Deniz Oral

Short term oral minocycline treatment of meibomianitis

Aim: To evaluate the clinical impact, aqueous tear parameters, and meibomian gland morphology in patients with primary meibomianitis before, during, and 3 months after a course of oral minocycline. Methods: 16 patients were prospectively enrolled, 11 male and five female (mean age 69 years old). Each patient received routine clinical evaluations before, after 3 months therapy, and at 6 month study follow up visit. The clinical appearance, tear volume, flow and turnover, evaporation, Schirmer I test, meibomian gland dropout, lissamine green staining, and bacteriology wer evaluated. Results: Improvement was observed in clinical signs of meibomianitis at the second and third visits. Microbial culture findings improved. Decreased aqueous tear volume and flow, and increased evaporation rate range at 35–45% relative humidity (RH) (p<0.05) were also detected. Other related tear parameters did not change. Meibomian gland dropout showed no improvement. Conclusions: 3 months of oral minocycline resulted in clinical improvements in all meibomianitis signs that persisted for at least 3 months after discontinuation despite decreased aqueous tear volume and flow with increased evaporation (35–45% RH). However, there was improvement in the turbidity of secretions. Short term minocycline therapy probably has efficacy in the management of meibomianitis that extends beyond eradication of bacteria.

Evaluation of corneal topography with Orbscan II in first-degree relatives of patients with keratoconus.

Purpose: To evaluate the corneal topographic characteristics of first-degree relatives of patients with keratoconus with corneal topography to determine the incidence of clinical keratoconus and topographic abnormalities. Methods: Between February and August 2006, Orbscan II analysis was done in 144 eyes of 72 cases who were first-degree relatives of patients diagnosed with clinical keratoconus. The findings were compared with preoperative Orbscan analyses of 52 clinically normal individuals who underwent laser in situ keratomileusis surgery and did not develop corneal ectasia in 3 years of follow-up. Results: In 8 of the 72 first-degree relatives of patients with keratoconus, clinical keratoconus was diagnosed by the topographic pattern in Orbscan and clinical examination (group 1). The remaining 64 subjects (group 2) were compared with the control group (group 3). The central corneal thickness was 523.7 ± 40.4 μm in group 2, whereas it was 546.3 ± 33.1 μm in group 3 (P < 0.05). The central corneal thickness, thinnest pachymetric reading, posterior elevation value, distance between the greatest anterior/posterior elevation points, and corneal center, posterior best fit sphere (BFS) values, posterior BFS:anterior BFS ratio, and irregularity values were significantly different between group 2 and group 3 (P < 0.05). Conclusions: The keratoconus incidence was found to be 11% in first-degree relatives of patients with keratoconus as opposed to a reported incidence of keratoconus of 0.05% in the general population. In first-degree relatives of patients with keratoconus who did not have a topographic keratoconus pattern, abnormal corneal topographic values were detected. The asymptomatic relatives of patients with keratoconus should undergo a thorough preoperative analysis for subtle topographic abnormalities before any keratorefractive surgery.

Hyperopic laser in situ keratomileusis in eyes with previous radial keratotomy

PURPOSE: To assess the safety and efficacy of hyperopic laser in situ keratomileusis (LASIK) in eyes with previous radial keratotomy (RK). SETTING: Zale Lipshy University Hospital Laser Center for Vision, University of Texas Southwestern Medical Center, Dallas, Texas, USA. METHODS: Thirty‐eight eyes of 25 patients were treated with LASIK for secondary hyperopia after RK using a Visx Star S2, S3, S4, or LADARVision excimer laser. Retreatment was done in 7 eyes. The main outcome measures were manifest refraction spherical equivalent (MRSE), uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), predictability of treatment, and complications. RESULTS: Preoperative mean MRSE was +2.39 diopters (D) ± 1.28 (SD) (range +0.87 to +6.00 D). At the last visit (25 eyes with minimum follow‐up of 12 months, including retreatments), the mean follow‐up was 23.3 ± 7.3 months (range 12 to 34 months), the mean MRSE was +0.11 ± 0.71 D, and the UCVA was 20/40 or better in 24 eyes (96%). Although no significant change in the mean MRSE was observed, the postoperative mean refractive cylinder showed a gradual increase over the follow‐up period. No eye lost more than 2 lines of BSCVA. CONCLUSIONS: Laser in situ keratomileusis was a safe and effective treatment with good predictability for the correction of consecutive hyperopia after RK. Cylindrical errors were difficult to correct, and astigmatic correction tended to regress over time. Retreatments are safe when old flaps were relifted.

