Preperimetric Glaucoma Diagnosis and Management

Definition and Diagnostic Elements

The American Academy of Ophthalmology defines preperimetric glaucoma as the presence of glaucomatous optic nerve or retinal nerve fiber layer (RNFL) damage without detectable visual field defects on standard automated perimetry (SAP) 1, 2
Optic Nerve Head (ONH) examination is critical for identifying early structural changes, including vertical elongation of the optic cup with decreased neuroretinal rim width, cup enlargement, and diffuse or focal narrowing of the neuroretinal rim 1, 3
RNFL assessment, including beta-zone parapapillary atrophy, is also essential for diagnosis 1, 3
Intraocular Pressure (IOP) measurement, including multiple measurements at different times of day, is necessary to assess fluctuations and document time of day for each measurement 1, 2
Gonioscopy is essential to exclude angle closure or secondary causes of IOP elevation 1, 2

Central Corneal Thickness (CCT) measurement is important, as thinner corneas are associated with higher risk of progression 3, 5
Structural imaging, including stereoscopic optic disc photography and Optical Coherence Tomography (OCT) of ONH, RNFL, and macular ganglion cell complex, is useful for diagnosis and monitoring 3, 6
Standard Automated Perimetry (SAP) is used to assess visual field defects, although it may be normal in preperimetric glaucoma by definition 4

Thinner central corneal thickness is a risk factor for progression from preperimetric to perimetric glaucoma 7

The American Academy of Ophthalmology recommends a complete history, including ocular history, race/ethnicity, family history of glaucoma, and systemic conditions, to assess risk factors for progression 7, 8
Treatment decisions should be based on risk assessment, with high-risk patients considered for IOP-lowering therapy 5, 7
IOP-lowering therapy, such as latanoprost 0.005% once daily, can reduce IOP and slow disease progression 1, 2

Untreated low-risk patients should be followed up every 12 to 24 months, while treated or high-risk patients require more frequent follow-up (every 3-6 months) until stable 7
At each follow-up visit, visual acuity measurement, slit-lamp biomicroscopy, IOP measurement, and periodic ONH and RNFL evaluation should be performed 6, 7