Lattice Corneal Dystrophy Research Articles

Can unilateral lattice dystrophy be triggered by cataract surgery in an elderly patient?

ABSTRACT Purpose Aim is to report unilateral lattice corneal dystrophy (LCD) possibly triggered after cataract surgery in an elderly patient and to demonstrate anterior segment optic coherence tomography (AS-OCT) findings. Case Report A 77-year-old male presented with irritation and photophobia in the left eye. His medical history revealed that the patient had undergone cataract surgery on the left eye 5 months ago and his symptoms exaggerated after the surgery. Best corrected visual acuity (BCVA) was 20/32 in OD and 20/63 in OS. Slit lamp examination indicated clear cornea with nuclear sclerosis in the right eye, multiple fine lattice lines at the level of middle stroma in the left eye. The lattice lines extended radially but did not involve the limbus. The overlying epithelium was intact. AS-OCT was consistent with LCD in the left eye with the presence of hyperreflective material at the level of the middle stroma. In contrast, AS-OCT in the right eye showed a normal, healthy cornea. Conclusion LCD is an inherited disease that can rarely present with unilateral involvement. Apart from its unilaterality and lack of limbal-limbal extension, the time of onset of the lattice lines is another distinguishing feature of this case report. Herein, clinical findings appeared at an older age compared to the literature. In addition, the occurrence of findings after phacoemulsification surgery has raised the question that environmental factors may trigger the emergence of unilateral LCD in patients with genetic predisposition. It is not yet known whether unilateral LCD is an asymmetric and asynchronous presentation of bilateral LCD or a different entity triggered by external factors. AS-OCT enables to demonstrate the corneal microstructural changes, and confirm the diagnosis of unilateral LCD by showing that the fellow eye is healthy.

Ophthalmic drug effects on the amyloidogenesis of a transforming growth factor β-induced protein (TGFBIp) peptide fragment

Drugs that can treat one disease may either be detrimental or beneficial toward another due to possible cross-interactions. Therefore, care in choosing a suitable drug for patients with multiple diseases is crucial in successful patient management. This study explores several currently available ophthalmic drugs used to treat common ocular diseases to understand how they can affect the amyloidogenesis of a transforming growth factor β-induced protein (TGFBIp) peptide fragment found in abundance in the corneal protein aggregation deposits of lattice corneal dystrophy (LCD) patients. Results from this study provided supporting evidence that some drugs intended to treat other diseases can enhance or inhibit fibrillar aggregation of TGFBIp peptide, which may have potential implication of affecting the disease progression of LCD by either worsening or ameliorating it. Comparisons of the different properties of ophthalmic compounds explored in this study may also provide some guidance for future design of drugs geared toward the treatment of LCD.

IC3D Classification of Corneal Dystrophies-Edition 3.

The International Committee for the Classification of Corneal Dystrophies (IC3D) was created in 2005 to develop a new classification system integrating current information on phenotype, histopathology, and genetic analysis. This update is the third edition of the IC3D nomenclature. Peer-reviewed publications from 2014 to 2023 were evaluated. The new information was used to update the anatomic classification and each of the 22 standardized templates including the level of evidence for being a corneal dystrophy [from category 1 (most evidence) to category 4 (least evidence)]. Epithelial recurrent erosion dystrophies now include epithelial recurrent erosion dystrophy, category 1 ( COL17A1 mutations, chromosome 10). Signs and symptoms are similar to Franceschetti corneal dystrophy, dystrophia Smolandiensis, and dystrophia Helsinglandica, category 4. Lisch epithelial corneal dystrophy, previously reported as X-linked, has been discovered to be autosomal dominant ( MCOLN1 mutations, chromosome 19). Classic lattice corneal dystrophy (LCD) results from TGFBI R124C mutation. The LCD variant group has over 80 dystrophies with non-R124C TGFBI mutations, amyloid deposition, and often similar phenotypes to classic LCD. We propose a new nomenclature for specific LCD pathogenic variants by appending the mutation using 1-letter amino acid abbreviations to LCD. Pre-Descemet corneal dystrophies include category 1, autosomal dominant, punctiform and polychromatic pre-Descemet corneal dystrophy (PPPCD) ( PRDX3 mutations, chromosome 10). Typically asymptomatic, it can be distinguished phenotypically from pre-Descemet corneal dystrophy, category 4. We include a corneal dystrophy management table. The IC3D third edition provides a current summary of corneal dystrophy information. The article is available online at https://corneasociety.org/publications/ic3d .

