Natural history and predictors for progression in pediatric keratoconus.

We studied the demographic and clinical predictors associated with keratoconus progression in a pediatric population. Retrospective cohort study. We evaluated 305 eyes without previous surgeries from 168 patients, 9 to < 18 years old, and with a minimum 36-month follow-up in a hospital corneal ambulatory.

Technical notes on prism-dioptre and Prentice's rule.

Purpose: To show an alternative interpretation for prism-dioptre and access Prentice's rule accuracy.

Methods: Algebraic calculation.

Results: The prism-dioptre can be expressed as a percentage of the distance between the prism and the plane of prismatic dislocation.

Herpes simplex keratitis revisited.

The degree to which viral infection and the host's immune reaction to viral particles participate in the inflammatory process across various forms of herpetic keratitis has remained controversial. This fact has created conflicts regarding the classification of and therapeutic planning for such morbidities. This review aims to stimulate reflection on the classifications' adequacy, nomenclatures, and therapeutic approaches related to these entities.

Three-year follow-up in advanced pediatric keratoconus: thin corneas may not have pachymetry properly assessed after crosslinking.

Aim: To analyze the crosslinking (CXL) effects in pediatric keratoconus, and to identify the patients' corneal characteristics whose pachymetry could not be adequately evaluated by Scheimpflug method after procedure.

Methods: Consecutive pediatric patients with progressive keratoconus underwent CXL were included. Best-corrected visual acuity (BCVA) and spheric equivalent (SE) were measured before and after CXL.

Sagitta of ophthalmic lenses.

Purpose: To propose alternative formulas for the sagitta calculation of ophthalmic lenses.

Methods: Equation factoring.

Results: The conventional sagitta formula is algebraically inconsistent when applied to curves with direction-oriented radii.