Prototype posterior chamber phakic IOL - 35 year follow up.

Purpose: To present a case involving a rarely seen prototype posterior chamber phakic IOL (PC-pIOL) in a highly myopic patient with bilateral cataract. Observations: A 64-year-old male presented to our clinic with poor vision in both eyes. Clinical examination revealed bilateral mature cataract, phacodonesis as well as a PC-pIOL implanted 35 years ago to address his high myopia. The visual acuity (VA) was 20/200 in the right eye and no light perception in the left eye. PC-pIOL extraction as well as 23G pars plana vitrectomy (PPV) and fragmentation surgery was scheduled for the right eye. The left eye was treated conservatively. Successful extraction of the PC-pIOL was performed while it was easy to remove. It was a bow-tie shaped lens with a collar-stud-like button in the middle which extended anteriorly into the anterior chamber through the pupil. PPV with lens fragmentation was successful and the patient was left aphakic in order to avoid the placement of a zero diopter IOL. Final best corrected VA was 20/25 one month post-surgery. Conclusions and importance: Removal of this rarely seen pIOL was performed without difficulty while excellent VA was achieved. Aphakia following complete vitrectomy represented a viable option in this case. Furthermore, we highlight the clinical manifestations associated with this IOL more than three decades after implantation.

Corneal Irregularity Induced by Transepithelial Photorefractive Keratectomy in a Patient With Partial Limbal Stem Cell Deficiency.

PURPOSE: The aim of this study was to present a case of transepithelial photorefractive keratectomy (trans-PRK) laser ablation in a patient with partial limbal stem cell deficiency (LSCD) that resulted in corneal irregularity. METHODS: A 23-year-old man with bilateral partial LSCD underwent trans-PRK for myopia correction 2 months before presentation to our department. Trans-PRK ablation was performed with a phototherapeutic keratectomy ablation profile set at 60 µm in the OD and 57 µm in the OS and 8 mm zone. At the time of presentation, the patient complained of decreased visual acuity. Corrected distant visual acuity was 20/20 (-3.25, -0.75 × 180 degrees) and 20/50 (-3.00, -3.00 × 180 degrees) in the OD and the OS, respectively. No further ocular history was reported other than prolonged soft contact lens use for myopia. Pre-trans-PRK tomography (WaveLight Oculyzer II diagnostic system, WaveLight GmbH, Germany) revealed bilateral superior steepening with corresponding epithelial thinning as obtained by the epithelial map using Optovue optical coherence tomography (Visionix Luneau technology). Slit-lamp examination showed bilateral superficial neovascularization, suggestive of early-stage LSCD. RESULTS: A nonuniform laser stromal ablation resulting in corneal irregularity and decreased visual acuity was observed 2 months postoperatively. During the 6-month follow-up, corneal tomography was stable with only minimal improvement. At that time, corrected distant visual acuity remained 20/20 (-2.75, -0.75 × 160 degrees) in the OD and 20/50 (-3.00, -3.00 × 180 degrees) in the OS. CONCLUSIONS: Trans-PRK seems to be a contraindication in cases with corneal epithelial irregularities and could lead to abnormal and nonuniform stromal ablation .

The Multifarious Effects of Various Glaucoma Pharmacotherapy on Corneal Endothelium: A Narrative Review.

Corneal endothelium is a single cell layer that is mainly responsible for maintaining corneal clarity. Endothelial damage secondary to toxicity, stress, or genetic predisposition are common and in conjunction with the low regenerative ability of the cells, making their preservation critical for maintaining visual acuity. Patients with glaucoma, who are estimated to be close to 80 million worldwide, have a plethora of reasons for developing endothelial damage, being exposed to a spectrum that extends from various medical and surgical interventions to the disease itself. The wide spectrum of glaucoma pharmacotherapy that has been recently extended by addition of newer classes of medications has been the focus of extensive research on its effects on corneal endothelium. Both basic and clinical research have attempted to shine a light on the complex mechanisms associated with the effects of glaucoma medication on corneal endothelium and to answer the important question as to whether these findings are clinically significant. The aim of this review is to summarize and present current literature of the various findings, both from in vivo and in vitro studies that have focused on the complex relationship between different classes of glaucoma medication and their effect on corneal endothelium.

