Long-term comparison of full-bed deep lamellar keratoplasty with penetrating keratoplasty in treating corneal leucoma caused by herpes simplex keratitis

Outcomes of large-diameter deep anterior lamellar keratoplasty and converted two-piece mushroom penetrating keratoplasty for herpetic corneal scars

PURPOSE

To report the clinical outcomes of large diameter deep anterior lamellar keratoplasty (DALK) and converted two-piece microkeratome-assisted mushroom keratoplasty (MK) for herpetic corneal scars.

METHODS

In this single-centre study, large diameter (9 mm) DALK was attempted in consecutive patients with herpetic corneal scars. In case of macroperforation or unsatisfactory clearance of the optical zone, the procedure was intraoperatively converted to two-piece microkeratome-assisted MK. Outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism, endothelial cell density (ECD), immunologic rejection, herpetic recurrence and graft failure rates in the two groups.

RESULTS

DALK was successfully performed in 98 of 120 eyes, while the remaining 22 eyes required intraoperative conversion to MK. At 5 years, mean logMAR BSCVA was 0.10 ± 0.12 in the DALK group and 0.09 ± 0.15 in the MK group (P = 0.75). Refractive astigmatism at 5 years was 2.8 ± 1.4 D in the DALK group and 3.0 ± 1.7 D in the MK group (P = 0.67). ECD was higher in the DALK group than in the MK group at all time points (P < 0.001), with a mean annual cell loss of 10.9% after MK and 4.2% after DALK. The 5-year risk for immunologic rejection (DALK: 3%, MK: 5%, P = 0.38), herpetic recurrence (DALK: 6%, MK: 9%, P = 0.38), and graft failure (DALK: 4%, MK: 5%, P = 0.75) were comparable in both groups.

CONCLUSION

Large diameter (9 mm) DALK yields excellent visual and clinical outcomes in eyes with herpetic corneal scars. In case of intraoperative complications, DALK can be converted to two-piece microkeratome-assisted MK to maximize the refractive benefit of a large diameter graft while minimizing the risk of endothelial failure.

Management and prevention of corneal graft rejection

The management of an episode of corneal graft rejection (CGR) is primarily by corticosteroids. Immunomodulators are useful for long-term immunosuppression and in dealing with cases of high-risk (HR) corneal grafts. The classical signs of CGR following penetrating keratoplasty (PKP) include rejection line, anterior chamber (AC) reaction, and graft edema. However, these signs may be absent or subtle in cases of endothelial keratoplasty (EK). Prevention of an episode of graft rejection is of utmost importance as it can reduce the need for donor cornea significantly. In our previous article (IJO_2866_22), we had discussed about the immunopathogenesis of CGR. In this review article, we aim to discuss the various clinical aspects and management of CGR.

TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface

The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

Safety and Efficacy of Double Lamellar Keratoplasty for Corneal Perforation

INTRODUCTION

To assess the outcomes of double lamellar keratoplasty in the treatment of corneal perforation secondary to various keratopathies.

METHODS

In this prospective non-comparative interventional case series, 15 eyes from 15 consecutive patients with corneal perforation were chosen to undergo double lamellar keratoplasty, which is characterized by two layers of lamellar grafting in the perforated area. The posterior graft was separated from a relatively healthy and thin lamellar graft of the recipient, and the anterior graft was transplanted from the donor lamellar cornea. Preoperative characteristics and postoperative examination and relevant complications throughout the study were recorded.

RESULTS

Nine men and six women with an average age of 50.73 ± 19.89 (range, 9-84) years were enrolled. The median follow-up period was 18 (range, 12-30) months. In all postoperative patients, the integrity of the eyeball was successfully rebuilt, and the anterior chambers were formed without aqueous leakage. At the last visit, best-corrected visual acuity improved in 14/15 patients (93.3%). Slit-lamp microscopy showed that all treated eyes remained fully transparent. Anterior segment optical coherence tomography revealed that the double-layer structure of the treated cornea was clear in the early postoperative stage. In vivo confocal microscopy revealed intact epithelial cells, sub-basal nerves, and clear keratocytes in the transplanted cornea. No immune rejection or recurrence was detected during the follow-up period.

CONCLUSIONS

Double lamellar keratoplasty presents a new therapeutic option for patients undergoing corneal perforation, and it provides improvement in visual acuity and reduces the risk of postoperative adverse events.

Long-Term Outcomes of Big Bubble Deep Anterior Lamellar Keratoplasty in Mucopolysaccharidoses: A Retrospective Case Series and Review of the Literature

PURPOSE

The purpose of this study was to report the long-term surgical and visual outcomes of patients with mucopolysaccharidoses (MPS) after big bubble deep anterior lamellar keratoplasty (BB-DALK).

METHODS

This was a retrospective case series of patients with MPS who underwent BB-DALK at a single academic institution. All patients had corneal clouding secondary to MPS limiting visual acuity for which keratoplasty was indicated. Each patient was evaluated and underwent surgery by a single surgeon. Reported data included age at keratoplasty, sex, MPS type, best spectacle-corrected visual acuity, change in pachymetry, ocular comorbidities, surgical complications, and MPS-related medication use.

