Esin Sogutlu Sari

Long-Term Results of Deep Anterior Lamellar Keratoplasty for the Treatment of Keratoconus

PURPOSE To evaluate the long-term endothelial cell density (ECD) changes and visual and refractive outcomes after deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in eyes with keratoconus. DESIGN Retrospective interventional case series study. METHODS setting: Single hospital. patients: Two hundred forty-one eyes of 214 patients who underwent DALK for moderate to advanced keratoconus. main outcome measures: Intraoperative and postoperative complications, postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction, topographic astigmatism, and ECD. RESULTS Two hundred thirty-four procedures (97%) were completed as DALK. Big bubble was successfully achieved in 193 eyes (82.4%). In 7 eyes (3%), the procedure was converted to penetrating keratoplasty because of Descemet membrane macroperforations. Microperforations occurred in 18 eyes (7.5%). The mean follow-up time was 50.5 ± 22.2 months (range 24 to 96 months). UCVA was lower than 20/100 in all eyes preoperatively and better than 20/100 in 191 eyes (81.6%) postoperatively. BSCVA was 20/40 or better in 187 eyes (79.9%) and 20/20 or better in 38 eyes (16.2%). The mean (± SD) preoperative ECD that was possible in 166 eyes was 2797 ± 561 cells/mm(2). Mean (± SD) endothelial cell loss was 8.1% ± 4.6% at 1 year, 10.5% ± 5.7% at 2 years, 15.1% ± 14.8% at 6 years, and 22.5% ± 15.9% at 8 years. Stromal graft rejection episodes occurred in 4 eyes, which resolved with appropriate therapy. CONCLUSIONS Deep anterior lamellar keratoplasty that uses the big-bubble technique is effective in patients with keratoconus. Long-term endothelial cell loss was moderate and lower than penetrating keratoplasty grafts.

Comparison of 2 intrastromal corneal ring segment models in the management of keratoconus

PURPOSE: To compare the outcomes of implantation of 2 models of intrastromal corneal ring segments (ICRS) to manage keratoconus. SETTING: Kartal Training and Research Hospital, Istanbul, Turkey. METHODS: This study evaluated eyes with keratoconus that had implantation of Keraring ICRS (Group A) or Intacs ICRS (Group B). The corneal tunnels were created mechanically or with a femtosecond laser. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, keratometry (K) readings (Orbscan II), and complications in the 2 groups were compared. RESULTS: Group A comprised 100 eyes and Group B, 68 eyes. The postoperative increase in UDVA and CDVA was statistically significant in both groups (P<.05). Group A had greater improvement in CDVA than Group B at 6 months and 1 year (both P<.001). At 1 year, the decrease in the mean maximum K power was statistically significant in Group A (51.27 diopters [D] ± 4.46 [SD] to 47.87 ± 3.39 D) and in Group B (51.12 ± 4.54 D to 47.58 ± 3.66 D) (P<.05). The mean reduction in maximum K was statistically significantly greater in Group A at 6 months and 1 year (P = .018 and P = .024, respectively). There were no statistically significant differences in visual or refractive results between femtosecond laser and mechanical tunnel creation. CONCLUSION: Although both ICRS models were effective and safe in managing keratoconus, the Keraring ICRS led to more improvement in CDVA and UDVA and a greater reduction in the maximum K value. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Penetrating keratoplasty versus deep anterior lamellar keratoplasty: comparison of optical and visual quality outcomes.

Purpose To evaluate and compare visual and optical performance outcomes by means of analysis of the contrast sensitivity function (CSF) and ocular higher order aberrations (HOA) in patients with keratoconus who had deep anterior lamellar keratoplasty (DALK) or penetrating keratoplasty (PK). Methods In this prospective, randomised case series, 174 eyes of 140 consecutive patients with moderate to advanced keratoconus were included. The big-bubble technique was attempted to perform DALK. Intraoperative and postoperative complications, uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), refraction, topographic astigmatism, CSF and ocular HOA were evaluated. Results The DALK and PK groups consisted of 99 and 75 eyes, respectively. Postoperative BSCVA was 20/40 or better in 64 eyes (85%) in the PK group and and 82 eyes (83%) in the DALK group (p>0.05). The mean spherical equivalent and maximum keratometry were −1.50 (−6.25 to +4.75) and 46.85 (40.60 to 56.00) in the PK group and −2.25 (−8.75 to +4.00) and 46.90 (40.60 to 53.60) in the DALK group, respectively. The differences were not statistically significant (p=0.08 and p=0.66, respectively). No significant differences in photopic contrast sensitivity were found for each of the spatial frequencies (p>0.05 for all). However, mesopic contrast sensitivity for three cycles/degree was significantly higher in the DALK group (p=0.01). No significant differences between groups were detected for any of the aberrometric parameters (p>0.05). Conclusions DALK is an alternative treatment option in eyes with moderate to advanced keratoconus, providing comparable results to PK in terms of visual acuity, refraction, CSF and HOA.

