Corneal Research Articles

Focusing on systematic therapy of dry eye

Dry eye is an ocular surface disease caused by multiple factors, which is characterized by imbalance of tear film homeostasis, changes of ocular surface micro-environments and ocular uncomfortable symptoms.Tear film instability, tear hyperosmolarity, ocular surface inflammation and damage and corneal neurosensory abnormalities play etiological roles in the process of dry eye.Dry eye seriously affects work and life quality of the patients.With the progress of science and technology, the treatment of dry eye is becoming more diversified.The therapeutic methods are different for mild, moderate and serous dry eye.The choice of therapies actually depends on the individual state and condition of therapeutic institutions.A systemic, standardized and comprehensive therapy is associated with the improvement of treatment outcome.This article systematically summarizes the traditional and emerging treatments of dry eye, which are clinically feasible and can provide reference for choosing treatment methods. Key words: Dry eye; Therapy, systemic; Treatment outcome; Drug therapy; Physical therapy; Meibomian gland dysfunction

Clinical efficacy of allogeneic corneal stromal lenticules transplantation on corneal dermoid

Objective To evaluate the efficacy of dermoidectomy combined with allogeneic corneal stromal lenticules transplantation for the treatment of corneal dermoid. Methods Twelve eyes of 12 cases with corneal dermoid underwent dermoidectomy combined with allogeneic corneal stromal lenticules transplantation from Mar. 2015 to Apr. 2017. All cases were followed up for 6-24 months. The efficacy were observed. Results All cases were cured and no recurrence occurred. Corneal grafts were transparent in 10 cases completely and the corneal epithelium healed well during followed-up. Corneal grafts edema and neovascularization occurred in 2 cases and recovered transparent after anti-rejection therapy. Conclusion Dermoidectomy combined with allogeneic corneal stromal lenticules transplantation is a new and effective method for the treatment of corneal dermoid. Key words: Dermoid, corneal; Lenticules, stromal, corneal; Corneal transplantation

Observation on the efficacy of the drug-soaking amniotic membrane transplantation for bacterial corneal ulceration

Objective To observe the efficacy of the drug-soaking amniotic membrane transplantation(AMT)in the treatment of bacterial corneal ulceration. Methods Prospective, non-comparative series case study. Fifteen eyes of 15 patients with bacterial ulceration were performed single or multilayered AMT. The wound healing time of the corneal ulceration, stromal inflammation subsided and decrease of corneal neovascularization were observed.The follow up time was 6-13 months. Results The stromal inflammation was improved at 7-14 days after surgery. Epithelial defects healed within 14-30 days after surgery. The visual acuity were improved in all patients but the corneal opacity and cataract were not changed. No complication occurred during the follow-up time. Conclusion The drug-soaking AMT for the treatment of bacterial keratitis can reduce dosing frequency, reduce the burden on patients and medical staff. Key words: Amnion, transplantation; Ulceration, corneal, bacterial; Corneal neovascularization

Vitrectomy combined with extraction of large intraocular foreign body through corneal limbus incision

Objective To observe 23-gauge vitrectomy combined with extraction of large intraocular foreign body (IOFB) through corneal limbus incision. Methods The data of 10 eyes of 10 patients of large IOFB with injury of lens who underwent 23-gauge vitrectomy between Jan. 2017 and Jun. 2018 were retrospectively analyzed. Results IOFB of all eyes were extracted in once operation. The follow-up time was 6-12 months. The BCVA after surgery in all patients improved significantly(χ2=5.495, P=0.019). There was no other intraoperative or postoperative complication. Conclusion Conclusion 23-gauge vitrectomy combined with extraction of larger IOFB through corneal limbus incision is effective. Key words: Foreign body, intraocular; Limbus corneal; Vitrectomy, 23-gauge

A case of delayed endophthalmitis after corneal perforating wound caused by cactus thorn

A case of delayed endophthalmitis after corneal perforating wound caused by cactus thorn