RESULTS

Outcomes of 12 eyes from 7 patients with MPS type I (Hurler, Scheie, and Hurler-Scheie) are reported using the newest nomenclature. The mean follow-up was 5.58 years (range: 1-10 years). All cases underwent BB-DALK with a type 1 big bubble during the surgery. Two cases (16.6%) required rebubbling because of partial Descemet membrane detachment. One case was complicated by a suture abscess and required a penetrating keratoplasty. No episodes of rejection occurred. Statistically significant improvement in the best spectacle-corrected visual acuity (from a mean 0.85-0.33 logarithm of the minimum angle of resolution, P = logarithm of the minimum angle of resolution 0.0054) and pachymetry (mean reduction of -145.4 μm, P = 0.0018) was observed.

CONCLUSIONS

BB-DALK seems to be an acceptable long-term surgical option in patients with MPS. Our findings suggest that this technique is reproducible and can achieve clear corneal grafts with good visual results on a long-term follow-up.

Evidence in the prevention of the recurrence of herpes simplex and herpes zoster keratitis after eye surgery

OBJECTIVE

Herpetic keratitis, either due to herpes simplex keratitis (HSK) or herpes zoster ophthalmicus (HZO), can recur after eye surgery.º Prophylaxis is postulated as necessary to avoid it. The objective of this study was to review the scientific evidence on the preventive methods used in the perioperative period in patients previously affected by HSK/HZO.

METHODS

An exhaustive search was carried out in the PubMed and Web of Science databases to identify relevant articles on prophylaxis and risk of recurrence of HSK/HZO in patients undergoing eye surgery up to 31 December 2019.

RESULTS

There is strong evidence that oral prophylaxis should be recommended after penetrating keratoplasty in patients who have previously had HSK/HZO. For other types of surgery, the evidence is less compelling. However, a latent period of inactivity should be considered between disease and oral prophylaxis.

CONCLUSIONS

Penetrating and lamellar keratoplasty, corneal crosslinking, cataract surgery, and photorefractive and phototherapeutic surgery cause an alteration of the subbasal nerve plexus of the cornea. Due to surgical trauma, as well as the modulation of the ocular immune response caused by steroids applied in the postoperative period, it is possible to induce the reactivation of HSK/HZO, which is common in some cases. Within this article, we discuss the available evidence for HSK/HZO prophylaxis in eye surgery. Further studies are necessary to define the real risk of HSK/HZO recurrence after ocular surgeries, particularly in cataract surgery, and to confirm the efficacy of perioperative prophylaxis with anti-HSK/HZO antivirals.

Corneal endothelial regeneration in human eyes using endothelium-free grafts

Background

To report on corneal endothelial regeneration, graft clarity, and vision recovery when using endothelium-free grafts.

Methods

We evaluated the donor’s cell viability using trypan blue staining and dual staining with calcein acetoxy methyl ester and ethidium homodimer-1. To preserve eyeball integrity, we performed therapeutic penetrating keratoplasty using cryopreserved donor tissue without endothelium on 195 consecutive patients who suffered from corneal perforation due to progressive primary corneal disease such as herpes simplex keratitis, fungal keratitis, ocular thermal burns, keratoconus, and phlyctenular keratoconjunctivitis. Of these, 18 eyes recovered corneal graft clarity and underwent periodic slit-lamp microscopy, A-scan pachymetry, and in vivo confocal microscopy to observe the clinical manifestations, variations in corneal thickness, and repopulation of the corneal endothelial cells on the donor grafts.

Results

No viable cells were detected in the cryopreserved corneas. After the therapeutic penetrating keratoplasty, notable corneal graft edema was observed in all 18 eyes for 1–4 months, and no corneal endothelial cells were detected on the grafts during this period. Thereafter, we observed gradual and progressive regression and final resolution of the stromal edema, with complete recovery of corneal graft clarity. Through periodic confocal microscopy, we observed the corneal endothelium’s regenerating process, along with single cells bearing multiple nuclei and cell division-like morphology. The regenerated endothelium on the grafts reached a mean cell density of 991 cells/mm². Remarkable vision rehabilitation was achieved in all 18 patients.

Conclusions

We obtained conclusive evidence that host-derived endothelial cells can regenerate a new endothelium over the endothelium-free graft, which possesses normal functions for corneal clarity and vision recovery.

Ultrastructural Alterations of Grafted Corneal Buttons: The Anatomic Basis for Stromal Peeling Along a Natural Plane of Separation

PURPOSE

To examine the ultrastructure of the natural plane of separation in grafted corneas and evaluate the outcomes of stromal peeling.

DESIGN

Interventional case series.

METHODS

In this multicenter study, stromal peeling was attempted in 96 consecutive eyes with unsatisfactory vision following penetrating keratoplasty (PK) for keratoconus (n = 79), herpetic keratitis (n = 11), and granular dystrophy (n = 6). Stromal exchange was performed by (1) 9 mm partial-thickness trephination; (2) creation of a corneal flap across the PK wound; (3) opening of the stromal component of the PK wound until a smooth, translucent natural plane was identified; (4) severing the attachment of the PK scar; (5) stromal peeling along the identified plane; and (6) suturing of donor lamella. Grafted corneas from cases that mandated conversion to PK were processed for transmission electron microscopy.

RESULTS

The natural plane of separation was identified in all cases. Stromal exchange was successfully completed in 84 cases (87.5%). Snellen visual acuity ≥20/40 and ≥20/25 was reached in 93% and 72% of cases at 3 years (n = 49) and 86% and 62% at 4 years (n = 21) postoperatively. Mean endothelial cell loss at 1 year was 6.6% ± 9.5%. Stromal peeling occurred along a plane lined with a continuous layer of keratocytes separating pre-Descemet membrane (DM) stroma, DM, and endothelium from the anterior stroma. Pre-DM stroma was made of poorly organized lamellae containing widely spaced, randomly arranged collagen fibrils.

