Extrusion of Femtosecond Laser-Implanted Intrastromal Corneal Ring Segments in Keratoconic Eyes: Prevalence, Risk Factors, and Clinical Outcomes.

PURPOSE: To evaluate the prevalence, possible risk factors, and clinical results of femtosecond laser implanted intrastromal corneal ring segment (ICRS) extrusion in keratoconic eyes. Patients and Methods. This is a retrospective observational study evaluating 333 eyes of 269 patients who were subjected to femtosecond laser-implanted Keraring ICRS in the Sohag Refractive Center, Sohag, Egypt, from January 2014 to January 2019. The study included eyes with channels created by a femtosecond laser (60 kHz IntraLase femtosecond system; Advanced Medical Optics, Santa Ana, California, USA) with implantation of Keraring intrastromal corneal ring segments (Mediphacos, Belo Horizonte, Brazil). Patient data and causes of Keraring extrusions were identified as being those rings that migrated or showed melting of the cornea with no other reason which required segment removal. RESULTS: Seven eyes were found to fit the criteria of ring extrusion (2.1%) out of the 333 eyes which had Keraring implantation. All extruded rings were from patients with keratoconus grade 3, with eccentric cones, and with femtosecond creation of the tunnel. Four eyes belonging to 3 patients (57.1%) had a history of vernal Keratoconjunctivitis, yet they did not show signs of activity at the time of implantation. They reported excessive rubbing just before they presented with conjunctival hyperemia and foreign body sensation. Five eyes (71.4%) showed chronic sun exposure. The mean minimal corneal thickness was 401.85 µm (range 384-420 µm), while the mean maximum keratometry was 61 D (range 55.18-68.96 D). Most of the extruded rings had large arcs. Six eyes had crosslinking (CXL) at the same session of the Keraring implantation. The simultaneous CXL treatment is considered as a possible significant risk factor for ring extrusion. CONCLUSION: ICRS is an effective reversible option for patients with keratoconus who are intolerant to hard contact lenses, yet the choice of cases and ring segments is mandatory for satisfactory results. Moreover, meticulous history taking and examination reduces the incidence of complications including extrusion.

Clinical outcomes of transepithelial photorefractive keratectomy versus femtosecond laser assisted keratomileusis for correction of high myopia in South Egyptian population.

AIM: To evaluate the safety and efficacy of transepithelial photorefractive keratectomy (t-PRK) with adjuvant mitomycin C (MMC) versus femtosecond laser assisted keratomileusis (Femto-LASIK) in correction of high myopia. METHODS: Prospective randomized comparative study including 156 eyes of 156 patients with high myopia and a spherical equivalent refraction (SER) <-6.00 D. They were divided randomly into two groups: Group A included 72 eyes treated with t-PRK with adjuvant MMC and Group B included 84 eyes treated with Femto-LASIK. Visual acuity, SER, corneal topography, pachymetry and keratometry were assessed for 12mo postoperatively. RESULTS: The preoperative mean SER was -8.86±1.81 and -9.25±1.70 D in t-PRK MMC group and Femto-LASIK respectively (P=0.99) which improved to -0.65±0.43 D and -0.69±0.50 D at 12mo follow up. Mean SER remained stable during the 12mo of follow-up, with no statistically significant difference between the two groups (P=0.64). In t-PRK MMC group, only six eyes needed retreatment after six months of follow up. And two eyes showed haze (one reversible haze grade 2, while the other had dense irreversible haze grade 4). CONCLUSION: t-PRK MMC provides safe and satisfactory visual outcomes and acceptable risk as Femto-LASIK in patients with high myopia.

Pattern of Intermediate Uveitis in an Egyptian Cohort.

Purpose: To describe the clinical experience with intermediate uveitis at six Egyptian tertiary eye centers.Methods: A multicenter retrospective chart review of all patients with intermediate uveitis seen at six ocular inflammation referral clinics in Egypt between January 2010 and January 2017.Results: The study included a total of 781 patients with intermediate uveitis. The study cohort comprised of 282 male and 499 female patients. In over half of our cohort (58.77%), no specific cause could be confirmed. The remaining patients had sarcoidosis (16.26%), tuberculosis (14.85%), multiple sclerosis (9.09%), and TINU (1.02%). By the end of our study, 62% of the affected eyes had a BCVA better than 20/40Conclusion: More than 40% of our patients with intermediate uveitis had sarcoidosis, tuberculosis, multiple sclerosis, or TINU as the underlying etiology. Owing to their potential morbidity, these diseases need to be considered in Egyptian patients presenting with intermediate uveitis.