OPHTHALMIC EXAMINATION OF THE CAPTIVE WESTERN LOWLAND GORILLA (GORILLA GORILLA GORILLA)

Abstract This study examined the captive western lowland gorilla (Gorilla gorilla gorilla) eye as compared and contrasted with the human eye. Bilateral ophthalmic examinations of western lowland gorillas (n = 5) while under general anesthesia were performed opportunistically, including slit-lamp biomicroscopy, dilated fundus examination, cycloplegic retinoscopy, Schiotz tonometry, corneal diameter and thickness measurements, A-scan and B-scan ultrasonography, keratometry, and cultures of the eyelid margins and bulbar conjunctiva. Mean spherical equivalent refractive error by cycloplegic retinoscopy was +1.20 ± 0.59 diopters. Mean intraocular pressure by Schiotz tonometry was 12.0 ± 4.3 mm Hg. Mean optic nerve head cup to disc ratio was 0.42 ± 0.11. Mean horizontal corneal diameter was 13.4 ± 0.8 mm, and mean vertical cornea diameter was 12.7 ± 0.8 mm. Mean central corneal thickness by ultrasound pachymetry was 489 ± 52 μm. Mean axial length of the eye by A-scan was 22.75 ± 0.71 mm. Mean lens thickness by A-scan was 4.23 ± 0.34 mm. Mean anterior chamber depth by A-scan was 4.00 ± 0.26 mm. Mean keratometry reading was 44.38 ± 1.64 diopters. Eyelid margin and bulbar conjunctival cultures isolated Candida sp. (n = 5), Staphylococcus aureus (n = 4), Staphylococcus epidermidis (n = 3), Staphylococcus saccharolyticus (n = 3), and Micrococcus sp. (n = 3). This study suggests important similarities between western lowland gorilla and human eyes. These similarities may allow diagnostics, techniques, and equipment for human eye surgery, such as those used for cataract extraction and intraocular lens implantation, to be successfully utilized for gorillas.

Comparison of LADARVision and Visx Star S3 laser in situ keratomileusis outcomes in myopia and hyperopia.

Purpose: To compare visual outcomes with 2 commonly used excimer lasers, the Autonomous LADARVision (LV) (Alcon Laboratories Inc.) and the Visx Star S3 (S3), in the performance of myopic and hyperopic astigmatic laser in situ keratomileusis (LASIK). Setting: Zale Lipshy University Hospital Laser Center for Vision, University of Texas Southwestern Medical Center, Dallas, Texas, USA. Methods: In this retrospective single‐center 3‐surgeon cohort comparison, 100 consecutive LV‐treated myopic eyes with a mean manifest refraction spherical equivalent (MRSE) of –3.22 diopters (D) (range 0 to –6.00 D) (mean astigmatism 0.95 D [range 0 to 4.00 D]) were compared with 100 consecutive S3‐treated eyes with a similar MRSE (mean MRSE –3.19 D; mean astigmatism 0.66 D [range 0 to 2.75 D]). Forty‐one consecutive LV‐treated hyperopic eyes with a mean MRSE of +2.59 D (range +1.00 to +6.00 D) (mean astigmatism 0.89 D [range 0 to 3.50 D]) were compared with 25 consecutive S3‐treated eyes with a similar MRSE (mean MRSE +2.70 D; mean astigmatism 0.87 D [range 0 to 2.75 D]). The following outcomes were compared: uncorrected visual acuity, refractive predictability and stability, gain or loss of best spectacle‐corrected visual acuity, and need for enhancement. Results: Statistically significant differences in outcomes were found between lasers in the treatment of hyperopia and hyperopic astigmatism. No outcome differences between lasers were found in the treatment of myopia and myopic astigmatism. Conclusion: The LV and S3 lasers yielded equivalent results in myopic LASIK between 0 and −6.00 D; however, the LADARVision yielded statistically significantly better results in hyperopic LASIK between +1.00 and +6.00 D.

