**5. Conclusion**

This study clearly showed that the APOE polymorphism represents a major risk factor for ophthalmic/neurodegenerative diseases and this study together with previous studies pointed to a possible association between APOE alleles and PG/PEX in defined populations. However, the association between APOE genotype and PG/PEX seems to differ among studied popula‐ tions, indicating a modifying rather than a direct genetic effect. Although our results indicated *ε4* allele to be significantly associated with the development of primary glaucoma (POAG and PACG) and PEX in a Saudi population. Further studies are warranted to understand the role of APOE allelic isoforms in various ethnic populations and to predict the predisposition to degenerative eye diseases like PEX and glaucoma.