Comparison of mechanical and femtosecond laser tunnel creation for intrastromal corneal ring segment implantation in keratoconus: Prospective randomized clinical trial

PURPOSE: To compare the outcomes of mechanical and femtosecond laser–assisted tunnel creation for intrastromal corneal ring segment (ICRS) implantation in eyes with keratoconus. SETTING: Kartal Training and Research Hospital, Istanbul, Turkey. METHODS: In this prospective study, consecutive eyes with keratoconus were randomly assigned to have ICRS tunnel creation with a mechanical device or a femtosecond laser. Keraring ICRS with a 5.0 mm diameter and 160‐degree arc length were implanted in all cases. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and keratometry (K) readings were measured preoperatively and 1 year postoperatively, and the data in the mechanical group and the femtosecond group were compared statistically. RESULTS: One year postoperatively, there was significant improvement in UDVA, CDVA, K readings, spherical equivalent (SE), and manifest sphere and cylinder in both groups (P<.05). The UDVA improved by 2.4 lines in the mechanical group and 2.0 lines in the femtosecond group and the CDVA by 3.3 lines and 2.7 lines, respectively; the mean reduction in maximum keratometry was 4.50 diopters (D) and 4.70 D, respectively, and the mean reduction in SE, 3.18 D and 3.09 D, respectively. There were no statistically significant differences between the 2 groups in visual or refractive results (P>.05). Anterior corneal perforation, superficial segment placement, and segment extrusion occurred in 1 eye each in the mechanical group. Segment migration occurred in 1 eye in the femtosecond group. CONCLUSION: Despite intraoperative complications in the mechanical group, the visual and refractive outcomes were similar to those in the femtosecond group. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Intrastromal Corneal Ring Segment Implantation for the Treatment of Keratoconus

Purpose: To evaluate the safety and efficacy of intrastromal corneal ring segment implantation using both mechanical and femtosecond-assisted tunnel creation for the treatment of patients with keratoconus. Methods: A retrospective noncomparative interventional study including 96 eyes of 75 patients with keratoconus. All patients had contact lens intolerance and clear central corneas. Corneal tunnels were made using a femtosecond laser in 26 eyes (femtosecond group) and mechanically in 70 eyes (mechanical group). The Keraring (Mediphacos, Belo Horizonte, Brazil) was implanted in each eye, and a complete ophthalmic examination was performed, including visual acuity, refraction, and keratometric readings. Results: The mean preoperative uncorrected visual acuity for all eyes was 1.40 ± 0.39 logarithm of the minimal angle of resolution (logMAR) (mean ± SD) and improved to 0.60 ± 0.34 logMAR at the sixth month (n = 96, P < 0.001) and 0.50 ± 0.32 (n = 54, P < 0.001) at the 18th month. The mean preoperative best spectacle-corrected visual acuity (BSCVA) for all eyes (n = 96) was 0.68 ± 0.36 logMAR. The mean BSCVA was 0.29 ± 0.21 (n = 96, P < 0.001) at the sixth month and improved to 0.26 ± 0.20 (n = 54, P < 0.001) at the 18th month. There was a significant reduction in spherical equivalent refractive error from −5.88 ± 3.65 diopters (D) (n = 96) to −2.26 ± 1.98 D (n = 54, P < 0.001) at the 18th month. The mean preoperative maximum keratometry (Kmax) was 53.58 ± 5.90 D and decreased to 49.02 ± 4.70 (n = 96, P < 0.001) at 6 months and 48.57 ± 4.36 D (n = 54, P < 0.001) at the 18th month. Sixth month results of the mechanical versus femtosecond groups were as follows: improvement in uncorrected visual acuity (2.08 vs. 1.50 lines), improvement in BSCVA (2.93 vs. 2.19), reduction in spherical equivalent (3.78 vs. 3.75 D), and reduction in maximum keratometry (4.66 vs. 4.62 D). There was no statistically significant difference between both groups for any parameter. Conclusions: Keraring implantation is effective for the treatment of keratoconus, providing safety and good visual outcomes after both mechanical and femtosecond-assisted tunnel creation.