Surgery for cataract with extremely shallow anterior chamber after trabeculectomy

Objective To investigate the efficacy of surgery for cataract with extremely shallow anterior chamber after trabeculectomy. Methods The data of 5 eyes of 5 cases of cataract with extremely shallow anterior chamber after trabeculectomy from Jan. 2017 to Mar. 2018 were analyzed retrospectively. Preoperative manifestation of all cases were cystoid or flat filtering blebs, anterior and posterior synechia, disappeared anterior chamber, mature white lens and high intraocular pressure (IOP). All patients underwent vitreous puncture and fluid releasing via the pars plana combined with goniosynechialysis, phacoemulsification and intraocular lens implantation. The patients were followed up for 6-12 months. Results The anterior chamber was formed in all 5 cases during operation. Preoperative best corrected visual acuity were light perception or hand motion, and the postoperative visual acuity was 0.2-0.4. The mean preoperative IOP was (38.80±11.44) mmHg (1 mmHg=0.133 kPa), and the mean postoperative IOP at the final visit was (15.80±2.02) mmHg (P<0.01). The difference of IOP was statistically significant between before and after operation. Anterior chamber disappeared before operation, and the mean postoperative central anterior chamber depth at the final visit was significantly increased to (2.81±0.21) mm (P<0.001). At 6 months after operation, the loss rate of corneal endothelial cells was 18.4%. No severe complication occurred during and after operation. Conclusion The combined surgery for the treatment of cataract with extremely shallow anterior chamber after trabeculectomy can resolve pupillary block, deepen the anterior chamber and reduce IOP. Key words: Cataract; Anterior chamber, shallow, extremely; Glaucoma; Puncture, vitreous

Prospective study on amelioration of pterygium combined with free autogenous conjunctival flap transplantation for the treatment of 45 patients with primary pterygium

Objective To explore the application effect of amelioration of pterygium combined with free autogenous conjunctival flap transplantation in patients with primary pterygium. Methods 90 cases (90 eyes) of primary pterygium treated in our hospital were grouped according to random number table. 45 cases in control group were treated with traditional pterygium excision, and 45 cases in observation group were treated with pterygium combined with free autogenous conjunctival flap transplantation. The operative condition (length of operation, incision size, blood loss during operation, healing time of corneal epithelium), the effect of operation and corneal astigmatism [corneal dispersion (CAD)], naked eye [uncorrected visual acuity (UCVA)] and tear film rupture time [break up time (BUT)] before and after operation were observed and compared. The incidence of complications, recurrence rate and quality of life (SF-36) before and after operation were compared between the two groups. Results The incision size, operative time, intraoperative blood loss and corneal epithelial healing time in the observation group were smaller than those in the control group (P 0.05). The complication rate in the observation group was 2.22% (1/45), which was lower than that in the control group 17.78% (8/45) (P<0.05). The recurrence rate of the observation group was 2.22% (1/45), which was lower than that of the control group 17.78%(8/45) (P<0.05). 3 months after operation, the SF-36 scores of the two groups were all higher than those before operation, and the SF-36 score of the observation group was higher than that of the control group 3 months after operation (P<0.05). Conclusions Free autogenous conjunctival flap transplantation combined with amelioration of pterygium can improve corneal astigmatism and visual function of the patients with primary pterygium, and promote corneal epithelial healing, with small incision, less bleeding and longer operation, which can reduce the incidence of postoperative complications and the recurrence rate, and help to improve the quality of life of the patients. Key words: Pterygium; Ophthalmologic surgical procedures; Conjunctiva; Transplantation, autologous

Application effect of bandage corneal contact lens in ptosis during surgical treatment

