assessing CIE risk factors by using standardized methods. A larger sample size is needed to determine relationships between patient-reported behaviors and exposures, microbial bioburden, and CIE development. Keywords: adverse events, contact lenses, corneal infiltrative events, microbial culturing A recent report from the US Centers for Disease Control and Prevention (CDC) called to light the substantial burden associated with contact lens-related complications. 1 The CDC report estimated that contact lens-related keratitis results in nearly 1 million doctor visits each year and carries an associated cost of $175 million. 1 This estimate does not include the additional &apos;&apos;costs&apos;&apos; to the patient such as pain or discomfort, missed school or work, and potential for permanent loss of vision. Approximately 37 million people in the United States currently wear contact lenses and, due to the increasing prevalence of myopia, more and younger patients are expected to begin wearing contact lenses to aid in its management

Correction of presbyopia with GP contact lenses

Presbyopia can be safely and effectively corrected with gas permeable (GP) multifocal (bifocal) contact lenses, but statistics indicate that they remain the most underutilized contact lenses on the market. We believe that practitioners have been &ldquo;turned off of&rdquo; GP multifocals due to their experiences with older generations of these lenses, which tended to be difficult to fit, with poor visual results. Fortunately, GP multifocals have come a long way, and practitioners who avoid fitting them are missing out on an important niche market. With this booklet, we hope to show you just how far GP multifocals have come and demonstrate the ease with which they can now be fit and managed

Effect of lens diameter on lens performance and initial comfort of two types of GP lenses for keratoconus: a pilot study

Purpose: The purpose of this pilot study was to determine the effect of varying lens diameter of two types of keratoconic lenses on lens performance and initial comfort with participants with either centered or oval cones. Methods: Sixteen eyes of ten keratoconic participants were fitted with lenses of five diameters i.e. 8.7, 9, 9.6, 10.1 and 10.4 diameters and two commercially available lens types; “KCGP-1” and “KCGP-2”. Lensmovement, centration and initial comfort were assessed. Results: Ten subjects (2 female and 8 male, sixteen eyes) were enrolled to participate in the pilot study, themean age was 40.4 ± 14.33 years. Six eyes were in the early centred cone group, five in the early oval cone group and five in the late oval cone group. The lenses with the 9.6 lens diameter (TD) decentered the least for all lenses (p = 0.001). When compared to cone type, the 8.7/9 were more decentered for the late oval and late centred cones (p = 0.009). The movement of the smaller KCGP-1 was greater than the KCGP-2 for the centered early cones (p = 0.001) and the movement decreased for the larger KCGP-2 lenses for all cone types but not significantly (p > 0.05). The KCGP-1 lenses were more significantly comfortable than the KCGP-2 lenses for the centered cones (p = 0.003). Only for the early oval cones, was the larger KCGP-2 lenses more comfortable (p = 0.04). Conclusions: Lens diameter affects comfort and centration especially for the small (8.7/9) and large (10.4/10.1) diameters in this pilot study. Lens movement was not correlated with comfort