Central Toxic Keratopathy After Collagen Cross-Linking: A Case Series.

PURPOSE: The aim of this study was to report a case series of central toxic keratopathy (CTK) after collagen cross-linking (CXL) in keratoconus. METHODS: This is a retrospective case series between January 2020 and September 2021. In this period, CXL was performed for progressive keratoconus in 964 eyes. CXL was performed using the epithelium-off accelerated protocol in all patients with a riboflavin soak time of 20 minutes and a UVA light exposure of 9 mW for 10 minutes using the Avedro KXL (Glaukos Inc, Aliso Viejo, CA) cross-linking system. RESULTS: Twelve of 964 eyes (1.2%) developed CTK within 1 week of CXL. All patients presented with well-circumscribed, central disciform haze that was broader in the anterior stroma and narrower in the posterior stroma. We noted initial flattening in keratometry up to 3 months post-CXL in these patients, which gradually steepened over 12 months, but did not reach preoperative levels. We also noted exuberant flattening in pachymetry in the first 3 months, which improved over 12 months. There was a statistically significant decrease in pachymetry in patients who developed CTK at 3 and 12 months postoperatively when compared to patients who underwent CXL but did not develop CTK. CONCLUSIONS: Several reports of CTK postrefractive surgery have been described previously. However, the association of CXL in the development of CTK has not been described previously. Here, we elucidated the clinical features of CTK after CXL and how it differs from corneal scarring or haze that occurs post-CXL.

Iatrogenic Descemet membrane detachment in the donor lenticule during Descemet stripping automated endothelial keratoplasty.

A female patient in her 60s presented with an 8-month history of decreased vision in her right eye. She was diagnosed with pseudophakic bullous keratopathy (PBK), and Descemet stripping automated endothelial keratoplasty (DSAEK) surgery was planned. Intraoperative Descemet membrane detachment (DMD) occurred while inserting the lenticule using the Sheets glide technique. The detachment of the Descemet membrane was detected immediately, and air descemetopexy was performed intraoperatively. Postoperatively, the donor lenticule was attached properly to the stromal bed, except for a focal DMD approximately 3 mm in the inferior part of the lenticule. A second descemetopexy was performed 5 days later, resulting in a complete attachment. A DMD in DSAEK lenticule is an extremely rare complication. Early detection and timely intervention with descemetopexy helped achieve a good anatomical and functional outcome.

The Evolution of Diagnostics for Keratoconus: From Ophthalmometry to Biomechanics.

PURPOSE: To enumerate the various diagnostic modalities used for keratoconus and their evolution over the past century. METHODS: A comprehensive literature search including articles on diagnosis on keratoconus were searched on PUBMED and summarized in this review. RESULTS: Initially diagnosed in later stages of the disease process through clinical signs and retinoscopy, the initial introduction of corneal topography devices like Placido disc, photokeratoscopy, keratometry and computer-assisted videokeratography helped in the earlier detection of keratoconus. The evolution of corneal tomography, initially with slit scanning devices and later with Scheimpflug imaging, has vastly improved the accuracy and detection of clinical and sub-clinical disease. Analyzing the alteration in corneal biomechanics further contributed to the earlier detection of keratoconus even before the tomographic changes became evident. Anterior segment optical coherence tomography has proven to be a helpful adjuvant in diagnosing keratoconus, especially with epithelial thickness mapping. Confocal microscopy has helped us understand the alterations at a cellular level in keratoconic corneas. CONCLUSION: Thus, the collective contribution of the various investigative modalities have greatly enhanced earlier and accurate detection of keratoconus, thus reducing the disease morbidity.

Compression Sutures to Treat Acute Hydrops in a Case of Bilateral Post-Laser In Situ Keratomileusis Ectasia.

ABSTRACT: This a case report of acute hydrops with interface fluid syndrome in a patient with post-laser in situ keratomileusis (LASIK) ectasia treated with compression sutures. A patient with post-LASIK ectasia presented with acute hydrops and fluid accumulation in the LASIK flap-stromal interface sequentially in both eyes. Full thickness compression sutures were applied to appose the edges of the Descemet tear, and this resulted in a rapid resolution of stromal edema and interface fluid. The patient had best distance visual acuities of 20/40 and 20/60 at the last follow-up in the right and left eyes, respectively. Hydrops along with fluid in the interface needed early intervention to prevent complications such as epithelial ingrowth and interface haze. Compression sutures were useful in this case to help bridge the gap between the margins of Descemet tear, hastening the resolution of stromal edema and interface fluid.