Microsporidial keratoconjunctivitis - first outbreak in Japan.

BACKGROUND: Most cases of microsporidial keratoconjunctivitis are found in the Southern hemisphere. Our purpose was to investigate the first outbreak of microsporidial keratoconjunctivitis in Japan among healthy, immunocompetent soccer players from the same team during a 1-month period. CASE PRESENTATION: This study is an observational case series. The medical records were analyzed for five cases with microsporidial keratoconjunctivitis who presented within September 2022. All five cases were males between 28 and 36 years old. These previously healthy individuals belonged to the same football team. Their eyes were considered susceptible to contaminated water or dirt from the turf at game and practice sites. All cases involved unilateral conjunctivitis, with scattered round white lesions that showed positive fluorescein staining in the corneal epithelium. All cases experienced diminution of vision in the affected eye. In three cases, direct smears showed spores of approximately 2-3 µm in diameter. Polymerase chain reaction (PCR) analysis of corneal scrapes revealed partial amplification of microsporidial 18 S ribosomal RNA gene in four cases. Sequences of PCR products from all four cases showed 100% identity with strains of Vittaforma corneae previously reported from an outbreak in Singapore. All cases were treated with topical therapy, including voriconazole, fluorometholone, and levofloxacin. Four eyes underwent corneal scraping. After treatment, all eyes healed without residual opacities. CONCLUSIONS: Only a few sporadic case reports of this disease have previously been reported in Japan. We detected V. corneae in our case series, representing what appears to be the first outbreak of microsporidial keratoconjunctivitis in Japan. Exposure to contaminated water or soil, in addition to inadequate sanitary facilities, represents a potential source of infection. Further investigations to clarify the characteristics of microsporidia seem warranted.

Evaluation of the anterior chamber angle by anterior segment optical coherence tomography after implantable phakic contact lens implantation in myopic eyes.

PURPOSE: To evaluate the changes in the angle of the AC and lens vault after IPCL implantation by AS-OCT in myopic patients. METHODS: This was a prospective observational study involving 30 myopic eyes implanted with IPCL. AS-OCT was used to evaluate lens vault and AC angle parameters including anterior chamber angle, angle opening distance and trabecular-iris space area (TISA) at 1, 3 and 6 months postoperatively. RESULTS: All 3 AC angle parameters were significantly reduced at the 1st postoperative month compared to preoperative values, but remained stable thereafter with no significant change at the 3rd or 6th postoperative months. The lens vault showed no significant change over the entire follow-up period. CONCLUSION: IPCL implantation is a safe method for correction of myopia with stable AC angle narrowing over the course of 6 months postoperatively as monitored using AS-OCT.

In vivo microscopic and optical coherence tomography classification of neurotrophic keratopathy.

Neurotrophic keratopathy (NK) is a rare degenerative corneal disorder characterized by instability of epithelial integrity with consequent epithelial defects that can worsen up to persistent epithelial defects with stromal melting and ulceration. The pathogenesis of NK springs from a variable degree of damage to the trigeminal nerve plexus, leading to a reduction or total loss of corneal sensitivity. Mackie classification (1995) distinguishes three stages of NK, based on the severity of clinical presentation. The technological innovations in corneal diagnostic imaging allow clinicians to accurately study the morphometry and morphology of corneal structure with microscopic resolution. In this study, 45 patients affected by NK at different stages underwent in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) with particular attention to analyze subbasal nerve plexus fibers and the stromal structure. At the light of IVCM and AS-OCT observations, we propose a different staging of NK with respect to the Mackie's classification that takes into account the severity of subbasal nerve fibers damage and the extension in depth of stromal ulceration; this classification better defines, at the time of diagnosis, the cellular and structural alterations in the affected corneas, with possible prognostic and therapeutic values in the management of NK.

Epithelial map-guided anterior stromal micropuncture for the treatment of recurrent corneal erosion syndrome.