Classic lattice corneal dystrophy: a brief review and summary of treatment modalities.

To provide a brief summary and comparison of the most recent literature on available and theorized treatment modalities for classic lattice corneal dystrophy (LCD). This paper aims to support practitioners in their management of this disease. A search was carried out on available literature through PubMed and Google Scholar of English language articles up to January 2023 that relate to the treatment of LCD. Due to scarcity of literature regarding specific novel therapies for LCD, results from other corneal pathologies (granular corneal dystrophy, corneal scarring) are sometimes included for contrast, which is clearly denoted. LCD is a slowly progressive disease that leads to recurrent epithelial corneal erosions, stromal haze, corneal opacification, substantial discomfort, and visual impairment. Due to its autosomal-dominant inheritance pattern, this disease can persist throughout ancestral lines and requires consistent treatment and follow-up. An optimal management plan is necessary to (1) prolong years of life with best achievable visual acuity; (2) treat painful recurrent corneal erosions as they occur; (3) ensure proper follow-up throughout the life of a patient, as well as monitor at-risk offspring; and (4) monitor efficacy of treatment. This paper addresses (1) treatment for early disease including corneal epithelial debridement, photo therapeutic keratectomy (PTK), femtosecond laser-assisted lamellar keratectomy (FLK), and others; (2) treatment for late disease including full thickness keratoplasties and anterior lamellar keratoplasties; and (3) potential future treatment considerations including a wide variety of topical/systemic, genetic, and regenerative approaches.

A Novel Heterozygous TGFBI c.1613C>A Pathogenic Variant is Associated With Lattice Corneal Dystrophy in a Chinese Family

To investigate the gene mutations and relationship of clinical manifestation in a Chinese family with familial lattice corneal dystrophy (LCD). Single-family case-control study. A family with familial LCD was recruited for this study. A total of 10 affected and 13 healthy family members participated in this research. Clinical features were examined by slit-lamp examination and anterior segment optical coherence tomography (AS-OCT). Peripheral blood samples were collected from each participant, and genomic DNA was extracted. Whole-exome sequencing (WES) analysis was performed, and the pathogenic variants of LCD were identified using bioinformatics tools and confirmed by Sanger sequencing. Slit-lamp examination revealed diffuse grayish-white punctate, linear, and "lattice-like" opacities in the corneal epithelium and superficial corneal stroma. AS-OCT revealed an irregularly shaped cornea. The corneal epithelium and anterior corneal stroma showed high-reflective deposits and bulges. The clinical appearance of the patients fit the pattern and features of autosomal dominant inheritance of LCD type I (LCD I). A novel pathogenic variant of exon 12 in TGFBI was found by WES analysis, in which cytosine at position 1613 was substituted by adenine (c.1613C>A), and the amino acid was changed from threonine to lysine (p.T538K). Mutated genes and proteins were predicted to be deleterious. A novel heterozygous pathogenic variant (c.1613C>A) of TGFBI was identified in the Chinese family with LCD I.

Effects of the pharmaceutical formulation of topical medications on corneal epithelial healing after phototherapeutic keratectomy.