Objective To study the application effect of bandage corneal contact lens in ptosis during surgical treatment. Methods A total of 62 patients(73 eyes) with primary congenital ptosis in the First People′s Hospital of Xiantao from March 2013 to March 2016 were randomly divided into group A, group B and group C. All of the three groups were treated by shortening levator palpebrae superioris muscle.The A group[20 cases(24 eyes)]began to wear bandage corneal contact lens during the operation.The B group[22 cases(25 eyes)]began to wear bandage corneal contact lens at the end of surgery.And the C group[20 cases(24 eyes)]took conventional methods for covering operative eyes.Postoperative follow-up lasted for 3 months, the postoperative FL staining scores and ocular pain severity were compared among the three groups. Results Comparison of postoperative FL staining scores: there was no statistically significant difference between B group and C group at postoperative 1 day(q=0.537, P>0.05), but the differences between B group and A group were statistically significant (q=10.876, 11.298, all P 0.05), but the differences between group A/B and group C were statistically significant (q=8.747, 7.201, all P 0.05). Comparison of postoperative ocular pain severity: there were no statistically significant differences among the three groups at postoperative 1 day (q=0.986, 0.586, 0.410, all P>0.05). At postoperative 7 days, there was no statistically significant difference between A group and B group (q=0.948, P>0.05), but the differences between A/B group and C group were statistically significant (q=4.743, 3.843, all P 0.05). Postoperative upper eyelid radian and double eyelid plasty in all of 62 cases(73 eyes) was satisfied and the width of palpebral fissure when look straight was normal and locating above superior margin of pupil, but there were 16 eyes with slightly hypophasis which were all naturally closed good after 1 to 2 months without surgical incision infection and corneal infection. Conclusion It is effective to protect the cornea since intraoperative application of bandage corneal contact lens, and it with high safety to wear corneal contact lens shortly after surgery, which can promote corneal epithelial wound healing, reducing incidence of exposure keratitis, at the same time, it can obviously relieve ocular pain in patients. Key words: Contact lenses; Cornea; Bandages; Blepharoptosis; Surgical procedures, operative; Epithelium, corneal; Eye pain; Keratitis

Early changes in posterior corneal elevation and related factors after femtosecond laser assisted LASIK and SBK

Objective To compare the early change of posterior corneal elevation with femtosecond laser assisted laser in situ keratomileusis (FS-LASIK) and sub-Bowman keratomileusis (SBK) by Oculyzer and analyze the related factors after FS-LASIK. Methods A longitudinal observational study was designed.Ninety-one eyes of 46 patients with myopia or myopic astigmatism in the First Affiliated Hospital of Anhui Medical University from January to April in 2016 were divided into FS-LASIK group (53 eyes of 27 patients), SBK group (38 eyes of 19 patients) according to the patients' wishes and each part of corneal elevation change values were explored after FS-LASIK and SBK surgeries.The posterior corneal elevation was measured at twenty-seven measuring points along the central, paracentral, midperipheral and peripheral zone (vertex and 1, 2 and 3 mm radius) using Oculyzer preoperatively, l day, 7 days and 1 month postoperatively, respectively.Written informed consent was obtained from each patient before the surgery. Results In the FS-LASIK group, the posterior corneal elevation difference values in the central zone were (-0.924±1.859), (-1.151±1.586) and (-0.940±1.994)μm 1 day, 7 days and 1 month postoperatively, respectively.In the periphery zone, the elevation difference values were (1.046±1.667), (1.172±1.566) and (1.023±1.622)μm.In the paracentral and midperipheral zone, the cornea displayed slightly backward or forward shift.In SBK group, the posterior corneal elevation difference values of the vertex were (-0.684±1.454), (-1.053±1.723) and (-0.553±1.572)μm 1 day, 7 days and 1 month after operation, respectively.In the paracentral and midperipheral zone displayed the same trend with FS-LASIK group, and in the periphery, the values were (1.207±1.317), (1.327±1.529) and (1.208±1.415)μm.There were no statistically significant differences in posterior corneal elevation between the two surgery modes among the three time points (all at P>0.05). At 1 month postoperatively, only two independent variables, which were spherical equivalent (SE) and ablation depth (AD) entered the regression in the central and paracentral zones.Independent variables, such as central thinnest corneal thickness (TCT), SE, AD, residual bed thickness (RBT) and the ratio of AD and TCT (AD/TCT) did not enter the regression in other two areas. Conclusions The posterior corneal elevation in the central 6 mm area shows tiny change in the early stage and the variation is larger 7 days after operation in the two groups, but it does not result in keratectasia.With the increase of SE and AD, the posterior corneal elevation is more likely to be affected. Key words: Myopia; Femtosecond laser assisted laser in situ keratomileusis; Sub-Bowman keratomileusis; Posterior corneal elevation; Oculyzer

