Effects of penetrating keratoplasty suture removal on corneal topography and refraction.
OBJECTIVE
To study the refractive and topographic modifications induced by penetrating keratoplasty suture removal.


METHODS
We retrospectively studied 50 corneas from 50 patients who had undergone penetrating keratoplasty. All of the eyes were examined before and after all sutures were removed at 10.8+/-4.7 months and 20.3+/-7.9 months after keratoplasty. Subjective refraction, best spectacle-corrected visual acuity (LogMAR units), and corneal topography (EyeSys 2000R device) were recorded.


RESULTS
Suture removal decreased the subjective cylinder by an average of 0.91+/-2.32 D (p = 0.004) and modified the corneal topographic pattern (p = 0.03) and shape (p < 0.001) distribution. The change in subjective cylinder correlated with the variation of the steepest meridian power (r(s) = 0.46; p < 0.001). It correlated with the change in topographic pattern (r(s) = 0.59; p < 0.001). The subjective spherical equivalent increased (hyperopization) by an average of 0.61+/-2.24 D (p = 0.01). After suture removal, the prolate shape was less frequent, and the oblate shape was more frequent than before suture removal. Best spectacle-corrected visual acuity increased by an average of 0.8+/-2.0 lines (p = 0.004). The change in subjective cylinder correlated with the change in visual acuity (r(s) = 0.36; p = 0.006).


CONCLUSIONS
Suture removal modifies the corneal topographic pattern and shape. It decreases the subjective cylinder and induces an hyperopization. Visual-acuity improvement after suture removal mainly is explained by the decrease in astigmatism. Suture removal seems particularly helpful in corneas with a bow-tie pattern.
Touzeau
O
O
Department of Ophthalmology, Hôpital Saint Antoine, Paris, France.
Borderie
V M
VM
Allouch
C
C
Scheer
S
S
Laroche
L
L
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012029:Refraction, Ocular; D013536:Suture Techniques; D014792:Visual Acuity