Changes in Corneal Sensation, Epithelial Damage, and Tear Function After Descemet Stripping Automated Endothelial Keratoplasty

Changes in ocular surface and Meibomian gland after penetrating Keratoplasty

Background

To acquire desirable outcomes of penetrating keratoplasty (PKP), various factors affecting graft survival, visual function, and subjective symptom should be considered. As ocular surface and meibomian gland function are associated with these factors, this study aims to investigate changes of ocular surface and meibomian gland parameters after PKP.

Methods

This retrospective case series study included 24 eyes of 24 patients who underwent penetrating keratoplasty. Examinations on lipid layer thickness (LLT), meiboscore, tear meniscus area (TMA), tear breakup time (TBUT), corneal fluorescein staining (CFS), Schirmer I test (SIT), Ocular Surface Disease Index (OSDI), and meibomian gland functions were performed before and at 1 week, 1 month, 6 months, and 12 months after surgery.

Results

Compared to baseline (2.9 ± 0.6 s), TBUTs were longer at 1 week (4.4 ± 0.5 s, P = 0.027) and 6 months (4.4 ± 0.5, P = 0.048) after surgery. CFS values improved from baseline (6.5 ± 1.1) to 6 months (3.5 ± 0.6, P = 0.023) and 12 months (3.3 ± 0.7, P = 0.001) after surgery. Meibum quality value worsened at 1 week and 12 months after surgery and meibomian gland expressibility value worsened at 1 week and 6 months after surgery compared to baseline. OSDI scores improved at 6 and 12 months after surgery. Meiboscore showed no change throughout the follow up period. The patients with high preoperative meiboscore had worse meibomian gland expressibility at 6 and 12 months and meibum quality at 6 months postoperatively compared to their baseline and to those of patients with low preoperative meiboscore.

Conclusions

After penetrating keratoplasty, ocular surface parameters including corneal staining, TBUT, and OSDI significantly improved whereas meibomian gland parameters showed deteriorations, which was marked in patients with high preoperative meiboscore. Thus, perioperative management of MGD is recommended for patients who undergo penetrating keratoplasty, especially in patients with advanced MGD.

Nerve Growth Factor Changes and Corneal Nerve Repair after Keratoplasty

SIGNIFICANCE

Measured tear concentration of nerve growth factor is correlated with postoperative corneal reinnervation among patients who undergo keratoplasty. This may be a future therapeutic target for post-keratoplasty corneal nerve regeneration.

PURPOSE

To determine the relationship between changes in the content of nerve growth factor (NGF) in tear fluid and corneal subepithelial nerve regeneration in patients after keratoplasty.

METHODS

In this retrospective study, 30 eyes of 28 patients (15 males, 13 females; mean age 42.8 [range 16–73] years) who underwent primary keratoplasty for the first time were recruited through the clinics of the Department of Ophthalmology, Jilin University affiliated First Hospital, between May and December 2015. All patients underwent a complete ophthalmic examination preoperatively. Tear fluid samples were collected to detect the content of NFG at different time points in the follow-up period (day 1 preoperatively and days 1, 7, 30, and 90 postoperatively) and analyzed correlations between NFG content and age, infective factors, and variables of the surgical procedure as well as with subepithelial nerve repair at 30 and 90 days postoperatively.

RESULTS

The NFG content in tear fluid on day 1 postoperatively was lower than that on the day preceding surgery; however, it was higher than the preoperative value on postoperative days 7, 30, and 90 (F = 5.046, P < 0.05). Further, the NFG content of tear fluid at 30 days postoperatively correlated with the surgical procedure (coefficient = −2.775, P = 0.010); however, no significant correlation was found on postoperative day 1 (coefficient = −1.315, P> 0.05). At all study time points, the NFG content of tear fluid had no correlation with infective factors or age (P> 0.05). Postoperatively, at day 30, small nerve buds were observed in the periphery of the corneal graft in 13 eyes (43.3% of cases) but not in 17 eyes (56.7% of cases), which showed a significant correlation with the NFG content of tear fluid (coefficient = −3.370, P = 0.010). By postoperative day 90, small nerve buds were observed in the periphery of the corneal graft in 24 eyes (80.0% of cases) and showed a significant correlation with the NFG content of tear fluid (coefficient = −2.750, P = 0.006).

CONCLUSIONS

The NFG content in tear fluid increases with the increasing ratio of small nerve buds indicating corneal nerve regeneration. NFG promotes subepithelial nerve regeneration in patients after keratoplasty.

A year of cornea in review: 2013

PURPOSE

The goal of this study was to provide an update of significant corneal literature published in 2013.

DESIGN

This study is a systematic literature review.

METHODS

We conducted a systematic review of the English-language literature published from January 1, 2013, to December 31, 2013, using the following PubMed search and Medical Subject Headings terms: cornea transplantation, keratoplasty, Descemet membrane endothelial keratoplasty, Descemet stripping endothelial keratoplasty, cross linking, pre-Descemet's layer, Rho-associated kinase, keratoprosthesis, infectious keratitis, corneal dystrophy, corneal astigmatism, and keratoconus.

RESULTS

This review summarizes relevant and innovative original articles, review articles, and novel techniques from the following journals: American Journal of Ophthalmology, British Journal of Ophthalmology, Cornea, Graefe's Archive for Clinical and Experimental Ophthalmology, Investigative Ophthalmology & Visual Science, JAMA Ophthalmology, Journal of Cataract and Refractive Surgery, Journal of Refractive Surgery, and Ophthalmology. Case reports, abstracts, letters to the Editor, and unpublished work were excluded, as well as articles e-published ahead of print in 2012 that were discussed in the previous review. One hundred twenty-seven articles met the criteria for this review.

CONCLUSIONS

This review summarizes significant cornea-related literature from 2013.