Tono-Pen XL tonometry during application of a suction ring in rabbits

<p>Abstract</p> <p>Background</p> <p>The purpose of this study is to evaluate the use of Tono-Pen XL in measuring IOP during the application of a suction ring in rabbit eyes with manometrically controlled IOP.</p> <p>Methods</p> <p>Tono-Pen XL was calibrated against direct manometry in 10 rabbit eyes. A suction ring was then applied in 4 rabbit eyes and the IOP was determined manometrically during suction ring application at 350 mmHg vacuum pressure. Finally, in 6 catheterized rabbit eyes the IOP was measured with Tono-Pen XL during suction ring application at suction vacuum from 350 to 650 mmHg, while keeping actual IOP stable at 30 mmHg and 60 mmHg.</p> <p>Results</p> <p>Linear regression analysis revealed that the Tono-pen XL was reliable for IOPs between 10 and 70 mmHg (R²= 0.9855). Direct manometry during suction ring application showed no statistically significant variation of Tono-Pen XL readings when the incanulation manometry intraocular pressure changed from 30 mmHg to 60 mmHg and no statistically significant correlation between suction vacuum and IOP measurements.</p> <p>Conclusion</p> <p>Tono-Pen XL measurements are unreliable during the application of a suction ring on living rabbit eyes even when the actual IOP is forced to be within the validated range of Tono-Pen XL measurements. This inaccuracy is probably related to altered corneal and scleral geometry and stress.</p

Coenzyme Q10 Reduces Ethanol-Induced Apoptosis in Corneal Fibroblasts

Dilute ethanol (EtOH) is a widely used agent to remove the corneal epithelium during the modern refractive surgery. The application of EtOH may cause the underlying corneal fibroblasts to undergo apoptosis. This study was designed to investigate the protective effect and potential mechanism of the respiratory chain coenzyme Q10 (CoQ10), an electron transporter of the mitochondrial respiratory chain and a ubiquitous free radical scavenger, against EtOH-induced apoptosis of corneal fibroblasts. Corneal fibroblasts were pretreated with CoQ10 (10 µM) for 2 h, followed by exposure to different concentrations of EtOH (0.4, 2, 4, and 20%) for 20 s. After indicated incubation period (2–12 h), MTT assay was used to examine cell viability. Treated cells were further assessed by flow cytometry to identify apoptosis. Reactive oxygen species (ROS) and the change in mitochondrial membrane potential were assessed using dichlorodihydrofluorescein diacetate/2′,7′-dichlorofluorescein (DCFH-DA/DCF) assays and flow-cytometric analysis of JC-1 staining, respectively. The activity and expression of caspases 2, 3, 8, and 9 were evaluated with a colorimetric assay and western blot analysis. We found that EtOH treatment significantly decreased the viability of corneal fibroblasts characterized by a higher percentage of apoptotic cells. CoQ10 could antagonize the apoptosis inducing effect of EtOH. The inhibition of cell apoptosis by CoQ10 was significant at 8 and 12 h after EtOH exposure. In EtOH-exposed corneal fibroblasts, CoQ10 pretreatment significantly reduced mitochondrial depolarization and ROS production at 30, 60, 90, and 120 min and inhibited the activation and expression of caspases 2 and 3 at 2 h after EtOH exposure. In summary, pretreatment with CoQ10 can inhibit mitochondrial depolarization, caspase activation, and cell apoptosis. These findings support the proposition that CoQ10 plays an antiapoptotic role in corneal fibroblasts after ethanol exposure

Descemet&rsquo;s scroll in syphilitic interstitial keratitis: a case report with anterior segment evaluation and a literature review

Ngamjit Kasetsuwan,1,2 Usanee Reinprayoon,1,2 Patchima Chantaren2 1Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, 2Ophthalmology Department, King Chulalongkorn Memorial Hospital, Bangkok, Thailand Purpose: To present a case of syphilitic interstitial keratitis with Descemet&rsquo;s scrolls, as well as its characteristic findings in an anterior segment investigation in relation to the histopathologic findings from a literature review. Case presentation: A case report of a 64-year-old woman with syphilitic infection presented with band keratopathy and retrocorneal scrolls. Slit-lamp photography, confocal microscopy, anterior segment optical coherence tomography (AS-OCT), and ultrasound biomicroscopy were performed. Four previous reports were reviewed to describe the pathogenesis, natural history, and histopathologic and immunohistologic findings of the Descemet&rsquo;s scroll. Results: The spectacle-corrected visual acuity was 20/50 and 20/30 in the right and left eyes, respectively. The scrolls appeared as a translucent web extending from Descemet&rsquo;s membrane into the anterior chamber. Confocal microscopy showed decreased endothelial cell density, pleomorphism, polymegathism, and hyperreflective fibrocellular rods with central hollow. The AS-OCT and ultrasound biomicroscopy showed rod-shaped retrocorneal scrolls. The corneal thickness was 494 microns, as measured by AS-OCT. The corneal lesion remained stable during the 6-year follow-up period without the need for keratoplasty, while the previous literature reported spontaneous and postoperative corneal decompensation. Conclusion: We present a case of syphilitic interstitial keratitis with rare Descemet&rsquo;s scrolls featuring relatively good visual acuity. Although we did not obtain the corneal tissue for examination, the anterior segment investigation provides insight into the underlying histopathology and natural disease history. The central hollow and cellular component seen during confocal microscopy might correspond to the amorphous core and the abnormal endothelial cells in the histopathologic findings. Failure to detect the corneal endothelium due to stromal opacity in these cases is possible, however, compromised endothelium may present. Keywords: confocal microscopy, Descemet&rsquo;s membrane, endothelium, retrocorneal membrane, retrocorneal scroll

