Three-Year Results of Simultaneous Transepithelial Phototherapeutic Keratectomy and Conventional Photorefractive Keratectomy (Cretan Protocol Plus) Followed by Corneal Crosslinking for Keratoconus.

PURPOSE: The aim of this study was to present the 3-year outcomes after simultaneous transepithelial phototherapeutic keratectomy (t-PTK) and conventional photorefractive keratectomy (PRK) followed by corneal crosslinking (CXL) for keratoconus. METHODS: In this prospective, interventional case series, patients with progressive keratoconus underwent simultaneous t-PTK and conventional PRK followed by CXL (Cretan protocol plus). Visual, refractive, and topographic outcomes were evaluated along with endothelial cell density (ECD) preoperatively and at 1, 2, and 3 years postoperatively. RESULTS: Twenty-two patients (31 eyes) were enrolled. No intraoperative or postoperative complications were observed in any of the patients. Logarithm of the minimum angle of resolution (logMAR) mean uncorrected and mean corrected distance visual acuity improved from 0.81 ± 0.40 and 0.18 ± 0.21 preoperatively to 0.38 ± 0.33 ( P < 0.001) and 0.06 ± 0.12 ( P < 0.001) at 3-year follow-up. Mean spherical equivalent improved from -5.39 ± 3.89 diopters (D) preoperatively to -2.29 ± 2.65 D ( P < 0.001) at 3 years postoperatively. Mean corneal astigmatism reduced from -4.70 ± 2.86 D preoperatively to -3.55 ± 2.45 D ( P = 0.001) at 3 years postoperatively. No ECD alterations were observed throughout the 3-year follow-up ( P > 0.05). CONCLUSIONS: Simultaneous t-PTK and conventional PRK followed by CXL seems to be an effective and safe treatment for progressive keratoconus over 3-year follow-up.

Evolution of corneal flattening after repeated corneal cross-linking during a 6-year follow-up.

PURPOSE: To report the evolution of corneal flattening after repeated corneal cross-linking (CXL) in a patient with progressive keratoconus during a 6-year follow-up. METHODS: Case report. RESULTS: A 27-year-old female underwent CXL for progressive keratoconus. Postoperatively, corneal topography revealed keratoconus progression with an increase of 1.20 diopters (D) in maximum keratometry (Kmax) and CXL was repeated. After the second treatment, a continuing significant corneal flattening (up to 16.00 D in Kmax) was observed during the first 5 years followed by stabilization during the last sixth year of follow-up. Both uncorrected and corrected distance visual acuity were improved while corneal thickness was decreased. There were no complications such as corneal opacification or endothelial cells decrease during the follow-up period. CONCLUSION: Repeated CXL can induce an excessive corneal flattening more pronounced during the first years of follow-up followed by stabilization thereafter.

Intraocular Lens Refractive Index and Its Impact on External Surface Reflections.

PURPOSE: To determine and compare the origin of the external surface reflections produced by commonly used intraocular lenses (IOLs). METHODS: The specular reflection taking place at the anterior surface of eight types of IOLs (IOL power = 22.00 diopters [D]) with different refractive indices (RIs), optical design, and ultraviolet and blue light-filtering function were measured. The experimental set-up included a laser beam light source (3.5 mW, 532 nm) and a saline-filled model eye containing the IOL to be examined. External surface reflections were measured using a power meter, and the IOL surface reflectance (%) was compared among the eight IOLs investigated. RESULTS: External reflections from the anterior surface of the studied implants increased as the RI of the IOL material increased. The IOL models composed of high RI material (RI = 1.56 ± 0.02) were found to have a more than threefold higher external surface reflections compared to those with low RI (RI = 1.45 ± 0.02). Ultraviolet or blue light-filtering functions showed no significant correlation with the external reflectance. CONCLUSIONS: IOLs with a high RI are associated with external surface reflections that are more than threefold higher than those with lower RI. The "cat's eye" phenomenon seen in pseudophakic eyes by an outside observer strongly depends on the RI, but is independent of the filter incorporated in the IOL. [J Refract Surg. 2021;37(6):398-402.].

Small incision lenticule extraction retreatment in a patient with high residual refractive error after photorefractive keratectomy: A case report.

A 36-year-old male underwent uneventful small incision lenticule extraction (SMILE) for the correction of his high residual refractive error 12 years after photorefractive keratectomy (PRK). Preoperatively, uncorrected distance visual acuity (UDVA) was counting fingers in both eyes. Corrected distance visual acuity was 20/20 in the right and 20/30 in the left eye due to amblyopia. One month after SMILE, UDVA was 20/20 and 20/30 in the right and left eye, respectively; post-PRK corneal haze had reduced. During the 4-year follow-up, UDVA remained stable and there were no complications. SMILE could be a good alternative approach for retreatment in post-PRK patient.

