Refractive change following pseudophakic vitrectomy.
BACKGROUND
To assess the occurrence and magnitude of refractive change in pseudophakic eyes undergoing 20 gauge pars plana vitrectomy without scleral buckling and to investigate possible aetiological factors.


METHODS
Retrospective case note review of 87 pseudophakic eyes undergoing 20 gauge pars plana vitrectomy for a variety of vitreo-retinal conditions over a three-year period. Anterior chamber depth (ACD) was measured before and after vitrectomy surgery in 32 eyes. Forty-three pseudophakic fellow eyes were used as controls.


RESULTS
Eighty-seven eyes (84 patients) were included in the study. Mean spherical equivalent refraction prior to vitrectomy was -0.20 dioptres, which changed to a mean of -0.65 dioptres postoperatively (standard deviation of refractive change 0.59, range-2.13 to 0.75 dioptres) (p < 0.001). Sixty-one of the 87(70%) eyes experienced a myopic shift and 45(52%) eyes had a myopic shift of -0.5 dioptres or more. Mean fellow eye refraction was -0.19 dioptres preoperatively and -0.17 dioptres postoperatively (p = 0.14)(n = 37)Mean ACD preoperatively was 3.29 mm and postoperatively 3.27 mm (p = 0.53) (n = 32) and there was no significant change in ACD with tamponade use. Regression analysis revealed no statistically significant association between changes in anterior chamber depth, as well as a wide variety of other pre-, intra and postoperative factors examined, and the refractive change observed.


CONCLUSIONS
Significant refractive changes occur in some pseudophakic patients undergoing 20 g pars plana vitrectomy. The mean change observed was a small myopic shift but the range was large. The aetiology of the refractive change is uncertain.
Sunderland Eye Infirmary, Queen Alexandra Road, Sunderland, Tyne and Wear, UK. sineadambyrne@hotmail.com
Sinead
S
Byrne
James
J
Ng
Anthony
A
Hildreth
Jean-Pierre
JP
Danjoux
David Hw
DH
Steel
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000473:pathology; D005128:Eye Diseases / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000209:etiology* / Q000503:physiopathology*; D011183:Postoperative Complications; D019591:Pseudophakia / Q000473:pathology / Q000601:surgery*; D012029:Refraction, Ocular; D012164:Retinal Diseases / Q000601:surgery; D012189:Retrospective Studies; D014821:Vitrectomy; D014822:Vitreous Body