Preoperative surgeon evaluation of corneal endothelial status: the Viability Control of Human Endothelial Cells before Keratoplasty (V-CHECK) study protocol

INTRODUCTION

The success of keratoplasty strongly depends on the health status of the transplanted endothelial cells. Donor corneal tissues are routinely screened for endothelial damage before shipment; however, surgical teams have currently no means of assessing the overall viability of corneal endothelium immediately prior to transplantation. The aim of this study is to validate a preoperative method of evaluating the endothelial health of donor corneal tissues, to assess the proportion of tissues deemed suitable for transplantation by the surgeons and to prospectively record the clinical outcomes of a cohort of patients undergoing keratoplasty in relation to preoperatively defined endothelial viability.

METHODS AND ANALYSIS

In this multicentre cohort study, consecutive patients undergoing keratoplasty (perforating keratoplasty, Descemet stripping automated endothelial keratoplasty (DSAEK), ultra-thin DSAEK (UT-DSAEK) or Descemet membrane endothelial keratoplasty) will be enrolled and followed-up for 1 year. Before transplantation, the endothelial viability of the donor corneal tissue will be evaluated preoperatively through trypan blue staining and custom image analysis to estimate the overall percentage of trypan blue-positive areas (TBPAs), a proxy of endothelial damage. Functional and structural outcomes at the end of the follow-up will be correlated with preoperatively assessed TBPA values.

ETHICS AND DISSEMINATION

The protocol will be reviewed by the ethical committees of participating centres, with the sponsor centre issuing the final definitive approval. The results will be disseminated on ClinicalTrials.gov, at national and international conferences, by partner patient groups and in open access, peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05847387.

Plug the pit: a surgical technique for optic disc pit

Purpose: To present a recently described surgical technique for the treatment of optic disc pit (ODP) and evaluate its outcomes.

Methods: A patient presented with refractory serous macular detachment and secondary full thickness macular hole associated with ODP, for which he had already undergone pars-plana vitrectomy with internal limiting membrane peeling and autologous serum application over the optic disc pit. A recently described surgical technique was carried out to treat this case. In this procedure, a silicone punctal plug was used to close the ODP. The macular hole was closed with a human amniotic membrane graft. Endotamponade was carried out with 1000cs silicone oil.

Results: Postoperatively, the serous macular detachment subsided and the punctal plug and amniotic membrane graft were in situ. Patient’s visual acuity improved from counting fingers to 6/38 at one year postoperative.

Conclusion: This technique appears to be safe and effective in resolving long standing serous macular detachment associated with ODP, which was refractory to the conventional intervention. However, more cases and longer follow-ups are needed to affirm the safety and efficacy of this recently described procedure.

Epithelial Flap Corneal Cross-linking

PURPOSE

To compare standard epithelium-off corneal cross-linking (standard Epi-Off CXL) to corneal cross-linking with an epithelial flap (Epi-Flap CXL).

METHODS

Patients who had undergone sequential bilateral CXL for progressive keratoconus were included in this comparative interventional case series. One eye was treated with the Epi-Off CXL technique and the fellow eye with the Epi-Flap CXL technique. Postoperative pain was measured using the Verbal Rating Scale and corneal densitometry using a Scheimpflug camera. Sex, age, corrected distance visual acuity, keratometry, and corneal thickness were also recorded.

RESULTS

Twenty-four eyes of 12 patients with keratoconus with a mean age of 27.15 ± 5.15 years were included. The Verbal Rating Scale scores were significantly lower in patients who had Epi-Flap CXL on the first (1.00 [interquartile range (IQR): 0.00 to 1.00] vs 3.00 [IQR: 3.00 to 3.75], P = .01) and third (0.00 [IQR: 0.00 to 1.00] vs 1.00 [IQR: 0.00 to 1.00], P = .01) postoperative day compared to the Epi-Off CXL group. No pain was observed in both groups after the third day. After 12 months, the Epi-Flap CXL group showed significantly less anterior corneal haze (measured as corneal densitometry) compared to the patients treated with Epi-Off CXL (P = .01). Both groups demonstrated stability of keratometry and corneal thickness at 12 months after CXL (P < .01).

CONCLUSIONS

Epi-Flap CXL is associated with less postoperative pain and anterior stromal haze in patients undergoing CXL for progressive keratoconus with no loss of efficacy. [J Refract Surg. 2021;37(11):741-745.].

A New Surgical Technique to Deliver Riboflavin Beneath Corneal Epithelium: The Corneal Cross-Linking Epi-Pocket

PURPOSE

To describe a new technique to deliver riboflavin into the corneal stroma during Corneal Cross-Linking (CXL) without the removal of corneal epithelium.