Evaluation of corneal biomechanical properties modification following intrastromal correction of presbyopia using femtosecond laser

Objective To investigate the changes of corneal biomechanics of intrastromal correction (INTRACOR) femtosecond technique to treat presbyopia. Methods A prospective, clinical self-control clinical trial was designed.Twenty-four presbyopic patients with emmetropia or mild hyperopia were enrolled in this study.The INTRACOR procedure was performed using the Technolas femtosecond laser in the nondominant eye.Uncorrected distance visual acuity (UCDVA), uncorrected near visual acuity (UCNVA) and spherical equivalent (SE) were recorded in preoperation and postoperative 12 months, and the quality of life of postoperative patients was evaluated.The corneal deformation parameters including highest concavity deformation amplitude (HC-DA), highest concavity peak distance (HC-PD), highest concavity radius (HC-R), non-contact intraocular pressure and the central corneal thickness (CCT) were measured using the Corvis ST visualization biomechanical analyzer in preoperation and postoperative 1 month, 3, 6 and 12 months, respectively.This study followed the Declaration of Helsinki.Written informed consent was obtained from each subject prior to entering study cohort.This study protocol was approved by Ethic Committee of Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine (No.SDZYYDXYKYYLL2011.06). Results Compared with preoperation, UCNVA of all 24 (100%) eyes was improved at 12 months postoperatively with minimal or no change in UCDVA.The mean spherical equivalent was (+ 0.35 ± 0.29)D and (-0.37 ± 0.29)D before and 12 months after operation, with a significant difference beteeen them (t=-7.39, P 0.05). Compared with preoperation, the postoperative 1 month, 3, 6, 12 months HC-R values were significantly declined, HC-DA values were significantly increased, with significant differences between them (all at P 0.05). Corneal aspherical index (Q Value) was -0.28±0.10 at 12 months postoperatively, which was increased compared with the preoperation, and the maximum value added value (diff-K) of the central corneal curvature was (2.55±0.81)D. Conclusions INTRACOR treatment of presbyopia can effectively improve near vision, increase postoperative corneal biomechanical maximum HC-R and HC-DA, negatively increase the corneal central curvature increased aspheric index, which suggests that corneal biomechanics of central cornea is weakened after intrastromal femtosecond presbyopic treatment, and the hyperprolate mutifocal corneal shape is formed under normal intraocular pressure. Key words: Presbyopia; Femtosecond laser; Intrastromal correction; Perspective study; Corneal biomechanics; Corneal aspherical index

The associations between corneal biomechanical parameters and glaucoma

Glaucoma is one of the leading causes of blindness worldwide.Various factors are related to the development and progression of glaucoma.High intraocular pressure is an important risk factor.In recent years, many studies have focused on other potential risk factors for glaucoma, such as intraocular pressure-independent factors, including vascular factors, central corneal thickness, etc.The relationship between corneal biomechanical parameters and glaucoma has been attracting more and more attentions.The corneal biomechanics measurement instruments include ocular response analyzer (ORA) and corneal visualization scheimpflug technology (Corvis-ST), which are all commonly used in clinical practice.Some studies showed that the corneas in glaucoma patients were more easily to deform.Corneal biomechanical characteristics may reflect the anatomic structure weakness of the eyeball.For example, more easily deforming of cornea results in smaller tolerance of sclera and lamina cribros to intraocular pressure, which makes the optic disc more vulnerable.This may be one of the causes of glaucomatous optic nerve damage.Corneal biomechanical parameters have a certain extent relationship with the severity of glaucoma.In order to probe into the pathogenesis of glaucoma deeply, we reviewed corneal biomechanics characteristics, application of corneal biomechanical properties measuring instruments in clinical practice and the relationships between corneal biomechanics characteristics and the development and progression of glaucoma, as well as the therapeutic effectiveness of glaucoma. Key words: Glaucoma; Corneal biomechanical parameters; Ocular response analyzer; Corneal visualization scheimpflug technology