Optical coherence tomography angiography in Parkinson's disease: a systematic review and meta-analysis.

BACKGROUND: To examine the association between optical coherence tomography angiography (OCTA) retinal measurements and Parkinson's disease (PD). METHODS: We searched MEDLINE and EMBASE from inception up to November 5th, 2021 for studies examining the differences between OCTA retinal measurements in PD patients and healthy controls. We used the Hartung-Knapp-Sidik-Jonkman random-effects method to combine study-specific standardized mean differences (SMD) in pooled effect estimates and a meta-analytic extension of the E-value metric to quantify the confounding bias capable of nullifying the pooled estimates. RESULTS: Nine eligible studies for our systematic review were identified through our search strategy. The pooled SMD between the retinal vessel density of PD patients and healthy participants in the whole superficial vascular plexus (SVP), foveal SVP, parafoveal SVP and foveal avascular zone (FAZ) was -0.68 (95% CI: -1.18 to -0.17, p value = 0.02, n = 7 studies), -0.14 (95% CI: -0.88 to 0.59, p value = 0.62, n = 5 studies), -0.59 (95% CI: -1.41 to 0.23, p value = 0.12, n = 5 studies) and -0.20 (95% CI: -0.79 to 0.38, p value = 0.39, n = 5 studies), respectively. An unmeasured confounder would need to be associated with a 3.01-fold, 1.54-fold, 2.81-fold and 1.70-fold increase in the risk of PD and OCTA retinal measurements, in order for the pooled SMD estimate of vessel density in whole SVP, parafoveal SVP and FAZ, respectively, to be nullified. CONCLUSIONS: Our results provide evidence on an inverse association between whole SVP vessel density and PD.

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.

"Corneal Plication" for the Management of Progressive Corneal Graft Protrusion in Patients With Keratoconus: a New Technique.

PURPOSE: The purpose of this study was to present a new surgical technique, namely corneal plication, for the management of high astigmatism and progressive corneal graft protrusion after penetrating keratoplasty (PKP) for keratoconus. METHODS: New surgical approach description. RESULTS: A 61-year-old woman with a history of bilateral keratoconus was referred to our institute for the management of progressive corneal graft protrusion in her left eye 25 years after PKP. On presentation, the uncorrected distance visual acuity in the involved eye was counting fingers, whereas slit-lamp examination revealed a clear graft with a crescentic area of thinning in the inferior host cornea, extending from 4 to 9 o'clock that resulted in significant graft protrusion and astigmatism. We proceeded with a novel surgical approach that included "folding" and suturing the thinned, diseased corneal tissue and thus creating a form of corneal plication. No intraoperative or postoperative complications were observed, and uncorrected distance visual acuity was 0.32 6 months after the operation. CONCLUSIONS: Corneal graft plication may represent a realistic alternative to more invasive procedures, currently used for the management of this long-term post-PKP complication in patients with keratoconus because it is a nonperforating technique that seems to provide satisfactory anatomical and visual outcomes without the need for any tissue excision or regrafting.

Combined Astigmatic Arcuate Keratotomy with Descemet Automated Endothelial Keratoplasty.

We report the results of simultaneous astigmatic arcuate keratotomy (AK) and Descemet automated endothelial keratoplasty (DSAEK). A 55-year-old patient with a history of high myopia was referred for the management of bullous keratopathy secondary to an anterior chamber phakic intraocular lens (pIOL). IOL explantation through a 5.5-mm corneal incision, cataract extraction, and posterior chamber IOL implantation, combined with DSAEK, were performed. Postoperatively, increased astigmatism up to 2.0 diopters (Dpt) was observed, attributed to the large corneal incision, and remained stable, despite suture removal at 3 months. One year postoperatively, the graft showed signs of progressive endothelial dysfunction. A combined procedure of astigmatic AK and DSAEK was thus performed. After 6 months, topographic astigmatism was significantly reduced to 0.5 Dpt and best-corrected visual acuity increased. In conclusion, simultaneous astigmatic AK and DSAEK could be an effective combination for treating patients with well-documented pre-existing astigmatism and endothelial decompensation.

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.].

Long-Term Follow-Up of Combined Photorefractive Keratectomy and Corneal Crosslinking in Keratoconus Suspects.

