OBJECTIVE: To report the use of anterior segment optical coherence tomography (AS-OCT) for superficial keratectomy (SK) in anterior corneal opacity.
METHODS: The characteristics of 43 eyes (39 patients) with various lesions responsible for anterior corneal opacity were included in this retrospective non-comparative study. AS-OCT was performed on all eyes before surgery. The thickness of corneal opacity and the underlying healthy stroma were measured. SK was performed on each individual.
RESULTS: Four types of anterior corneal opacity were evaluated, including corneal degeneration (26/43), Reis-Bücklers corneal dystrophy (8/43), alkali burn (1/43) and corneal tumors (8/43). Based on AS-OCT images, all eyes showed abnormal hyper-reflective signals in the superficial cornea to less than one-third of the normal corneal thickness in the deepest corneal opacity. All 43 eyes underwent an SK procedure. In addition, 1 eye with alkali burns and 7 eyes with corneal tumors were combined with amniotic membrane transplantation. All eyes restored transparency without significant complications.
CONCLUSIONS: AS-OCT is a valuable method for objective preoperative and noninvasive assessments of anterior corneal opacities and is useful for guiding SK.

To retrospectively evaluate the effectiveness and outcome of lamellar keratoplasty using acellular bioengineering cornea (BioCorneaVetTM) for the treatment of feline corneal sequestrum (FCS). The medical records of cats diagnosed with FCS that underwent lamellar keratoplasty with BioCorneaVetTM between 2018 and 2021 with a minimum of 3 months of follow-up were reviewed. Follow-up examinations were performed weekly for 3 months, and then optical coherence tomography (OCT) examination was performed on select patients at 0, 3, 6, and 12 months post-operatively. A total of 61 cats (30 left eyes and 32 right eyes) were included. The Persian breed was overrepresented, 48/61 (78.69%). Four different thicknesses of acellular bioengineering cornea were used (200, 300, 400, or 450 microns), and the mean graft size was 8.23 mm (range, 5.00-12.00 mm). Minor complications were composed of partial dehiscence, and protrusion of the graft occurred in 7/62 eyes (11.29%). The median postoperative follow-up was 12.00 months (range, 3-41 months). A good visual outcome was achieved in 60/62 eyes (96.77%), and a mild to moderate corneal opacification occurred in 2/62 (3.23%). No recurrence of corneal sequestrum was observed. From the results, lamellar keratoplasty using acellular bioengineering cornea (BioCorneaVetTM) is an effective treatment for FCS, providing a good tectonic support and natural collagen framework, and resulting in satisfactory visual and cosmetic effects.

UNASSIGNED: To evaluate the outcomes of transepithelial phototherapeutic keratectomy (transepithelial PTK) for treatment of posttraumatic recurrent corneal erosions.
UNASSIGNED: Twenty-four eyes of 22 patients with posttraumatic recurrent corneal erosions who were treated with transepithelial PTK from April 2018 to July 2020 were included in this retrospective study. The rates of recurrent erosions and complications were evaluated during the follow-up after surgery. Visual acuity and refraction were recorded preoperatively and 1 year after surgery. Total corneal astigmatism, total corneal irregular astigmatism, and total corneal spherical aberrations were recorded using corneal tomography preoperatively and 1 year after surgery.
UNASSIGNED: Mean postoperative follow-up was 13 months (range: 12-32 months). None of the patients suffered from any complications or further erosions. Uncorrected distance visual acuity, best-corrected distance visual acuity, spherical equivalent, and cylinder remained stable at 1-year postoperatively compared with the baseline (P = 0.214, P = 0.461, P = 0.084, and P = 0.879, respectively). Moreover, there was no significant difference in total corneal astigmatism, total corneal irregular astigmatism, and total corneal spherical aberrations between baseline and 1-year postoperative visit (P = 0.938, P = 0.136, and P = 0.981, respectively).
UNASSIGNED: Transepithelial PTK was an effective treatment for patients with posttraumatic recurrent corneal erosions.

