PURPOSE: To use the anterior corneal surface higher order aberrations as a tool to detect and grade keratoconus using corneal map analysis videokeratoscopy. METHODS: A prospective observational comparative study of 80 eyes was performed. The eyes were divided into two groups. Group A comprised 40 eyes of 20 asymptomatic individuals with no ocular pathology. Mean sphere was -0.03 diopters (D) (range: +0.75 to -0.75 D), mean cylinder was -0.27 D, mean average K was 43.28 D, and mean uncorrected visual acuity (UCVA) was 1.01. Group B comprised 40 eyes of 25 patients with keratoconus. Mean sphere was -3.70 D (range: +2.00 to -10.00 D), mean cylinder was -3.82 D, mean average K was 49.29, and mean best spectacle-corrected visual acuity (BSCVA) was 0.61. RESULTS: In group A, mean root-mean-square (RMS) of spherical (Z ₄ and Z ₆ ), coma-like (Z ₃ , Z ₅ , and Z ₇ ), and higher order aberrations (Z^sub 3-7^) were 0.38 µm, 0.35 µm, and 0.52 µm, respectively. In group B, mean RMS of spherical, coma-like, and higher order aberrations were 1.06 µm, 2.90 µm, and 3.14 µm, respectively, for a 6.0-mm simulated pupil diameter. Mean RMS differences between the two groups were 0.68 µm (P≤.0002), 2.55 µm (P≤.0001), and 2.61 µm (P≤.0001) for spherical, coma-like, and total higher order aberrations, respectively. In group B, according to Amsler-Krumeich classification, the mean RMS of coma-like aberration was 1.87 µm in grade I (14 eyes), 2.97 µm in grade II (11 eyes), 3.46 µm in grade III (12 eyes), and 5.20 µm in grade IV (3 eyes). CONCLUSIONS: Corneal higher order aberrations, especially coma-like aberrations, are significantly higher in eyes with keratoconus than normal eyes. Coma-like aberrations, with the aid of a corneal aberrometry map, are good indicators for early detection and grading of keratoconus. [J Refract Surg. 2006;22:539-545.]

Extended depth-of-focus (EDOF) is a new intraocular lens (IOL) technology in the treatment of presbyopia. In contrast to multifocal (MF) IOLs, EDOF lenses create a single elongated focal point, rather than several foci, to enhance depth of focus. In this way, EDOF IOLs aim to reduce photic phenomena, glare, and halos, which have been reported in MF IOLs. A potential disadvantage is a decrease of retinal image quality if the amount of the aberrations is excessively increased. Frequently, EDOF IOLs are combined with MF optical designs; for this reason, EDOF IOLs are commonly a subject of confusion with optical multifocality concepts. The aim of this article is to clarify what an EDOF IOL is and to discuss the recently reported outcomes with these IOLs. We propose naming lenses that have combined optical designs as “hybrid IOLs.”

To evaluate long-term results and stability of intracorneal ring segment (Intacs) implantation for keratoconus correction. Vissum, Instituto Oftalmológico de Alicante and University of Miguel Hernandez, Alicante, Spain. This retrospective study comprised 13 eyes operated on between April 2000 and December 2001 that had Intacs implantation for keratoconus correction. The outcomes were evaluated at 6, 12, 24, and 36 months in all eyes and at 48 months (6 eyes). Mean best spectacle-corrected visual acuity (BSCVA) increased from 0.46 (20/50) preoperatively to 0.66 (20/30) postoperatively (P< or =.001). Mean decrease of inferior-superior (I-S) asymmetry was 2.81 diopters (D) (P< or =.02), and the average K-value was 3.13 D (P< or =.001). Mean difference between 6 and 36 months (stability) showed no significant difference regarding BSCVA (P< or =.5) and I-S asymmetry (P< or =.6). Although a significant increase was noticed in the average K by 1.67 D (P< or =.002), at 36 months it did not reach the initial preoperative values. Intacs increased the BSCVA and decreased I-S asymmetry with stability up to 36 months. In spite of the decrease of the K-values at 6 months, a further significant increase was detected 36 months after surgery.