Corneal cross-linking (CXL) combined with refractive surgery for the comprehensive management of keratoconus: CXL plus.

The past two decades have witnessed an unprecedented evolution in the management of keratoconus that demands a holistic approach comprising of inhibiting the ectatic progression as well as visual rehabilitation. The advent of corneal cross-linking (CXL) in the late 1990s resulted in long-term stabilization of the ectatic cornea along with limited reduction in corneal steepening and regularization of corneal curvature. However, CXL as a standalone procedure does not suffice in rehabilitating the functional vision especially in patients who are unwilling or intolerant towards contact lenses. The concept of "CXL plus" was proposed which incorporates adjunctive use of refractive procedures with CXL in order to overcome the optical inefficiency due to corneal irregularity, decrease the irregular astigmatism, correct the residual refractive error and improve functional visual outcome in keratoconus. Several refractive procedures such as conductive keratoplasty (CK), photorefractive keratectomy (PRK), transepithelial phototherapeutic keratectomy (t-PTK), intrastromal corneal ring segments (ICRS) implantation, phakic intraocular lens (PIOL) implantation and multiple other techniques have been combined with CXL to optimize and enhance the CXL outcome. This review aimed to summarize the different protocols of CXL plus, provide guidelines for selection of the optimum CXL plus technique and aid in decision-making for the comprehensive management of cases with primary keratoconus in addition to discussing the future and scope for innovations in the existing treatment protocols.

A New Surgical Approach for the Management of Acute Corneal Hydrops Complicated With Corneal Perforation.

PURPOSE: To report an unusual case of a patient with keratoconus and acute hydrops complicated with corneal perforation and describe its management using a new surgical approach. METHODS: A case report and new surgical approach description. RESULTS: A 47-year-old female patient with a history of keratoconus and implantable contact lens surgery presented at our institute with symptoms of acute corneal hydrops in her right eye. On examination, best corrected visual acuity was of counting fingers in the involved eye. Slit-lamp examination revealed a small inferotemporal corneal perforation, surrounded by marked corneal edema and a positive Seidel test. Initial attempts of conservative treatment with cyanoacrylate tissue adhesive application and bandage soft contact lens placement were ineffective. We decided to proceed with an inferior, lamellar wedge resection of the diseased corneal tissue. One month postoperatively, the cornea remained clear, whereas best corrected visual acuity was 0.1. CONCLUSIONS: Lamellar wedge resection could represent an alternative surgical approach for keratoconic patients, with eccentric acute hydrops and subsequent corneal perforation that provides rapid visual rehabilitation.

Burr-Assisted Anterior Lamellar Keratoplasty (DALK) in Patients with Corneal Stromal Scarring: A Case Series.

PURPOSE: To describe a modified technique of deep anterior lamellar keratoplasty (DALK) assisted by diamond ophthalmic burr (DOB) in two patients with corneal stromal scarring. METHODS: Two patients with corneal stromal scarring underwent a modified DALK technique with corneal stromal polishing assisted by a DOB until the level of the Descemet membrane. RESULTS: There were no intra- or postoperative complications. Six months postoperatively, the corneal graft was clear, while corrected distance visual acuity improved in both cases. CONCLUSIONS: Burr-assisted DALK seems to represent an alternative surgical technique in patients with corneal stromal scarring.

Using corneal graft from keratoconic donor for lamellar and penetrating keratoplasties.

We report the use of two corneal grafts derived from a donor, with a history of early stage keratoconus, for lamellar and penetrating keratoplasty. The first graft was used to perform Descemet stripping automated endothelial keratoplasty (DSAEK) in a patient with endothelial dysfunction and advanced pseudoexfoliative glaucoma. The second graft was used for an emergency penetrating keratoplasty in a patient with corneal perforation secondary to uncontrolled herpes keratitis. In the first case, 1 year postoperatively, the graft was clear and attached with no signs of rejection or failure. In the second case, the perforation did not relapse after keratoplasty and the globe retained its structural integrity during the 1-year follow-up.

Femtosecond-Assisted Elliptical LASIK Flap for the Correction of Post-Arcuate Keratotomy Residual Astigmatism.