OBJECTIVE: The goal of this study was to investigate the clinical outcomes of transepithelial phototherapeutic keratectomy (transepithelial PTK) for the treatment of severe band keratopathy.
METHODS: A consecutive series of severe band keratopathy cases treated with transepithelial PTK were retrospectively analysed between January 2018 and December 2019. Severe band keratopathy was defined as corneal plaques apparent in the obscuration of iris details. Patients\' medical histories, preoperative and postoperative symptomatic relief, cosmesis, best-corrected visual acuity (BCVA), complications, and recurrences were analysed.
RESULTS: Seventeen eyes of 16 patients were included in the study, with a mean follow-up of 9.8 ± 5.2 months (3 to 19 months). The mean age of the patients was 15.8 ± 10.2 years (8 to 46 years). Symptoms were significantly or completely relieved in all patients (100%). The results of cosmesis were good in 14 eyes (82.4%). Among those eyes that had BCVA of hand motion or better preoperatively, seven eyes (100%) showed an improvement in BCVA postoperatively. There were no complications or recurrences associated with transepithelial PTK treatment during the follow-up period.
CONCLUSIONS: Transepithelial PTK is an effective treatment to eliminate corneal opacity and alleviate symptoms in patients with severe band keratopathy. This technique could be an alternative approach to managing severe band keratopathy.

OBJECTIVE: To analyze the keratectasia area (KEA) shown in corneal topography before and after corneal cross-linking (CXL) in patients with progressive keratoconus (KC) and figure out whether KEA is appropriate for evaluating the effect of CXL.
METHODS: A retrospective analysis was conducted in 34 eyes from 24 progressive KC patients who have underwent CXL from 2015 to 2017. Area with K-value more than 47D shown in the corneal topography was marked and identified as KEA. Keratometry (K1, K2, and Kmax), KEA, thinnest corneal thickness (TCT), and endothelial cell density (ECD) were evaluated preoperatively or at months 3, 6, and 12 postoperatively. The changes of KEA before and after operation were evaluated. The relation of KEA and other parameters, including Kmax and TCT, was analyzed.
RESULTS: Linear regression model revealed the KEA, Kmax, K1, and K2 decreased after CXL in model y = 0.9622 -0.02408 x (P<0.05), y = 0.9982 -0.003469 x(P<0.05), y = 0.9977 + -0.001347 x(P<0.05), y = 0.9992 + -0.001779 x(P<0.05) (y represents KEA, Kmax, K1, or K2; x represents time (month)). The KEA is significantly decreased in early stage (before month 3) (P<0.05); however, the Kmax, K1, and K2 have no significant decrease in early stage (P= 0.09, 0.19, 0.32).
CONCLUSIONS: The KEA is more sensitive than K-value in describing the morphological changes of cornea after CXL, especially in early stage after treatment.

Biological materials derived from the extracellular matrix (ECM) of tissues serve as scaffolds for rebuilding tissues and for improved wound healing. Cornea trauma represents a wound healing challenge as the default repair pathway can result in fibrosis and scar formation that limit vision. Effective treatments are needed to reduce inflammation, promote tissue repair, and retain the tissue\'s native transparency and vision capacity. Tissue microparticles derived from cornea, cartilage and lymph nodes were processed and screened in vitro for their ability to reduce inflammation in ocular surface cells isolated from the cornea stroma, conjunctiva, and lacrimal gland. Addition of ECM particles to the media reduced expression of inflammatory genes and restored certain tear film protein production in vitro. Particles derived from lymph nodes were then applied to a rabbit lamellar keratectomy corneal injury model. Application of the tissue particles in a fibrin glue carrier decreased expression of inflammatory and fibrotic genes and scar formation as measured through imaging, histology and immunohistochemistry. In sum, immunomodulatory tissue microparticles may provide a new therapeutic tool for reducing inflammation in the cornea and ocular surface and promoting tissue repair. STATEMENT OF SIGNIFICANCE: Damaged cornea will result in scar tissue formation that impedes vision, and new therapies are needed to enhance wound healing in the cornea and to prevent fibrosis. We evaluated the effects of biological scaffolds derived extracellular matrix (ECM) during corneal wound healing. These ECM particles reduced inflammatory gene expression and restored tear film production in vitro, and reduced scar formation and fibrosis genes in the wounded cornea, when applied to in vivo lamellar keratectomy injury model. The immunomodulatory tissue microparticles may provide a new therapeutic tool for reducing inflammation in the cornea and ocular surface and promoting proper tissue repair.

