Review Article
Volume 11 Issue 4 - 2020
Ocular Disorders and Associated Drug Development Challenges: The Current Scenario
Deepakkumar Mishra, Shilpkala Gade and Thakur Raghu Raj Singh*
School of Pharmacy, Queen’s University Belfast, Medical Biology Centre, Belfast, UK
*Corresponding Author: Thakur Raghu Raj Singh, Reader in Pharmaceutics, School of Pharmacy, Queen’s University Belfast, Medical Biology Centre, Belfast, Northern Ireland, United Kingdom.
Received: March 04, 2020; Published: May 29, 2020


Vision is one of the most important human sense and hence eye diseases leading to impairment of vision have been the hot topic for drug delivery research lately. Diseases like glaucoma, cataract, age-related macular degeneration, diabetic retinopathy and trachomatous trichiasis have been known for their potential of visual impairment as well as blindness. A vast amount of research has been done in understanding the pathophysiology, risk factors and drug development and drug delivery challenges associated with these diseases, but the clinical success achieved so far is very sparse. This leading to the requirements for the better understanding of the ocular diseases which can be translated to better drug delivery systems. The current review is formulated with the aims to provide a concise summary of these ocular disorders and to address the challenges in their drug development research.

Keywords: Ocular Drug Delivery Systems; Age-Related Macular Degeneration; Glaucoma; Cataract; Diabetic Retinopathy; Trachoma


  1. Lamoureux E and Pesudovs K. “Vision-specific quality-of-life research: A need to improve the quality”. American Journal of Ophthalmology (2011): 151.
  2. Bourne RRA., et al. “Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and meta-analysis”. The Lancet Global Health's 5 (2017): e888-e897.
  3. World report on vision (2019) ISBN 9789241516570.
  4. Pascolini D and Mariotti SP. “Global estimates of visual impairment: 2010”. British Journal of Ophthalmology 96 (2012): 614-618.
  5. Wong WL., et al. “Global prevalence of age-related macular degeneration and disease burden projection for 2020 and 2040: A systematic review and meta-analysis”. The Lancet Global Health's (2014): 2.
  6. Bourne RRA. “Vision 2020”. Current Opinion in Ophthalmology (2019): 1.
  7. Thompson J and Lakhani N. “Cataracts”. Primary Care: Clinics in Office Practice 42 (2015): 409-423.
  8. Occhiutto ML., et al. “Nanotechnology for Medical and Surgical Glaucoma Therapy-A Review”. Advances in Therapy (2019).
  9. Rozing MP., et al. “Age-related macular degeneration: A two-level model hypothesis”. Progress in Retinal and Eye Research (2019): 100825.
  10. Jenkins AJ., et al. “Biomarkers in diabetic retinopathy”. Review of Diabetic Studies 12 (2015): 159-195.
  11. Habtamu E., et al. “Predictors of Trachomatous Trichiasis Surgery Outcome”. Ophthalmology 124 (2017): 1143-1155.
  12. Jung JH., et al. “Targeted drug delivery in the suprachoroidal space by swollen hydrogel pushing. Investig”. Investigative Ophthalmology and Visual Science 59 (2018): 2069-2079.
  13. Photocoagulation for Diabetic Macular Edema. “Early Treatment Diabetic Retinopathy Study Report Number 1 Early Treatment Diabetic Retinopathy Study Research Group”. Archives of Ophthalmology 103 (1985): 1796-1806.
  14. Schulenburg WE., et al. “A comparative study of argon laser and krypton laser in the treatment of diabetic optic disc neovascularisation”. British Journal of Ophthalmology 63 (1979): 412-417.
  15. Maguen E., et al. “Lasers in ophthalmology”. Biomedical Photonics Handbook (2003).
  16. Yang Y., et al. “Intravitreal Corticosteroids In Diabetic Macular Edema”. Retina 35 (2015): 2440-2449.
  17. Chatziralli I., et al. “Dexamethasone Intravitreal Implant in Diabetic Macular Edema: Real-Life Data from a Prospective Study and Predictive Factors for Visual Outcome”. Diabetes Therapy 8 (2017): 1393-1404.
  18. Hoang QV., et al. “Effect on intraocular pressure in patients receiving unilateral intravitreal anti-vascular endothelial growth factor injections”. Ophthalmology 119 (2012): 321-326.
