Managing Post-Keratoplasty Astigmatism: High-Tech vs. Low-Tech Imaging Techniques for Guiding Suture Manipulation.

Astigmatism is a visually significant condition that can develop after keratoplasty. The management of post-keratoplasty astigmatism can be performed both when transplant sutures are in place and when they have been removed. Fundamental for astigmatism management is its identification and characterization in terms of type, amount, and direction. Commonly, post-keratoplasty astigmatism is evaluated through corneal tomography or topo-aberrometry; however, many other techniques can be used in case these instruments are not readily available. Here, we describe several low-tech and high-tech techniques used for post-keratoplasty astigmatism detection in order to quickly understand if it contributes to low vision quality and to determine its characteristics. The management of post-keratoplasty astigmatism through suture manipulation is also described.

Assessment of Corneal Angiography Filling Patterns in Corneal Neovascularization.

The purpose of the paper is to describe vascular filling patterns in corneal neovascularization (CoNV) and evaluate the effect of corneal lesion location, CoNV surface area and multi-quadrant CoNV involvement on the filling pattern. It is a retrospective study of patients who were investigated for CoNV using fluorescein angiography (FA) or indocyanine green angiography (ICGA) between January 2010 and July 2020. Angiography images were graded and analyzed multiple independent corneal specialists. The corneal surface was divided into four quadrants and patient information was obtained through electronic records. A total of 133 eyes were analyzed. Corneal lesions were located on the peripheral (72%) or central (28%) cornea. Central lesions were associated with multi-quadrant CoNV more frequently than peripheral lesions (p = 0.15). CoNV located within the same quadrant of the corneal lesion was often first to fill (88.4%). In multi-quadrant CoNV, the physiological inferior-superior-nasal-temporal order of filling was usually respected (61.7%). Central lesions resulted in larger CoNV surface area than peripheral lesions (p = 0.09). In multi-quadrant CoNV, the largest area of neovascularization was also the first to fill in (peripheral lesion 74%, central lesion 65%). Fillings patterns in healthy corneas have previously been reported. Despite CoNV development, these patterns are usually respected. Several factors that may influence filling patterns have been identified, including corneal lesion location, CoNV surface area and aetiology of CoNV. Understanding filling patterns of neovascularization allows for the identification of areas at higher risk of developing CoNV, aiding in earlier detection and intervention of CoNV.

Changes in pupillometry associated with dissipated energy during phacoemulsification.

PURPOSE: To investigate the effect of ultrasound level during phacoemulsification on pupil dynamics. METHODS: Comparative retrospective study on patients who underwent routine cataract surgery at the Royal Liverpool University Hospital. Clinical parameters, anterior chamber measurements, axial length, surgeon grade, time of surgery, level of ultrasound used (cumulative dissipated energy, CDE), intra- and post-operative complications were collected. Pupil diameters were collected before and 4 ± 1 weeks after surgery in static scotopic, mesopic, photopic pupil conditions. Also, pupil dynamic measurements after luminous stimulus were recorded. Changes in static pupil diameters, relative dilation at 3.5 s after luminous stimulus, and time to reach 75% and 95% of maximum dilation were measured. RESULTS: Forty-eight eyes of 24 patients (13 males) were included with a mean age of 73.1 ± 14.6 years. Mean CDE value was 18.11 ± 10.56. Mean scotopic pupil diameters decreased by 0.24 ± 0.48 mm (p = 0.021) in the operated eye. Significant correlation was found between reduction in scotopic pupil diameter and CDE (p = 0.05). A generalized linear model confirmed that the level of CDE was significantly associated with reduction in scotopic pupil diameter (p = 0.026). Patients who underwent surgeries with lower CDE (0 < CDE ⩽ 10 and 10 < CDE ⩽ 20) did not experience significant changes in scotopic pupil diameter after surgery (p = 0.28 and p = 0.79, respectively) as opposed to those with higher CDE (CDE > 20; p = 0.03). CONCLUSION: Phacoemulsification cataract surgery and the cumulative dissipated energy may be associated with changes in pupil behaviour.

DSAEK Centration and Interface Folds: Surgical Management.