Corneal biomechanical properties of patients with pseudoexfoliation syndrome.

Purpose: To assess the corneal biomechanical properties of patients with pseudoexfoliation syndrome (PEX syndrome). Methods: Fifty-two eyes of 52 patients (27 unilateral and 25 bilateral) and 42 eyes of 42 age-matched control subjects were enrolled in the study. Metrics of corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF), were measured with the ocular response analyzer (ORA). The ORA also determined the values of Goldmann-correlated intraocular pressure and corneal-compensated intraocular pressure. Central corneal thickness (CCT) was measured by the ORA integrated handheld ultrasonic pachymeter. The values recorded by the ORA were compared between eyes with PEX syndrome and those without PEX syndrome. Eyes with unilateral PEX syndrome and fellow eyes without PEX syndrome were also compared. Results: The mean CH and CRF of all eyes with PEX syndrome were significantly lower than those of control eyes (P < 0.05). Neither corneal-compensated intraocular pressure nor Goldmann-correlated intraocular pressure showed a statistically significant difference in both the groups. Mean CCT values also did not show significant difference. Comparison of the unilateral eyes with PEX syndrome with the apparently normal fellow eyes revealed no significant difference between the mean CCT, mean CH, and mean CRF values (P > 0.05). However, the mean corneal-compensated intraocular pressure and Goldmann-correlated intraocular pressure were relatively higher in the PEX syndrome eye (P < 0.05). There was no significant difference between the mean CCT values of these groups (P > 0.05). Conclusions: The CH and CRF decrease in both unilateral and bilateral PEX syndrome suggested that PEX syndrome has a weakening effect on corneal biomechanical properties. Moreover, in subjects with clinically unilateral PEX syndrome, these properties were closer to eyes with PEX syndrome than to normal control eyes.

A Comparison of Induced Astigmatism in Conventional and Wavefront-guided Myopic LASIK Using LADARVision4000 and VISX S4 Platforms

PURPOSE To evaluate and compare the surgically induced astigmatism in myopic eyes undergoing conventional and wavefront-guided LASIK. METHODS A retrospective review was performed of the charts of 200 myopic eyes of 121 patients who underwent either custom or conventional treatments via the VISX S4 or LADARVision4000 platforms (50 consecutive eyes in each of the four groups). The primary outcome measure was manifest refraction, which was evaluated preoperatively and at 3 months postoperatively. The magnitude and axis of the unintended surgically induced astigmatism were calculated using vector analysis. The Student t test was used to compare the magnitudes of the surgically induced astigmatism and the absolute angle of error. RESULTS The mean preoperative manifest cylinder was 0.66 +/- 0.38 diopters (D) for conventional VISX S4 and 0.68 +/- 0.39 D for VISX CustomVue (P = .795), and 0.76 +/- 0.56 D for LADARVision and 0.61 +/- 0.36 D for LADAR CustomCornea (P = .114). The success index was 0.19 +/- 0.41 for VISX S4 and 0.49 +/- 0.49 for VISX CustomVue (P = .0013), and 0.25 +/- 0.47 for LADARVision and 0.20 +/- 0.39 for LADAR CustomCornea (P = .5721). The absolute mean angle of error was 4.4 +/- 13.9 degrees for VISX S4 versus 14.9 +/- 23.9 degrees for VISX CustomVue (P = .0085), and 6.1 +/- 12.30 for LADARVision versus 3.9 +/- 11.1 degrees for LADAR CustomCornea (P = .3501). Of the VISX CustomVue eyes, 32% had an absolute angle of error > 10 degrees, as compared to 10% for both the VISX S4 and LADAR CustomCornea eyes (P = .013), and 16% for the LADARVision group (P = .056). CONCLUSIONS Wavefront-guided ablation is associated with higher surgically induced astigmatism and larger astigmatic axis shift on the VISX platform as compared to the LADAR CustomCornea and the LADAR and VISX conventional platforms. Care should be emphasized mainly during registration/alignment to minimize surgically induced astigmatism in wavefront-guided LASIK.