Corneal endothelium after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus: A four-year comparative study

Purpose: To compare the status of corneal endothelium and central corneal thickness within the first four postoperative years after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in patients with keratoconus. Materials and Methods: Thirty-nine eyes (Group A) which had PK and 44 eyes (Group B) which had DALK for the treatment of keratoconus were included in this retrospective study. The endothelial cell density (ECD), the mean endothelial cell area and the coefficient of variation of cell area were assessed with a non-contact specular microscope, and the central corneal thickness (CCT) was measured with an ultrasound pachymeter. Results: Mean ECD loss rate at two years was 36.24% in Group A and 18.12% in Group B (P<0.001). Mean ECD loss rate at four years was 47.82% in Group A and 21.62% in Group B (P<0.001). Mean annual ECD loss rate was calculated 14.12% per year in Group A and 5.78% per year in Group B. In the PK group, increase in mean CCT was 15.60% in two years and 15.03% in four years, while in the DALK group, mean CCT increased by 8.05% in two years and 9.31% in four years. Conclusions: As the majority of ectatic disorders such as keratoconus occur in young people, long-term endothelial cell survival following treatment with keratoplasty is essential for the long-term visual ability. Our finding that corneal endothelial cell loss in the DALK group occurs at a slower rate than in the PK group suggests DALK as a safer alternative to PK in these selected patients.

Pediatric refractive surgery and its role in the treatment of amblyopia: meta-analysis of the peer-reviewed literature.

PURPOSE To provide an overview of the visual outcomes after pediatric refractive surgery in anisometropic amblyopia and to analyze the relationship of these outcomes with age and type of refractive surgery. METHODS Systematic searches in PubMed, Embase, and Web of Science databases without data restrictions and a search by surveillance of the literature regarding pediatric refractive surgery were performed. Only studies reporting individual data of pediatric cases (age 1 to 17 years) undergoing photorefractive keratectomy (PRK), laser epithelial keratomileusis (LASEK), and LASIK were included. A total of 15 articles including data from a total of 213 amblyopic eyes were considered: LASIK in 95 eyes and surface ablation in 118 eyes. Changes in uncorrected (UDVA) and corrected distance visual acuity (CDVA) were investigated as well as their relation with age and ablation type. RESULTS A significant increase in logMAR UDVA and CDVA was found in the overall sample of amblyopic eyes after surgery (P<.001). A significant correlation was found between age and preoperative CDVA (r=0.34, P<.001) as well as between age and the change in CDVA after surgery (r=-0.38, P<.001). The change in UDVA was significantly superior for eyes undergoing surface ablation compared to those undergoing LASIK (P=.04). Corneal haze was the predominant complication, which was reported in 5.3% of LASIK cases and 8.5% of surface ablation cases. CONCLUSIONS Laser refractive surgery is an effective option for improving the visual acuity in children with an amblyopic eye in association with anisometropia.

A Single 210-Degree Arc Length Intrastromal Corneal Ring Implantation for the Management of Pellucid Marginal Corneal Degeneration

PURPOSE To determine the visual and refractive outcomes of 210-degree arc length intrastromal corneal ring segment (ICRS) implantation in eyes with pellucid marginal corneal degeneration (PMCD). DESIGN Retrospective, consecutive case series. METHODS Sixteen consecutive eyes of 10 patients who underwent a single 210-degree ICRS implantation by femtosecond laser for the management of PMCD and completed at least 1 year follow-up were included. A complete ophthalmic examination was performed preoperatively and postoperatively, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest spherical and cylindrical refractions, spherical equivalent, and keratometric readings. RESULTS The mean follow-up period was 30.7 months (range 12 to 36 months). No intraoperative complication was observed. White deposits around the segments were noted in 2 of 16 eyes (12.5%) at the first postoperative year. The mean UCVA showed significant improvement, from 1.69 +/- 1.02 logarithm of the minimal angle of resolution (logMAR) preoperatively to 0.64 +/- 0.43 logMAR at the 36th month (n = 11, P < .001). The mean preoperative BSCVA was 0.88 +/- 0.68 logMAR; after 36 months, this improved to 0.35 +/- 0.34 (P < .001). At the 36th month, UCVA was improved in all eyes (n = 11, range: gain of 1 to 6 lines), whereas BSCVA was improved in 9 eyes (81.8%, range: gain of 2 to 7 lines) and remained unchanged in 2 eyes (18.1%); UCVA was 20/40 or better in 3 eyes (27%) and BSCVA was 20/40 or better in 8 eyes (72.7%). There was a significant reduction in the spherical equivalent refractive error, from -4.40 +/- 1.85 diopters (D) preoperatively to -1.86 +/- 0.60 D (P < .001), and the mean maximum keratometric power decreased from 49.70 +/- 4.32 D to 46.08 +/- 2.84 D (P < .001) after 36 months. The mean cylindrical refraction decreased from -4.39 +/- 1.86 D preoperatively to -2.38 +/- 1.35 D at 36 months (P < .001). CONCLUSION A single 210-degree arc length ICRS implantation using a femtosecond laser for patients with PMCD provides good visual and refractive outcomes.