CONCLUSIONS

Ultrastructural alterations in the stromal microarchitecture of grafted corneas provide evidence of a natural plane of separation identified intraoperatively. Stromal peeling can be successfully performed in post-PK eyes with various stromal pathology.

Corneal Graft Success Rates in HSV Keratitis: A Systematic Review

Herpes Simplex Virus (HSV) has worldwide prevalence. The primary objective of this systematic review was to compare penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) regarding the efficacy and complications of the treatment of corneal scarring caused by herpes simplex keratitis. Out of the 469 articles identified during the combined search of the literature based on the PubMed and Cochrane libraries, 10 retrospective and 2 prospective studies published from January 2010 to December 2019 were included. The study outcomes indicated that both surgical approaches resulted in a comparable improvement of visual acuity (VA). However, DALK demonstrated fewer complications in the majority of studies. Higher graft survival rates were associated with higher acyclovir (ACV) doses (above 800 mg/day), topical steroid and antibiotic drops. In conclusion, in terms of postoperative VA, both PK and DALK demonstrate comparable efficacy. However, DALK, which is applied in less severe HSK cases, is associated with fewer complications and better graft survival rates. High dosages of ACV, topical steroids and antibiotics contribute significantly to improved postoperative outcomes.

Ocular surgery after herpes simplex and herpes zoster keratitis

PURPOSE

The recurrence of herpetic stromal keratitis (HSK) and herpes zoster ophthalmicus (HZO) has been reported after a variety of ocular surgeries. The aim of this study was to review the evidence on the preventive methods employed in the perioperative period in patients having undergone HSK/HZO.

METHODS

The PubMed and Web of Science databases were the main resources used to conduct the medical literature search. An extensive search was performed to identify relevant articles concerning the prophylaxis against and risk of HSK/HZO recurrence in patients undergoing ocular surgery up to December 31, 2019.

RESULTS

The disturbance of the corneal nerve plexus occurs during several ocular surgeries including penetrating keratoplasty, lamellar keratoplasty, corneal cross-linking, cataract surgery, as well as photorefractive and phototherapeutic procedures. Such trauma, as well as modulation of the ocular immunological response caused by steroids applied postoperatively, might engender the HSK/HZO reactivation which is not uncommon. There is strong evidence that oral prophylaxis should be recommended just after surgery in patients undergoing penetrating keratoplasty and having suffered from HSK/HZO. For other types of surgeries, the evidence is less compelling; nevertheless, a period of disease quiescence and oral prophylaxis should still be considered.

CONCLUSIONS

Within the article, we discuss the available evidence for HSK/HZO prophylaxis in ocular surgery. Additional studies would be required to define the real risk of HSK/HZO recurrence following eye surgeries, and particularly cataract surgery, and to confirm the utility of perioperative HSK/HZO prophylaxis.

Initial High-Dose Prophylaxis and Extended Taper for Mushroom Keratoplasty in Vascularized Herpetic Scars

PURPOSE

To report the outcomes of initial high-dose and extended taper of antiviral and steroid prophylaxis for the treatment of eyes with high-risk vascularized herpetic corneal scars that underwent 2-piece mushroom keratoplasty (MK).

DESIGN

Prospective interventional case series.

METHODS

In this single-center study, 52 consecutive eyes with vascularized (≥2 quadrants) herpetic corneal scars underwent 2-piece microkeratome-assisted MK. Initial high-dose and extended taper of combined oral and topical antiviral and steroid prophylaxis was administered. Outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism (RA), endothelial cell density, immunologic rejection, herpetic recurrence, and graft failure rates.

RESULTS

Excluding patients with vision-impairing comorbidities, baseline BSCVA (1.73 ± 0.67 logMAR) significantly improved annually during the first 2 years (P < .001, P = .016), reaching 0.17 ± 0.18 logMAR at year 2, and remaining stable up to 10 years (P = .662). At 2 years, 86% of eyes saw ≥20/40, 55% saw ≥20/25, and 18% saw ≥20/20 Snellen BSCVA. RA exceeded 4.5 diopters in 7% of cases after wound revision for high-degree astigmatism in 7 cases. Endothelial cell loss was 40.9% at 1 year with an annual decline of 3.1% over 10 years. The 10-year cumulative risk for immunologic rejection, herpetic recurrence, and graft failure was 9.7%, 7.8%, and 7.6%, respectively.

CONCLUSIONS

Initial high dose and extended taper of antiviral and steroid prophylaxis for MK in high-risk, vascularized herpetic corneal scars achieves clinical outcomes that remain stable for up to 10 years after surgery with minimal risk of immunologic rejection, herpetic recurrence and graft failure.

A retrospective study comparing DALK and PKP in the treatment of necrotizing stromal keratitis

PURPOSE

To compare the clinical outcomes of deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PKP) in the treatment of necrotizing stromal keratitis (NSK).

METHODS

A retrospective study of NSK patients who underwent keratoplasty between January 2015 and December 2017 in the Third Xiangya Hospital was carried out. Data including preoperative and postoperative best corrected visual acuity (BCVA), intraocular pressure, graft survival rates, corneal endothelial cell density, corneal topography and thickness were reviewed and analyzed by SPSS 23.0 software.

