[Bach, M. (2007). The Freiburg Visual Acuity Test-Variability unchanged by post-hoc re-analysis. Graefe's Arch. Clin. Exper. Ophthalmol., 245 (7), 965-971.10.1007/s00417-006-0474-4]Search in Google Scholar
[Brown, B., Lovie-Kitchin, J. E. (1989). High and low contrast acuity and clinical contrast sensitivity tested in a normal population. Optom. Vis. Sci., 66 (7), 467-473.10.1097/00006324-198907000-00010]Search in Google Scholar
[Carney, L. G., Lembach, R. G. (1991). Management of keratoconus: Comparative visual assessments. CLAO J., 17 (1), 52-58.]Search in Google Scholar
[de Freitas Santos Paranhos, J., Avila, M. P., Paranhos, A. Jr., Schor, P. (2010). Evaluation of the impact of intracorneal ring segments implantations on the quality of life of patients with keratoconus using the NEI-RQL (National Eye Institute Refractive Error Quality of life) instrument. Brit. J. Ophthalmol., 94 (1), 101-105.10.1136/bjo.2009.161562]Search in Google Scholar
[de Freitas Santos Paranhos, J., Paranhos, Jr. A., Avila, M. P., Schor, P. (2011). Analysis of the correlation between ophthalmic examination and quality of life outcomes following intracorneal ring segment implantation for keratoconus. Arquivos Brasileiros de Oftalmologia, 74 (6), 410-413.10.1590/S0004-27492011000600005]Search in Google Scholar
[Hess, R. F., Carney, L. G. (1979). Vision through an abnormal cornea: A pilot study of the relationship between visual loss from corneal distortion, corneal edema, keratoconus, and some allied corneal pathology. Investig. Ophthalmol. Vis. Sci., 18 (5), 476-83.]Search in Google Scholar
[Jinabhai, A., O’Donnell, C., Radhakrishnan, H., Nourrit, V. (2012). Forward light scatter and contrast sensitivity in keratoconus patients. Contact Lens Anterior Eye, 35 (1), 22-27.10.1016/j.clae.2011.07.001]Search in Google Scholar
[Kennedy, R. S., Dunlap, W. P. (1990). Assessment of the Vistech contrast sensitivity test for repeated-measures applications. Optom. Vis. Sci., 67 (4), 248-251.10.1097/00006324-199004000-00003]Search in Google Scholar
[Kymes, S. M., Walline, J. J., Zadnik, K., Gordon, M. O., the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study Group. (2004). Quality of life in keratoconus. Amer. J. Ophthalmol., 138 (4), 527-535.10.1016/j.ajo.2004.04.031]Search in Google Scholar
[Kymes, S. M., Walline, J. J., Zadnik, K., Sterling, J., Gordon, M. O., on behalf of the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study Group. (2008). Changes in the quality of life of people with keratoconus. Amer. J. Ophthalmol., 145 (4), 611-617.10.1016/j.ajo.2007.11.017]Search in Google Scholar
[Marsack, J. D., Parker, K. E., Pesudovs, K., Donnelly, W. J. 3rd., Applegate, R. A. (2007). Uncorrected wavefront error and visual performance during RGP wear in keratoconus. Optom. Vis. Sci., 84 (6), 463-469.10.1097/OPX.0b013e31802e64f0]Search in Google Scholar
[Owsley, C. (2003). Contrast sensitivity. Ophthalmol. Clin. North Amer., 16 (2), 171-177.10.1016/S0896-1549(03)00003-8]Search in Google Scholar
[Rabinowitz, Y. S. (1998). Keratoconus. Survey Ophthalmol., 42 (4), 297-319.10.1016/S0039-6257(97)00119-7]Search in Google Scholar
[Stein, R., Stein, R. (2011). Corneal collagen crosslinking: A major breakthrough in the management of keratoconus, pellucid marginal degeneration, and ectasia after LASIK. Ophthalmol. Rounds, 9 (1), 1-5.]Search in Google Scholar
[Jadidi, K., Mosavi, S. A., Nejat, F., Naderi, M., Janani, L., Serahati, S. (2015). Intrastromal corneal ring segment implantation (Keraring 355°) in patients with central keratoconus: 6-month follow-up. J. Ophthalmol., doi: 10.1155/2015/916385.]Search in Google Scholar
[Zadnik, K., Mannis, M. J., Johnson, C. A. (1984). An analysis of contrast sensitivity in identical twins with keratoconus. Cornea, 3 (2), 99-103.10.1097/00003226-198402000-00004]Open DOISearch in Google Scholar
[Zadnik, K., Mannis, M. J., Johnson, C. A., Rich, D. (1987). Rapid contrast sensitivity assessment in keratoconus. Amer. J. Optom. Physiol. Opt., 64 (9), 693-697.10.1097/00006324-198709000-000083688190]Search in Google Scholar