PURPOSE: To present the long-term outcomes of photorefractive keratectomy (PRK) combined with accelerated corneal cross-linking (CXL) for refractive error correction in a series of keratoconus suspects. SETTING: University practice. DESIGN: Retrospective case series. METHODS: A series of patients with topographic findings suspicious for keratoconus underwent simultaneous PRK and prophylactic accelerated CXL (5 minutes with intensity of 18 mW/cm2) for the correction of their refractive error. The results were recorded for more than 4 years postoperatively. RESULTS: Ten eyes of 5 patients were included. Mean follow-up was 58.2 months (range from 54 to 62 months). Mean age at presentation was 25 years (range from 22 to 32 years). Mean spherical equivalent (SE) refraction was -2.76 (standard deviation [SD] 0.97D, range from -1.25 to -4.00 diopters [D]), while mean central corneal thickness was 511µm (SD 13µm, range from 485 to 536 µm). At last, follow-up 9 out of 10 eyes had SE refraction within ± 0.50D and all eyes had SE within ± 1.00D. None of the eyes lost any line of corrected distance visual acuity (CDVA), whereas 1 eye gained one line of CDVA. All eyes demonstrated stability of their results during the follow-up period. CONCLUSION: Simultaneous PRK followed by prophylactic accelerated CXL (PRK plus) appeared to be a safe and effective option for the correction of the refractive error in this series of keratoconus suspect patients, without compromising corneal stability for up to 5 years postoperatively.

Repeated Corneal Cross-linking (CXL) in Keratoconus Progression After Primary Treatment: Updated Perspectives.

Background: Corneal collagen cross-linking (CXL) has recently become the preferred practice in the management of progressive keratoconus and other corneal ectasias as it has been proven to be successful in halting progression of the disease with an excellent safety and efficacy profile. However, there is a known variation regarding the response to CXL, depending on several parameters related either to the treatment protocol, patient characteristics, or corneal biomechanical properties. In fact, continuing progression of keratoconus has been noted in some cases despite prior treatment with CXL.Methods: The aim of this article is to provide an updated review of all published results on repeated-CXL, focusing on the indications and the efficacy of repeated treatment and highlighting possible explanations of progression after primary CXL. Conclusions: The diagnosis of primary treatment failure should always be made based on specific clinical and imaging criteria, with repeated and consistent measurements, in order to exclude pseudoprogression. In cases of confirmed progression, physicians need to decide whether repeating CXL could be an option to enhance corneal stability without any complications.

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.

Accuracy of dynamic contour tonometry, Goldmann applanation tonometry, and Tono-Pen XL in edematous corneas.

PURPOSE: To investigate in vitro the accuracy of dynamic contour tonometry, Goldmann applanation tonometry, and Tono-Pen XL in edematous corneas. METHODS: Experimental study included 20 freshly enucleated porcine eyes. Epithelium was debrided, and eyes were divided in four groups. Groups were immersed in 35%, 40%, 50%, and 60% glycerin solutions for 3 hours. Subsequently, globes were mounted in a special holder, and their intraocular pressure was hydrostatically adjusted. Intraocular pressure was measured by means of dynamic contour tonometry, Goldmann applanation tonometry, and Tono-Pen XL while adjusting true intraocular pressure to 17, 33, and 50 mm Hg. Ultrasound pachymetry was performed. RESULTS: Mean corneal thickness was 914.5 ± 33.3 µm (730-1015 µm). In true intraocular pressure of 33 mm Hg, Goldmann applanation tonometry and dynamic contour tonometry significantly underestimated true intraocular pressure (mean Goldmann applanation tonometry: 14.7 ± 4.8 mm Hg, p < 0.001, mean dynamic contour tonometry: 21.6 ± 6.8, p < 0.001). Tono-Pen XL also underestimated, but difference was not statistically significant (Tono-Pen XL: 27.9 ± 9.7, p = 0.064). In true intraocular pressure of 50 mm Hg, all three methods significantly underestimated (Goldmann applanation tonometry: 17.6 ± 5.3 mm Hg, p < 0.001, dynamic contour tonometry: 26.8 ± 6.3 mm Hg, p < 0.001, Tono-Pen XL: 35.6 ± 8.4 mm Hg, p < 0.001). The error in measured intraocular pressure for each method (true minus measured intraocular pressure) was significantly correlated to true intraocular pressure (p < 0.001). The intraocular pressure measurements of each eye taken under true intraocular pressure of 17 and 33 mm Hg with the three methods were correlated to each other. Measurements taken under intraocular pressure of 50 mmHg were not correlated to each other. Corneal thickness was not correlated to intraocular pressure measurement. CONCLUSION: Goldmann applanation tonometry, dynamic contour tonometry, and Tono-Pen XL underestimate intraocular pressure when measured under edematous conditions. Tono-Pen XL showed better accuracy, especially in lower true intraocular pressure. The measurement error increases when true intraocular pressure increases in all three methods.