We report the application of an elliptical femtosecond laser-assisted in situ keratomileusis (LASIK) flap for the management of post-arcuate keratotomy (AK) residual astigmatism. An 82-year-old male was referred to our institute for evaluation of his right eye due to residual regular astigmatism 1 year after AK. On examination, uncorrected distance visual acuity (UDVA) was 20/50 and corrected distance visual acuity was 20/25 (+3.25 -5.50 × 125). Slit-lamp examination revealed two 70-arc length peripheral corneal incisions at the 7.50-mm zone. The patient underwent femtosecond-assisted LASIK for the correction of residual astigmatism. An elliptical LASIK flap was adjusted intraoperatively with a 2-dimension diameter of 7.98 × 6.69 mm in order to avoid intersection of the flap with the AK incisions. The short flap diameter was placed along the meridian of the incisions and the long diameter in the perpendicular meridian, corresponding to the excimer laser astigmatic ablation pattern. No intraoperative or postoperative complications were encountered. Six months postoperatively, UDVA improved to 20/25 with a manifest refraction of pl -0.75 × 5. No AK incision flap-related complications were observed.

Predictors of Visual Acuity Improvement and Supernormal Vision After Refined Single-Step Transepithelial Photorefractive Keratectomy.

PURPOSE: To investigate predicting factors of visual acuity improvement and achieving uncorrected (UDVA) or corrected (CDVA) distance visual acuity supernormal vision (⩾ 15/10; Snellen 20/13) 1 year after refined transepithelial photorefractive keratectomy (TransPRK). METHODS: In this retrospective case series, a total of 155 eyes with myopia (mean ± standard deviation = -3.53 ± 1.81 diopters) with and without astigmatism (range = 0.25 to 4.50 diopters) were recruited and observed for 1 year. Patients underwent refined single-step TransPRK using the SCHWIND AMARIS 500 laser (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). The main predicting factors of postoperative supernormal vision and visual acuity improvements were sought by statistical modeling. RESULTS: Logistic models showed mesopic contrast sensitivity, high laser fluence, and coma higher-order aberration (HOA) as predicting factors for both UDVA and CDVA super-normal vision. Myopia, astigmatism, dynamic cyclotorsion correction, optical zone, and transitional zone showed associations only in simple models and were not retained in multivariable models. According to the linear regression models, CDVA, mesopic contrast sensitivity, coma HOA, and keratometry were common predictors of both postoperative UDVA and CDVA improvement compared to preoperative UDVA. Astigmatism, optical and transitional zones, and high laser fluence were common predictors only in simple regression models. CONCLUSIONS: Through statistical modeling, preoperative CDVA, mesopic contrast sensitivity, coma HOA, and simulated keratometry were found to be the main factors that predicted improvement of both postoperative CDVA and UDVA compared to preoperative CDVA. Furthermore, mesopic contrast sensitivity, coma HOA, and high laser fluence were the common predictors of achieving both CDVA and UDVA supernormal vision 1 year after refined single-step TransPRK. [J Refract Surg. 2019;35(12):771-780.].

Long-term Comparison of Combined t-PTK and CXL (Cretan Protocol) Versus CXL With Mechanical Epithelial Debridement for Keratoconus.

PURPOSE: To compare the long-term outcomes of corneal cross-linking (CXL) for the treatment of keratoconus using two different techniques for epithelial removal: transepithelial phototherapeutic keratectomy (t-PTK) and mechanical epithelial debridement. METHODS: In this prospective, comparative, interventional case series, 26 patients (30 eyes) with progressive keratoconus underwent CXL treatment. Fifteen eyes (13 patients) underwent epithelial removal with t-PTK (Cretan protocol) and 15 eyes (13 patients) underwent mechanical epithelial debridement (Dresden protocol) during CXL. Visual, refractive, and keratometric outcomes were evaluated preoperatively and at 1, 2, 3, and 4 years postoperatively. RESULTS: No intraoperative or postoperative complications were observed in any of the patients. In the Cretan protocol group, mean uncorrected (UDVA) and corrected (CDVA) visual acuity improved from 0.99 ± 0.42 and 0.33 ± 0.28 logMAR preoperatively to 0.75 ± 0.32 (P = .018) and 0.21 ± 0.16 (P = .024) logMAR at 4 years postoperatively, respectively. In the Dresden protocol group, mean UDVA improved from 0.83 ± 0.47 logMAR preoperatively to 0.63 ± 0.40 logMAR (P = .033) at 4 years postoperatively, whereas mean CDVA did not demonstrate a statistically significant improvement postoperatively (P > .05). In the Cretan protocol group, mean corneal astigmatism improved from -6.19 ± 4.54 diopters (D) preoperatively to -4.68 ± 3.10 D (P = .041) at last follow-up, whereas in the Dresden protocol group there was no statistically significant difference postoperatively (P > .05). CONCLUSIONS: Epithelial removal with t-PTK during CXL (Cretan protocol) resulted in better visual, refractive, and keratometric outcomes compared with mechanical epithelial debridement over a long-term follow-up. [J Refract Surg. 2019;35(10):650-655.].