RESULTS

Fifty patients were involved. Twenty-five patients received DALK, and the other half received PKP. The average follow-up period was 10.28 ± 5.92 months. At the end of the follow-up period, there were no significant differences in postoperative BCVA, recurrence of virus, graft rejection or graft failure between the two groups. There were also no significant differences in average central corneal thickness postoperatively at 3 months. However, the average corneal endothelial cell density at 3 months was significantly higher in the DALK group (2121.12 ± 450.80 cell/mm² in the DALK group versus 1812.16 ± 340.38 cell/mm² in the PKP group, P = 0.009).

CONCLUSION

Both DALK and PKP could increase visual acuity and prevent the progression of NSK. There were no significant differences between DALK and PKP in postoperative BCVA, rate of rejection, graft failure or recurrence rate. DALK significantly reduced the loss of corneal endothelial cells.

Approaches toward enhancing survival probability following deep anterior lamellar keratoplasty

The greatest advantage of deep anterior lamellar keratoplasty over full-thickness corneal transplantation is the elimination of graft failure caused by endothelial rejection. Despite this advantage, a deep anterior lamellar keratoplasty graft can fail because of several factors, such as complications related to the donor-recipient interface, graft epithelial abnormalities, graft vascularization, stromal graft rejection, and recurrence of herpetic keratitis. Increased deep anterior lamellar keratoplasty graft survival is mainly built upon optimization of the ocular surface to provide a hospitable environment for the graft. Any predisposing factors for graft epithelial abnormalities, corneal neovascularization, and preexisting vernal keratoconjunctivitis should be identified and treated preoperatively. Prompt recognition and appropriate treatment of interface-related complications and stromal graft rejection usually result in good anatomic outcomes, with no detrimental effects on vision.

Phacoemulsification in eyes with corneal opacities after deep anterior lamellar keratoplasty

To evaluate the maneuverability and efficacy of phacoemulsification and intraocular lens (IOL) implantation in eyes with corneal opacities after deep anterior lamellar keratoplasty (DALK), twelve eyes of 12 patients with mild to moderate corneal opacities after DALK and coexisting cataracts were analyzed retrospectively. Phacoemulsification and IOL implantation assisted with anterior capsule staining, as well as non-invasive optical fiber illumination, were performed on all eyes. No intraoperative or postoperative complications were noted. Mean corrected distance visual acuity (logMAR) improved from 1.24±0.17 to 0.73±0.22. Post-phaco intraocular pressure was maintained between 13 to 20 mm Hg in all cases throughout the follow-up period. Mean endothelial cell density decreased from 2258.42±205.94 to 1906.25±174.23 cells/mm². Phacoemulsification and IOL implantation are safe and valid in eyes with mild to moderate corneal opacities after DALK and coexisting cataracts when assisted with anterior capsule staining and non-invasive optical fiber illumination.

Therapeutic Challenges and Prognosis of Descemet's Membrane Endothelial Keratoplasty in Herpes Simplex Eye Disease

PURPOSE

To describe the functional outcome, postoperative complications, and complication management of Descemet's membrane endothelial keratoplasty (DMEK) in corneal decompensation secondary to Herpes simplex eye disease (HED).

METHODS

This retrospective interventional case series included 17 eyes that received DMEK for endothelial decompensation secondary to HED. Complete ophthalmological examination, including corrected-distance visual acuity (CDVA), anterior segment slit-lamp, and optical coherence tomography assessment, were performed preoperatively and postoperatively at regular follow-up intervals. Visual outcome and complication rates were compared with those of 72 consecutive eyes that received DMEK for Fuchs endothelial corneal dystrophy (FECD) and pseudophakic bullous keratopathy (PBK) during the same period.

RESULTS

Mean follow-up time was 11.1 ± 5.9 months (range 6-27). CDVA improved from 1.16 ± 0.46 logMAR to 0.62 ± 0.44 logMAR (P = 0.001). Corneal pachymetry significantly decreased from 695 ± 53 μm at day 1 to 569 ± 88 μm at 2 months (P < 0.001). Postoperative complications occurred in 12 eyes, including primary graft failure (12%), endotheliitis (29%), corneal ulcers (35%), and cystoid macular edema (18%). Most complications occurred shortly after surgery, with a median delay of 2.5 months. In comparison, the complication rates for DMEK in FECD and PBK were significantly lower (no graft failure, P = 0.005; no endotheliitis, P < 0.001; no corneal ulcers, P < 0.001 and 3% cystoid macular edema, P = 0.046).

CONCLUSIONS

DMEK surgery significantly improved CDVA in patients with endothelial decompensation due to HED. The rate of postoperative complications was higher than for FECD and PBK. Close follow-up is mandatory and the rate of postoperative inflammatory events suggests that patients should be kept on high doses of oral valacyclovir.

Effects of corneal thickness distribution and apex position on postoperative refractive status after full-bed deep anterior lamellar keratoplasty

OBJECTIVE

To investigate the effects of corneal thickness distribution and apex position on postoperative refractive status after full-bed deep anterior lamellar keratoplasty (FBDALK).

METHODS

This is a retrospective analysis of patients who were diagnosed with advanced keratoconus between 2011 and 2014 in our hospital. The base of the cone in all patients did not exceed the central cornea at a 6-mm range. The FBDALK was performed by a same surgeon. All patients had a complete corneal suture removal and the follow-up records were intact. Patients who had graft-bed misalignment or who were complicated with a cataract or glaucoma were excluded. Uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), and Pentacam examination data were recorded at two years postoperatively. The recorded data included the superior-inferior (S-I) and nasal-temporal (N-T) corneal thickness differences in 2, 4, 6, and 8 mm diameter concentric circles with the corneal apex as the center (S-I_{2 mm}, S-I_{4 mm}, S-I_{6 mm}, S-I_{8 mm}, N-T_{2 mm}, N-T_{4 mm}, N-T_{6 mm}, and N-T_{8 mm}), the linear, X-axis, and Y-axis distance between the corneal pupillary center and the cornea apex, total corneal astigmatism at a zone of 3 mm diameter from the corneal apex (TA_{3 mm}), the astigmatic vector values J₀ and J₄₅, and the corneal total higher-order aberration for 3 and 6 mm pupil diameters (HOA_{3 mm} and HOA_{6 mm}). Statistical analysis was performed by SPSS 15.0.