PURPOSE: To describe a method to center a Descemet stripping automated endothelial keratoplasty lamellar graft and address interface folds. METHODS: A novel technique to center a Descemet stripping automated endothelial keratoplasty graft without undue manipulation of endothelial surface using a STC-6 needle passed obliquely through the anterior corneal surface to engage and progress the lenticule along the posterior surface after injection of air. RESULT: Centration of graft achieved and macroscopic folds resolved. CONCLUSIONS: Here, we describe an atraumatic and reproducible method for graft centration.

Free-Floating DMEK in the Host Anterior Chamber: Surgical Management.

PURPOSE: To describe a method to visualize and manage a completely detached Descemet membrane endothelial keratoplasty (DMEK) tissue scroll in the anterior chamber. METHODS: A 56-year-old male patient with pseudophakic bullous keratopathy, who underwent uncomplicated DMEK surgery, had a complete graft detachment diagnosed at 1-week follow-up. The graft was reattached using a new technique, that is, the free-floating graft was stained in the anterior chamber with trypan blue, immediately followed by air injection to separate the host stroma from the dye. The stained DMEK graft was opened by gentle tapping and attached to the host stroma by air tamponade. RESULT: This technique allowed sufficient staining of DMEK tissue to further evaluate and correct the graft orientation inside the anterior chamber without compromising the stroma. The DMEK graft was attached 1 week after the reattachment procedure. The cornea cleared confirming the functionality of the endothelial cells. CONCLUSIONS: The technique described may be useful in the cases of complete detachment of DMEK tissue and poor visualization of the DMEK tissue orientation. Staining with trypan blue under a "protective" air bubble can provide sufficient visualization to ensure the unfolding of DMEK tissue and reduce the risk of host stromal staining.

The Influence of Speed During Stripping in Descemet Membrane Endothelial Keratoplasty Tissue Preparation.

PURPOSE: To evaluate whether the speed of stripping a Descemet membrane endothelial keratoplasty graft influences the graft scroll width. METHODS: Human corneas suitable for research were selected for the study. Pairs of corneas were randomly divided into 2 groups: 1 cornea was stripped with a slow speed (group 1) and the contralateral with a fast speed (group 2). Slow speed was defined as the total time greater than 150 seconds or speed <0.057 mm/s. Fast peeling was defined as less than 75 seconds or speed >0.11 mm/s. The grafts acquired were evaluated by microscopy for the graft scroll width and endothelial cell density change pre- and post-preparation. RESULTS: Twenty corneas of 10 donors were included in the analysis. The mean donor age was 68.6 ± 7.58 years. The mean total time of the tissue preparation in group 1 was 282.7 ± 28 seconds and in group 2 was 126 ± 50 seconds (P-value = 0.00000047). The mean speed of stripping in group 1 was 0.045 ± 0.006 mm/s and in group 2 was 0.266 ± 0.093 mm/s (P-value = 0.000027). The graft width in group 1 was 6.4 ± 0.92 mm and in group 2 was 2.87 ± 0.32 mm (P-value = 0.00000014). The mean endothelial cell loss in group 1 was 389 ± 149 cells/mm and in group 2 was 186 ± 63.44 cells/mm (P-value = 0.00134). CONCLUSION: We found a correlation between the speed of stripping, scroll width, and endothelial cell loss. Slow-peeled Descemet membrane endothelial keratoplasty grafts result in a wider scroll width but were associated with a greater reduction in endothelial cell density.

Conjunctival Biopsy Site in Mucous Membrane Pemphigoid.

PURPOSE: To investigate if there is an association between the location of the conjunctival biopsy site (lesional, perilesional, or nonaffected) and the result of the direct immunofluorescence (DIF) test in patients with suspected mucous membrane pemphigoid (MMP) involving the ocular surface. DESIGN: Retrospective case series. METHODS: Records of patients with clinically suspected ocular MMP were reviewed to determine the location of the conjunctival biopsy. Conjunctival biopsy locations were defined as "lesional," "perilesional," and "nonaffected" conjunctiva. The DIF was considered positive when there was deposition of at least 1 of either IgM, IgG, IgA, or C3 at the basement membrane of the specimen; nondiagnostic when only fibrinogen was found at the same location; and negative when none of these features were present. RESULTS: The records of 41 patients were analyzed. Of these, 32 were eligible to be included in the study. Biopsies were lesional in 22% of cases (7/32), perilesional in 22% (7/32), and from nonaffected conjunctiva in 56% (18/32). DIF results were positive in 14% of lesional biopsies, in 86% of perilesional biopsies, and in 17% of those from nonaffected conjunctiva (P = .003). Perilesional biopsies gave higher positive DIF than lesional biopsies (P = .029). CONCLUSIONS: Perilesional conjunctival biopsies are associated with an increase in positive DIF results. These results support the need to sample perilesional conjunctival tissue in patients with suspected MMP.

