Surgery-related factors influencing corneal neovascularization after low-risk keratoplasty.
OBJECTIVE
To identify the speed of corneal neovascularization (CNV) after penetrating keratoplasty (PK) and to evaluate the influence of surgery-related factors on postkeratoplasty CNV in keratoconus patients.


METHODS
Prospective, longitudinal, observational, case series study.


METHODS
All consecutive primary PKs performed for keratoconus by four experienced surgeons between January 1, 2000 and December 31, 2002 at our department were included (n=66 patients). Standardized corneal photographs taken preoperatively and at 6 weeks, 3, 6, 12, 18, and 24 months postoperatively were evaluated. Limbus suture distance (LSD), limbus graft distance (LGD), inner suture angle (ISA), and maximal extension of CNVs in digitized pictures with 100-fold magnification were measured at each of the 16 suture turning points at every timepoint.


RESULTS
Forty-four (67%) out of 66 corneal grafts developed some degree of CNV after PK, most commonly from around the 12 o'clock position. The mean speed of CNV growth was 114 microm/month with the fastest growth occurring during the first six weeks after PK. There was an inverse correlation between CNV and LSD, LGD, and ISA (all P<.001). Ninety percent of all CNVs developed with LSD<406 microm and with LGD<1000 microm. Superior limbal localization between 11 and 1 o'clock is an independent risk factor for postoperative neovascularization, too (P<.001).


CONCLUSIONS
Small LSD, small LGD, and narrow stitching with small ISA were identified as potentially modifiable surgical risk factors for CNV after PK. The speed of CNV outgrowth was most pronounced in the first weeks after PK making early postoperative controls for CNV growth and initiation of antiangiogenic treatment important.
Lam
Vinh M
VM
Department of Ophthalmology, University of Erlangen-Nürnberg, Erlangen, Germany, and Ho Chi Minh Eye Hospital, Ho Chi Minh City, Viet Nam.
Nguyen
Nhung X
NX
Martus
Peter
P
Seitz
Berthold
B
Kruse
Friedrich E
FE
Cursiefen
Claus
C
D000293:Adolescent; D000328:Adult; D016510:Corneal Neovascularization / Q000209:etiology*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000601:surgery*; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D012307:Risk Factors; D013536:Suture Techniques / Q000009:adverse effects*