RESULTS

A total of 47 eyes of 46 patients met the criteria and were included in this study. The mean follow-up time was (28±7) months. The mean UCVA was 0.45±0.23 (logMAR) (MAR: minimum angle of resolution) and the mean BSCVA was 0.19±0.15 (logMAR), which were all significantly positively correlated with postoperative TA_{3 mm} and HOA_{3 mm}. The mean S-I corneal thickness differences were (44.62±37.74) μm, and the mean N-T was (38.57±32.29) μm. S-I_{2 mm} was significantly positively correlated with J₀ (r=0.31), J₄₅ (r=0.42), HOA_{3 mm} (r=0.37), and HOA_{6 mm} (r=0.48). S-I_{4 mm} and S-I_{8 mm} were significantly positively correlated with HOA_{3 mm} (r=0.30, r=0.40) and HOA_{6 mm} (r=0.46, r=0.35). The X-axis distance between corneal pupillary center and corneal apex was significantly positively correlated with J₄₅ (r=0.29).

CONCLUSIONS

In patients with advanced keratoconus after FBDALK, the unevenly distributed thickness at corneal pupillary area and the misalignment of corneal apex and pupillary center might cause significant regular and irregular astigmatism, which affected the postoperative visual quality.

Assessments of tear meniscus height, tear film thickness, and corneal epithelial thickness after deep anterior lamellar keratoplasty

OBJECTIVE

To assess the lower tear meniscus height (LTMH), central tear film thickness (CTFT), and central corneal epithelial thickness (CCET) after deep anterior lamellar keratoplasty (DALK).

METHODS

This was a retrospective cross-sectional study of 20 patients who had DALK in one eye over a three-month period. LTMH, CTFT, and CCET of the operated eyes and the unoperated fellow eyes were measured using high-definition optical coherence tomography (HD-OCT). Correlations between three OCT assessments and age, time following surgery, graft size, bed size, and the number of residual sutures were analyzed.

RESULTS

Compared to patients with keratoconus, patients with other corneal conditions had significantly higher CCET in the fellow eye (P=0.024). For all patients, CCET in the operated eye was significantly negatively correlated with the number of residual sutures (R=-0.579, P=0.008), and was significantly positively correlated with time following surgery (R=0.636, P=0.003). In the fellow eye, a significant positive correlation was found between age and CCET (R=0.551, P=0.012), and a significant negative correlation between age and CTFT (R=-0.491, P=0.028). LTMH was found to be significantly correlated between operated and fellow eyes (R=0.554, P=0.011). There was no significant correlation between LTMH and age, bed/graft size, time following surgery, or residual sutures (all possible correlations, P>0.05).

CONCLUSIONS

Patients with keratoconus tend to have a thinner central corneal epithelium. Corneal epithelium keeps regenerating over time after DALK. DALK did not induce a significant change in tear volume compared with the fellow eye. Postoperative tear function might depend on an individual's general condition, rather than on age, gender, bed/graft size, time following surgery, or residual sutures.

Case Report: Acute Hydrops with Descemet Membrane Schisis in Corneal Ectasia after Radial Keratotomy

SIGNIFICANCE

As patients with previous radial keratotomy (RK) are still occasionally encountered, recognition of the anatomy of post-RK corneas and management of their complications remain relevant. High-definition anterior segment optical coherence tomography (AS-OCT) is a very useful tool to assess these postsurgical corneas.

PURPOSE

To describe a case of acute corneal hydrops with Descemet membrane schisis after RK with observation by AS-OCT.

CASE REPORT

A 43-year-old woman presented with a 9-day history of sudden vision loss, foreign body sensation, and photophobia in her left eye. She had undergone bilateral RK 25 years ago at her local hospital. Slit-lamp examination revealed marked corneal edema and stromal clefts in the central cornea along with radial surgical scars in her left eye. Pentacam imaging showed the typical pattern of a post-RK cornea with ectasia in her right eye. Multiple dilacerations of collagen lamellae and fluid-filled intrastromal cysts together with epithelial edema were observed in her left eye using AS-OCT. A Descemet membrane detachment with schisis was also shown by AS-OCT. After 5 months of medication with topical 0.1% fluorometholone eye drops four times daily together with 3% ofloxacin eye ointment once daily, the corneal edema, Descemet membrane detachment, and Descemet membrane schisis had completely resolved resulting in pan-stromal scarring.

CONCLUSIONS

This report describes acute corneal hydrops with Descemet membrane schisis after RK imaged using high-definition AS-OCT. The acute hydrops was possibly caused by corneal ectasia or underlying keratoconus, which was aggravated by RK. High-definition AS-OCT is a useful tool to demonstrate the details of different corneal layers and to observe the resolving process of acute hydrops. Topical medications consisting of antibiotic, lubrication, and corticosteroid can be used to treat the acute event effectively.