Central retinal vein occlusion complicating spontaneous dural carotid-cavernous fistula after phacoemulsification.

In this report, we are presenting a case of a 49-year-old female complaining of defective vision in the left eye. The main complaints were: pain, redness, mild proptosis, and high intraocular pressure. She had a history of uneventful phacoemulsification surgery 3 months prior to presenting to us. Investigations revealed a macular edema caused by central retinal vein occlusion and computed tomography angiography showed an early opacified left cavernous sinus with a dilated superior ophthalmic vein along with a fistula between the meningeal branches of the carotid arteries and the cavernous sinus. Improvement of ocular symptoms was achieved after endovascular treatment by transarterial and transvenous embolization.

Evaluation of Corneal Higher-Order Aberrations by Scheimpflug-Placido Topography in Patients with Different Refractive Errors: A Retrospective Observational Study.

PURPOSE: To report the characteristics of anterior and posterior corneal high-order aberrations in patients with different refractive errors. SETTING: This study was conducted at Sohag Refractive Center, Sohag, Egypt. DESIGN: This is a retrospective observational study. METHODS: This study evaluated 750 patients (750 eyes) who were seeking refractive surgery. The eyes were stratified into five groups (150 eyes/group) based on refractive error: mild-to-moderate myopia, high myopia, hyperopia, simple myopic astigmatism, and simple hypermetropic astigmatism. All patients were subjected to comprehensive ophthalmological examination including corneal topography and corneal aberrometry using the Scheimpflug-Placido topography (Sirius, CSO, Italy). RESULTS: Coma aberration was statistically significant when compared in all five groups (P=0.01). It was highest in the hypermetropia group (0.26 ± 0.12 µm) but lower in the moderate myopia, high myopia, myopic astigmatism, and hypermetropic astigmatism groups. Spherical aberration was lowest in the hypermetropia group and significantly different from that in the other groups. Trefoil was statistically insignificant when all groups were compared (P=0.062) but was highest in the myopic astigmatism group (0.24 ± 0.25 µm). Total RMS peaked in the hypermetropia group (0.99 ± 0.70). CONCLUSIONS: In normal corneas and regular refractive errors, the cornea-induced high-order aberration was minimal, and all types of refractive errors were associated with certain types of high-order aberrations, with a significant increase in spherical aberration in the hypermetropia group.

Corneal Endothelial Cell Density and Morphology in Healthy Egyptian Eyes.

PURPOSE: To evaluate the corneal endothelial cell density and morphology in normal Egyptian eyes. METHODS: In total, 568 healthy eyes of 568 Egyptian volunteers aged 20 to 85 years were examined using noncontact specular microscopy for the central corneal thickness (CCT), mean endothelial cell density (MCD), coefficient of variation (CV) in cell area, mean cell area (MCA), and hexagonal cell (Hex) percentage. Variables were compared between sexes and between different age groups. RESULTS: The mean CCT, MCD, and MCA were 514.45 ± 43.04 µm, 2647.50 ± 382.62 cells/mm2, and 390.59 ± 149.94 µm2, respectively. MCD and MCA showed no significant differences between men and women (P=0.171 and 0.099, respectively), whereas CV (%) and Hex (%) showed significant differences (P=0.024 and 0.015, respectively). CCT (P=0.007, r = -0.113) and MCD (P < 0.001, r = -0.357) exhibited a significant negative correlation with age, whereas CV (%) (P < 0.001, r = 0.341) and MCA (P=0.008, r = 0.111) exhibited a significant positive correlation. The mean rate of endothelial cell loss from 20 to 85 years of age was 0.3% per year. CONCLUSIONS: Our results provide normative data for the corneal endothelium in healthy Egyptian eyes, thus increasing the knowledge base for corneal endothelial cell parameters in healthy Egyptian eyes. Furthermore, our findings can be used as baseline values for comparisons between Egyptian and other populations and for studies of the endothelial cell reserve and capacity for intraocular surgery and corneal transplantation.

Outcomes of Corneal Tattooing by Rotring Painting Ink in Disfiguring Corneal Opacities.