PURPOSE: To introduce the use of corneal epithelial mapping by anterior segment optical coherence tomography (AS-OCT) as an ancillary testing for the identification of areas of loose epithelial adherence in recurrent corneal erosion syndrome (RCES), and the subsequent treatment of the latter with anterior stromal puncture (ASP). METHODS: Five patients were presented with RCES following traumatic corneal abrasions. Following resolution of acute episodes, AS-OCT epithelial mapping was performed revealing in all patients an area of increased epithelial thickness (hot spot) corresponding to the site of loose attachment of the epithelium to the epithelial basement membrane. ASP to the area of epithelial thickening, as delineated by the epithelial map, was performed. RESULTS: To date, none of the patients has shown any signs of disease recurrence over a period ranging from 6 to 20 months following the application of epithelial map-guided ASP. CONCLUSIONS: AS-OCT epithelial mapping can reveal the exact area of loose epithelial adherence in RCES. Hence, epithelial mapping can delineate the target area for treatment with ASP and may decrease the high failure rates of ASP.

Study on the classification of Descemet membrane detachment after cataract surgery with AS-OCT.

In this article, the significance of anterior segment optical coherence tomography (AS-OCT) to aid the clinical diagnosis and treatment of Descemet membrane (DM) detachment after phacoemulsification combined with intraocular lens implantation was retrospectively analyzed using 26 patients (26 eyes). The location and scope of DM detachment, its causative factors and the percentage of each detachment type are considered for clinical treatments. Based on the location and scope, the detachment can be divided into three types: (1) simple, (2) symmetrical and (3) complete DM detachment. Simple detachment, confined to the area of surgical incision (detachment range <1/4 corneal area), occurred in 69.20 % of cases (18/26), in which the DM detachment in the anterior lip accounted for 42.30% (11/26) and in the posterior lip accounted for 26.90% (7/26). Symmetrical DM detachment, referring to detachment (1/4 cornea area < detached area <1/2 corneal area) that appeared symmetrically on the surgical incision and the opposite site, accounted for 19.20% (5/26). Complete DM detachment (>1/2 of the corneal area), accounted for 11.50% (3/26). Interestingly, our findings suggest that the DM detachment after phacoemulsification is closely related to the location (simple and symmetrical DM detachment) and the skillfulness (complete DM detachment) of the surgical incision. Therefore, appropriate classification of DM detachment by AS-OCT and wise selection of surgical location can better guide cataract surgery in the future.

An unusual case of feline acute corneal hydrops: atypical disease presentation and possible in vivo detection of Descemet's membrane detachment in the cat's unaffected eye.

A 1-year-old, female spayed, domestic shorthair cat presented for blepharospasm of the right eye. Slit-lamp biomicroscopic examination showed focal corneal ulceration and presumptive keratomalacia of the right eye. Examination of the left eye was normal apart from a focal endothelial opacity. Within the first 24 h of medical management, the right eye developed marked corneal edema and globular anterior protrusion of the corneal surface consistent with feline acute corneal hydrops (FACH). Surgical management consisted of a bridge conjunctival graft, nictitating membrane flap, and temporary tarsorrhaphy. Resolution of corneal edema and pain occurred in the right eye within 24 days. Spectral domain optical coherence tomography (SD-OCT) of the anterior segment was performed in both eyes. Conjunctival tissue from the bridge graft precluded examination of deeper corneal structures in the right eye. The left eye displayed a focal separation of the corneal endothelium and Descemet's membrane from the overlying stroma. These SD-OCT findings are similar to the analogous syndrome found in humans and represent a potential etiology for FACH of the right eye in the case presented here. Unfortunately, the cat was lost to follow-up and the progression of this lesion to FACH in the left eye could not be determined.

Idiopathic pigmented vitreous cyst without autofluorescence: a case report.

BACKGROUND: Vitreous cysts are rare clinical findings and seldom cause visual disturbance. They are generally classified as congenital or acquired and are considered idiopathic when the etiology can not be determined. A previous electron microscopic observation on an idiopathic pigmented vitreous cyst has confirmed its pigment epithelial origin. However, the specific kind of pigment epithelium involved remains unclear. CASE PRESENTATION: A 39-year-old female presented with a round-shaped floater causing frequent visual disturbance in the left eye. A pigmented, non lobulated and freely mobile vitreous cyst was observed in the anterior vitreous by slit lamp examination and anterior segment optical coherence tomography. The pigment clumps on the cyst wall showed no autofluorescence. No persistent hyaloid artery or connection between the cyst and ocular structures was found by fundus fluorescein angiography and B-scan ultrasound. Serum tests for cysticercoids, sparganosis and toxoplasma were negative. A diagnosis of idiopathic vitreous cyst was made and no intervention was given. The cyst sank to the inferior part of the vitreous and the patient felt less visual disturbance during one-year follow-up. CONCLUSIONS: We described the features of a pigmented vitreous cyst revealed by autofluorescence and anterior segment optical coherence tomography for the first time. The intact retina, the absence of lipofuscin of the cyst and its location in the anterior vitreous led to the hypothesis that the cyst may originate from the ciliary pigment epithelium rather than the retinal pigment epithelium.