To determine the effect of the formulation of topical medications on the healing of corneal epithelial cells after phototherapeutic keratectomy (PTK). Retrospective cohort study. We studied 271 eyes of 189 consecutive patients (aged 67.6 ± 11.8 years) who had undergone PTK for granular corneal dystrophy (n = 140), band keratopathy (n = 47), or lattice corneal dystrophy (n = 2). Postoperatively, generic or brand-named levofloxacin, 0.1% betamethasone, or 0.1% bromfenac sodium hydrate was applied topically. Patients were examined on postoperative days 1, 2, and 5 and weekly thereafter. The time to re-epithelialization was assessed by use of Kaplan-Meier and Cox proportional hazards analyses. The time to re-epithelialization was significantly longer with generic 0.5% levofloxacin, at 8.2 ± 3.5 days, than with 0.5% Cravit (levofloxacin), at 6.7 ± 3.5 days (P = 0.018), or with 1.5% Cravit, at 6.3 ± 2.6 days (P = 0.000). In addition, the time to re-epithelialization was significantly longer with generic 0.1% betamethasone (Sanbetason), at 7.3 ± 3.4 days, than with brand-name 0.1% betamethasone (Rinderon), at 6.1 ± 2.5 days (P = 0.0002). The Cox proportional hazards model indicated that the use of generic formulations for levofloxacin eye drops and 0.1% betamethasone was a significant factor that delayed corneal re-epithelialization (hazard ratio [HR] = 0.72, P = 0.002 and HR = 0.77, P = 0.006, after adjustment for age). Re-epithelialization was significantly shorter in band keratopathy than in corneal dystrophy (HR = 1.56, P = 0.004). No other factors, including age, bandage contact lens, and diabetes mellitus, were significantly associated with time to re-epithelialization. Corneal epithelial healing can be significantly affected by different antibacterial or steroid eye drops. Clinicians need to be aware that a generic formulation may affect corneal epithelial healing.

Management of Stromal Corneal Dystrophies; Review of the Literature with a Focus on Phototherapeutic Keratectomy and Keratoplasty.

Corneal dystrophies are a group of non-inflammatory inherited disorders of the cornea. This review considers treatment options for epithelial-stromal and stromal corneal dystrophies: namely Reis-Bücklers, Thiel-Behnke, lattice, Avellino, granular, macular and Schnyder corneal dystrophies. Where there is visual reduction, treatment options may include either phototherapeutic keratectomy (PTK) or corneal transplantation. Due to the anterior location of the deposits in Reis-Bücklers and Thiel-Behnke dystrophies, PTK is considered the treatment of choice. For lattice, Avellino, granular and macular corneal dystrophies, PTK provides temporary visual improvement; however, with recurrences, repeat PTK or a corneal transplant would be needed. For Schnyder dystrophy, should treatment be required, PTK may be the preferred option due to the potential for recurrence of the disease in corneal transplantation. This review discusses the literature and evidence base for the treatment of corneal dystrophies in terms of visual outcomes and recurrence rate.

Topical Losartan: Practical Guidance for Clinical Trials in the Prevention and Treatment of Corneal Scarring Fibrosis and Other Eye Diseases and Disorders.

Losartan is an angiotensin II receptor blocker (ARB) that impedes transforming growth factor (TGF) beta signaling by inhibiting activation of signal transduction molecule extracellular signal-regulated kinase (ERK). Studies supported the efficacy of topical losartan in decreasing scarring fibrosis after rabbit Descemetorhexis, alkali burn, and photorefractive keratectomy injuries, and in case reports of humans with scarring fibrosis after surgical complications. Clinical studies are needed to explore the efficacy and safety of topical losartan in the prevention and treatment of corneal scarring fibrosis, and other eye diseases and disorders where TGF beta has a role in pathophysiology. These include scarring fibrosis associated with corneal trauma, chemical burns, infections, surgical complications, and persistent epithelial defects, as well as conjunctival fibrotic diseases, such as ocular cicatricial pemphigoid and Stevens-Johnson syndrome. Research is also needed to explore the efficacy and safety of topical losartan for hypothesized treatment of transforming growth factor beta-induced (TGFBI)-related corneal dystrophies (Reis-Bu¨cklers corneal dystrophy, lattice corneal dystrophy type 1, and granular corneal dystrophies type 1 and type 2) where deposited mutant protein expression is modulated by TGF beta. Investigations could also explore the efficacy and safety of topical losartan treatments to reduce conjunctival bleb scarring and shunt encapsulation following glaucoma surgical procedures. Losartan and sustained release drug delivery devices could be efficacious in treating intraocular fibrotic diseases. Dosing suggestions and precautions that should be considered in trials of losartan are detailed. Losartan, as an adjuvant to current treatments, has the potential to augment pharmacological therapeutics for many ocular diseases and disorders where TGF beta plays a central role in pathophysiology.

