Irit Bahar

Comparison between femtosecond laser mushroom configuration and manual trephine straight-edge configuration deep anterior lamellar keratoplasty

Aim To compare outcomes and complications of femtosecond laser (FSL) mushroom configuration and manual trephine (MT) straight-edge configuration deep anterior lamellar keratoplasty (DALK). Methods A cohort of 19 consecutive eyes that underwent FSL DALK was compared with 19 consecutive eyes that underwent MT DALK. Surgery was performed for eyes with keratoconus, corneal ectasia and scarring. Patient demographics, best-corrected visual acuities (BCVAs), refraction and complications were compared. Results Groups were comparable for age, gender and preoperative BCVA. Rates of intraoperative and postoperative complications were low and comparable between the groups. These included intraoperative Descemets membrane (DM) perforation which did not require conversion to penetrating keratoplasty; stromal rejection successfully treated with topical steroids; postoperative DM detachment; delayed epithelial healing and increased intraocular pressure which resolved with topical anti-glaucoma drops. At 3u2005months, the mean BCVA was significantly better in the FSL group compared with the MT group (p=0.00002). At 6u2005months and 1u2005year, there was no significant difference between mean BCVA between the two groups. Mean spherical equivalent, cylindrical astigmatism and keratometric cylinder preoperatively and at 3, 6 and 12u2005months postoperatively were similar between the two groups. Conclusions FSL or trephine DALK are viable options for keratoconus, ectasia and corneal scars. Earlier visual recovery occurs with FSL mushroom configuration compared with MT straight-edge DALK.

Serum Cytokine Levels in Active Uveitis and Remission

Serum levels of interleukin(IL)-8, IL-6, and (TNF)-α were measured in 25 patients during active uveitis and uveitis in remission and compared to age-matched controls. Levels of IL-8 and IL-6 were significantly elevated in patients with active disease and were decreased during remission. IL-8 levels were highest in patients with anterior uveitis, with greatest difference between active disease and remission. No consistent pattern was observed for TNF-α. In conclusion, serum cytokine levels are elevated in active noninfectious uveitis. The rise in IL-8 may suggest innate immune mechanisms in the acute disease, while IL-6 participates in modulation of inflammation in the chronic disease.

Elevated plasma levels of interleukin 8 in patients with acute anterior ischaemic optic neuropathy.

Background/aim: Alterations of the immune system may have a role in thrombogenesis. Artery sites occluded with thrombi apparently release pro-inflammatory cytokines. Non-arteritic anterior ischaemic optic neuropathy (NAION) results from occlusion of the blood supply to the optic nerve. The aim of this study was to analyse levels of pro-inflammatory cytokines in patients with acute event of NAION. Methods: Study participants included 10 patients (12 eyes) with NAION and 20 age matched controls with the same risk factors for atherosclerosis disease. Peripheral blood samples were obtained immediately at the acute onset of NAION. Plasma interleukin 8 (IL-8), IL-6, and tumour necrosis factor alpha (TNF-α) levels were measured immediately following diagnosis and during the follow up intervals. Results: The plasma levels of IL-8 were significantly higher in NAION patients at the time of diagnosis in comparison to the control group (p u200a=u200a 0.002), and decreased during the follow up period (6–12 months) (pu200a=u200a0.05). There were no differences in plasma levels of IL-6 and TNF-α between NAION patients and controls, either in the acute phase or during the follow up period. Conclusion: Plasma levels of IL-8 are elevated during the acute phase of NAION, but not IL-6 and TNF-α. These elevated levels are in accordance with other acute vascular thrombosis. The clinical significance of these findings should be further evaluated.

Changes in Corneal Curvatures and Anterior Segment Parameters after Descemet Stripping Automated Endothelial Keratoplasty

Purpose: To evaluate the influence of Descemet stripping automated endothelial keratoplsty (DSAEK) on corneal curvature and the anterior segment parameters obtained with the Pentacam rotating Scheimpflug camera. Methods: A total of 9 eyes of 9 consecutive patients (3 men, 6 women) were evaluated preoperatively, at 1 and 3 months postoperatively with the Pentacam. We compared preoperative and 1- and 3-month postoperative measurements of anterior and posterior corneal curvature, anterior and posterior corneal astigmatism, anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA) width, central corneal thickness (CCT), and the corneal volume (CV). Results: Preoperative CCT decreased from 687 ± 85 microns to 631 ± 68 microns at 3 months after surgery (pu2009=u20090.07). Anterior mean K reading of the cornea flattened from 43.3 ± 1.65 diopter before surgery to 42.7 ± 1.5 diopter at 3 months (pu2009=u20090.03). Anterior corneal astigmatism did not change significantly. Posterior mean K reading of the cornea steepened significantly from -5.6 ± 0.6 diopter preoperatively to -7.2 ± 0.4 diopter at 3 months (pu2009=u20090.007). Posterior corneal astigmatism increased accordingly from 0.52 ± 0.17 diopter before surgery to 0.95 ± 0.57 diopter at 3 months (pu2009=u20090.07). CV increased significantly from 65.8 ± 5.6 µl before surgery to 85.2 ± 4.2 µl at 3 months (pu2009=u20090.007). ACA, ACD, and ACV did not change significantly following DSAEK surgery. The average postoperative spherical equivalent changed from 0.5 ± 2.5 D before surgery to 1.41 ± 0.59 D three months after surgery (pu2009=u20090.05). Conclusions: DSAEK significantly increased posterior corneal k-reading, posterior corneal astigmatism, and corneal volume, resulting in a mild hyperopic shift. This observation should be taken into consideration when performing a triple procedure.

Corneal wound malapposition after penetrating keratoplasty: an optical coherence tomography study

Aims: To examine the wound configuration after penetrating keratoplasty (PKP) using anterior segment optical coherence tomography (OCT). Methods: All PKP patients who were examined for routine follow-up, between November and December 2006, after having all their sutures removed were included. Patients underwent clinical examination, refraction, corneal topography, aberrometry and Visante anterior segment OCT. Results: 204 graft–host sections from 27 eyes (25 patients, mean age 51.6 (SD 17.7) years) were analysed. Although all the graft–host junctions had continuous smooth epithelial surfaces, 124 of them (60.8%) had internal graft–host malappositions such as gapes (15.7%), steps (30%) or protrusions (15.2%). Keratoconus patients had significantly more graft steps (p<0.05) while those transplanted for endothelial dysfunctions had more protrusions (p<0.01). Graft oversizing significantly increased the size of malappositions. Internal gapes or steps significantly reduced the graft–host touch. Intraocular pressure (IOP), final refraction and final keratometric cylinder were all significantly correlated with the presence and size of the malapposition, while steeper keratometry and tilt aberrations correlated with diminished graft–host touch. Conclusions: After PKP, internal graft–host malapposition is relatively common and associated with increased ametropia, astigmatism, IOP and optical tilt aberrations.

Clinical outcome of wavefront-guided laser in situ keratomileusis in eyes with moderate to high myopia with thin corneas

Purpose: To evaluate the clinical outcome of wavefront‐guided laser in situ keratomileusis (LASIK) for the treatment of moderate to high myopia associated with a thin cornea. Setting: Enaim Laser Medical Center, Tel Aviv, Israel. Methods: This retrospective study included 98 eyes of 49 patients with moderate to high myopia (−5.20 to −10.35 diopters [D]) and thin corneas (456 to 498 μm) treated with wavefront‐guided LASIK (Zyoptix, Bausch & Lomb) and followed for 36 months. Preoperative wavefront analysis was performed with a Hartmann‐Shack aberrometer, and treatment was performed with the Technolas 217 z excimer laser system (Bausch & Lomb). Final refraction data, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), optic zone size, ablation depth, optical aberrations, and night glare complaints were evaluated. Results: Mean patient age was 28 years ± 7 (SD), and mean preoperative spherical equivalent refraction was −7.06 D (range −5.20 to −10.35 D). Final UCVA ranged between 6/6 and 6/30. The safety index of the technique was 1.03, and the efficacy index was 0.67. Undercorrection of more than 0.50 D was observed in 41.3% of the high‐myopic eyes (−7.00 to −10.35 D, n = 58) compared with 10% in the moderately myopic eyes (−5.00 to −6.75 D, n = 40). A significant reduction in spherical aberration (Symbol) was found 12 months postoperatively in all eyes. Night glare was documented in 4 eyes (4%) in the high myopia group. There were no cases of corneal ectasia. Symbol. No caption available. Conclusion: Zyoptix was safe in eyes with moderate to high myopia with relatively thin corneas (<498 μm). For myopia between −7.00 D and −10.35 D, a small optical zone (4.3 to 5.6 mm) may be applied as night glare was relatively rare, but significant undercorrection should be expected.

First 100: learning curve for Descemet stripping automated endothelial keratoplasty

Purpose Endothelial keratoplasty is largely replacing penetrating keratoplasty for the routine treatment of corneal endothelial failure. The aim of the study was to describe the performance, complications, and outcome of the first 100 Descemet stripping automated endothelial keratoplasty (DSAEK) procedures performed at a major medical center, with an emphasis on the learning curve. Methods A retrospective, comparative case series study was conducted by a single surgeon at a tertiary, university-affiliated medical center. Data were collected on 100 consecutive DSAEK procedures performed between September 2008, when the technique was introduced in the ophthalmology department, and January 2011. Main outcome measures include best-corrected visual acuity, graft dislocation rate, primary failure rate, and endothelial cell loss. Findings were compared between the first (early group) and last (late group) 50 cases. Results Mean (SD) logMAR best-corrected visual acuity at 1 year improved from 1.02 ± 0.36 to 0.38 ± 0.35 in the early group (p<0.05) and from 0.93 ± 0.48 to 0.25 ± 0.21 in the late group (p<0.05) (n = 86). Although the late group included more complex cases (presence of anterior chamber intraocular lens, need for combination cataract surgery or secondary scleral intraocular lens fixation), graft dislocation was more common in the early group (20% versus 10%, p = 0.26). Primary and late graft failures occurred only in the early group (12% vs 0, p = 0.03). Conclusions Rates of primary failure and disc dislocation for DSAEK decrease as surgeons gain experience with the procedure, and the number of functional grafts increases accordingly. Visual outcome improves regardless of surgical experience.

Half-top-hat--a new wound configuration for penetrating keratoplasty.

Aims: To describe a new, simpler method of achieving the advantages of a lamellar wound configuration in penetrating keratoplasty (PKP)—the half-top-hat (HTH) configuration. Methods: The donor corneal button was prepared in a top-hat configuration, as previously described. It consisted of a central, full-thickness part, 7–8 mm in diameter, surrounded by a peripheral lamellar wing of deep stroma and endothelium that was 0.5 mm in width (wing diameter 8–9 mm). The recipient bed was prepared by a straight full thickness trephination with a suction trephine. The donor button was positioned by sliding the peripheral wing under the recipient bed. Sixteen 10-0 interrupted sutures and a single continuous 16-bite 11-0 nylon sutures were placed. The interrupted sutures were passed so as to go through the wing, in order to ensure a good apposition of the wing to the inner corneal surface of the recipient. Anterior segment optical coherence tomography (Visante OCT) was used to image the position and alignment of the corneal graft postoperatively. Results: Ten eyes of 10 patients (mean (SD) age: 73.7 (11.4) years, 7 females) underwent HTH PKP. The donor lenticule diameter was 7.7 (0.3) mm (wing diameter 8.7 (0.3) mm). The mean follow-up time was 2.4 (0.7) months. The last median visual acuity was 20/200 (range 20/80-counting fingers), and the last IOP was 18.2 (8.8) mm Hg. No major intraoperative complications were noted. No postoperative events of graft rejection were documented. No anterior surface misalignment was noted either clinically or by OCT. One patient had a rise in IOP postoperatively. Conclusions: Half-top-hat wound configuration is a valid alternative in penetrating keratoplasty. Its advantages include better apposition of donor and recipient corneas, improved tectonic strength to prevent graft dehiscence, the possibility of early sutures removal and being a simpler procedure to perform.

Half top hat wound configuration for penetrating keratoplasty: 1-year results

Aims: To compare the 1-year outcomes after half-top-hat (HTH) penetrating keratoplasty (PK) versus top-hat (TH) PK and regular PK. Methods: We reviewed the clinical notes of 87 consecutive patients who had undergone either HTH PK (23 eyes), TH PK (36 eyes) or regular PK (35 eyes) at Toronto Western Hospital between 2002 and 2007. We evaluated best-corrected visual acuity (BCVA), topographic and refractive results, high-order ocular aberrations, endothelial cell counts and complication rates. Results: The three groups of patients did not differ significantly in their demographics (age, gender and laterality), donor endothelial cell counts, preoperative visual acuity or intraocular pressure (IOP). At 12 months postoperatively, BCVA was similar in the three groups, as was the mean spherical equivalent and cylinder. The time to sutures removal was significantly shorter in the HTH PK versus regular PK groups (3.8 (1.2) vs 9.7 (1.1) months, p<0.0001), and the endothelial cell counts were significantly higher (pu200a=u200a0.003). The IOP was higher in the HTH PK patients than in regular PK patients (pu200a=u200a0.04). All high-order aberrations tested were significantly higher in the HTH PK than in the regular PK groups (p<0.01). Regular PK had a higher rate of astigmatism treated with relaxing incisions (nu200a=u200a7 vs nu200a=u200a2 in HTH PK) and dehiscence of wound incision (nu200a=u200a2, versus nu200a=u200a0 in HTH PK). Conclusions: BCVA and refractive results are similar after half-top-hat, top-hat and regular PK. Half-top-hat PK substantially speeds up visual recovery and contributes to significantly higher endothelial cell counts in the grafts 1 year after surgery.

Zig Zag versus Top Hat configuration in IntraLase-enabled penetrating keratoplasty

Aim To compare the outcomes with IntraLase-enabled keratoplasty using (IEK) Top Hat (TH) versus Zig Zag (ZZ) configuration. Methods Retrospective comparative series of 24 eyes that underwent TH and 10 eyes that underwent ZZ IEK. Results There were no significant differences in LogMar Best-spectacle corrected visual acuity (TH- IEK=0.3; ZZ-IEK=0.18, p=0.18), spherical equivalent (TH-IEK=−3.55±3.7 dioptres (D); ZZ-IEK=−2.69±4.85 D, p=0.60), manifest cylinder (TH- IEK=3.79±2.43 D; ZZ- IEK=4.61±3.29 D, p=0.45), topographic astigmatism (TH-IEK=3.67±2.34 D; ZZ-IEK=4.26±1.1 D, p=0.63), total higher-order aberrations (TH- IEK=8.26±3.53; ZZ-IEK=8.1±4.71, P=0.92), endothelial cell density change from baseline (TH- IEK= −41.55%±15.86; ZZ-IEK=−25.45%±30.66, p=0.22) or time to suture removal in months (TH- IEK=7.48±4.07; ZZ- IEK=6.93±2.71, p=0.75). There was no difference in requirements for astigmatic keratectomy (TH-IEK=54.2%±13; ZZ-IEK=50%±5, OR=1.18) or complications (TH-IEK=25%±6; ZZ-IEK=30%±3, OR=0.78). Conclusions TH-IEK and ZZ-IEK have comparable visual and refractive outcomes, wound healing and endothelial cell counts at 1-year.