5-year efficacy of all surface laser ablation with cross-linking (ASLA-XTRA) for the treatment of myopia.

BACKGROUND: The purpose of our study is to examine the long (5-year) efficacy of the all surface laser ablation (ASLA) combined with accelerated cross-linking (CXL) for the treatment of myopia without the use of mitomycin-C (MMC). METHODS: This retrospective study consisted of 202 eyes of 118 myopic (SD: 2.41, range: - 1.50 to - 12.75 D) patients (44 males, 74 females). Mean age was 28.50 years (SD: 6.45, range: 18 to 51 years) that underwent ASLA with accelerated CXL for the treatment of their myopia. RESULTS: The patients underwent routine postoperative assessment on the 1st, 3rd, 7th day and in the 1st, 3rd, 6th and 12th month, 30th month (±6 months), 4th and 5th year. The mean spherical equivalent (SEq) refractive error changed from - 6.41 ± 2.41 D preoperatively to - 0.02 ± 0.53 D at 5 years postoperatively. The haze score was 0.18, 0.25 and 0.28 at 1, 3 and 6 months postoperatively. At 12 months after the treatment, no eyes had significant corneal haze and in all the following postoperative time intervals the haze traces were gone. CONCLUSION: ASLA combined with accelerated CXL (ASLA-XTRA) appears to be safe, efficacious and offering very good refractive results. The potential additional benefits of this modality are the stabilizing effect of the refraction and its sterilization effect on the treated cornea without the potential side effects of MMC.

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.

Simultaneous Penetrating Keratoplasty and Implantation of a New Scleral-Fixated, Sutureless, Posterior Chamber Intraocular Lens (Soleko, Carlevale): A Novel Technique.

PURPOSE: To describe a novel technique of combined penetrating keratoplasty (PKP) with implantation of a new scleral-fixated, sutureless, posterior chamber intraocular lens (PC-IOL) (Soleko, Carlevale). METHODS: New surgical approach description. RESULTS: We describe a novel technique for the management of PKP graft failure and posttraumatic aphakia with repeat-PKP and simultaneous implantation of a new scleral-fixated, sutureless PC-IOL. The postoperative course was uneventful, and the patient reported marked improvement in his vision. Up to 6 months postoperatively, the graft showed no signs of failure or rejection, the intraocular lens remained well-positioned, and no complications were observed. CONCLUSIONS: The favorable final outcome of our patient suggests that simultaneous PKP and implantation of this new scleral-fixated, sutureless PC-IOL may represent an efficient and effective method for the management of aphakia combined with corneal scarring.

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.

Resolution of Corneal Fibrosis After Descemet's Stripping Automated Endothelial Keratoplasty: A Case Report.

PURPOSE: To report the resolution of anterior corneal fibrosis after Descemet's stripping automated endothelial keratoplasty (DSAEK), in a patient with chronic corneal edema and anterior stromal scarring. METHODS: A 63-year-old woman, with a history of Fuchs endothelial dystrophy, presented with increasing discomfort and gradual visual loss in her right eye. Clinical examination revealed long-standing bullous keratopathy accompanied by marked subepithelial fibrosis (SEF). Based on the low postoperative visual potential due to glaucomatous optic neuropathy, we decided to proceed with DSAEK. RESULTS: During the follow-up period, SEF was found to gradually resolve. Corneal clarity was restored and an improvement in visual acuity was observed up to 12 months after surgery. CONCLUSION: DSAEK alone may represent an effective therapeutic option for the restoration of impaired corneal clarity in patients with long-standing corneal edema and concomitant anterior subepithelial scarring.