METHODS

Keratoconus patients underwent CXL for progressive keratoconus. Riboflavin was delivered by manually creating an epithelial pocket (CXL Epi-Pocket). Verbal rating scale was recorded postoperatively. Best-corrected visual acuity, keratometric indices, corneal thickness and corneal densitometry were recorded at baseline and at 12-month follow-up.

RESULTS

Eighteen eyes of 18 patients were included in the study. At a 12-month follow-up, best-corrected visual acuity, K1, K2 and densitometry values were stable. Maximum keratometry (Kmax) reduced from 55.31 ± 6.21 (SD) to 52.34d ± 4.12d (SD) (P value = 0.032). the thinnest point went from 441 ± 21.18 (SD) to 425.4 ± 19.02 (SD) um (P value = 0.041). The verbal rating scale at 1, 2 and 3 days postoperatively were 1.76 ± 0.19 (SD), 1.02 ± 0.51 (SD) and 0.28 ± 0.14 (SD).

CONCLUSIONS

CXL Epi-Pocket is able to deliver riboflavin to halt the progression of keratoconus at a 12-month follow-up.

Persistent loss of marginal corneal arcades after chemical injury

Changes in the limbal microvasculature following a chemical eye injury are essential for prognosis and management. At the slit lamp, it can be difficult to assess, here using fluorescein and indocyanine green angiography we show that anterior segment angiography may be informative to assess objectively the limbal microvascular changes over the follow-up period.

Influence of Corneal Visualization Scheimpflug Technology Tonometry on Intraocular Pressure

Purpose

To investigate the effect of Corneal Visualization Scheimpflug Technology tonometry (CST) on intraocular pressure (IOP).

Design

Cohort study.

Participants

Patients with and without primary open-angle glaucoma (POAG) were included.

Methods

Intraocular pressure was measured using the Icare rebound tonometer (ICRT; Icare Finland Oy) and the biomechanically corrected IOP (bIOP) using the CST. Intraocular pressure was measured at baseline with ICRT, followed by a CST measurement in one eye with the fellow eye acting as a control. Icare measurements were repeated at 10 seconds and 1, 2, 4, 8, 15, 30, and 60 minutes in both eyes. The ratio of test eye IOP to fellow eye IOP was used to control for intrasubject variation.

Main Outcome Measures

Intraocular pressure change following Corneal Visualization Scheimflug Technology tonometry.

Results

Forty participants (mean age, 54.09 ± 20.08 years) were included comprising 20 patients with POAG and 20 patients with no ocular abnormalities other than cataract. Mean central corneal thickness was similar in those without POAG (547.4 ± 55.05 μm) and with POAG (520.22 ± 37.59 μm; P = 0.14). No significant change was found in IOP measured with the ICRT in the fellow eye versus the 1-hour period in either the healthy (P = 0.87) or POAG (P = 0.92) group. Significant changes were found in IOP after CST measurement for both healthy (P < 0.01) and glaucomatous (P < 0.01) eyes. After the CST measurement, the IOP reduced continuously from a mean of 13.75 mmHg to 10.84 mmHg at 4 minutes for healthy eyes and from 13.28 mmHg to 11.11 mmHg at 8 minutes for glaucomatous eyes before approaching (83% for healthy eyes and 92% POAG eyes) the pre-CST measurement at 1 hour.

Conclusions

Corneal Visualization Scheimpflug Technology tonometry causes a significant reduction in IOP in both glaucomatous and healthy eyes that lasts for at least 1 hour afterward.

Globe salvage treatment in group D and group E retinoblastoma

Importance: Globe salvage marks the treatment success of retinoblastoma. Background: To evaluate four treatment strategies in group D and group E retinoblastoma. Design: Retrospective case series in a tertiary hospital. Participants: 81 patients with Group D and Group E retinoblastoma. Methods: Participants were divided into four sets. In set I, eyes received primary intravenous chemotherapy (IVC), cryotherapy (CT), laser therapy (LT) and Intravitreal Chemotherapy with Melphalan (IViC). In set II, primary IVC was combined with second line IVC, CT, LT and IVT-M. Set III eyes received primary IVC and Intra-arterial chemotherapy (IAC), CT, LT and IViC. Set IV eyes received IAC, CT, LT and IViC. Treatment failure was defined as inadequate response during or after IVC or IAC. Main Outcome Measures: globe salvage and enucleation rates. Results: 52 eyes were included in group D and 29 in group E. In group D, globe salvage was obtained in 8 out of 11 eyes in Set I, 13 out of 19 eyes in set II, 5 out 6 eyes in set III, and 13 out of 16 eyes in set IV. In group E, enucleation was performed in 17 eyes. Global salvage was obtained in 0 out of 2 eyes in set I, 2 out of 3 eyes in set II, 3 out of 5 in set III, and in 1 out of 2 eyes in set IV. Conclusions: IVC with adjuvant IAC, LT, CT and IViC has shown favorable results as a treatment method for group D and group E retinoblastoma.