Bilateral choroidal neovascular membrane in a young patient with Sorsby fundus dystrophy: the value of prompt treatment.

A 45-year-old man had developed a choroidal neovascular membrane (CNVM) in his left eye at the age of 38 years and had received six intravitreal ranibizumab injections with resulting visual acuities of 6/60 in the affected eye and 6/4 in the unaffected right eye (Snellen charts). Family history and genetic testing revealed tissue inhibitor of metalloproteinase-3 (TIMP3) gene positive Sorsby fundus dystrophy (SFD). The patient has been under regular follow-up since. At the age of 45 years, he presented with subretinal fluid accumulation in his right eye suggestive of CNVM and received six intravitreal ranibizumab injections, which maintained visual acuity of 6/7.5 in his right eye. Although SFD is a rare condition, it should be suspected and ruled out in young patients presenting with suspicious fundoscopic findings and subretinal fluid on optical coherence tomography. Early intervention can possibly delay macular fibrosis and loss of vision secondary to SFD associated with CNVM.

Tear of Retinal Pigment Epithelium following YAG Laser Posterior Capsulotomy in a Patient on Anti-VEGF Treatment for AMD: Six Months' Follow-Up.

PURPOSE: To present a rare case of retinal pigment epithelium (RPE) rupture following YAG laser posterior capsulotomy (YAG PC) in a patient with exudative age-related macular degeneration (AMD). MATERIALS AND METHODS: An 85-year-old pseudophakic male patient on ranibizumab 0.5 mg/0.05 ml treatment due to exudative AMD received YAG PC for dense posterior capsule opacification (PCO) in his right eye. The patient had received his last intravitreal ranibizumab injection 3 months before YAG PC; his macula appeared stable on fundoscopy and optical coherence tomography scans at repeated visits, but his vision deteriorated to counting fingers due to PCO. RESULTS: Following left eye posterior YAG PC, his best-corrected visual acuity (BCVA) improved to 6/12 (Snellen chart). Despite satisfactory visual results, the patient developed a parafoveal inferotemporal RPE rupture. A decision for further treatment with ranibizumab (0.5 mg/0.05 ml) intravitreal injections was made. After a total of 7 injections, the patient was clinically stable and his BCVA was 6/18 (Snellen chart). CONCLUSIONS: RPE rupture is a well-known, serious complication in patients with exudative AMD, which often has devastating results on patients' vision. Offering YAG PC to those patients could lead to a rupture of the RPE even in cases which appear to be stable and well controlled. Clinicians should be aware of this complication and inform the patients accordingly.

Visual outcomes and corneal changes after intrastromal femtosecond laser correction of presbyopia.

PURPOSE: To assess the effect of intrastromal femtosecond laser presbyopia treatment on uncorrected near visual acuity (UNVA) and corneal integrity over an 18-month period. SETTING: Department of Ophthalmology, International Vision Correction Research Centre, University of Heidelberg, Heidelberg, Germany. DESIGN: Clinical trial. METHODS: The UNVA (at 40 cm), corneal pachymetry, and true net power were evaluated preoperatively and 1, 3, 6, 12, and 18 months after femtosecond intrastromal presbyopic treatment (Intracor). Endothelial cell density (ECD) was measured preoperatively and 3, 6, and 12 months postoperatively. Data were analyzed with the Wilcoxon test at a P=.01 level of significance. RESULTS: The median UNVA improved significantly from 0.7 logMAR preoperatively to 0.4 logMAR, 0.2 logMAR, 0.2 logMAR, 0.3 logMAR, and 0.2 logMAR at 1, 3, 6, 12, and 18 months, respectively (all P<.001). The median corneal true net power increased significantly by 1.1 diopters (D) to 0.7 D, 0.8 D, 1.0 D, and 0.9 D, respectively (all P<.001); pachymetry showed no significant thinning postoperatively. There was no significant difference in ECD between preoperatively and postoperatively. CONCLUSIONS: Intrastromal femtosecond presbyopic treatment yielded a significant and stable gain of UNVA and corneal steepening without significant loss of endothelial cells or corneal thinning up to 18 months postoperatively. No significant regression of visual acuity or further corneal steepening occurred during the follow-up period. FINANCIAL DISCLOSURE: Dr. Auffarth and Dr. Holzer received lecture and consulting fees from Technolas Perfect Vision GmbH. No author has a financial or proprietary interest in any material or method mentioned.