BACKGROUND: Corneal ectasia after small-incision lenticule extraction (SMILE) is uncommon. To our knowledge, this is the first report of 3-year results of combined phototherapeutic keratectomy (PTK) and corneal collagen cross-linking (CXL) for corneal ectasia after SMILE.
METHODS: Herein, we describe a case of prominent corneal ectasia after SMILE treated with PTK combined with CXL 3 years ago. After surgery, maximum corneal keratometry, mean corneal keratometry, spherical equivalent and uncorrected distance visual acuity were significantly improved at follow-up intervals.
CONCLUSIONS: Transepithelial PTK combined with CXL for corneal ectasia after SMILE may be an effective and safe treatment in the long term.

The purpose of this study was to investigate the subacute effects of Rose Bengal (RB) and 532 nm green light-induced photochemical crosslinking (RB-PCL) on rabbit thin corneal stability and safety in vivo.
Rabbit thin corneal models with 250 μm thickness were created by photorefractive keratectomy surgery. Photochemical crosslinking with green light (wavelength 532 nm) at an illumination intensity of 0.4 W/cm2 for 250 s (100 J/cm2 ) was performed, followed by antibiotic treatment and slit lamp monitoring for four weeks. At the end of week four, corneal biomechanical stiffness, biochemical resistance to collagenase digestion, and corneal cellular morphology were assessed. The penetration depth of RB into the corneal stromal was measured by confocal microscopy.
At the end of week 4, RB-PCL had increased corneal tensile strength by an average 2.5-fold and had extended the corneal collagenase digestion time from 10.17 ± 2.93 to 15.83 ± 2.64 days. RB penetrated approximately 90 µm into the corneal stroma. RB-PCL did not alter the corneal endothelial and stromal morphology at the cellular or subcellular levels, according to electron microscopic examination.
RB and 532 nm green light irradiation effectively induced crosslinking in rabbit thin cornea, by increasing both the biomechanical stiffness and the biochemical resistance without evidence of morphological damage to the corneal endothelium or stroma. This study demonstrated the efficacy of RB-PCL in strengthening thin cornea at four weeks after the treatment, providing a potential and possibly better option for treating corneal ectasia disorders in cases where corneal thickness is less than 400 µm. Lasers Surg. Med. 50:324-332, 2018. © 2017 Wiley Periodicals, Inc.