Combined DSAEK and intraocular lens flipping with retropupillary fixation in a patient with anterior chamber iris-claw intraocular lens and corneal edema.

An 84-year-old monocular woman was referred to our institution for the management of corneal decompensation in her only eye, the right eye. The patient had secondary implantation of an anterior chamber iris-claw intraocular lens (IOL) for IOL dislocation in the setting of pseudoexfoliation syndrome 2 years before presentation. Descemet-stripping automated endothelial keratoplasty (DSAEK) combined with retropupillary repositioning of the iris-claw IOL using a flipping technique was performed for the treatment of corneal edema. No intraoperative or postoperative complications occurred. Six months postoperatively, the corneal graft was attached and clear and the retropupillary iris-claw IOL was well positioned. The uncorrected distance visual acuity and corrected distance visual acuity improved from counting fingers preoperatively to 20/200 and 20/63, respectively, after surgery. Combined DSAEK and retropupillary refixation of a prepupillary iris-claw IOL using the flipping technique was a safe technique in this patient with corneal decompensation.

Combined Pupilloplasty and Retropupillary Iris-Claw Intraocular Lens Implantation with DSAEK in a Patient with Traumatic Iridoplegia, Aphakia and Corneal Decompensation.

PURPOSE: To report the management of a patient with traumatic mydriasis, aphakia and corneal decompensation with a triple procedure: simultaneous pupilloplasty and retropupillary iris-claw intraocular lens (IOL) implantation combined with Descemet stripping automated endothelial keratoplasty (DSAEK). RESULTS: An 88-year-old woman was referred to our Institute for consultation on her left eye. The patient had undergone surgical removal of the IOL, without re-implantation, in her left eye 10 months prior to presentation due to traumatic IOL dislocation. At the time of examination, corrected distance visual acuity was counting fingers and intraocular pressure was 10 mmHg. Slit-lamp examination revealed iridoplegia, aphakia and corneal edema. The patient underwent simultaneous pupilloplasty and retropupillary iris-claw IOL implantation combined with DSAEK. Six months postoperatively, the corneal graft was attached and clear, the iris was well reconstructed and almost round, and the iris-claw IOL was in place. CONCLUSIONS: Simultaneous pupilloplasty and retropupillary iris-claw IOL implantation combined with DSAEK was shown to be a safe surgical technique in a patient with traumatic mydriasis, aphakia and corneal decompensation.

Resolution of epithelial ingrowth after combined photorefractive keratectomy and corneal crosslinking in a patient with post-LASIK ectasia.

A 34-year-old man was referred to our institute for evaluation of the left eye because of corneal ectasia 10 years after bilateral laser in situ keratomileusis (LASIK). Three months before his referral, the patient had a flap lift for the management of interface fluid accumulation. Topography demonstrated post-LASIK corneal ectasia and slitlamp evaluation revealed epithelial ingrowth in the stromal interface inferiorly. The patient underwent uneventful combined photorefractive keratectomy (PRK) and corneal crosslinking (CXL) to stabilize the corneal ectasia and improve his functional vision. One month after the treatment, slitlamp evaluation revealed complete resolution of stromal interface epithelial ingrowth. At 12 months postoperatively, significant visual and topographic improvement was noted without any evidence of epithelial ingrowth recurrence or corneal ectasia progression. Combined PRK-CXL seemed to not only treat the corneal pathology of this patient successfully, resulting in visual and topographic improvement, but it also resolved the stromal interface epithelial ingrowth.

Comparison of Single-Step Transepithelial Photorefractive Keratectomy With or Without Mitomycin C in Mild to Moderate Myopia.