Rapid detection of fungal keratitis with DNA-stabilizing FTA filter paper.

Purpose. Polymerase chain reaction (PCR) is increasingly important for the rapid detection of fungal keratitis. However, techniques of specimen collection and DNA extraction before PCR may interfere with test sensitivity. The purpose of this study was to investigate the use of DNA-stabilizing FTA filter paper (Indicating FTA filter paper; Whatman International, Ltd., Maidstone, UK) for specimen collection without DNA extraction in a single-step, nonnested PCR for fungal keratitis. Methods. Specimens were collected from ocular surfaces with FTA filter discs, which automatically lyse collected cells and stabilize nucleic acids. Filter discs were directly used in single-step PCR reactions to detect fungal DNA. Test sensitivity was evaluated with serial dilutions of Candida albicans, Fusarium oxysporum, and Aspergillus fumigatus cultures. Test specificity was analyzed by comparing 196 and 155 healthy individuals from Switzerland and Egypt, respectively, with 15 patients with a diagnosis of microbial keratitis. Results. PCR with filter discs detected 3 C. albicans, 25 F. oxysporum, and 125 A. fumigatus organisms. In healthy volunteers, fungal PCR was positive in 1.0% and 8.4% of eyes from Switzerland and Egypt, respectively. Fungal PCR remained negative in 10 cases of culture-proven bacterial keratitis, became positive in 4 cases of fungal keratitis, but missed 1 case of culture-proven A. fumigatus keratitis. Conclusions. FTA filter paper for specimen collection together with direct PCR is a promising method of detecting fungal keratitis. The analytical sensitivity is high without the need for a semi-nested or nested second PCR, the clinical specificity is 91.7% to 99.0%, and the method is rapid and inexpensive.

Comparison and reproducibility of corneal thickness and curvature readings obtained by the Galilei and the Orbscan II analysis systems.

PURPOSE: To compare central corneal thickness (CCT) and keratometry readings using the Galilei dual Scheimpflug analyzer, the Orbscan II anterior segment analysis system, and the Sonogage ultrasound (US) pachymeter. SETTING: Lucerne Eye Clinic, Cantonal Hospital, Lucerne, Switzerland. METHODS: In a prospective single-center study, 85 eyes of 45 healthy volunteers were examined with the Orbscan II and Galilei systems in random order followed by Sonogage US pachymetry. The CCT and keratometry measurements were compared using a paired t test. To assess the intraobserver and interobserver reproducibility of the 2 keratometers, 9 volunteers were examined 3 times by 4 independent observers and the intraclass correlation coefficient (ICC) was calculated. RESULTS: The mean CCT was 551.7 microm+/-36.6 (SD) with the Galilei, 554.8+/-45.1 microm with the Orbscan II, and 558.5+/-38.4 microm with the Sonogage. The CCT readings of the Galilei and Orbscan II did not differ significantly (P= .12). The mean keratometry readings with the Galilei and Orbscan II were similar, although both the steep (Ks) and flat (Kf) axes tended to be flatter with the Galilei system. The ICCs for CCT, Kf, and Ks were high with both keratometers (0.98, 0.97, 0.84 for Galilei and 0.97, 0.96, 0.95 for Orbscan II, respectively), indicating that variation in measurements was mainly due to true subject-to-subject variation rather than observer error. CONCLUSION: Keratometry and pachymetry readings with the Galilei and Orbscan II systems showed good concordance and high reproducibility, which would allow the examinations to be delegated to nonmedical personnel.