Objective: To investigate the treatment effect of keratectomy combined with intrastromal injection of voriconazole on fungal keratitis. Methods: Retrospective study. Ninety-eight fungal keratitis patients (98 eyes) were treated by keratectomy combined with intrastromal injection of voriconazole in Shandong Eye Hospital from January 2013 to May 2015. The corneal ulcers were mostly located in the paracentral or peripheral cornea, which incompletely blocked the pupil area. Slit lamp and anterior segment optical coherence tomography (AS-OCT) were used for lesion detection. The maximum lesion diameter was ≤5 mm, and the maximum depth was not more than half of the full corneal thickness. Because the anti-fungal drug treatment for 3-7 days was not effective, keratectomy was performed with intrastromal injection of voriconazole. The excision extension was 0.5 mm greater than the ulcer diameter, and keratectomy could be repeated until the infiltrative tissues were completely removed. Anti-fungal drug therapy was carried on after surgery. The wound healing and complications were observed. Results: All the subjects were diagnosed as fungal keratitis by corneal scraping and confocal microscopy. With an average lesion diameter of (3.72±1.23) mm, the corneal ulcers were located in the paracentral cornea in 30 patients (30.6%) and in the peripheral cornea in 68 patients (69.4%). The infiltrative depth of 74.5% of the cases detected by AS-OCT were ≤1/2 corneal thickness. The fungal keratitis in 95 cases was cured successfully. Conjunctival flap covering surgery (2 cases) and penetrating keratoplasty (1 case) were performed when the conditions were poorly controlled. Among the 95 cured cases, the ulcer healing time ranged from 3 to 19 days, and ≤7 days in more than half of the cases (48 cases). The average corneal thickness was (433.2±119.3) μm at 3 months, and the corneal endothelial cell density was (2 344.0±404.6) cells/mm(2). The uncorrected visual acuity was improved in 71(74.7%) eyes, of which 3 cases had a vision of 1.0. Conclusions: For fungal keratitis with a lesion diameter of<6 mm and a depth not more than half of the full corneal thickness, keratectomy combined with intrastromal injection of voriconazole could achieve ideal outcomes. The visual acuity recovered quickly, the therapy course was shortened, and the necessity of keratoplasty and other high risk surgeries was reduced. (Chin J Ophthalmol, 2017, 53: 682-688).
目的： 探讨角膜病灶切除联合基质内注射伏立康唑治疗真菌性角膜溃疡的临床疗效。 方法： 回顾性系列病例研究。收集2013年1月至2015年5月在山东省眼科医院应用角膜病灶切除联合基质内注射伏立康唑治疗的真菌性角膜溃疡患者98例（98只眼），其中男性71例，女性27例，年龄（51.9±11.5）岁。溃疡均位于角膜旁中央或周边部，未完全遮挡瞳孔区，裂隙灯显微镜结合眼前节光学相干层析扫描仪(AS-OCT)检查溃疡及浸润的深度≤1/2角膜厚度。入院后常规局部和全身使用抗真菌药物治疗3~7 d，如溃疡无明显好转或浸润加重，应用角膜病灶切除联合基质内注射伏立康唑的方法治疗。切除范围大于角膜溃疡直径0.5 mm，剥切深度略深于角膜浸润深度，彻底切除病灶后给予角膜基质内注射伏立康唑。观察角膜感染控制和角膜上皮愈合时间，随访有无真菌复发及视力变化等。 结果： 98例患者通过角膜刮片及共焦显微镜检查明确诊断为真菌性角膜溃疡，术前裂隙灯检查溃疡平均直径（3.72±1.23）mm；溃疡位于周边角膜的30例（30.6%），角膜旁中央68例（69.4%）。AS-OCT检查74.5%的患者感染浸润深度≤1/2角膜厚度。通过治疗95例（96.9%）患者感染得到控制，溃疡完全愈合，3例患者术后再次出现浸润，2例改行结膜瓣遮盖术，1例再次行穿透性角膜移植术。95例治愈患者角膜上皮愈合时间3~19 d，平均（8.58±3.87）d，溃疡愈合时间≤7 d的患者为48例（50.5%）。术后3个月病灶切除区域角膜平均厚度（433.2±119.3）μm，内皮细胞密度（2 344.0±404.6）个/mm(2)。71只眼（74.7%）视力较术前提高，达到1.0者3只眼。 结论： 角膜病灶切除联合基质内注射伏立康唑术对于直径小于6 mm，浸润深度不超过1/2角膜厚度的真菌性角膜溃疡可以快速控制感染，缩短药物治疗的时间，术后视力恢复快，减少了角膜移植和其他手术的必要性。（中华眼科杂志，2017，53：682-688）.