Axial Length and Proliferative Diabetic Retinopathy

PURPOSE: This study was conducted to investigate the relationship between axial length(AL) and proliferative diabetic retinopathy(PDR). METHODS: We reviewed the medical charts of the nondiabetic patients who had undergone cataract surgery and diabetic patients who had undergone vitrectomy or cataract surgery at Korea University Kuro Hospital between January, 1998 and July, 2000. Eyes with previous ocular surgery or other severe ocular disease were excluded from the analysis. Eyes with axial length greater than 24 mm were also excluded. The eyes were divided into 4 groups: Non-DM group, nondiabetic; Non-DR group, diabetic without retinopathy; NPDR group, with nonproliferative diabetic retinopathy; and PDR group, with proliferative diabetic retinopathy. Each group contained 42 eyes which were matched for age and sex. RESULTS: The AL values of each group were compared. The mean AL of the PDR group(22.2+/-0.8 mm) was significantly shorter than each of the other groups: Non-DM group(23.1+/-0.7 mm, p<0.05); Non-DR group(22.9+/-0.9 mm, p<0.05); NPDR group(22.8+/-0.8 mm, p<0.05). Within the PDR group, the eyes that had received preoperative panretinal photocoagulation(27 eyes, mean: 22.0+/-1.1 mm) showed a shorter AL than those that had not(15 eyes, mean: 22.7+/-0.8 mm), which was not statistically significant(P=0.08, t-test). CONCLUSION: The results suggest that a shorter axial length may be associated with severe proliferative diabetic retinopathy.

Macular Hemorrhage after Laser in Situ Keratomileusis

Macular hemorrhage which result from breaks of Bruch's membrane or from choroidal neovascularization can develop in high degenerative myopia, but its occurrence after photorefractive surgery has rarely been reported. We experienced a case of macular hemorrhage after laser in situ keratomileusis[LASIK]:A 28-year-old female patient with high myopia of -16.5 diopters, who had received successful LASIK operation on her left eye.complained of a sudden drop in vision 20 days postoperatively.On fundus examination, macular hemorrhages were detected on her left eye.Eventually the hemorrhages resolved, but more than 2 lines of her best corrected visual acuity were lost.During follow-up, a new hemorrhagic lesion was incidently found on the other eye. This case demonstrates that macular hemorrhages may develop after LASIK in eyes with high degenerative myopia, and lead to a permanent reduction in visual acuity.We should be alert to any potential retinal pathology in patients having refractive surgery.

Facial Asymmetry and Head Tilting in Superior Oblique Palsy

We identified facial asymmetry in 81 patients with a history of long standing head tilt due to congenital or early childhood onset superior oblique palsy(SOP). To determine facial asymmetry, full frontal photographs of face were taken for each patient in a straight ahead position. They were also evaluated for skull molding, sleeping habit and degree of head tilt. Facial asymmetry was noted in 62 of 81(76.5%) patients with early onset superior oblique palsy. Eighteen of 36(50%) patients with facial asymmetry had skull molding and sleeping habit to lay down on the one side of head. Incidence of facial asymmetry was high in patients with head tilt. In addition, one of 3(33.3%) patient less than 24 months of age showed constant head tilt and facial asymmetry. After surgical correction of superior oblique palsy, head tilt was eliminated and facial asymmetry gradually disappeared. Facial asymmetry was found in 5 of 9(55.6%) patients between 2 and 3 years of age, and in 25 of 28(89.3%) patients more than 3 years of age. Fortunately it gradually improved at the long term follow-up. This study shows that the facial asymmetry cold be produced by chronic head tilt from even less than 2 years of age. Skull molding may develop in infants who prefer to sleep on one side of head. To prevent the development of facial asymmetry, early surgery less than 2 years of age may be needed. Monitoring of head position during sleep may be important to prevent skull molding. If head tilt persist even after surgical correction of SOP, secondary scoliosis, contracture of the neck muscle or habit should be considered and physical therapy may be needed.

Corneal Endothelial Changes after Laser Assisted In Situ Keratomileusis

Laser assisted in situ keratomileusis(LASIK) is a widely used technique for correcting high myopia. Its technical methods and excellent clinical results are well known, but its potential risk on the corneal endothelium are poorly known. We used specular microscope to underwent LASIK for the correction of myopia. The mean preoperative refraction was ?4.5 diopters (range, -10.00 to -23.50 diopters.). The average endothelial cell densities were 2,817+/-205 cells/mm2 (mean +/-SD) preoperatively and 2,789+/-211 cells/mm2 3 months postoperatvely, corresponding to fall of 28 cells/mm2. This fall in endothelial cell density was not statistically significant (P>0.05). But significant correlation between the change in cell density and the residual corneal thickness was found(P>0.05). These results suggest that LASIK is a predictable and safe method for correcting high myopia, but care is recommended when doing deep corneal ablation. Long term follow-up may be needed to confirm its safety.

The Effects of Minoxidil Versus Mitomycin C on the Filteing Surgery for Glaucoma in Rabbits

We compared the effect of topical minoxidil after filtering surgery with that of mitomycin C (MMC) application in rabbits. Fourty-nine eyes were divided into the minoxidil-treated eyes, MMC_treated eyes and control eyes. Intraocular pressure (IOP) in minoxidil-treated eyes and MMC-soaked eyes were significantly lower than that of the control eyes at postoperative 1 and 3 days. MMC-soaked eyes had lower IOPs than the minoxidil-treated and control eyes, but IOPs in the minoxidil- and control eyes were similar at days 5 to 21. IOP survival in the MMC-treated eyes was significantly longer than in both the minoxidil-treated and control eyes. These results suggest that topical minoxidil can cause reduction of IOP at the early postoperative period. Howver, the IOP lowering effect of Minoxidil did not last as long as that of MMC soaking. Further study is necessary to enhance the efect of topical minoxidil including its method of application and optimal concentration.