AIM: To evaluate corneal tattooing with Rotring painting ink (Rotring Ink, Hamburg, Germany) as an available and affordable surgical technique to improve cosmetic appearance in the eyes with disfiguring corneal opacities. METHODS: Fifty-three blind eyes with corneal disfiguring opacities underwent corneal tattooing using Rotring painting ink (Rotring Ink, Hamburg, Germany) by multiple transepithelial intrastromal injections under topical anesthesia. Complete ophthalmic examination and ocular ultrasonography were performed, and photographs of the patients' eyes were taken. Follow-up period was at least 12 months. RESULTS: On the first postoperative day, all patients presented with mild conjunctival injection and foreign body sensation. After the end of the follow-up period, 51 patients (96%) were satisfied of cosmetic appearance while only 2 patients (4%) post-op cosmetic results were less than their expectations; however, they were better in appearance. No major complications like corneal erosions; corneal ulcers or corneal melting was noted in any case. CONCLUSIONS: Corneal tattooing with Rotring painting ink in blind disfigured eyes achieves favourable cosmetic results and is associated with high patient satisfaction. With better case selection, a high post-op satisfaction was achieved. Corneal tattooing acts as an alternative to more sophisticated and expensive cosmetic reconstructive surgery. This trial is registered with ISRCTN46626979.

Femtosecond-assisted intracorneal ring segment complications in keratoconus: from novelty to expertise.

OBJECTIVES: To document the difference between complication rate in the early curve of practicing intracorneal stromal rings and after gaining experience. PATIENTS AND METHODS: A retrospective study of 623 eyes of 417 patients with keratoconus who underwent Keraring implantation using femtosecond laser for channel creation. RESULTS: The main outcome measures were reported intraoperative and postoperative complications. The overall complication rate was 12.7% (79 eyes) over the 4 years with 34 eyes in the first year (5.5%) and six eyes in the fourth year (0.96%). Over the 4 years of our practice, intraoperative complications were 7.1% and postoperative complications were 5.6%. Yet, there was a significant difference in intraoperative complications between the first and the fourth year where it was 3.5% and 0.48%, respectively. This also applies to the postoperative complication rate, which decreased from 1.9% to 0.5% in the fourth year. CONCLUSION: Complications with femtosecond-assisted intracorneal stromal ring procedure can be reduced by experience, making this procedure a safe and effective means of treating keratoconus. Yet, there are some complications that cannot be avoided such as sterile keratitis.

Air Bubble Technique for Fundus Visualization during Vitrectomy in Aphakia.

PURPOSE: To evaluate the efficacy and safety of air bubble technique for vitrectomy in aphakia. STUDY DESIGN: Prospective interventional uncontrolled case series. METHODS: This study included 53 eyes of 53 patients who are phakic and indicated for phacovitrectomy (7 eyes, group 1), aphakic and indicated for vitrectomy (22 eyes, group 2), or underwent unplanned vitrectomy for immediate management of a phacoemulsification surgery complicated by rupture posterior capsule with dropped nucleus, fragments, or IOL (24 eyes, group 3). Cases with complicated vitreoretinal pathology were not included in this study. All vitrectomy surgeries were conducted by the air bubble technique in the anterior chamber. Main outcomes included anatomical success, visual acuity, and intraoperative and postoperative complications. RESULTS: The surgical success was achieved in 50 eyes (94.3%). Conversion to BIOM viewing system was needed in the retinal detachment cases of groups 1 and 2. The mean overall LogMAR visual acuity was significantly improved from 1.29 ± 0.58 preoperatively to 0.56 ± 0.19 at the final visit, 6 months postoperatively (P < 0.001). CONCLUSION: The air bubble technique as visualization method for vitrectomy in aphakia is an effective and cheap technique for immediate management of complications of phacoemulsification surgery. This trial is registered with Pan African Clinical Trial Registry PACTR201709002466296.

Optical Coherence Tomography Reveals New Insights into the Accommodation Mechanism.

Purpose. To evaluate the movement of the anterior and posterior lens poles during naturally stimulated accommodation in children using anterior segment optical coherence tomography (OCT). Methods. This is a prospective, observational, noncomparative case series including 18 eyes of nine children. Analysis of the anterior segment in the accommodated and unaccommodated state (with cycloplegia) was done using anterior segment OCT. The main outcome measures were the position of the anterior and posterior lens poles (in relation to the cornea) and lens thickness (LT). Results. A Statistically significant forward movement of the anterior lens pole and backward movement of the posterior lens pole with an increase in LT were found during accommodation (P < 0.001). There was no significant difference between the degree of movement of the anterior lens pole and the posterior lens pole during accommodation (P = 0.944). Conclusions. Anterior segment OCT provides a rapid noncontact method for studying accommodation in children. The backward movement of the posterior lens pole during accommodation nearly equals the forward movement of its anterior pole. These data minimize the theoretical hydraulic effect of the vitreous during accommodation, adding more support to the capsular theory of Helmholtz.