Posterior-corneal-elevation-detection

In this study done in Ibaraki, Japan, keratoconus and cornea researchers wanted to see whether  three-dimensional (3D) corneal and anterior segment optical coherence tomography (CAS-OCT) or  a rotating Scheimpflug camera combined with a Placido topography system (Scheimpflug camera with topography) was better to study the cornea. They wanted to see how it would be best to detect the signs of early keratoconus disease. Their goal was to asses if  normal eyes and forme fruste keratoconus could be separated based on that criteria. They found out that both systems worked equally good. Our own Los Angeles Keratoconus Expert feels an early cornea topography works equally good in the hands of an experienced keratoconus expert.

Sex and keratoconus

RESULTS: The women were older, more likely to report a family history of keratoconus, more likely to be nonwhite, and less likely to complete college than men. Vogt’s striae and monocular and binocular high-contrast entrance acuity were the only visual characteristics that varied between men and women in the multivariate model. Women were more likely than men to report ocular symptoms of dryness and complaints based upon a composite score of ocular symptoms. Women reported more hours per day of near work and were less likely to report the ability to wear contact lenses for enough hours to permit reading at home in the evening. Women reported more visits to their eye care practitioner during the previous 12 months. NEI-VFQ results revealed differences in self-reported difficulty with distance activities and driving.

Contact lens causes scarring

Multivariate analyses of 5-year prospective data from the CLEK Study cohort showed that baseline corneal curvature, contact lens wear, corneal staining, and younger age were predictive of the development of corneal scarring. The 5-year incidence of scarring is 13.7% for the overall sample and 38.0% for those eyes with corneal curvature greater than 52 D that wore contact lenses. Contact lens wear increased the risk of incident scarring more than 2-fold. These findings suggest a causal contribution of contact lens wear to corneal scarring in keratoconus

Keratoconus associated systemic diseases

The most common presentation of the keratoconus is as a sporadic disorder, but it has long been recognized that a significant minority of patients exhibit a family history as an autosomal dominant mode of inheritance. Most investigators suggest complete penetrance of predisposing factors with variable phenotypic expression. In some patients heterozygous mutations in the VSX1 gene are described as the underlying gene defect. An association with Down syndrome, monosomia X (Turner syndrome), Leber’s congenital amaurosis, mitral valve prolaps, collagenosis, retinitis pigmentosa and Marfan syndrome is described. The role of corneal cells in the pathogenesis of keratoconus is supported by the published reports of recurrence of keratoconus in eyes after penetrating keratoplasty due to graft repopulation by the recipient cells.

CLEK collaborative longitudinal evaluation of keratoconus

METHODS: The CLEK Study is an 8-year, multi-center, natural history study of 1209 patients with keratoconus who were examined annually for 8 years. Its goals are to prospectively characterize changes in vision, corneal curvature, corneal status, and vision-specific quality of life.

RESULTS: CLEK Study subjects had a mean age at baseline of 39.3+/-10.9 years. At study entry, 65% of the patients wore rigid contact lenses, and 14% reported a family history of the disease. Subjects exhibited a 7-year decrease in high- (2.03 letters) and low- (4.06 letters) contrast, best-corrected visual acuity, with 19% demonstrating decreases of 10 or more letters in high-contrast, best-corrected acuity and 31% of subjects demonstrating decreases of 10 or more letters in low-contrast, best-corrected acuity in at least one eye. Subjects exhibited an average 8-year increase in corneal curvature of 1.60D in the flat corneal meridian, with 24% demonstrating increases of 3.00D or more. The 8-year incidence of corneal scarring was 20%, with younger age, corneal staining, steeper baseline corneal curvature, contact lens wear, and poorer low-contrast visual acuity predictive of corneal scarring. Data from the National Eye Institute Visual Function Questionnaire suggest that the effect of keratoconus on vision-specific quality of life is disproportionate to its low prevalence and clinical severity.

Toric lens for keratoconus

A 55-year-old man with forme fruste keratoconus with a preoperative uncorrected distance visual acuity (UDVA) of 20/800 and a refraction of -6.50-3.00×135 and a 46-year-old man with a claw-shaped topographic pattern, a family history of keratoconus, and a UDVA of 20/800 with a refraction of -5.00-3.00×85. The refraction had been stable for at least 5 years in both patients. Phacoemulsification and implantation of an acrylic toric IOL were uneventful. One year postoperatively, the UDVA was 20/25 in both cases, with a refraction of -0.25-0.50×140 and 0.25-0.50×60, respectively. No progression and no IOL rotation were observed. Toric IOLs may provide excellent outcomes in patients with stable and nonprogressive corneal ectasia