Anterior Segment Examination
As discussed previously, corneal enlargement and opacification are important signs associated with glaucoma in patients younger than 3 years. Corneal diameter can be measured with calipers or a ruler (Fig 8-11). The normal corneal diameter is approximately 9.5–10.5 mm in full-term newborns, increasing to 11–12 mm by 1 year of age. Table 11-11 compares normal pediatric measurements with adult measurements. A corneal diameter greater than 11.5 mm in a newborn and greater than 12.5 mm in children above the age of 1 year is suggestive of glaucoma. A difference in corneal diameter of 0.5 mm or greater between both eyes of the same patient may suggest glaucoma. Corneal edema may be due to elevated IOP or Haab striae and may range from a mild haze to dense opacification of the corneal stroma (Fig 9-11). Retroillumination after pupillary dilation may help make Haab striae visible. Evaluation for other anterior segment anomalies, such as aniridia, iridocorneal adhesions, and corectopia, may provide insight into the underlying diagnosis.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.