Corneal Higher-order Aberrations and Visual Improvement Following Corneal Transplantation in Treating Herpes Simplex Keratitis

PURPOSE

To examine corneal higher-order aberrations (HOAs) and visual improvement following corneal transplantation in treating corneal scar caused by herpes simplex keratitis (HSK).

DESIGN

Retrospective consecutive case series.

METHODS

This study included a total of 52 eyes: 18 eyes of normal subjects, and 34 eyes of consecutive patients with corneal scar owing to HSK who underwent penetrating keratoplasty (PKP, 17 eyes) or deep anterior lamellar keratoplasty (DALK, 17 eyes). HOAs of the anterior, posterior surfaces and the total cornea were analyzed by anterior segment optical coherence tomography. The correlations between corneal HOAs and visual improvement were also analyzed.

RESULTS

Mean logarithm of the minimal angle of resolution (logMAR) visual acuity significantly improved from 1.40 ± 0.70 to 0.46 ± 0.45 after corneal transplantation (P < .0001). Mean corneal HOAs of the anterior surface significantly decreased after corneal transplantation (PKP: from 1.16 ± 0.59 μm to 0.58 ± 0.35 μm, P = .035, DALK: from 0.94 ± 0.57 μm to 0.37 ± 0.18 μm, P = .004). Visual acuity following corneal transplantation was correlated with the corneal HOAs at 12 months (r = 0.53, P = .01). Visual improvement at 3, 6, and 12 months was positively correlated with preoperative HOAs of the total cornea and posterior surface (all P < .01).

CONCLUSIONS

Preoperative corneal HOAs were associated with the visual improvement in treating corneal scar caused by HSK. Thus, the preoperative assessment of corneal HOAs, especially of the posterior surface, is important in the decision to perform corneal transplantation in eyes with HSK.

Long-term outcomes of the Boston type I keratoprosthesis in eyes with previous herpes simplex virus keratitis

Purpose

To report the long-term outcomes of the Boston type I keratoprosthesis (Kpro) in eyes with prior herpes simplex virus (HSV) keratitis.

Methods

Retrospective review of all Kpro procedures performed by a single surgeon from 1 May 2004 to 1 January 2015.

Results

13 of 173 Kpro procedures were performed in 11 eyes with prior HSV keratitis. There was not a significant difference in the percentage of eyes with and without prior HSV keratitis with preoperative (9% vs 8%, p=1.00) or postoperative (57% vs 60%, p=1.00) corrected distance visual acuity (CDVA) ≥20/200 or in the percentage of contralateral eyes with preoperative CDVA ≥20/50 (55% vs 30%, p=0.18). While several postoperative complications occurred approximately twice as often in eyes with prior HSV keratitis, including persistent epithelial defect (63.6% vs 34.1%; p=0.10), corneal infiltrate (27.3% vs 12.3%; p=0.17) and sterile vitritis (18.2% vs 9.4%; p=0.31), only cystoid macular oedema (45.5% vs 12.3%; p=0.01) was significantly more common. Similarly, while the Kpro retention failure rate in eyes with prior HSV keratitis was twice than that in eyes without it (0.15 vs 0.07 per year), the difference was not statistically significant (p=0.09).

Conclusion

As greater than half of patients with unilateral HSV keratitis undergoing Kpro implantation have CDVA ≥20/50 in the contralateral eye, and as the Kpro retention failure rate in eyes with prior HSV keratitis is twice than that in eyes without prior HSV keratitis, caution should be exercised when considering Kpro implantation in these patients.

New histopathologic and ultrastructural findings in Reis-Bücklers corneal dystrophy caused by the Arg124Leu mutation of TGFBI gene

Background

Reis-Bücklers corneal dystrophy (RBCD) was consistently reported as a corneal dystrophy only affected Bowman’s layer and superficial corneal stroma, and superficial keratectomy was a recommendation surgery for treatment in literatures. The study reported new histopathological and ultrastructural findings in RBCD caused by the Arg124Leu mutation of transforming growth factor induced (TGFBI) gene in a four-generation Chinese pedigree.

Methods

Subjects including eight patients and seven unaffected family members received slit-lamp biomicroscopy and photography. DNA was obtained from all subjects, and exons 4 and 11 to 14 of TGFBI gene were analyzed by polymerase chain reaction and the products were sequenced. Anterior segment optical coherence tomography (AS OCT) and in vivo confocal microscopy were conducted for ten eyes of five patients. Based on the results of AS OCT and in vivo confocal microscopy, deep anterior lamellar keratoplasty (DLKP) using cryopreserved donor cornea was applied for four eyes of four patients. Four lamellar dystrophic corneal buttons were studied by light and transmission electron microscopy, and TGFBI immunohistochemistry.

Results

Eight patients had typical clinical manifestations of RBCD presenting recurrent painful corneal erosion starting in their early first decades, along with age-dependent progressive geographic corneal opacities. TGFBI sequencing revealed a heterozygous mutation, Arg124Leu in all eight patients. Anterior segment optical coherence tomography and in vivo confocal microscopy showed the dystrophic deposits involved not only in subepithelial and superficial stroma, but also in mid- or posterior stroma in four examined advanced eyes. Light microscopy showed Bowman’s layer was absent, replaced by abnormal deposits stain bright red with Masson’s trichrome. In superficial cornea, the deposits stacked and produced three to five continuous bands parallel to the corneal collagen lamellae. In mid- to posterior stroma, numerous granular or dot- like aggregates were heavily scattered, and most of them presented around the nuclei of stromal keratocytes. Transmission electron microscopy revealed the multiple electron-dense rod-shaped deposits aggregated and formed a characteristic pattern of three to five continuous bands in superficial cornea, which were similar to those seen under light microscopy. In mid- to posterior stroma, clusters of rod-shaped bodies were scattered extracellular or intracellular of the stromal keratocytes between the stromal lamellae suggesting the close relationship between mutated proteins and keratocyte.

