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PURPOSE: To obtain normative values of angle kappa in a normal population by synoptophore and Orbscan II and to compare the reliability of these devices. METHODS: Three hundred consecutive healthy individuals were enrolled in the study. A complete orthoptic and ophthalmologic examination was performed. Synoptophore and Orbscan II corneal topography were used to measure angle kappa. To evaluate the association of the angle kappa and refraction measures, individuals were further classifi ed according to the degree of myopia and hyperopia. The spherical equivalent error measures were grouped into six categories: уϪ3.00 diopters (D); Ϫ2.75 to Ϫ1.50 D; Ϫ1.25 to Ϫ0.50 D; ϩ0.50 to ϩ1.25 D; ϩ1.50 to ϩ2.75 D; and уϩ3.00 D. Paired t test and Pearson's correlation test were used for statistical analysis.

Diabetes affects corneal biomechanics and results in lower CH values than those in healthy control subjects, which may cause clinically relevant high IOP measurements independent of CCT.

Purpose of review Obtaining precise post-operative target refraction is of utmost importance in today’s modern cataract and refractive surgery. Given the growing number of patients undergoing premium intraocular lens implantations, patient expectation continues to rise. In order to meet heightened patient expectations, it is crucial to pay utmost attention to patient selection, accurate keratometry and biometry readings, as well as to the application of correct intraocular lens power formula with optimized lens constants. This article reviews recent advances in the field of clinical biometry and intraocular lens power calculations. Recent findings Recently developed low-coherence reflectometry optical biometry is comparable to older ultrasonic biometric and keratometric techniques. In addition, the new IOL Master software upgrade has improved reproducibility and enhanced signal acquisition. Further, the modern lens power formulas currently determine the effective lens position and the shape of the intraocular lens power prediction curve more accurately. Summary In order to reach target refraction, precise biometric measurements are imperative. Understanding the strengths and limitations of the currently available biometry devices, allows prevention of high variability and inaccuracy, ultimately determining the refractive outcomes.

Herpes simplex keratitis (HSK) is a major cause of corneal blindness in the world. Following the primary infection, the virus enters into a latent phase. Recurrent infectious or immune keratitis cause structural damage to the cornea, scarring, and may lead to blindness. Several commercially available topical and oral antiviral drugs for HSK are currently available. However, toxicity and low patient compliance hamper their use in HSK. Further, oral antiviral drugs alone are not always effective in HSK. Thus, there had been a need for safe and effective topical antiviral agents against HSK. Systemic ganciclovir has been in use for the treatment of cytomegalovirus infections. Recently, topical ganciclovir has become available for use in patients with HSK. Ganciclovir 0.15% ophthalmic gel has been shown to be both safe and effective against viruses of the herpes family. Topical ganciclovir ophthalmic gel is well tolerated and does not cause significant toxic effects on the ocular surface. Several multicenter studies have revealed the potential role of ganciclovir ophthalmic gel in the treatment and prophylaxis of epithelial HSK. In this paper, we have reviewed the pharmacology, efficacy, side effects, and the role of ganciclovir ophthalmic gel 0.15% in the treatment of acute herpetic keratitis.

Purpose To analyze the morphology of corneal epithelial cells and keratocytes by in vivo confocal microscopy (IVCM) in patients with herpes simplex keratitis (HSK) as associated with corneal innervation. Design Prospective, cross-sectional, controlled, single-center study. Participants Thirty-one eyes with the diagnosis HSK and their contralateral clinically unaffected eyes were studied and compared with normal controls (n = 15). Methods In vivo confocal microscopy (Confoscan 4; Nidek Technologies, Gamagori, Japan) and corneal esthesiometry (Cochet-Bonnet; Luneau Ophthalmologie, Chartres, France) of the central cornea were performed bilaterally in all patients and controls. Patients were grouped into normal (>5.5 cm), mild (>2.5–5.5 cm), and severe (<2.5 cm) loss of sensation. Main Outcome Measures Changes in morphology and density of the superficial and basal epithelial cells, as well as stromal keratocytes were assessed by two masked observers. Changes were correlated to corneal sensation, number of nerves, and total length of nerves. Results There was a significant and gradual decrease in the density of superficial epithelial cells in HSK eyes, with 852.50±24.4 cells/mm2 in eyes with severe sensation loss and 2435.23±224.3 cells/mm2 in control eyes (p=0.008). Superficial epithelial cell size was 2.5-fold larger in HSK eyes (835.3 μm2) as compared to contralateral or normal eyes (407.4 μm2; p= 0.003). A significant number of hyperreflective desquamating superficial epithelial cells were present in HSK eyes with normal (6.4%), mild (29.1%) and severe (52.2%) loss of sensation, but were absent in controls. The density of basal epithelial cells, anterior keratocytes, and posterior keratocytes did not show statistical significance between patients and controls. Changes in superficial epithelial cell density and morphology correlated strongly with total nerve length, number, and corneal sensation. Scans of contralateral eyes did not show any significant epithelial or stromal changes as compared to controls. Conclusions IVCM reveals profound HSK-induced changes in the superficial epithelium, as demonstrated by increase in cell size, decrease in cell density, and squamous metaplasia. We demonstrate that these changes strongly correlate with changes in corneal innervation.

Measurement of IOP with the RBT is a highly reproducible method in schoolchildren showing high intraobserver and interobserver correlation and it seems to be very comfortable when performing IOP measurements in schoolchildren without an anesthetic.

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