Corneal remodeling and enhancement after small incision lenticule extraction

Small incision lenticule extraction (SMILE) is a new option for corneal refractive surgery, which has developed quickly in recent years.Although modern corneal refractive surgery has reached a high success rate, enhancement may be required after refractive surgery.Reasons for enhancement include initial overcorrection or undercor rection and refractive regression, corneal epithelium and stromal remodeling are two main factors contributing to refractive regression.The corneal remodeling process and the risk factors of enhancement after SMILE, and the potential enhancement strategies and their effects, and wound healing process and corneal biomechanics after enhancement are important issues in clinic.This article reviewed relevant literatures and focused on the above issues. Key words: Refractive surgery procedures; Small incision lenticule extraction; Corneal remodeling; Risk factor; Enhancement

The role of autophagy and potential therapeutic effect of autophagy regulation in cornea diseases

Autophagy is a metabolic process of lysosomal-mediated degradation of damaged proteins or aging organelles, which plays an important role in maintaining the stability of intracellular environment and achieving cell metabolism and circulation.Recent studies have shown that autophagy is closely related to the development of many ocular diseases, including cataract, glaucoma, retinal detachment, diabetic retinopathy and age-related macular degeneration.In keratopathy, including granular corneal dystrophy type 2 (GCD2), Fuchs corneal endothelium dystrophy (FECD), keratitis, keratoconus (KC), corneal injury and repair, dry eye and so on, autophagic disorder can affect corneal transparency, and even lead to blindness.Regulating autophagic activity may be one of the hotspots in the study of corneal disease.This article reviews the role of autophagy and the potential therapeutic effect of autophagy regulation in cornea diseases. Key words: Autophagy; Cornea diseases; Therapy

Cultivation and identification of keratoconus associated-fibroblasts

Objective To culture and identify corneal fibroblasts from human keratoconus patients (HKCs). Methods HKCs and corneal fibroblasts from human healthy controls (HCFs) were cultured by tissue block adherence method.Cellular morphology and ultrastructure were observed by inverted phase contrast microscope and electron microscopy respectively.Cell viability was detected by cell counting kit-8 (CCK-8) assay.α-Smooth muscle actin (α-SMA), collagen type 1 alpha 1 (COL1A1) and collagen type 3 alpha 1 (COL3A1) protein expression levels were detected by Western blot.This study protocol was approved by Ethic Committee of Xi'an No.1 Hospital (No.1504). Results Compared with HCFs, HKCs showed several distinguishing properties.First of all, its growth speed was faster, with collagen fibers decreased and attenuated.At the same time, mitochondrion swelled and mitochondrial cristae disappeared.Additionally, Golgi apparatus presented significant expansion and endoplasmic reticulum displayed severe swelling.There were statistically significant differences in A values between the two kinds of corneal fibroblasts at different time points after culture (Fgroup=5 023.13, P<0.01; Ftime=38 518.16, P<0.01), the A value of HKCs was significantly higher than that of HCFs at the same time point, and the difference was statistically significant (all at P<0.01). The relative expression of α-SMA, COL3A1 and COL1A1 was 120.00±5.77, 158.33±4.41 and 88.33±1.67, respectively in HKCs, the relative expression of α-SMA, COL3A1 and COL1A1 was 100.00±0.00, 100.00±0.00 and 100.00±0.00, respectively in HCFs, the relative expressions of α-SMA and COL3A1 were significantly increased in HKCs than those in HCFs, the relative expression of COL1A1 was significantly decreased in HKCs than that in HCFs, with significant differences between them (t=-3.46, P<0.05; t=-13.23, P<0.01; t=7.00, P<0.05). Conclusions HKCs are cultured and identied, which is suitable for establishing in vitro cell model of keratoconus. Key words: Keratoconus; Fibroblasts; Cell culture; Identification