Anterior Segment Changes in Patients With Glaucoma Following Cataract Surgery.

This prospective observational study investigates the impact of cataract surgery on anterior segment parameters in nonglaucomatous and primary open-angle glaucoma (POAG) eyes, utilizing anterior segment optical coherence tomography (AS-OCT). The study involved 42 Caucasian patients, divided into a control group and a POAG group. Comprehensive ophthalmic examinations were performed along with AS-OCT imaging and biometry preoperatively, as well as on one day, one week, and one month following cataract surgery. The results showed significant post-operative changes in anterior chamber depth (ACD) and angle width in both groups, suggesting that cataract surgery may influence the structural parameters associated with glaucoma risk and management. Specifically, a marked increase in ACD and improvement in angle-opening distances were observed, highlighting the potential of cataract extraction to alter intraocular fluid dynamics favorably. Despite these changes, the study noted an initial spike in increased intraocular pressure (IOP) in POAG patients immediately post-operative, which stabilized during follow-up. For the control group, IOP showed gradually reducing IOP values in the follow-up visits. The findings underscore the role of advanced imaging technologies in understanding glaucoma's pathophysiology and the potential benefits of cataract surgery in glaucoma patients. The study advocates for further research with a larger, more diverse patient population and extended follow-up to explore the long-term implications of cataract surgery on glaucoma dynamics, emphasizing the importance of personalized management and treatment strategies particularly for glaucoma patients.

Femtosecond laser assisted superficial lamellar keratectomy as a successful treatment of corneal opacity in a patient with Thiel Behnke corneal dystrophy.

INTRODUCTION AND IMPORTANCE: Thiel Behnke corneal dystrophy (TBCD) and Reis Buckler corneal dystrophy (RBCD) are Bowman's layer dystrophies with overlapping clinical features causing diagnostic confusion. However, each entity has typical histopathological features. We describe in this case the successful use of Femtosecond laser (FSL) in the treatment of TBCD-related corneal opacity. CASE PRESENTATION: We present a 54-year-old male with bilateral superficial corneal opacities consistent with TBCD based on clinical appearance, anterior segment optical coherence tomography (AS-OCT), and In vivo confocal microscopy. Management options were discussed with the patient before proceeding with Femtosecond Laser Assisted Superficial Lamellar Keratectomy (FSLASLK). The histopathological findings of the excised left anterior lamellar corneal flap were typical of TBCD and the patient had a satisfactory outcome. CLINICAL DISCUSSION: TBCD typically affects Bowman's layer centrally with progressive opacities involving the deeper layer of the corneal stroma and the periphery with advancing age. Histopathology typically shows subepithelial fibrosis with interrupted basement membrane and totally replaced Bowman's layer by uneven fibrous tissue forming the characteristic saw tooth pattern. The treatment of such cases is challenging with variable success and recurrence rates. Our case was managed successfully using FSL. CONCLUSION: TBCD, even though a rare type of dystrophy, should be suspected based on the appearance of the corneal opacities clinically. It can be diagnosed by typical AS-OCT findings supported by histopathological confirmation and can be successfully treated by FSASLK.

A Review of the Diagnosis and Treatment of Limbal Stem Cell Deficiency.