Clinical and Histopathologic Characteristics and Template of the TGFBI p.(His626Arg) Missense Variant Lattice Corneal Dystrophy.

The aim of this study was to define, following the IC3D template format, the clinical and histopathologic phenotype of the p.(His626Arg) missense variant lattice corneal dystrophy (LCDV-H626R), the most common variant lattice dystrophy, and to record long-term outcome of corneal transplantation in this dystrophy. A database search and a meta-analysis of published data on LCDV-H626R were conducted. A patient diagnosed with LCDV-H626R who underwent bilateral lamellar keratoplasty followed by rekeratoplasty of 1 eye is described, including histopathologic examination of the 3 keratoplasty specimens. One hundred forty-five patients from at least 61 families and 11 countries diagnosed with LCDV-H626R were found. This dystrophy is characterized by recurrent erosions, asymmetric progression, and thick lattice lines that extend to corneal periphery. The median age is 37 (range, 25-59) years at the onset of symptoms, 45 (range, 26-62) years at the time of diagnosis, and 50 (range, 41-78) years at the time of the first keratoplasty, suggesting a median interval from the first symptoms to diagnosis and to keratoplasty of 7 and 12 years, respectively. Clinically unaffected carriers have been of age 6 to 45 years. Central anterior stromal haze and centrally thick, peripherally thinner branching lattice lines in the anterior to midstroma of the cornea were noted preoperatively. Histopathology of the host anterior corneal lamella showed a subepithelial fibrous pannus, a destroyed Bowman layer, and amyloid deposits extending to the deep stroma. In the rekeratoplasty specimen, amyloid localized to scarring along the Bowman membrane and to the margins of the graft. The IC3D-type template for LCDV-H626R should help diagnose and manage variant carriers. The histopathologic spectrum of findings is broader and more nuanced than what has been reported.

A Korean family with AGel amyloidosis presenting with progressive facial and bulbar palsies

AGel amyloidosis is an autosomal dominantly inherited disease caused by a <i>GSN</i> mutation, and affected patients typically present with the clinical triad of corneal lattice dystrophy, progressive cranial neuropathy, and cutis laxa. We report a Korean family with AGel amyloidosis with predominant manifestations of facial and bulbar muscle weakness. Whole-exome sequencing revealed a common missense mutation (p.Asp214Tyr) in <i>GSN</i>. This case strongly suggests that AGel amyloidosis should be considered when a patient presents with progressive facial and bulbar palsies.

Corneal irregularity and visual function using anterior segment optical coherence tomography in TGFBI corneal dystrophy

The purpose of this study was to evaluate corneal irregular astigmatism of patients with granular and lattice corneal dystrophy (GCD and LCD). 70 GCD, 35 LCD, and 81 control eyes were included. Anterior and posterior corneal topographic data obtained from anterior segment optical coherence tomography were expanded into four components via Fourier harmonic analysis. These components were compared with healthy eyes and the association between each component and best-corrected visual acuity (BCVA) was investigated. Anterior and posterior components increased in both GCD and LCD eyes. Anterior and posterior components of GCD2, anterior of LCD type 1 (LCD1), posterior of LCD type IIIA (LCD 3A), and type IV (LCD4) significantly increased. BCVA was significantly associated with anterior and posterior components in LCD eyes but not in GCD. The anterior components of LCD1, anterior and posterior of LCD3A, and posterior of LCD4, were positively correlated with BCVA. As conclusions, in GCD eyes, anterior and posterior components differed from those of the control but BCVA was not significantly associated with them. In LCD eyes, the anterior and posterior components increased, and BCVA was significantly associated with the anterior and posterior components.

The alterations of corneal biomechanics in adult patients with corneal dystrophy.