Deep Anterior Lamellar Keratoplasty versus Penetrating Keratoplasty for Macular Corneal Dystrophy: A Randomized Trial

PURPOSE To compare outcomes of big-bubble deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) for macular corneal dystrophy. DESIGN Prospective, randomized, interventional case series. METHODS setting: Single hospital. patients: Eighty-two eyes of 54 patients requiring keratoplasty for the treatment of macular corneal dystrophy without endothelial involvement were included. main outcome measures: Operative complications, uncorrected visual acuity, best-corrected visual acuity, contrast sensitivity function, higher-order aberrations, and endothelial cell density were evaluated. RESULTS The DALK and PK group consisted of 35 and 41 eyes, respectively. Best-corrected visual acuity after surgery was 20/40 or better 68.5% and 70.7% of the eyes in the DALK and PK groups, respectively (P > .05). No statistically significant differences between groups were found in contrast sensitivity function with and without glare for any spatial frequency (P > .05). Significantly higher levels of higher-order aberrations were found in the DALK group (P < .01). In both groups, a progressive and statistically significant reduction in endothelial cell density was found (P < .01). At the last follow-up, the mean endothelial cell loss was 18.1% and 26.9% in DALK and PK groups, respectively (P = .03). Graft rejection episodes were seen in 5 eyes (12.1%) in the PK group, and regrafting was necessary in 3 eyes (7.3%). Recurrence of the disease was documented in 5.7% and 4.8% of the eyes in the DALK and PK groups, respectively. CONCLUSIONS Deep anterior lamellar keratoplasty with the big-bubble technique provided comparable visual and optical results as PK and resulted in less endothelial damage, as well as eliminating endothelial rejection in macular corneal dystrophy. Deep anterior lamellar keratoplasty surgery is a viable option for macular corneal dystrophy without endothelial involvement.

Comparison of Astigmatic Keratotomy Results in Deep Anterior Lamellar Keratoplasty and Penetrating Keratoplasty in Keratoconus

PURPOSE To compare astigmatic keratotomy (AK) outcomes in high astigmatism after deep anterior lamellar keratoplasty (DALK) and after penetrating keratoplasty (PK) in keratoconus patients. DESIGN Prospective, comparative, interventional case series. METHODS This study comprised 20 eyes that underwent DALK and 24 eyes that underwent PK. After suture removal, all eyes had more than 5 diopters (D) of astigmatism and underwent standard manual 1-pair, 90-degree, and 90% corneal thickness AK incisions. The main outcome measures included preoperative and postoperative manifest refraction, uncorrected visual acuity, best spectacle-corrected visual acuity, surgically induced astigmatism, Orbscan II (Bausch & Lomb) corneal topography results, keratometric astigmatism, and complications. RESULTS All eyes completed 6 months of follow-up. The overcorrection rate was 35% and 41.6% in the DALK and PK groups, respectively (P=.75). At 6 months after AK, logarithm of the minimal angle of resolution uncorrected visual acuity improved from 0.88 ± 0.20 to 0.54 ± 0.26 and from 1.0 ± 0.34 to 0.53 ± 0.26 in the DALK and PK groups, respectively (P=.01 to P<.01). Best spectacle-corrected visual acuity improved from 0.16 ± 0.09 to 0.13 ± 0.08 and from 0.16 ± 0.12 to 0.11 ± 0.08 in the DALK and PK groups, respectively (P=.13 to P=.01). The mean refractive cylinder was decreased 2.74 ± 1.44 D in the DALK group and 3.18 ± 2.96 D in the PK group (P=.35). Surgically induced astigmatism was 6.10 ± 3.27 D in the DALK group and 7.15 ± 2.98 D in the PK group (P=.36). CONCLUSIONS The manual AK for the treatment of postkeratoplasty astigmatism after DALK and PK in keratoconus patients is a safe and effective surgical procedure, allowing similar refractive cylinder reduction and improvement in uncorrected visual acuity and best spectacle-corrected visual acuity.