Limbal stem cell deficiency (LSCD) can cause significant corneal vascularization and scarring and often results in serious visual morbidity. An early and accurate diagnosis can help prevent the same with a timely and appropriate intervention. This review aims to provide an understanding of the different diagnostic tools and presents an algorithmic approach to the management based on a comprehensive clinical examination. Although the diagnosis of LSCD usually relies on the clinical findings, they can be subjective and non-specific. In such cases, using an investigative modality offers an objective method of confirming the diagnosis. Several diagnostic tools have been described in literature, each having its own advantages and limitations. Impression cytology and in vivo confocal microscopy (IVCM) aid in the diagnosis of LSCD by detecting the presence of goblet cells. With immunohistochemistry, impression cytology can help in confirming the corneal or conjunctival source of epithelium. Both IVCM and anterior segment optical coherence tomography can help supplement the diagnosis of LSCD by characterizing the corneal and limbal epithelial changes. Once the diagnosis is established, one of various surgical techniques can be adopted for the treatment of LSCD. These surgeries aim to provide a new source of corneal epithelial stem cells and help in restoring the stability of the ocular surface. The choice of procedure depends on several factors including the involvement of the ocular adnexa, presence of systemic co-morbidities, status of the fellow eye and the comfort level of the surgeon. In LSCD with wet ocular surfaces, autologous and allogeneic limbal stem cell transplantation is preferred in unilateral and bilateral cases, respectively. Another approach in bilateral LSCD with wet ocular surfaces is the use of an autologous stem cell source of a different epithelial lineage, like oral or nasal mucosa. In eyes with bilateral LSCD with significant adnexal issues, a keratoprosthesis is the only viable option. This review provides an overview on the diagnosis and treatment of LSCD, which will help the clinician choose the best option amongst all the therapeutic modalities currently available and gives a clinical perspective on customizing the treatment for each individual case.

Recombinant Human Nerve Growth Factor (Cenegermin)-Driven Corneal Wound Healing Process: An Evidence-Based Analysis.

Purpose: To evaluate anterior segment optical coherence tomography (AS-OCT) to detect the wound healing process as per monitoring the effectiveness of cenegermin to treat moderate to severe neurotrophic keratoplasty. Methods: A retrospective chart review was realized to identify patients treated with cenegermin at the Clinica Oculistica, University of Genoa, Italy. All patients underwent careful examinations at baseline and follow-up visits. AS-OCT scans centered on the minimum corneal thickness (CT) area were always performed. We compared findings of AS-OCT with the findings from the slit-lamp examination. A linear regression analysis was used to evaluate factors associated with corneal healing. A further analysis, including a control group treated with 50% autologous serum (AS), was done to investigate and compare the efficacy of cenegermin. Results: Data from 16 eyes were studied. The average patients' age was 60.9 ± 21.1 years; five (31.2%) eyes experienced persistent epithelial defect and 11 (68.8%) eyes had neurotrophic corneal ulcer. The average reepithelialization time was 3.9 ± 0.5 weeks in the cenegermin group versus 5.9 ± 1.9 weeks in the AS group (p < 0.01). The AS-OCT scans revealed an average CT at the thinnest point of 276.3 ± 74.1 µm before treatment with an average increase of 176.5 ± 60.3 µm at the end of the cenegermin treatment (B = -0.15; p = 0.035). The AS-OCT percentage increase in corneal thickness between the two groups was statistically significant (p < 0.02). Conclusion: Understanding the cascade of events involved in the nerve growth factor-driven corneal wound healing process is clinically meaningful for the clinician. AS-OCT is an effective tool for systematic anterior segment imaging, allowing the detailed detection of the front-to-back layered corneal structure for quantitative analysis and monitoring of the healing process.

Deep Learning for Anterior Segment Optical Coherence Tomography to Predict the Presence of Plateau Iris.

Purpose: The purpose of this study was to evaluate the diagnostic performance of deep learning (DL) anterior segment optical coherence tomography (AS-OCT) as a plateau iris prediction model. Design: We used a cross-sectional study of the development and validation of the DL system. Methods: We conducted a collaboration between a referral eye center and an informative technology department. The study enrolled 179 eyes from 142 patients with primary angle closure disease (PACD). All patients had remaining appositional angle after iridotomy. Each eye was scanned in four quadrants for both AS-OCT and ultrasound biomicroscopy (UBM). A DL algorithm for plateau iris prediction of AS-OCT was developed from training datasets and was validated in test sets. Sensitivity, specificity, and area under the receiver operating characteristics curve (AUC-ROC) of the DL for predicting plateau iris were evaluated, using UBM as a reference standard. Results: Total paired images of AS-OCT and UBM were from 716 quadrants. Plateau iris was observed with UBM in 276 (38.5%) quadrants. Trainings dataset with data augmentation were used to develop an algorithm from 2500 images, and the test set was validated from 160 images. AUC-ROC was 0.95 (95% confidence interval [CI] = 0.91 to 0.99), sensitivity was 87.9%, and specificity was 97.6%. Conclusions: DL revealed a high performance in predicting plateau iris on the noncontact AS-OCT images. Translational Relevance: This work could potentially assist clinicians in more practically detecting this nonpupillary block mechanism of PACD.