To evaluate the changes of corneal biomechanics in granular, lattice and macular corneal dystrophy (GCD, LCD and MCD), and to assess the agreement of intraocular pressure (IOP) between Corvis ST tonometer (CST) and Goldmann applanation tonometer (GAT) and the agreement of central corneal thickness (CCT) between CST and ultrasound pachymeter (USP) in patients with corneal dystrophy. Fifty-nine eyes with corneal dystrophy (26 eyes with GCD, 18 eyes with LCD and 15 eyes with MCD) and 48 eyes from healthy subjects were included in this study. All subjects received ocular examination and anterior segment photography under slit-lamp microscope. Corneal biomechanical parameters were obtained using CST. IOP and CCT were obtained using GAT and USP, respectively. Mixed-effects models were fitted for group comparisons and Bland-Altman analyses were applied for assessing the agreement of IOP or CCT between devices. GCD, LCD and MCD showed higher First Applanation Deformation Amplitude (A1DA) and Corvis Biomechanical Index (CBI), and a lower Stiffness Parameter at First Applanation (SPA1), compared to controls. After CCT adjustment, MCD group showed a higher A1DA compared to GCD or LCD. The IOP measured by CST demonstrated an overestimated bias to the one obtained by GAT in all groups. The CCT measured by CST and USP showed good agreement in healthy eyes but not in those with corneal dystrophy. Corneal biomechanical alterations were observed in GCD, LCD and MCD. IOP and CCT measured by CST should be interpreted carefully in eyes with corneal dystrophy.

Recurrence and Visual Outcomes of Phototherapeutic Keratectomy in Lattice Corneal Dystrophy: A Cohort Study.

To evaluate recurrence and visual outcomes of phototherapeutic keratectomy (PTK) in lattice corneal dystrophy. Kaplan-Meier survival analyses were retrospectively performed. Recurrence was defined as central biomicroscopic findings of recurrence with decreased visual acuity: loss of at least two lines or visual acuity ≤ 20/40) at any time during the follow-up. Twenty-two virgin eyes and 10 with previous keratoplasty (20 patients; 13 women and 7 men) were studied during a mean of 4.7 ± 3.5 years (range: 11 months to 18 years). One and 5 years after the first PTK (PTK1), 1 of 32 and 12 of 32 eyes, respectively, recurred. The cumulative probabilities of recurrence were 3%, 48%, and 89% in the whole sample at 1, 5, and 10 years, respectively. All cases in the virgin group and 8 eyes in the previous keratoplasty group improved their visual acuity. There were no significant differences in recurrence probability between groups (log-rank test; P = .86). A second PTK (PTK2) was performed in 15 of 32 eyes, with 6 postoperative recurrences recorded. The cumulative probabilities of recurrence in the whole sample were 18%, 30%, and 44% at 1, 3, and 5 years, respectively. Visual acuity improved in 11 of 13 eyes in the virgin group and 2 of 2 eyes in the previous keratoplasty group. Recurrence probability after PTK1 and PTK2 was similar in the whole sample (log-rank test; P = .637). Persistent graft edema after PTK1 in one eye was the only complication found. PTK can be an effective, safe, and repeatable treatment to delay keratoplasty in symptomatic lattice corneal dystrophy. [J Refract Surg. 2022;38(1):43-49.].

An Arg124Cys mutation in transforming growth factor β-induced gene associated with lattice corneal dystrophy type I in a Chinese pedigree.

Purpose:To identify a clinical and genetic form of a large Chinese family with an autosomal-dominant lattice corneal dystrophy type I (LCD I).Methods:The patients’ eyes were examined on the basis of slit-lamp microscopy, and other clinical records were also collected. Genomic DNA was extracted from peripheral leukocytes of the affected patients and their unaffected family members. Each previous reported mutation of the transforming growth factor β-induced gene (TGFBI) gene was amplified by touch-down polymerase chain reaction and directly sequenced to verify the disease-causing mutation.Results:Typical clinical features of LCD I were found by slit-lamp photography in these affected Chinese pedigrees. A heterozygous single base-pair transition from C to T (c.418 C > T), leading to amino acid substitution Arg124Cys (R124C) in the encoded TGFBI protein, was detected in all of the eighteen affected patients. The same mutation was not found in unaffected family members.Conclusion:The R124C mutation hot spot, which was relatively rare in China, was responsible for LCD I in the large family. Molecular genetic analysis of TGFBI gene can offer an accurate diagnosis of patients with lattice corneal dystrophies in the clinical treatment.