Intraocular Implantable Collamer Lens with a Central Hole Implantation: Safety, Efficacy, and Patient Outcomes

Trakanta Wannapanich,1,&ast; Ngamjit Kasetsuwan,1– 3,&ast; Usanee Reinprayoon1– 3 1Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand; 2Chula Refractive Surgery Center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand; 3Excellence Center for Cornea and Limbal Stem Cell Transplantation, Department of Ophthalmology, King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand&ast;These authors contributed equally to this workCorrespondence: Ngamjit Kasetsuwan, Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok, 10330, Thailand, Tel +6622564142, Email [email protected]: This review summarizes the available literature and provides updates on the efficacy, safety, and patient outcomes of phakic intraocular lens implantation using implantable collamer lens (ICL), with a focus on newer models with a central port (EVO/EVO+ Visian Implantable Collamer Lens, STAAR Surgical Inc.). All studies included in this review were identified from the PubMed database and were reviewed for relevancy of their topic. Data on hole-ICL implantation performed between October 2018 and October 2022 in 3399 eyes showed a weighted average efficacy index of 1.03 and a weighted average safety index of 1.19 within an average follow-up of 24.7 months. The incidence of complications such as elevated intraocular pressure, cataract, and corneal endothelial cell loss was low. Moreover, both quality of vision and quality of life improved after ICL implantation, confirming the benefits of this procedure. In conclusion, ICL implantation is a promising refractive surgery alternative to laser vision correction with excellent efficacy, safety, and patient outcomes.Keywords: posterior chamber lens, phakic intraocular lens, Visian ICL, phakic refractive lens, refractive surger

Recurrent rates and risk factors associated with recurrent painful bullous keratopathy after primary phototherapeutic keratectomy

Ngamjit Kasetsuwan, Kanokorn Sakpisuttivanit, Usanee Reinprayoon, Vilavun Puangsricharern Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand Objective: To assess the recurrent rate, mean survival time, and risk factors associated with recurrent painful bullous keratopathy (BK) after primary treatment with phototherapeutic keratectomy.Methods: Medical records from 72 patients (72 eyes) who had phototherapeutic keratectomy for painful BK were evaluated. Data for sex, age, duration of BK, associated ocular and systemic diseases (hypertension, diabetes mellitus, ischemic heart disease, asthma, dyslipidemia, and rheumatoid arthritis), frequency and degree of pain (grade 1&ndash;3), visual acuity, corneal thickness, intraocular pressure, and laser setting were extracted and analyzed.Results: The mean age of the patients was 64.2&plusmn;11.4 years. The mean preoperative duration of BK was 15.0&plusmn;11.0 months. Most patients had pseudophakic BK (69.40%). Majority of the cases had grade 3 degree of pain (48.60%). Glaucoma and hypertension were markedly found among these patients (51.40% and 19.40%, respectively). Preoperative mean intraocular pressure and corneal thickness were 13.70&plusmn;4.95 mmHg and 734.1&plusmn;83.80 &micro;m, respectively. The mean laser diameter and depth were 8.36&plusmn;1.22 mm and 38.89&plusmn;8.81 &micro;m, respectively. Systemic disease was significantly associated with the risk for developing recurrent painful BK (P=0.022, hazard ratio [HR] 1.673, 95% confidence interval [CI] 1.08&ndash;2.58). The overall recurrent rate was 51%. The average duration time of recurrent painful BK was 17.3&plusmn;12.9 months (range 1&ndash;50 months). The median survival time before recurrence was 29.0&plusmn;6.6 months.Conclusion: Systemic disease was found to be the only risk factor significantly associated with the development of recurrent painful BK. Low recurrent rate and long mean survival time showed that phototherapeutic keratectomy was effective in relieving recurrent painful BK and can be used as an alternative procedure for patients waiting for corneal transplantation. Keywords: bullous keratopathy, recurrent painful, phototherapeutic keratectomy, PTK, risk factor, mean survival tim