[Posterior segment complications following laser assisted in situ keratomileusis [LASIK]: a report of 5 cases]

To report complications involving the posterior segment after laser assisted in situ keratomileusis [LASIK] in 5 myopic patients ranging in age from 26 to 38 years. Case on developed bilateral cilioretinal artery obstruction in association with ischemic optic neuropathy. Case two presented with nonsimultaneous bilateral delayed-onset optic neuropathy. In case three, aggravation of the symptoms and signs of Stargardt's maculopathy was noticed. Case four showed rapid progression and worsening of diabetic retinopathy in both her eyes. In case five, early onset unilateral macular hemorrhage was observed. The increased intraocular pressure LASIK surgery may disturb blood flow in posterior ciliary arteries and choroid. The deleterious effect of LASIK on ocular circulation may result in sight threatening complications in predisposed patients

[Effect of graft-recipient disparity on refractive outcomes in keratoconus]

Purpose: to compare the refractive results of penetrating keratoplasty [PK] in two groups of patients with keratoconus undergoing corneal grafting with different amounts of donor-recipient disparity [0.25 and 0.5 mm]

Methods: as a randomized clinical trial and after performing a complete ocular examination and vitreous length measurement, 30 patients with keratoconus were randomly assigned in two groups: 15 patients underwent PK with 0.25 mm graft-recipient disparity and the other 15 patients underwent the operation with 0.5 mm disparity. One surgeon performed all the operations using a single running suture technique. Best corrected visual acuity and refractive errors were evaluated 1 year after PK and also two months after suture removal

Results: one year after PK and also 2 months after suture removal there was no statistically significant difference in BCVA between the two groups. Mean spherical and mean spherical equivalent refractive error was better in the 0.25 mm group, however this difference was not statistically significant [P> 0.05]. In vitreous length range of 16.2-17.7 mm [20 patients] mean spherical equivalent refractive error was -1.6 and -3.6 D in the 0.25 mm and 0.50 mm disparity groups, respectively [P= 0.03]. Mean spherical error was also better in the 0.25 mm group as compared with the 0.5 mm group [-0.8 versus -2.6 D, P= 0.05]. Mean astigmatic refractive error was minimally different between the two groups

Conclusion: less donor-recipient disparity [0.25 mm Vs 0.50 mm] seems to lead to better refractive outcomes in penetrating keratoplasty for eyes with keratoconus and vitreous length of 16.2- 17.7 mm