Corneal wavefront–guided customized laser in situ keratomileusis after penetrating keratoplasty

Purpose To assess the efficacy and safety of corneal wavefront‐guided custom laser in situ keratomileusis (LASIK) to correct refractive errors and higher‐order aberrations (HOAs) after penetrating keratoplasty (PKP). Setting Beyoglu Eye Training and Research Hospital, Istanbul, Turkey. Design Noncomparative case series. Methods The study comprised consecutive patients who were unable to tolerate spectacles or contact lenses for the correction of anisometropia after PKP and had corneal wavefront‐guided custom LASIK. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction spherical equivalent (MRSE), and corneal HOAs were recorded before and after LASIK. Results The study evaluated 11 eyes (10 patients). The mean follow‐up after LASIK was 24.3 months ± 11.7 (SD) (range 9 to 36 months). The mean MRSE was −2.97 ± 1.66 diopters (D) (range −0.50 to −5.38 D) preoperatively and −0.88 ± 0.96 D (range −2.75 to 0.5 D) postoperatively. The mean total higher‐order root mean square (RMS) was 4.65 ± 1.14 &mgr;m (range 2.26 to 5.94 &mgr;m) preoperatively and 2.71 ± 1.31 &mgr;m (range 1.22 to 5.33 &mgr;m) postoperatively. Postoperatively, the UDVA improved in 7 eyes and remained unchanged in 4 eyes. The CDVA improved in all eyes postoperatively even cases in which the attempted astigmatic correction was not totally achieved. Conclusions Corneal wavefront‐guided custom LASIK after PKP did not totally correct both refractive errors and HOAs because of the high volume of laser ablation required and inadequate corneal stromal thickness. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Comparison of non-contact methods for the measurement of central corneal thickness

BACKGROUND AND OBJECTIVE This study examined the repeatability of and agreements between central corneal thickness measurements obtained by four different non-contact pachymetry devices. PATIENTS AND METHODS Seventy-eight eyes of 39 subjects were included. Central corneal thickness of each eye was measured by Visante optical coherence tomography (OCT) (Carl Zeiss Meditec Inc., Dublin, CA), Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany), Orbscan IIz topography (Bausch & Lomb Surgical Inc., San Dimas, CA), and slit-lamp OCT (SL-OCT) (Heidelberg Engineering GmbH, Heidelberg, Germany). Inter-device agreements and correlations and repeatability of each device were examined. RESULTS All measurement methods correlated well with each other with a correlation coefficient greater than 0.90 and P value of less than .001 for all comparisons. However, Pentacam overestimated central corneal thickness: 546.7 ± 38.2, 535.5 ± 42.7, 531.7 ± 37.6, and 531.2 ± 36.0 μm for Pentacam, Orbscan IIz, Visante OCT, and SL-OCT, respectively (P < .001 for all comparisons versus Pentacam). Despite good correlation, magnitude of differences was high and this bias was proportional (ie, not constant across a range of corneal thickness values) for the following pairs: Orbscan versus Visante OCT, Orbscan versus SL-OCT, and Orbscan versus Pentacam (P < .001 for all comparisons). CONCLUSION Although measurements obtained by various non-contact methods correlate well, numerical agreement of the results may not be sufficient for their interchangeable use in clinical practice.

AS-OCT as a tool for flap thickness measurement after femtosecond-assisted LASIK.

BACKGROUND AND OBJECTIVE to investigate the efficacy of anterior segment optical coherence tomography (AS-OCT) for calculating flap thickness in femtosecond laser-assisted laser in situ keratomileusis. PATIENTS AND METHODS fifty-one eyes of 26 patients with myopia and myopic astigmatism were included in this prospective study. High-resolution corneal images were evaluated at 1 week and 1 month postoperatively. Images along the horizontal meridian were measured with the flap tool at seven points. RESULT measurements at vertex and at 1 mm nasally and temporally from the vertex were indistinct but easily defined. Although statistically not significant, flaps were found to be thinner in the central cornea and thicker in the periphery (P > .05). CONCLUSION AS-OCT provides detailed high-resolution images for quantitative evaluation of the flap-stroma relationship, but it may not be precise in the central 2-mm area of the cornea. Despite this, AS-OCT is an imaging tool with significant utility.