The effect of Fluconazole anterior chamber irrigation combined with extended care in patients with severe fungal corneal ulcer

Objective To investigate the effect of fluconazole anterior chamber irrigation combined with extended nursing on severe fungal corneal ulcer patients after debridement combined with amniotic membrane transplantation. Methods A total of 90 patients with severe fungal corneal ulcer who were included in the inclusion criteria were divided into two groups by random number table method, 45 patients in each group.Patients in the control group were treated with debridement combined with amniotic membrane transplantation.Discharge guidance was given at discharge, and regular telephone follow-up was conducted after discharge.On the basis of the control group, the patients in the experimental group were given fluconazole anterior chamber irrigation combined with extended care. Six months later, compliance behavior, therapeutic efficacy and complications were compared between the two groups. Results The total effective rate of treatment in the experimental group was 90.00%, which was significantly higher than that in the control group's 52.50%, and the difference was statistically significant(P<0.01). Compliance behavior of patients in the experimental group was significantly higher than that in the control group, and the difference was statistically significant(P<0.05). The incidence of complications such as corneal stromal edema, subepithelial fog formation, drug toxic keratitis was significantly lower in the experimental group than in the control group, and the difference was statistically significant(P<0.01). Conclusions In patients with severe fungal corneal ulcer, fluconazole injection was used to flush the anterior chamber after surgery, and the concentration of antifungal drugs in the aqueous chamber of the affected eye was increased, thus improving the effect of antifungal infection.By providing extended care for patients, the relationship between nurses and patients was strengthened, the patient compliance behavior and nursing cooperation were improved, the overall effect of treatment was ensured, the incidence of complications was reduced, and the safety of patients was guaranteed. Key words: Corneal ulcer; Fungus; Fluconazole; Therapeutic effect; Extended nursing

Big bubble assisted deep anterior lamellar keratoplasty for the treatment of descemetocele

Objective To evaluate the efficacy of deep anterior lamellar keratoplasty(DALK) assisted with big bubbles for the treatment of descemetocele. Methods The data of 7 eyes of 7 cases with descemetocele from Jun.2017 to Oct.2017 underwent DALK assisted with big bubbles with tissue-engineered cornea were analyzed retrospectively.The followed-up time was 6 months. Results All patients were managed to keep their eyeballs.There was no corneal perforation or descemet membrane detachment after DALK.At 14 days after surgery, no edema in the corneal stroma of all tissue engineering cornea occurred with the SL-OCT examination.At 6 months after surgery, the uncorrected visual acuity was 0.1- 0.3 in 6 eyes.The whole corneal neovascularization was observed in 1 eye, whose uncorrected visual acuity was HM.During follow-up, no recurrence occurred.No endothelial rejection, secondary glaucoma or cataract occurred.Mild epithelial immune rejection occurred in 4 eyes, and the grafts were restored to be transparent after anti-rejection treatment.One eye suffered temporary high IOP.The IOP returned to normal after medicine treatment. Conclusion DALK assisted with big bubble with tissue-engineered cornea is an effective method for the treatment of descemetocele. Key words: Keratoplasty, deep lamellar, big bubble, assisted with; Tissue-engineered cornea; Descemetocele

Efficacy of application of bandage contact lens for the treatment of corneal epithelial abrasions

