Keratoconus associated with Corneal Guttata

Abstract

ABSTRACT Purpose To describe clinical findings of cases with keratoconus and concomitant corneal guttata. Setting Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Brazil. Materials and methods In a retrospective study including 138 patients with clinical keratoconus, 22 eyes from 11 (8%) patients with keratoconus were identified with the presence of corneal guttata. Complete ophthalmologic examination was performed in all patients, including Scheimpflug rotation tomography (Pentacam HR, Oculus, Wetzlar, Germany), biomechanical study associated with noncontact tonometry [ocular response analyzer (ORA); Reichert, Depew, USA], and specular microscopy (LSM 12000, Bio-Optics, Oregon, USA). The amount of guttata was correlated with biomechanical and tomographic parameters by nonparametric Spearman test. Results The mean age was 51.8 ± 20.9 (from 25 to 81) years, nine patients were female (81.9%). The mean of corrected distance visual acuity was 0.20 (20/32) ± 0.49 [from 0 (20/20) to 1.9 (10/800)] LogMar. Eleven eyes had corneal guttae grade I, six eyes grade II, four eyes grade III, and one eye grade IV. The average central keratometric readings were 44.45 ± 2.54 (from 39.70 to 50.60) for flattest K (K1), 46.08 ± 2.69 (from 42.40 to 53.50) for steepest K (K2) and 45.24 ± 2.52 (from 42.00 to 52.20) for average K (Km). Maximal keratometric value (Kmax) averaged 47.63 ± 3.10 (from 43.5 to 55.8) D. The mean CCT was 482.54 ± 52.13 µm (from 398 to 585) and in the thinnest point 474.45 ± 50.32 µm (from 387 to 577). The mean of pachymetric progression indices were 0.83 ± 0.41 (from 0.2 to 2.03) (PPI Min), 1.24 ± 0.53 (from 0.7 to 2.73) (PPI Avg), and 1.79 ± 0.92 (from 0.88 to 4.67) (PPI Max). The mean of ART Min was 710.54 ± 372.47 (from 190.64 to 1985), of ART Avg was 433.18 ± 140.96 (from 141.75 to 678.37), and of ART Max was 315.64 ± 122.69 (from 102.78 to 539.78). The mean of front and back elevation at the thinnest point (using best fit sphere to 8 mm) was 5.35 ± 6.77 (from −4 to 20) and 19.15 ± 16.41 (from 1 to 50) respectively. Belin-Ambrósio deviation index (BAD D) was 3.05 ± 3 (from −0.34 to 11.55). The mean corneal hysteresis (CH) was 8.23 ± 2.05 (from 4.1 to 10.9), corneal resistance factor (CRF) was 7.67 ± 2.4 (from 3.4 to 11.3). The amount of guttata was statistically correlated with Km and K1 (Spearman, p > 0.05). Conclusion Keratoconus and cornea guttata can coexist in the same patient. This association can camouflage corneal thinning and protrusion associated with ectasia, but elevation, relational thickness, along with combined tomographic indices and biomechanical properties are altered. The diagnosis should be considered in the complete ophthalmic examination, including corneal topography, and tomographic characterization, along specular documentation of corneal endothelium. How to cite this article Ramos IC, Belin MW, Valbon BF, Luz A, Pimentel LN, Caldas DL, Ambrósio R Jr. Keratoconus associated with Corneal Guttata. Int J Kerat Ect Cor Dis 2012;1(3):173-178.