Early loss of central visual acuity in glaucoma

Area of Science:

• Ophthalmology
• Optometry
• Neuroscience

Background:

• Glaucoma commonly affects peripheral vision, with central visual acuity usually preserved until advanced stages.
• Early detection of visual field defects is crucial for managing glaucoma and preventing irreversible vision loss.

Purpose of the Study:

• To investigate the occurrence and characteristics of early central visual field defects in glaucoma patients.
• To identify potential mechanisms and risk factors associated with early central vision loss in glaucoma.

Main Methods:

• Retrospective case series of 10 glaucoma patients presenting with decreased visual acuity and central/centrocaecal scotomas.
• Analysis of glaucoma type, intraocular pressure, optic disc cupping, pupillary response, and visual acuity.
• Exclusion of other potential causes of visual impairment.

Main Results:

• Ten patients (25-79 years) exhibited early central visual field loss across various glaucoma types (open-angle, pigmentary, juvenile, Axenfeld's syndrome).
• Six patients not on miotics presented with a Marcus Gunn pupil; most experienced acuity loss at intraocular pressures below 30 mmHg.
• Seven patients had severe visual impairment (20/200 or less), with marked visual loss correlating to a cup-to-disc ratio of 0.8 or greater.

Conclusions:

• Decreased visual acuity with central field loss can be an early manifestation of glaucoma, challenging the traditional understanding of disease progression.
• Potential mechanisms include the extension of peripheral defects or direct involvement of the papillomacular bundle.
• This highlights the importance of assessing central visual function in the early diagnosis and management of glaucoma.