Dr. Shrikant Bharadwaj, an optometrist, educator and a well renowned researcher begins by explaining the importance of binocular vision for human being and the components help us in day to day life. He elaborates on the anatomical and stimulus requirements for binocular vision. He discusses how interocular difference in image quality can affect binocular vision, especially in special cases like keratoconus.
Dr Bharadwaj explains what is keratoconus in brief and lists the challenges the human brain faces in individuals with one keratoconic eye. He focuses his talks on visual consequences of having keratoconus with different forms of corrections
- Optics for keratoconus
- Image quality
- Image quality for keratoconus
- Clinical consequences of distorted optics
- Visual function in keratoconus
- Measurement of visual functions
- Monocular and binocular visual acuity
- Contrast sensitivity
- Stereoacuity
- Visual functions improvement with contact lens wear in keratoconus
- Visual acuity with CL wear in keratoconus
- Contrast sensitivity with CL wear in keratoconus
- Stereoacuity with CL wear in Keretoconous
After explaining the visual functions for patients with keratoconus, Dr. Bharadwaj points out the increased optical distortion is the primary cause of loss of visual function. His lab group also looked at the reason for poor stereoacuity in keratoconic patients.
Lastly, he concludes with a summary of the talk. The session ends with a Q and A for the live audience.
References
Papers
Optics of Keratoconus
Metlapally S, Bharadwaj SR, Roorda A, Nilagiri VK, Yu TT, Schor CM. Binocular cross-correlation analyses of the effects of high-order aberrations on the stereoacuity of eyes with keratoconus. J Vis. 2019 Jun 3;19(6):12.
https://pubmed.ncbi.nlm.nih.gov/31185094/
Nilagiri VK, Metlapally S, Schor CM, Bharadwaj SR. A computational analysis of retinal image quality in eyes with keratoconus. Sci Rep. 2020 Jan 28;10(1):1321.
https://pubmed.ncbi.nlm.nih.gov/31992755/
Computing image quality
Thibos LN, Hong X, Bradley A, Applegate RA. Accuracy and precision of objective refraction from wavefront aberrations. J Vis. 2004 Apr 23;4(4):329-51.
https://pubmed.ncbi.nlm.nih.gov/15134480/
Image Quality in Keratoconus
Nilagiri VK, Metlapally S, Schor CM, Bharadwaj SR. A computational analysis of retinal image quality in eyes with keratoconus. Sci Rep. 2020 Jan 28;10(1):1321.
https://pubmed.ncbi.nlm.nih.gov/31992755/
Clinical consequences of distorted optics
Davis LJ, Schechtman KB, Begley CG, Shin JA, Zadnik K. Repeatability of refraction and corrected visual acuity in keratoconus. The CLEK Study Group. Collaborative Longitudinal Evaluation of Keratoconus. Optom Vis Sci. 1998 Dec;75(12):887-96.
https://pubmed.ncbi.nlm.nih.gov/9875994/
Raasch TW, Schechtman KB, Davis LJ, Zadnik K; CLEK Study Group. Collaborative Longitudinal Evaluation of Keratoconus Study. Repeatability of subjective refraction in myopic and keratoconic subjects: results of vector analysis. Ophthalmic Physiol Opt. 2001 Sep;21(5):376-83.
Sawides L, de Gracia P, Dorronsoro C, Webster M, Marcos S. Adapting to blur produced by ocular high-order aberrations. J Vis. 2011 Jun 28;11(7):10.1167/11.7.21 21.
https://pubmed.ncbi.nlm.nih.gov/21712375/
Visual function in keratoconus
Ferdi AC, Nguyen V, Gore DM, Allan BD, Rozema JJ, Watson SL. Keratoconus Natural Progression: A Systematic Review and Meta-analysis of 11 529 Eyes. Ophthalmology. 2019 Jul;126(7):935-945.
https://pubmed.ncbi.nlm.nih.gov/30858022/
Monocular and binocular visual acuity
Nilagiri VK, Metlapally S, Kalaiselvan P, Schor CM, Bharadwaj SR. LogMAR and Stereoacuity in Keratoconus Corrected with Spectacles and Rigid Gas-permeable Contact Lenses. Optom Vis Sci. 2018 Apr;95(4):391-398.
https://pubmed.ncbi.nlm.nih.gov/29554011/
Kumar P, Bandela PK, Bharadwaj SR. Do visual performance and optical quality vary across different contact lens correction modalities in keratoconus? Cont Lens Anterior Eye. 2020 Dec;43(6):568-576.
https://pubmed.ncbi.nlm.nih.gov/32238301/
Sabesan R, Yoon G. Visual performance after correcting higher order aberrations in keratoconic eyes. J Vis. 2009 May 13;9(5):6.1-10.