Conclusions

The study offer evidences indicating DLKP is a viable treatment option for advanced RBCD to avoid recurrence, and the mutated TGFBIp in dystrophic corneas are of keratocytes origin.

Clinical evaluation of deep anterior lamellar keratoplasty using glycerol-cryopreserved corneal tissues for refractory herpetic stromal keratitis: An observational study

The study aimed to evaluate the therapeutic effects of deep anterior lamellar keratoplasty (DALK) using glycerol-cryopreserved corneal tissues (GCCTs) in patients with refractive herpes simplex keratitis (HSK). This article was a retrospective, noncomparative, and interventional case series. Patients with HSK underwent DALK using GCCTs at Shanghai Tongji Hospital from 2012 to 2015. The best spectacle corrected visual acuity, recurrent inflammation, graft status, postoperative central graft thickness, and pre/postoperative complications were detected. The follow-up ranged from 24.4 ± 5.6 months (range: 16-38 months). Overall, the best spectacle corrected visual acuity was increased from HM/10 cm to 0.15 before surgery to 0.41 ± 0.14 (range: 0.1-0.8; P < 0.05) at 12 months postoperatively. Intraoperative microperforation occurred in 4 eyes (14.81%), and rejection episodes were encountered in 3 of 27 eyes (11.1%), and all of the eyes reversed. HSK recurred in 2 eyes (7.41%), 1 eye with repeated recurring HSK, and eventually led to perpetual corneal opacity and the patient refused a retransplantation. The mean entire corneal thickness was 0.519 ± 0.018 mm (range: 0.5-0.56 mm) and the mean graft thickness was 0.405 ± 0.033 mm (range: 0.35-0.47 mm) in the final follow-up. The DALK using GCCTs was proven to be an effective and safe therapy in treating refractory HSK.

Aetiology-specific comparison of long-term outcome of deep anterior lamellar keratoplasty for corneal diseases

AIMS

To evaluate the long-term outcome of deep anterior lamellar keratoplasty (DALK) for the treatment of herpetic keratitis, keratoconus, stromal scars and corneal dystrophies.

METHODS

This retrospective consecutive case study includes 275 consecutive eyes of 254 patients who underwent DALK; 35 eyes with herpetic keratitis, 114 eyes with stromal scar, 93 eyes with keratoconus and 67 eyes with corneal dystrophy. Exclusion criteria included therapeutic DALK for the treatment of descemetocele or infectious keratitis, and eyes with limbal stem cell deficiency. Patients were examined at 1, 3 and 6 months, and 1, 3 and 5 years after DALK. Graft survival rate, best corrected visual acuity (BCVA), endothelial cell density (ECD) and postoperative complications were evaluated.

RESULTS

The mean postoperative follow-up duration was 51±41 months. The graft survival rate of all subjects was 96.8% at 1 year, 89.9% at 3 years, 83.5% at 5 years and 74.1% at 10 years. At 6 months, BCVA significantly improved from 1.14±0.54 to 0.22±0.21 in the keratoconus group, from 1.13±0.60 to 0.44±0.54 in the herpes group, from 1.00±0.59 to 0.49±0.38 in the stromal scar group and from 1.04±0.52 to 0.32±0.29 in the corneal dystrophy group (all, p<0.0001). BCVA stabilised after 6 months thereafter up to 5 years. ECD decreased just after DALK and maintained >1000 cell/mm(2) at 5 years in all groups.

CONCLUSIONS

DALK provides good visual acuity with slight ECD decrease over long term in all groups.

Graft rejection rate and graft failure rate of penetrating keratoplasty (PKP) vs lamellar procedures: a systematic review

Purpose

The aim of our investigation was to conduct a quantitative meta-analysis of the present world literature comparing the major surgical outcomes of penetrating keratoplasty (PKP) to lamellar procedures. Our goal is that clinicians, eye bank administrators, and health policy makers will be able to utilize this study in implementing decisions in regards to corneal transplantation.

Methods

Pooled measures of association were with odds ratios and because of study heterogeneity, the pooled effects were assumed to follow a random effects model (DerSimonian-Laird). The comparisons were between 1) PKP’s and all lamellar procedures (anterior AND posterior) and then 2) between PKP’s and all anterior lamellar procedures and 3) PKP and all posterior lamellar procedures.

Results

For PKP vs anterior lamellar procedures, the pooled odds ratio for rejection of PKP over lamellar keratoplasty (LK) was 3.56 (95% CI: 1.76-7.20) and for outright failure, the pooled odds ratio of PKP failure vs LK was 2.85 (95% CI: 0.84-9.66). For posterior lamellar procedures, the pooled odds ratio for rejection of PKP over LK was 1.52 (95% CI: 1.00-2.32). The pooled odds ratio for outright failure of PKP over posterior lamellar procedures was 2.09 (95% CI: 0.57-7.59). The follow up time was significantly longer for full transplants than for lamellar procedures.

Conclusions

For both anterior and posterior lamellar procedures, the odds ratios comparing rejection of full transplants to lamellar procedures (both anterior and posterior individually) were significantly higher in the PKP group. For outright failure, the PKP group also had a higher risk of failure than the lamellar groups but this was not statistically significant in either instance (anterior or posterior). Some of the clinical differences benefitting lamellar procedures may at least be partly explained by follow up time differences between groups and this needs to be accounted for more rigorously in future studies.

