What is DDLS in oct?

The disc damage likelihood scale (DDLS) is a tool for classifying glaucomatous structural changes to the optic disc based on the radial width of the neuroretinal rim at its thinnest location, or if no rim is present, the extent of absence of the rim.

What is RIM disc ratio?

The unit of measurement is the rim/disc ratio—that is, the radial width of the rim compared to the diameter of the disc in the same axis. When there is no rim remaining the rim/disc ratio is 0. The circumferential extent of rim absence (0 rim/disc ratio) is measured in degrees.

What is normal CDR in eye?

The average CDR is 0.4. However, CDR ratio in normal patients can range from 0.0 to 0.9 because of inter-individual variation in disc size and cup size. Normal CDRs range from less than 0.3 (66% of normal individuals) to greater than 0.5 (only 6–10% of normal individuals).

What is normal optic disc size?

Measuring optic disk size is an essential part of the optic nerve head for evaluation for glaucoma. The average human optic disc dimensions are 1.88mm vertically by 1.77mm horizontally, and can be grouped by vertical diameter into small (1.2-1.7mm), average (1.87-1.96mm), and large (2.03-2.27mm) disc sizes [1].

Is eye pressure of 15 high?

About 90 percent of people will fall between a pressure range of 10 and 21 with the average eye pressure being approximately 15 mm Hg. Eye pressure greater than 21 mm Hg is considered higher than normal, but even so, that does not mean eye pressure of 22 or higher is abnormal.

What is normal optic cup size?

The average vertical optic disc diameter is 1.88 mm (vertically ranging from 1,700–2,000 μm), and the average horizontal diameter is 1.77 mm (ranging from 1,600–1,800 μm). Thus, a normal healthy optic disc is usually vertically oval.

What is disc diameter?

The disc-macula: disc diameter (DM:DD) ratio is the ratio of the horizontal distance between the center of the optic disc and the macula to the mean diameter of the optic disc, as evaluated from fundus photographs.

What is cup-to-disc ratio in glaucoma?

The normal cup to disc ratio (the diameter of the cup divided by the diameter of the whole nerve head or disc) is about 1/3 or 0.3. There is some normal variation here, with some people having almost no cup (thus having 1/10 or 0.1), and others having 4/5ths or 0.8 as a cup to disc ratio.

What size should your optic nerve be?

1.2 to 2.5mm
The normal optic nerve head diameter varies in size from 1.2 to 2.5mm. There is some inconsistency in the literature as to what cutoffs to use for a small or large disc, but in general a disc can be considered small if ≤ 1.2 mm and large if ≥ 1.8 mm.

What is the disc damage likelihood scale (DDLs)?

y colleagues and I developed the Disc Damage Likelihood Scale (DDLS) to facilitate the diagnosis and management of glauco- ma.1,2The DDLS relies on the optic nerve as a direct indicator of disease.

What is the DDLs?

The DDLS, a quantitative optic disc staging system which takes into consideration disc size and position of the rim thinning, through an inexpensive method and by using the readily available slit lamp, can be used in different clinical settings, including areas with different levels of development and where resources are scarce.

Is the DDLs system useful to detect glaucoma?

Our findings suggest that the DDLS system is useful to detect glaucomatous damage, and has a diagnostic accuracy similar to newer and more expensive imaging devices.