  19. Massa H., et al. “Intravitreal fluocinolone acetonide implant (ILUVIEN®) for diabetic macular oedema: a literature review”. Journal of International Medical Research 47 (2019): 31-43.
  20. Minassian DC., et al. “Modelling the prevalence of age-related macular degeneration (2010-2020) in the UK: Expected impact of anti-vascular endothelial growth factor (VEGF) therapy”. British Journal of Ophthalmology 95 (2011): 1433-1436.
  21. Scotti F., et al. “Increased soluble urokinase plasminogen activator receptor (suPAR) levels in neovascular age-related macular degeneration: a role for inflammation in the pathogenesis of the disease? Graefe’s Arch”. Journal of Clinical and Experimental Ophthalmology 257 (2019): 899-903.
  22. Remulla JFC., et al. “Foveal electroretinograms and choroidal perfusion characteristics in fellow eyes of patients with unilateral neovascular age-related macular degeneration”. British Journal of Ophthalmology 79 (1995): 558-561.
  23. Sarks SH. “Ageing and degeneration in the macular region: A clinico-pathological study”. British Journal of Ophthalmology 60 (1976): 324-341.
  24. Spraul CW., et al. “Histologic and morphometric analysis of the choroid, Bruch’s membrane, and retinal pigment epithelium in postmortem eyes with age-related macular degeneration and histologic examination of surgically excised choroidal neovascular membranes”. Survey of Ophthalmology 44 (1999): 10-32.
  25. Ferris FL., et al. “Age-Related Macular Degeneration and Blindness due to Neovascular Maculopathy”. Archives of Ophthalmology 102 (1984): 1640-1642.
  26. Photodynamic Therapy for Age-Related Macular Degeneration | Health Link BC (2020).
  27. Gao Y., et al. “Anti-VEGF monotherapy versus photodynamic therapy and anti-vegf combination treatment for neovascular age-related macular degeneration: A meta-analysis”. Investigative Ophthalmology and Visual Science 59 (2018): 4307-4317.
  28. Markham A. “Brolucizumab: First Approval”. Drugs 79 (2019): 1997-2000.
  29. Weinreb RN., et al. “The pathophysiology and treatment of glaucoma: A review”. Journal of the American Medical Association 311 (2014): 1901-1911.
  30. Agarwal R., et al. “Current concepts in the pathophysiology of glaucoma”. Indian Journal of Ophthalmology 57 (2009): 257-266.
  31. Marquis RE and Whitson JT. “Management of Glaucoma: Focus on Pharmacological Therapy”. Drugs Aging 22 (2005): 1-21.
  32. Macoul KL and Pavan-Langston D. “Pilocarpine Ocusert System for Sustained Control of Ocular Hypertension”. Archives of Ophthalmology 93 (1975): 587-590.
  33. Pollack IP., et al. “The ocusert pilocarpine system: Advantages and disadvantages”. Southern Medical Journal 69 (1976): 1296-1298.
  34. Nair RV., et al. “Sustained release timolol maleate loaded ocusert based on biopolymer composite”. International Journal of Biological Macromolecules 110 (2018): 308-317.
  35. Lavik E., et al. “Novel drug delivery systems for glaucoma”. Eye 25 (2011): 578-586.
  36. Asbell PA., et al. “Age-related cataract”. Lancet 365 (2005): 599-609.
  37. Sweeney MHJ and Truscott RJW. “An impediment to glutathione diffusion in older normal human lenses: A possible precondition for nuclear cataractv”. Experimental Eye Research 67 (1998): 587-595.
  38. Cetinel S and Montemagno C. “Nanotechnology for the prevention and treatment of cataract”. Asia-Pacific Journal of Ophthalmology 4 (2015): 381-387.
  39. Thrimawithana TR., et al. “Drug delivery to the lens for the management of cataracts”. Advanced Drug Delivery Reviews 126 (2018): 185-194.