Peripheral deep anterior lamellar keratoplasty using a cryopreserved donor cornea for Terrien's marginal degeneration

OBJECTIVE

To evaluate the clinical efficacy of peripheral deep anterior lamellar keratoplasty (DALK) using a cryopreserved donor cornea for Terrien's marginal degeneration (TMD).

METHODS

Thirty-one eyes of 27 patients with TMD underwent peripheral DALK using cryopreserved donor corneas. According to the distance between the inner edge of the lesion and the limbus, a ring-shaped or D-shaped DALK was performed. All grafts were stored at -20 °C. Cryopreserved corneoscleral rims were prepared for ring-shaped grafts and cryopreserved whole eyeballs were prepared for D-shaped grafts. The general conditions, intraoperative performance, postoperative corneal reconstruction, astigmatism, best corrected visual acuity (BCVA), and various complications were analyzed.

RESULTS

Ring-shaped DALK was performed in 28 eyes and D-shaped DALK was performed in 3 eyes. Postoperative follow-up time was (28.4±24.8) months. There was evidence of inflammation before surgery in 12 eyes (38.7%) and intraoperative perforation occurred in 13 eyes (41.9%). The corneal structures of all eyes were reconstructed. Postoperative astigmatism and BCVA showed improvement (both P=0.00) except for cases that underwent D-shaped DALK. Ten eyes (32.2%) developed transient ocular hypertension and one eye (3.2%) developed secondary glaucoma. No primary disease recurrence or corneal allograft rejection was observed.

CONCLUSIONS

Peripheral DALK for TMD using cryopreserved donor tissue is an effective technique that eliminates rejection and extends the use of donor eyes. Inflammatory history or intraoperative perforation has no adverse effect on graft recovery. However, D-shaped DALK did not achieve good visual outcomes.

Corneal blindness and xenotransplantation

Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

Long-term comparison of full-bed deep anterior lamellar keratoplasty and penetrating keratoplasty in treating keratoconus

OBJECTIVE

To compare postoperative outcomes of full-bed deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in treating keratoconus.

METHODS

Seventy-five eyes of 64 patients who received full-bed DALK and 52 eyes of 51 patients who received PK between June 2000 and August 2010 were included in this retrospective study. Full-bed DALK was performed using Yao's hooking-detaching technique. PK was performed using a standard technique. Intraoperative and postoperative complications, visual acuity, rejection, graft survival, endothelial cell density, corneal sensation recovery, and re-innervation were compared between the two groups.

RESULTS

A best correct visual acuity of 0.5 or better was achieved in 90.7% of eyes after full-bed DALK and in 92.3% of eyes after PK (P=0.75). By the fifth postoperative year, graft endothelial cell loss reached 34.6% in the PK group vs. 13.9% in the full-bed DALK group (P<0.001). There were no statistical differences in corneal sensitivity recovery or corneal re-innervation between the groups (P>0.05). Intraoperative microperforation occurred in seven out of 75 (9.3%) eyes with a temporally postoperative double anterior chamber in two eyes in the full-bed DALK group. Postoperative complications in the PK vs. the full-bed DALK groups respectively were: rejection (7.7% vs. 0%, P=0.015), high intraocular pressure (IOP) (46.2% vs. 1.3%, P<0.001), secondary glaucoma (9.6% vs. 0%, P=0.006), complicated cataract (19.2% vs. 0%, P<0.001), and wound dehiscence (9.6% vs. 0%, P=0.006).

CONCLUSIONS

Both full-bed DALK and PK can offer long-term satisfactory visual outcomes for keratoconus. Graft rejection, secondary glaucoma, complicated cataracts, and constant endothelial cell loss were observed in eyes only after PK.

Therapeutic effect of deep anterior lamellar keratoplasty for active or quiescent herpetic stromal keratitis

PURPOSE

To evaluate the therapeutic effect of deep anterior lamellar keratoplasty (DALK) in patients with herpetic stromal keratitis (HSK).

METHODS

Forty-three eyes belonging to 42 patients with HSK, including 22 eyes in the active phase and 21 eyes in the quiescent phase, underwent DALK at the Shandong Eye Institute from January 2006 to December 2009. All patients with active disease had received intravenous acyclovir and amniotic membrane implants prior to DALK. Herpes simplex virus type 1 (HSV-1) antigens from excised corneal buttons were detected by immunohistochemistry.

RESULTS

The follow-up ranged from 1 to 4 years (mean, 29.1 months). Graft rejection occurred in one eye (2.3%) and was reversed. Among the other 42 survived grafts (97.7%), 37 remained clear at the last visit. The best spectacle-corrected visual acuity was 20/200 or better in 95.2% of eyes and 20/40 or better in 38.1% of eyes. Six eyes (14.0%) developed recurrent HSK, one of which received a second keratoplasty due to ineffective antiviral medication. There were no significant differences in endothelial cell density between 6 months and 12 months after the surgery. By immunohistochemistry, HSV-1 antigens were observed in the stroma of 18 of 32 corneal buttons.

CONCLUSIONS

DALK can not only remove the corneal lesions of HSK but also reduce latent or persistent viral loads in the cornea. In eyes with active or quiescent HSK but otherwise healthy endothelia, DALK seems to be safe and promising for its favorable visual outcome, graft survival rate, and low endothelial cell loss.