Measurements of anterior segment parameters using three different non-contact optical devices in keratoconus patients

AIM:To evaluate the measurements of anterior segment parameters using three different non-contact optical devices in keratoconus patients.·METHODS:A hundred and one eyes of 55 keratoconus patients were enrolled in this study.The mean age was26.2 ±8.9 years.The inclusion criteria were keratoconus stage I to III according to the Amsler-Krumeich keratoconus classification.All the measurements were done by the same operator,under the mesopic light condition and repeated with three different optical methods;Visante,Orbscan and Pentacam.The evaluated anterior segment parameters were anterior chamber depth(ACD),central and thinnest corneal thickness(CCT and TCT) and pupil diameter(PD).·RESULTS:The mean CCT measured by Visante,Orbscan and Pentacam were as follows:462.0 ±48.1μm,463.9±60.9μm,476.5±45.3μm,respectively(P =0.873).The mean ACD values were 3.34±0.33mm,3.26±0.33mm,3.49±0.40mm,respectively(P=0.118).The mean PD measurements were 5.11 ±1.14mm,4.80 ±0.85mm,3.80 ±1.38mm,respectively(P 【0.001).The mean TCT measurements of Visante,Orbscan and Pentacam were 437.9 ±48.2μm,447.6±60.6μm and 459.9±44.0μm,respectively(P =0.214).The Visante and Orbscan measured CCT similarly,while Pentacam measured CCT thicker than the other two.The Visante measured TCT thinner than the other two devices.In ACD measurements,Orbscan was the one giving the lowest values.PD was measured differently by the devices.·CONCLUSION:Although TCT,CCT and ACD measurements acquired by Visante,Orbscan and Pentacam in keratoconus patients are similar,PDmeasurements show large differences among the devices.

Laser in situ keratomileusis in adult patients with anisometropic amblyopia

AIM: To evaluate the increase in corrected distance visual acuity (CDVA) after laser in situ keratomileusis (LASIK) in adults with anisometropic amblyopia. · METHODS: The medical records of consecutive patients diagnosed with anisometropic amblyopia at the time of refractive evaluation who underwent LASIK were retrospectively reviewed. Patients with at least a two-line difference of visual acuity (VA) between the eyes with a spherical refractive error difference of at least 3.00 diopters (D) or an astigmatic difference of at least 2.00D were included. Patients with any other possible reason for amblyopia other than anisometropia or those who had undergone previous amblyopia treatment were excluded. Amblyopic eyes with myopia or myopic astigmatism were considered as group 1, hypermetropia or hypermetropic astigmatism constituted group 2, and mixed astigmatism patients comprised group 3. Uncorrected distance visual acuity (UDVA), subjective manifest refraction, and CDVA were analyzed at 1 week and 1 month, 3, and 6 months. ·RESULTS: The study included 57 eyes of 57 patients. There were 33 eyes in group 1, 12 eyes in group 2, and 12 eyes in group 3. The preoperative mean values for spherical equivalent of subjective manifest refraction (SE) in groups 1, 2, and 3 were (-4.66±1.97)D, (4.40±1.00)D, and (0.15±1.05)D, respectively. Mean CDVA improved 0.1 log units (1 line LogMAR) at 6 months (P 【0.05). Sixteen eyes (28%) exhibited an improvement in CDVA in week 1. Fourteen eyes (25% ) experienced two or more lines of CDVA improvement at month 6. There were no statistically significant differences among the groups in terms of CDVA (P 】0.05). Moreover, age, the amount ofpreoperative refractive error, and the levels of preoperative corrected and UDVA had no effect on postoperative CDVA improvement (P 】0.05). · CONCLUSION: Correction of refractive errors with LASIK produced significant CDVA improvement in adult patients with anisometropic amblyopia and no previous amblyopia treatment.