Microbial changes in conjunctival flora with 30-day continuous-wear silicone hydrogel contact lenses.
OBJECTIVE
To determine the effect of 30-day continuous-wear silicone hydrogel contact lenses on the conjunctival flora in asymptomatic wearers.


METHODS
The authors studied 29 eyes of 15 patients wearing Focus NIGHT & DAY silicone hydrogel contact lenses for up to 30 nights of continuous wear. The average age of the patients was 25.54 +/- 8.98 years. Cultures of the inferior cul-de-sac were taken bilaterally from all eyes, before and after lens wear in asymptomatic patients. The isolation and identification of bacteria were made by standard clinical laboratory methods.


RESULTS
The number of eyes whose conjunctival cultures were sterile before using the lenses significantly decreased (P = 0.0005), and the number of eyes with a growth of coagulase-negative staphylococci and diphtheroid rods in their conjunctival cultures significantly increased after using these lenses (P = 0.001 and P = 0.031, respectively). Conversely, a statistically significant difference was not found in the number of eyes that carried Propionibacterium acnes and Fusobacterium nucleatum in their conjunctival cultures before and after using the 30-day continuous-wear silicone hydrogel lenses (P = 0.998 and P = 0.488, respectively).


CONCLUSIONS
The results suggest that the sterility of the conjunctiva significantly decreased after using 30-day continuous-wear silicone hydrogel contact lenses. In addition, the number of bacteria of the normal conjunctival flora significantly increased after the use of these lenses. Contamination by the bacteria of the eyelids may be a possible colonization factor in this study group. Therefore, it is appropriate to examine the patients who wear these lenses more frequently.
Iskeleli
Güzin
G
Departments of Ophthalmology, Istanbul University, Cerrahpasa Faculty of Medicine, Istanbul, Turkey. giskeleli@superonline.com
Bahar
Hrisi
H
Eroglu
Ebru
E
Torun
Muzeyyen Mamal
MM
Ozkan
Sehirbay
S
D000293:Adolescent; D000328:Adult; D001419:Bacteria / Q000302:isolation & purification*; D001431:Bacteriological Techniques; D002648:Child; D003228:Conjunctiva / Q000382:microbiology*; D003262:Contact Lenses, Extended-Wear; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D012826:Silicone Elastomers
D012826:Silicone Elastomers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate