Apostolos Lazaridis

Topographic Analysis of the Centration of the Treatment Zone After SMILE for Myopia and Comparison to FS-LASIK: Subjective Versus Objective Alignment

PURPOSE To evaluate the centration of the treatment zone after small incision lenticule extraction (SMILE) and compare it to femtosecond laser-assisted LASIK (FS-LASIK). METHODS Sixty-nine myopic eyes of 36 patients who underwent SMILE were compared to 69 myopic eyes of 36 patients treated with FS-LASIK. All procedures were performed by a single surgeon using the VisuMax platform (Carl Zeiss Meditec, Jena, Germany). The Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) was used for preoperative and postoperative topography and pachymetry. The centration of the treatment zone was estimated pachymetrically by the distance of the thickest point on the corneal thickness differential map from the topographical center of the entrance pupil and the coaxial corneal light reflex. RESULTS In SMILE cases, the mean decentration of the lenticule from the center of the entrance pupil was 0.326 ± 0.196 mm (range: 0.014 to 1.062 mm), whereas the distribution of the lenticule centers demonstrated a nasalization pattern. In FS-LASIK cases, this value was 0.452 ± 0.224 mm (range: 0.02 to 1.040 mm), whereas the ablation centers were distributed randomly. In relation to the coaxial corneal light reflex, the decentration in SMILE was 0.315 ± 0.211 mm (range: 0.0 to 1.131 mm), whereas FS-LASIK eyes demonstrated a mean decentration of 0.516 ± 0.254 mm (range: 0.103 to 1.265 mm). The decentration from the reference point of its technique (coaxial corneal light reflex in SMILE, the entrance pupil center in FS-LASIK) was significantly more extended in the FS-LASIK group (P < .001). CONCLUSIONS The centration of the treatment zone as measured by the Pentacam was better for patient-controlled fixation during SMILE than active eye tracker-assisted FS-LASIK.

Visual Outcomes After Descemet Membrane Endothelial Keratoplasty Versus Descemet Stripping Automated Endothelial Keratoplasty-Comparison of Specific Matched Pairs.

Purpose: To compare visual rehabilitation after Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) for Fuchs endothelial dystrophy. Methods: The medical records of patients undergoing endothelial keratoplasty were retrospectively evaluated. A DMEK (n = 25 eyes) and a DSAEK (n = 25 eyes) group were formed. Specific matched pairs consisting of 1 DMEK and 1 DSAEK eye with the same preoperative best spectacle-corrected visual acuity (BSCVA) were built and compared with regard to visual rehabilitation, subjective refraction, central corneal thickness, and endothelial cell density. Results: Preoperative median BSCVA (logarithm of the minimal angle of resolution) was for both groups 0.7 (range, 0.2–1.70). At 12 months, median BSCVA was 0.0 (range, −0.08 to 0.7) after DMEK and 0.3 (range, 0.1–0.52) after DSAEK (P < 0.001). The spherical equivalent changed after DMEK from 0.0 D (range, −2.75 to 4.63 D) to 0.5 D (range, −1 to 2.5 D) and after DSAEK from −0.32 D (range, −2.50 to 1 D) to 0.63 D (range, −2.38 to 2 D). Central corneal thickness decreased from 718 &mgr;m (range, 566–1041 &mgr;m) to 533 &mgr;m (range, 460–605 &mgr;m) after DMEK and from 650 &mgr;m (range, 527–749 &mgr;m) to 605 &mgr;m (range, 486–650 &mgr;m) after DSAEK. Endothelial cell density decreased from 2448 cells/mm2 (range, 2106–3000 cells/mm2) to 1263 cells/mm2 (range, 589–2282 cells/mm2) after DMEK and from 2348 cells/mm2 (range, 2156–2781 cells/mm2) to 1327 cells/mm2 (range, 664–1972 cells/mm2) after DSAEK. Conclusions: DMEK patients showed faster rehabilitation and higher BSCVA at all postoperative visits; however, the decline in grafts endothelial cell count and change in the spherical equivalent were similar for both procedures.

Refractive Lenticule Transplantation for Correction of Iatrogenic Hyperopia and High Astigmatism After LASIK

PURPOSE To design a technique for intrastromal transplantation of stromal lenticules with specific refractive power for correction of post-LASIK induced hyperopia and astigmatism. METHODS A 28-year-old patient was referred for consultation after complicated LASIK for moderate myopia and astigmatism. The refractive error of the right eye was severely overcorrected due to data entry error. Post-LASIK refraction showed high astigmatism (right eye: +6.50 -9.00 @ 84°) and corrected distance visual acuity (CDVA) of 20/32. The corneal thickness was 282 µm. A refractive lenticule transplantation was performed due to contact lens intolerance, poor visual acuity, and severe anisometropia. A toric and myopic lenticule, obtained from a donor using the femtosecond lenticule extraction technique, was implanted under the flap to reduce the refractive error, bring the refraction of the eye to the level correctable by phakic intraocular lens, and restore corneal volume. RESULTS Six weeks postoperatively, the donor lenticule was spread smoothly in the interface with a minor temporal decentration in relation to pupil center. The refraction showed a reduction of astigmatism but a stronger myopization compared to preoperative calculations (right eye: -6.50 -4.00 @ 70°). At 3 months, the CDVA returned to the preoperative value of 20/32. One year postoperatively, corneal tomography showed no signs of ectasia and biomicroscopy revealed no signs of rejection. After implanting a toric myopic implantable collamer lens, the patient regained uncorrected distance visual acuity of 20/40 and full stereopsis. CONCLUSIONS The refractive lenticule transplantation technique offers a solution for rare cases of post-LASIK hyperopia and high astigmatism while restoring the volume of thin corneas. Moreover, it is a reversible procedure with low probability of rejection. [J Refract Surg. 2016;32(11):780-786.].

Corneal Clarity and Visual Outcomes after Small-Incision Lenticule Extraction and Comparison to Femtosecond Laser-Assisted In Situ Keratomileusis

Purpose. To evaluate corneal clarity and visual outcomes after small-incision lenticule extraction (SMILE) and compare them to femtosecond laser-assisted in situ keratomileusis (FS-LASIK). Materials and Methods. Fifty-eight myopic eyes of 33 patients who underwent SMILE were compared to 58 eyes of 33 patients treated with FS-LASIK. All procedures were performed using VisuMax® femtosecond laser and MEL 80® excimer laser (Carl Zeiss Meditec AG, Germany). Pentacam™ (Oculus, Germany) was used for pre- and 3-month postoperative corneal densitometry (CD) analysis. CD was evaluated at 3 optically relevant, concentric radial zones (0–2 mm, 2–6 mm, and 0–6 mm annulus) around the corneal apex and at 3 different anatomical corneal layers (anterior, central, and posterior). Associations of postoperative CD values with the lenticule thickness and ablation depth were examined. Preoperative and postoperative corrected distance visual acuity (CDVA) values were also compared. Results. After SMILE, the total CD (all corneal layers) at 0–6 mm annulus showed no significant change compared to preoperative values (P = 0.259). After FS-LASIK, the total CD was significantly reduced (P = 0.033). Three-month postoperative CD showed no significant differences between the 2 groups for all examined annuli (0–2 mm: P = 0.569; 2–6 mm: P = 0.055; and 0–6 mm: P = 0.686). Total CD after SMILE at 0–6 mm annulus displayed a weak negative association with the lenticule thickness (P = 0.079, R2 = 0.0532) and after FS-LASIK displayed a weak negative association with the ablation depth (P = 0.731, R2 = 0.0015). Postoperative CDVA was similar for both groups (P = 0.517). Conclusion. Quantification of corneal clarity using the Scheimpflug CD showed similar results before and 3 months after SMILE. Compared to FS-LASIK, no significant differences of corneal clarity and CDVA were found 3 months postoperatively.

Spontaneous Corneal Clearance in the Presence of a Partially Detached Graft after Non-Descemet Stripping Automated Endothelial Keratoplasty.

Purpose: To report the explantation of a detached and opaque donor disc as an alternative to secondary keratoplasty in a case of persistent graft detachment followed by spontaneous clearance of the recipient cornea after non-Descemet stripping automated endothelial keratoplasty (non-DSAEK). Methods: A 57-year-old man with cataract and bullous keratopathy after herpes simplex virus endotheliitis of the right eye and best spectacle-corrected visual acuity (BSCVA) of 0.1 underwent simultaneous phacoemulsification and non-DSAEK. Due to early detachment of the donor disc, two additional intracameral air injections were necessary in order to achieve graft attachment. However, the donor disc gradually detached and became fibrotic while the recipient cornea anterior to the detached graft became transparent and without any edema. Therefore, a mere explantation of the DSAEK graft was performed. Results: Four months after graft explantation, BSCVA was 0.5 and endothelial cell density (ECD) was 1,221 cells/mm2. After 13 months, BSCVA was still 0.6 while ECD had fell to 800, and 2 years later, the endothelium decompensated. BSCVA was 0.3 and ECD was not measurable. Conclusions: To our knowledge this is the first report of explantation of an endothelial graft as an alternative to re-keratoplasty in a case of spontaneous corneal clearance. This minimally invasive treatment may be considered in similar cases. However, due to the ongoing loss of endothelial cells after endothelial keratoplasty, a re-keratoplasty may still be needed in the long term.

Trends in Indications and Techniques of Corneal Transplantation from 1999 through 2015 at a Tertiary Referral Center in Athens, Greece

Introduction During the past decade, novel techniques of corneal transplantation allowing faster and better restoration of vision have emerged. The present cohort study describes a shift of indications and techniques that has occurred in the field of corneal transplantation over a 17-year period in Greece. Methods All patients undergoing keratoplasty between January 1999 and December 2015 at an academic tertiary referral center in Athens, Greece, were retrospectively reviewed. The annual incidence of keratoplasty indications and techniques was recorded and analyzed. Results A total of 1382 keratoplasty procedures were included. Leading indications were bullous keratopathy (BK) (37.5%), followed by allograft rejection (17.7%), corneal scar (12%), keratoconus (KC) (10.3%), and Fuchs endothelial dystrophy (FED) (8.8%). A decreasing trend was observed for KC (P=0.009) and an increasing trend for BK (P=0.003) and FED (P=0.001). In 2015, the incidence of penetrating keratoplasty (PK) had decreased from 100% (1999 to 2009) to 21.4%; for cases with isolated pathology of the corneal endothelium, DSAEK was the preferred technique (59.8%), while the respective rate of DMEK was 18.8%. Conclusion Herein, we observed an increasing trend of endothelial pathology among keratoplasty indications as well as a major shift in preferred techniques due to a wide adoption of the new EK procedures.

Response to the letter to the editor by Tsatsos et al. “To remove or not to remove (the AC-IOL)? This is the question. Letter regarding article Endothelial keratoplasty in eyes with a retained angle-supported intraocular lens by Droutsas et al.”

We thank colleagues Tsatsos et al. [1, 2] for sharing their experience on this controversial topic. Indeed, on the one hand, performing keratoplasty while leaving a stable anterior chamber intraocular lens (acIOL) in situ may be considered as the least invasive choice. On the other hand, exchanging an acIOL for a retroiridal one prior to keratoplasty restores the anterior segment anatomy to a better degree and may offer a longer graft survival. The combination of endothelial keratoplasty with IOL exchange and fixation of the secondary IOL by gluing through scleral flaps as proposed by Narang et al. [2, 3] is a promising new technique that has been performed on a small number of cases up to date. Thus, regardless of the fixation technique (i.e., sutured or glued), studies reporting long-term graft survival are needed to confirm the superiority of sclera-fixated IOLs versus acIOLs. We also agree with the comment of Tsatsos et al. regarding graft thickness in eyes with acIOL undergoing DSAEK. Indeed, as mentioned in ‘‘Results’’ section, we used thin or ultrathin DSAEK grafts with a diameter below 100 lm [1]. Finally, also in our case series, a well-positioned acIOL and a deep anterior chamber were prerequisites for leaving an acIOL in situ as suggested by Esquenazi et al. [4].

Isolated descemetorhexis for anterior synechiolysis prior to endothelial keratoplasty – case report and technique

Purpose To describe the utilization of descemetorhexis for reformation of the anterior chamber in eyes with central iridocorneal synechiae before endothelial keratoplasty (EK). Methods A 71-year-old man with a history of trabeculectomy complicated by hypotony presented with bullous keratopathy in the presence of extensive iridocorneal synechiae and a flat anterior chamber. In order to proceed with EK, synechiolysis with the use of viscoelastic and scissors was attempted. Despite successful dissection of the peripheral strands, the pupillary margin of the iris remained attached to the endothelium. Therefore, descemetorhexis was performed to detach the Descemet membrane along with central synechiae and create sufficient space for safe EK at a later stage. Results Corneal clarity was restored by ultrathin Descemet stripping automated endothelial keratoplasty, leaving a fibrous membrane in the pupillary plane, which was excised 2 months later, allowing an improvement of best-corrected visual acuity to 0.5. Conclusion Isolated descemetorhexis was successfully employed to reform the anterior chamber and proceed with EK in a case of bullous keratopathy and resistant iridocorneal synechiae. This stepwise approach may be considered in similar cases in order to avoid a more invasive treatment, ie, penetrating keratoplasty and synechiolysis.

Management and Outcomes of Retained Lenticules and Lenticule Fragments Removal After Failed Primary SMILE: A Case Series

PURPOSE To describe the management of and report the outcomes following the removal of retained lenticules or lenticule fragments after a complicated small incision lenticule extraction (SMILE). METHODS Three patients were referred for consultation due to intraoperative complications during SMILE. In case 1, the lenticule was torn during extraction and a central fragment was retained in the pocket. In case 2, the inferior part of the lenticule remained attached at the anterior plane and its detached, superior part was dislocated and folded at the inferior part of the pocket. In case 3, the lenticule was completely attached at the anterior plane. All cases underwent secondary surgery. The lenticule fragment was detached using the dissectors body and tip and was extracted using the advanced lenticule forceps. The retained lenticules were extracted after dissection of tissue bridges at the anterior plane and periphery. RESULTS Postoperatively, all eyes showed improvement of visual acuity and topographic regularization of the anterior corneal curvature. Complete removal of lenticule remnants was accomplished in cases 1 and 2. In case 3, the photodisruption during primary SMILE was incomplete at a peripheral area next to the incision. A small peripheral fragment, corresponding to the described peripheral area, remained attached after the lenticule removal and was left in situ but did not have any impact on visual acuity and quality. CONCLUSIONS Retained lenticules or lenticule fragments may induce irregular astigmatism and loss of visual acuity. Prompt removal restores visual acuity and induces the desired effect of the primary SMILE procedure. [J Refract Surg. 2017;33(12):848-853.].