The main basis is the signs and symptoms of PDS, intraocular pressure, glaucomatous visual field and optic disc changes are seen in the mid-peripheral iris spoke translucent area on fluoroscopic examination, which is the most characteristic. In addition, slit lamp examination shows Krukenberg’s pike shaped pigmentation on the posterior corneal wall, deep anterior chamber, posterior sunken iris with pigmentation, and pigmentation on the posterior surface of the lens near the equator after pupil dilation. Iris keratoscopy showed a wide atrial angle and dense pigmented bands on the trabeculae. PDS can be diagnosed with iris signs and some other signs; PG can be diagnosed if there are also pathologic high intraocular pressure glaucomatous visual field and optic disc changes. 1. iris pigment loss There are no other diseases associated with iris spoke transillumination defects in PDS/PG. In patients with congenital glaucoma, some patients occasionally have a transillumination defect visible in the distal periphery of the iris near its attachment, but it is not hub-and-spoke. Patients with exfoliation syndrome occasionally have pigment spreading, and the transillumination defect is mostly located at the pupillary margin or in scattered patches throughout the iris. Damage to the posterior surface of the iris due to trauma or surgery presents as irregular patches of iris pigment loss. Patients with posterior iris depigmentation due to severe uveitis also present with a regional patchy loss of pigment, but not a peripheral whorl-spoke defect. Occasionally, there may be a marbled transillumination defect in a normal eye, but it is very different from the changes seen in PDS/PG. 2. Uveitis If small pigment particles are floating in the atrial water they can be mistaken for white blood cells and misdiagnosed as uveitis. To make a correct diagnosis, it is important to note the typical signs of PDS and the lack of other signs of uveitis, such as conjunctival congestion, KP, and posterior iris adhesions. loss of pigment on the posterior surface of the iris in patients with PDS does not provoke an inflammatory response, although phagocytes can advance into the iris stroma. Herpes zoster keratoconjunctivitis can cause fan-shaped iris atrophy, and herpes simplex keratoconjunctivitis can cause extensive iris atrophy. Both do not have PDS-like iris transillumination defects. 3. Increased pigmentation of the trabecular meshwork Abnormal pigment dispersion can occur in eyes with syndromes other than PDS/PG. The pigment dispersion associated with exfoliation syndrome can lead to significant darkening of the trabecular meshwork. In many of these cases, the pigment mixes with the cystic membrane exfoliating material to form irregular, linen-like bands of pigment. A typical Krukenberg pike is not developed. The typical cystic membrane exfoliating material helps in the correct diagnosis. Patients with peripheral iris or ciliary body cysts occasionally have moderate pigmentation on the trabecular meshwork without a typical Krukenberg’s pike. Diagnosis is made with the help of observation of the characteristic transillumination defect of the peripheral iris PDS Definitive diagnosis requires the application of an iridocorneal keratoscope under dilated pupil conditions to detect subiris cysts. In both of these cases there is no pigmentation on the posterior surface of the peripheral lens. 4. Anterior and posterior segment melanoma Iris, ciliary body, or posterior segment melanoma (if the vitreous anterior border membrane is ruptured) can be accompanied by pigmentation dissemination. Pigmented tumor cells or pigment-filled phagocytes can cause considerable darkening of the anterior and posterior chambers. However, the typical symptoms of PDS/PG are lacking: there is no Krukenberg shuttle and there is no transillumination defect. The primary tumor is easily detected. Inflammation of the posterior surface of the iris may occasionally be accompanied by a moderate amount of pigment release, often aggregated in clusters in the inferior atrial horn, along with signs of inflammation. 5. Other implantation of a posterior chamber IOL can sometimes cause PG, when the abnormally positioned posterior chamber IOL and the iris are in prolonged postoperative contact and friction resulting in pigment release 6. exfoliation syndrome Mechanical friction between the peripapillary lens and the peripupillary iris in pigmentary glaucoma, similar to pigmentary glaucoma with iris transillumination defect Krukenberg’s shuttle, trabecular pigmentation and elevated intraocular pressure However, the following conditions are easily distinguished: (1) they are more common in older adults over 60 years of age and less common in those under 40 years of age; (2) they are unilateral in 50% of patients, regardless of gender and refractive error (myopia) tendency; (3) the transillumination defect is common in the pupil margin and surrounding iris and rarely in the mid-peripheral iris, and the trabecular meshwork pigmentation is not as dense as in pigmentary glaucoma (usually grade 2); (4) the most distinguishing feature is the grayish cephalic color of the pupil margin. is grayish dandruff-like granules or flocs at the pupillary margin and gray pseudoexfoliative material on the anterior capsule of the peripheral lens. Both disorders have been reported to coexist.