  40. Collin HB. “Trachoma”. Australian Journal of Optometry 53 (1970): 381-387.
  41. Trachoma (2020).
  42. Dawson CR., et al. “Guide to trachoma control in programmes for the prevention of blindness” (1981).
  43. Taylor HR., et al. “Trachoma”. Lancet 384 (2014): 2142-2152.
  44. Mohammadpour M., et al. “Trachoma: Past, present and future”. Journal of Current Ophthalmology 28 (2016): 165-169.
  45. Evans JR and Solomon AW. “Antibiotics for trachoma”. Cochrane Database of Systematic Reviews (2011): CD001860.
  46. Chin SA., et al. “Diversity of chlamydia trachomatis in trachoma-hyperendemic communities treated with azithromycin”. American Journal of Epidemiology 187 (2018): 1840-1845.
  47. Pfizer Announces Extension of Zithromax® Antibiotic Donation Program through 2025 to Help Eliminate World’s Leading Infectious Cause of Blindness | Pfizer (2020).
  48. Hai J., et al. “Targeted delivery of amoxicillin to C. trachomatis by the transferrin iron acquisition pathway”. PLoS One (2016): 11.
  49. Juliana FR., et al. “Promising approach in the treatment of glaucoma using nanotechnology and nanomedicine-based systems”. Molecules (2019): 24.
  50. Jung JH., et al. “Ocular drug delivery targeted by iontophoresis in the suprachoroidal space using a microneedle”. Journal of Controlled Release 277 (2018): 14-22.
  51. Kaur IP., et al. “Vesicular systems in ocular drug delivery: An overview”. International Journal of Pharmaceutics 269 (2004): 1-14.
  52. Gaudana R., et al. “Ocular drug delivery”. The AAPS Journal 12 (2010): 348-360.
  53. Goldstein DA., et al. “Suprachoroidal corticosteroid administration: A novel route for local treatment of noninfectious uveitis”. Translational Vision Science and Technology 5 (2016): 4-11.
  54. Lucentis® (ranibizumab) Abbreviated UK Prescribing Information”. Eye 31 (2017): S18-S20.
  55. Al-Khersan H., et al. “Innovative therapies for neovascular age-related macular degeneration”. Expert Opinion on Pharmacotherapy 20 (2019): 1879-1891.
  56. Update on the Age-Related Macular Degeneration (AMD) Drug Pipeline | BrightFocus Foundation (2020).
  57. Vellonen KS., et al. “A critical assessment of in vitro tissue models for ADME and drug delivery”. Journal of Controlled Release 190 (2014): 94-114.
  58. Martens TF., et al. “Coating nanocarriers with hyaluronic acid facilitates intravitreal drug delivery for retinal gene therapy”. Journal of Controlled Release 202 (2015): 83-92.
  59. Xu Q., et al. “Nanoparticle diffusion in, and microrheology of, the bovine vitreous ex vivo”. Journal of Controlled Release 167 (2013): 76-84.
  60. Peynshaert K., et al. “In vitro and ex vivo models to study drug delivery barriers in the posterior segment of the eye”. Advanced Drug Delivery Reviews 126 (2018): 44-57.
  61. Gade S., et al. “An Ex-Vivo Evaluation of Moxifloxacin Nanostructured Lipid Carrier Enriched In Situ Gel for Transcorneal Permeation on Goat Cornea”. Journal of Pharmaceutical Sciences 108 (2019): 2905-2916.
  62. Lin TC., et al. “Retinal prostheses in degenerative retinal diseases”. Journal of the Chinese Medical Association 78 (2015) 501-505.
  63. Moshirfar M., et al. “Comparison and analysis of FDA reported visual outcomes of the three latest platforms for LASIK: Wavefront guided visx idesign, topography guided wavelight allegro contoura, and topography guided nidek EC-5000 CATz”. Clinical Ophthalmology11 (2017): 135-147.
  64. Thakur RRS and Jones D. “Biodegradeable Implants for Sustained Intraocular Delivery of Small and Large Molecules”. ONdrug Delivery Magazine (2018): 28-31.
  65. Wykoff CC., et al. “Innovation in neovascular age-related macular degeneration: Consideration of brolucizumab, abicipar, and the port delivery system”. Ophthalmic Surgery, Lasers and Imaging Retina 49 (2018): 913-917.
Citation: Thakur Raghu Raj Singh., et al. ““Ocular Disorders and Associated Drug Development Challenges: The Current Scenario”. EC Ophthalmology 11.6 (2020): 92-101.

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