PURPOSE: To compare efficacy and safety of single-step transepithelial photorefractive keratectomy (PRK) with or without mitomycin C (MMC) in patients with mild to moderate myopia. METHODS: Patients with mild to moderate myopia (≤ -5.50 diopters [D]) underwent single-step transepithelial PRK using the Amaris laser (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). Total ablation depth (epithelium and stroma) was 160 µm or less. The right eye of each patient was treated with 0.02% MMC for 10 seconds, whereas the left eye did not receive any MMC. Corneal haze, endothelial cell indices, refraction, visual acuity, contrast sensitivity, and higher order aberrations were assessed preoperatively and postoperatively. RESULTS: In this comparative case series, 71 patients (16 men and 55 women; 142 eyes) were enrolled. Mean patient age was 27.97 ± 5.74 years. Mean preoperative spherical equivalent of patients' right and left eyes were -3.20 ± 1.20 and -3.30 ± 1.20 diopters, respectively (P = .70); other preoperative visual parameters were also comparable. Incidence of 2+ grade of haze was detected in 1 (2.5%) right and 2 (5.0%) left eyes (P > .99) 3 to 6 months postoperatively. Incidence of 1+ degree of haze was also comparable. No eye developed 3+ degrees or more of haze. One year postoperatively, both eyes achieved comparable refraction, visual acuity, contrast sensitivity, and higher order aberrations, and no greater than trace haze was detected. MMC-treated eyes suffered a greater loss of endothelial cell density (P < .001) and showed higher variance in cell size (P = .001). CONCLUSIONS: Single-step transepithelial PRK with or without MMC showed similar efficacy and incidence of haze in eyes with mild to moderate myopia with total ablation depths of 160 µm or less. However, MMC-treated eyes showed a worse profile of endothelial cell indices. Applications of MMC in this subgroup of patients may be reconsidered. [J Refract Surg. 2018;34(6):400-407.].

Mini descemet membrane stripping (m-DMES) in patients with Fuchs' endothelial dystrophy: A new method.

We present two cases with focal corneal edema due to Fuchs' endothelial dystrophy that were successfully treated with mini Descemet membrane stripping (m-DMES) (diameter of 3-4 mm; at the area of preexisting focal corneal edema) without endothelial replacement during cataract surgery. Specular microscopy demonstrated Fuchs' endothelial dystrophy and histopathologic evaluation confirmed the diagnosis. Anterior segment optical coherence tomography and confocal microscopy were used for the evaluation of the corneal tissue recovery course after the surgical procedure. In both patients, we observed an initial aggravation of corneal edema in the area of DM removal for two months followed by gradual improvement. At four months postoperatively, corneal edema had completely regressed resulting in corneal clearance and visual acuity improvement in both cases. M-DMES without graft insertion represents a promising alternative surgical technique that could be applied in specific cases of Fuchs' endothelial dystrophy with focal corneal edema.

Combined transepithelial phototherapeutic keratectomy and conventional photorefractive keratectomy followed simultaneously by corneal crosslinking for keratoconus: Cretan protocol plus.

PURPOSE: To evaluate the visual, refractive, and topographic outcomes after combined transepithelial phototherapeutic keratectomy (PTK) and conventional photorefractive keratectomy (PRK) followed simultaneously by corneal crosslinking (CXL) for keratoconus. SETTING: Vardinoyiannion Eye Institute of Crete, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece. DESIGN: Prospective case series. METHODS: Patients with progressive keratoconus had simultaneous conventional PRK followed by CXL; the corneal epithelium was removed using transepithelial PTK (Cretan protocol plus). The visual, refractive, and topographic outcomes and the endothelial cell density (ECD) were evaluated preoperatively and 1, 3, 6, and 12 months postoperatively. RESULTS: Forty-three patients (55 eyes) were enrolled. The mean uncorrected and corrected distance visual acuities improved significantly from 0.98 ± 0.63 (SD) logarithm of minimum angle of resolution (logMAR) and 0.20 ±â€¯0.23 logMAR preoperatively to 0.39 ±â€¯0.35 logMAR (P < .001) and 0.08 ±â€¯0.16 logMAR (P < .001) 12 months postoperatively, respectively. The mean spherical equivalent improved significantly from -4.67 ±â€¯4.00 diopters (D) preoperatively to -2.24 ±â€¯2.81 D (P < .001) at 12 months. The mean steep keratometry (K) and flat keratometry readings decreased significantly from 50.30 ±â€¯5.00 D and 45.62 ±â€¯3.10 D preoperatively to 46.27 ±â€¯3.90 D (P < .001) and 43.46 ±â€¯3.00 D (P < .001) 12 months postoperatively, respectively. No ECD alterations were observed throughout the follow-up (P > .05). CONCLUSION: Combined transepithelial PTK and conventional PRK followed simultaneously by CXL was effective in corneal stabilization and vision improvement in keratoconic patients.