Biomedical subjects

C Allouch

Publications and source records attributed to C Allouch.

21 records · Page 2Linked to original sources

PubMed1999

Effects of penetrating keratoplasty suture removal on corneal topography and refraction.

PURPOSE: 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). CONCLUSION: 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.

Adolescent↗

PubMed1999

[Effect of sodium hyaluronate administered at the end of penetrating keratoplasty on reepithelialization of the graft].

PURPOSE: To investigate the effect of sodium hyaluronate on reepithelialization time after penetrating keratoplaty. METHODS: We prospectly studied 56 consecutive penetrating keratoplasties. One group of patients (n = 22) received dexamethasone ointment at the end of surgery. The second group (n = 34) received sodium hyaluronate and topical dexamethasone. Postoperative reepithelialization time and graft central thickness were recorded. RESULTS: There was no statistical difference between both groups for epithelialization (4.6 + 3.2 days in the hyaluronate group and 4.4 + 2.3 days in the dexamathasone group) and for graft thickness at day one (710 + 85 microns for the former group and 713 + 84 microns for the latter group) and at day of reepithelialization (663 + 80 microns for the former group and 703 + 99 microns for the latter group). The epithelium aspect was different at the first postoperative day between both groups. CONCLUSION: The use of sodium hyaluronate at the end of penetrating keratoplasty improves the graft epithelium aspect at the first postoperative day, but it does not influence reepithelialization time. Further studies are needed to investigate the mechanism of sodium hyaluronate effect on corneal epithelium.

Aged↗

PubMed1999

[Comparison of EyeSys videokeratoscope algorithms in the evaluation of idiopathic and postoperative astigmatism].

PURPOSE: To compare the accuracy and reproducibility of the Eye Sys videokeratoscope algorithms for analyzing idiopathic and surgery-induced astigmatism analysis. METHODS: Refractive astigmatism, videokeratoscopy (axial, tangential and refractive power), autorefractometry, autokeratometry, and keratometry were recorded in 20 patients with idiopathic astigmatism, 40 patients who had undergone cataract surgery and 40 patients who had undergone penetrating keratoplasty. For each eye, 2 successive videokeratoscopy were recorded. RESULTS: Both cylinder and axis provided by the tangential algorithm are significantly less reproducible than the cylinder and axis provided by the axial and refractive algorithms (P < 0.001). Cylinders provided by the axial and refractive algorithms showed a stronger correlation with subjective cylinder (rs > 0.89; p < 0.001) than the cylinder provided by the tangential algorithm (rs = 0.66; p < 0.001). Both keratometric axis and autokeratometric axis showed the strongest correlation with subjective axis (rs > 0.92; p < 0.001). The accuracy and reproducibility were higher for the topographic "bow tie" patterns than for the other topographic patterns. CONCLUSION: The axial and refractive algorithms of the Eye Sys videokeratoscope are more accurate and reproducible than the tangential algorithm for analyzing idiopathic or surgery-induced astigmatism.

Algorithms↗