TY - JOUR
T1 - Melanocytes and iris color
T2 - Electron microscopic findings
AU - Imesch, Pascal D.
AU - Bindley, Colleen D.
AU - Khademian, Zarir
AU - Ladd, Bill
AU - Gangnon, Ronald
AU - Albert, Daniel M.
AU - Wallow, Ingolf H.L.
PY - 1996/4
Y1 - 1996/4
N2 - Objective: To quantitatively associate iris color with melanocyte pigment content. Methods: Autopsy eyes were classified as uniform-blue, uniform- hazel, or uniform-brown or showing a darker peripupillary ring. Using electron microscopic images and computerized image analysis, area, number, and size of mature melanosomes within the perinuclear cytoplasmic area only or within perinuclear and peripheral cytoplasmic areas of the superficial stromal melanocytes combined were measured. Results: Average melanosomal area per perinuclear cytoplasmic area (AMAC) and average number of melanosomes per perinuclear area (AMNC) significantly differed across iris color groups (overall P<.001). This result reflects the large difference between blue- uniform and all other color groups. A marginally significant (nominal) trend from blue-ring through brown-ring was also detected (P=.06 for AMAC and P=.07 for AMNC). The average perinuclear cytoplasmic area was larger in the central iris zone (within 1 mm around the pupillary margin) than in the intermediate iris zone (between 1 and 2 mm around the pupillary margin) (P=.002), but AMAC and AMNC did not significantly differ between zones. The average melanosome size did not differ significantly across color groups (P=.11). Conclusion: Differences in iris colors are at least partially attributed to variable AMNC and AMAC within superficial melanocytes.
AB - Objective: To quantitatively associate iris color with melanocyte pigment content. Methods: Autopsy eyes were classified as uniform-blue, uniform- hazel, or uniform-brown or showing a darker peripupillary ring. Using electron microscopic images and computerized image analysis, area, number, and size of mature melanosomes within the perinuclear cytoplasmic area only or within perinuclear and peripheral cytoplasmic areas of the superficial stromal melanocytes combined were measured. Results: Average melanosomal area per perinuclear cytoplasmic area (AMAC) and average number of melanosomes per perinuclear area (AMNC) significantly differed across iris color groups (overall P<.001). This result reflects the large difference between blue- uniform and all other color groups. A marginally significant (nominal) trend from blue-ring through brown-ring was also detected (P=.06 for AMAC and P=.07 for AMNC). The average perinuclear cytoplasmic area was larger in the central iris zone (within 1 mm around the pupillary margin) than in the intermediate iris zone (between 1 and 2 mm around the pupillary margin) (P=.002), but AMAC and AMNC did not significantly differ between zones. The average melanosome size did not differ significantly across color groups (P=.11). Conclusion: Differences in iris colors are at least partially attributed to variable AMNC and AMAC within superficial melanocytes.
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U2 - 10.1001/archopht.1996.01100130439015
DO - 10.1001/archopht.1996.01100130439015
M3 - Article
C2 - 8602783
AN - SCOPUS:0029921846
SN - 0003-9950
VL - 114
SP - 443
EP - 447
JO - Archives of ophthalmology
JF - Archives of ophthalmology
IS - 4
ER -