Comparison of the Meibomian Gland Openings by Optical Coherence Tomography in Obstructive Meibomian Gland Dysfunction and Normal Patients.

PURPOSE: The aim of this study was to use swept-source anterior segment optical coherence tomography (OCT) to explore imaging the meibomian gland openings and to identify their in vivo characteristics in patients with obstructive meibomian gland dysfunction (MGD) and healthy participants. METHODS: We enrolled 49 patients with MGD and 54 health controls in this case-control study. Each participant underwent slit-lamp examination, meibography, and OCT scanning. Sixteen patients with MGD underwent a repeat OCT examination after eyelid massage. The outcome measures included determinations of meibomian gland openings (orifices and terminal ducts) from OCT images and comparisons of the meibomian openings between patients with MGD and normal controls before and after meibomian gland massage. RESULTS: Using the same OCT scanning model, the number of visible orifices of the meibomian glands was similar between eyes with MGD and normal eyes (9.2 ± 2.3 vs. 9.7 ± 2.4). The mean diameter of the terminal ducts in patients with MGD was larger (120.22 ± 27.92 µm vs. 100.96 ± 20.30 µm) than in the normal controls, and had a larger coefficient of variation. Significant differences were observed in the mean diameter of the terminal ducts of patients with MGD before and after meibum gland massage (133.73 ± 27.81 µm vs. 102.26 ± 24.30 µm, p < 0.001). CONCLUSIONS: Patients with MGD have more diversified orifices and larger meibomian gland terminal duct diameters than normal subjects. In addition, meibomian gland terminal duct diameters seem to decrease in patients with MGD after meibum gland massage.

Comparison of radius of anterior lens surface curvature measurements in vivo using the anterior segment optical coherence tomography and Scheimpflug imaging.

BACKGROUND: To assess the radius of anterior lens surface curvature (RAL) measurements with anterior segment optical coherence tomography (AS-OCT) in comparison with Scheimpflug imaging. METHODS: This prospective, cross-sectional study was carried out at Zhongshan Ophthalmic Center, Guangzhou, China. We enrolled 59 eyes, including 30 eyes from 30 cataractous volunteers (59 to 87 years) and 29 eyes from 29 young participants (19 to 49 years). After mydriasis, the RAL was measured automatically by the built-in software in the AS-OCT (CASIA 2). The Scheimpflug images were measured with the build-in caliper tool of the Scheimpflug camera (Pentacam), and RAL were further calculated with the principle of best-fitted circle. Intraobserver and interobserver reproducibility of RAL measurement using Scheimpflug camera were evaluated with limit of agreement (LoA) and intraclass correlation coefficient (ICC). Consistency between RAL measurement of Scheimpflug camera and AS-OCT were assessed with LoA, correlation analysis and linear regression. RESULTS: For all subjects, intraobserver (LoA: -0.25 to 0.23 mm, ICC: 0.996) and interobserver reproducibility (LoA: -0.85 to 0.92 mm, ICC: 0.947) of RAL were good using Scheimpflug imaging. Both AS-OCT and Scheimpflug imaging found that the age-related cataract participants had smaller RAL (P=0.010, P=0.001 respectively). LoA of RAL measurement between AS-OCT and Scheimpflug imaging was -3.83 to -0.79 mm, and the Pearson correlation efficient was 0.909 (P<0.001). The RAL values measured by AS-OCT were significantly greater than that by Scheimpflug camera with a mean difference of 2.31 mm for all participants (P<0.001). The RAL measurement could be converted using the equation: YCASIA 2 =1.155 × XPentacam + 1.060. CONCLUSIONS: Both Scheimpflug camera system with internal caliper tool and the AS-OCT are fast and non-contact tools that could measure RAL successfully. The two measurement results are highly correlated and interchangeable through linear regression equation.