Objective To evaluate the efficacy of application of bandage contact lens for the treatment of corneal epithelial abrasions. Methods A non-randomized control study. The data of 25 eyes of 25 cases with corneal epithelial abrasions from Aug. 2016 to May 2018 were analyzed. All cases were divided into two groups. The contact lens group, 12 eyes of 12 cases, wore bandage contact lens continuously overnight. The bandaging group, 13 eyes of 13 cases, received pressure dressing after the use of Ofloxacin ointment. The efficacy was compared between the two groups, and the cost-effectiveness was analyzed. Results All cases were treated successfully without complication. The difference of ophthalmic pain score before treatment was not statistically significant between the two groups (P=0.953). The ophthalmic pain score of the two groups after treatment were lower than that before treatment (P=0.001, 0.005). The reduction of ophthalmic pain score was 1.75±0.45 in contact lens group, which was more significant than that in bandaging group(0.62±0.51, P=0.000). The difference of total costs was not statistically significant between the two groups (P=0.347). Conclusion Bandage contact lens is more effective in relieving ophthalmic pain than pressure dressing. Key words: Corneal, epithelial abrasions; Bandage, contract lens; Pain; Cost-effectiveness

Wood's Lamp Exam Is Not Sufficient to Rule Out Corneal Pathology

Slit lamp exam is considered the gold standard for diagnosing corneal and conjunctival pathology but is not available in all emergency departments, and

Trehalose in ophthalmology.

Trehalose, a disaccharide of glucose, is a naturally occurring nontoxic and nonreducing bioactive sugar. Trehalose is synthetized by many organisms when cells are exposed to stressful conditions, including dehydration, heat, oxidation, hypoxia or even anoxia. Although trehalose is not synthesized by mammalian cells, it has recently been demonstrated to have a number of important properties that indicate its utility in humans. Trehalose enables wound healing by protecting cells, especially cell membranes, from oxidative injury and dessication. When the injured cornea is treated with trehalose, corneal inflammation, scar formation and corneal neovascularization are suppressed. In dry eye disease, trehalose decreased cell apoptosis and reduced oxidative, inflammatory and proteolytic activity at the ocular surface. In UVB irradiated cornea, trehalose suppressed photodamage evoked by UVB rays. It decreased the intracorneal inflammation and reduced corneal neovascularization. Trehalose prevented postoperative fibrous scar formation after ocular surgery, such as glaucoma filtration surgery. The non-toxicity of trehalose allows its administration in humans for extended periods and enables its use in various disease states.

Evaluation of corneal and lens density changes after cross-linking in keratoconus

Background Corneal cross-linking (CXL) is an important modality for keratoconus therapy. Lens and corneal density are reported to change in keratoconus and with CXL. However, these changes are not well studied. Aim The aim of this study was to evaluate the changes in corneal and lens density in patients with keratoconus after corneal CXL. Patients and methods This is a prospective case series study that was conducted in a private Eye Laser Center, Menoufia Governorate, Egypt. The study consisted of patients with bilateral clinical keratoconus whose age ranging between 15 and 40 years with clear lenses. Bilateral minimum corneal thickness of 400 µm, measured with Pentacam, was essential. All study patients were examined preoperatively and 1, 3, and 6 months postoperatively. Ophthalmic examination included uncorrected distance visual acuity, corrected distance visual acuity, and manifest refraction as well as corneal thickness, thinnest location, maximal keratometric reading (Kmax), and corneal and lens densitometry measured by Pentacam. Results The preoperative mean corneal density on the axis 0–180 was 17.3±1.8, which changed to 20.7±2.01 after 6 months postoperatively (P=0.001). Although the preoperative mean corneal density on the axis of 90–270 was 17.4±2.06, it changed to 19.9±2.4 after 6 months postoperatively (P=0.04). No significant changes were encountered in lens density after CXL. Conclusion Corneal CXL significantly increased the corneal but not the lens density. This increase was maximal after 1 month and gradually returned toward the baseline. CXL is considered as a safe procedure for the lens.