Mutation effects on FAS1 domain 4 based on structure and solubility

Mutations in the fasciclin 1 domain 4 (FAS1–4) of transforming growth factor β-induced protein (TGFBIp) are associated with insoluble extracellular deposits and corneal dystrophies (CDs). The decrease in solubility upon mutation has been implicated in CD; however, the exact molecular mechanisms are not well understood. Here, we performed molecular dynamics simulations followed by solvation thermodynamic analyses of the FAS1–4 domain and its three mutants—R555W, R555Q, and A546T—linked to granular corneal dystrophy type 1, Thiel-Behnke corneal dystrophy and lattice corneal dystrophy, respectively. We found that both R555W and R555Q mutants have less affinity toward solvent water relative to the wild-type protein. In the R555W mutant, a remarkable increase in solvation free energy was observed because of the structural changes near the mutation site. The mutation site W555 is buried in other hydrophobic residues, and R557 simultaneously forms salt bridges with E554 and D561. In the R555Q mutant, the increase in solvation free energy is caused by structural rearrangements far from the mutation site. R558 separately forms salt bridges with D575, E576, and E598. Thus, we thus identified the relationship between the decrease in solubility and conformational changes caused by mutations, which may be useful in designing potential therapeutics and in blocking FAS1 aggregation related to CD.

In vivo confocal microscopy qualitative investigation of the relationships between lattice corneal dystrophy deposition and corneal nerves

BackgroundTo investigate the corneal neurotropic phenomenon in patients with lattice corneal dystrophy (LCD) with in vivo laser scanning confocal microscopy (IVCM).MethodsIVCM was performed on a total of 15 patients (28 eyes) with LCD annually at a follow-up. A collection of the data was acquired to be analyzed.ResultsAs indicated by the analysis, the LCD patients’ normal corneal stromal nerves (Grade 0) presented a decline with the prolongation of the follow-ups, corresponding to a gradual increase in grade I and II involving amyloid-wrapped nerve fibers, which demonstrated that the growing amount of amyloid deposit due to the corneal nerve invasion increased slowly over time.ConclusionsThe neurotropic phenomenon could increase with its severity in the corneal lesion of the patients with LCD, and also reflect the distribution of the corneal nerves, to some extent. IVCM provides a rapid, noninvasive way to observe the corneal nerves, which can be an efficient means of better understanding the development of LCD.

Deep anterior lamellar keratoplasty versus penetrating keratoplasty in the treatment of stromal corneal dystrophies

AIM: To compare the efficacy and safety of penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) in the treatment of stromal corneal dystrophy. METHODS: A systematic review and Meta-analysis was conducted for studies comparing visual acuity [best-corrected visual acuity (BCVA) (LogMAR)] and corneal endothelial cell count (ECC) as well as safety outcomes of DALK and PK surgeries, including graft-related outcomes and intraoperative and postoperative complications. Embase, PubMed, and Google Scholar were searched for eligible studies until June 2019. Continuous and dichotomous variables were expressed as weighted mean difference (WMD) and risk ratios (RRs), respectively, along with their respective 95% confidence intervals (CIs). RESULTS: Five comparative studies recruiting 350 patients with macular and/or lattice corneal dystrophy (59.71% males) were eventually included. No significant differences were noted in the mean BCVA after both types of surgeries. However, following DALK procedures, corneal ECC was significantly higher two years postoperatively (WMD=401.62 cell/mm2, 95%CI: 285.39-517.85, P<0.001), and graft and endothelial rejection rates were significantly lower (RR=0.30, 95%CI: 0.14-0.64, P=0.002; RR=0.09, 95%CI: 0.02-0.46, P=0.004, respectively) when compared to patients undergoing PK procedures. However, DALK procedures were associated with increased risks of intraoperative Descemet’s membrane perforations and postoperative double anterior chamber (All P<0.001). CONCLUSION: DALK procedures are relatively more efficacious over the follow up periods with better safety outcomes than PK in patients with stromal CDs, conerning rejection and better visual outcome.

Surgical outcomes of re-excimer laser phototherapeutic keratectomy (re-PTK)

To assess the surgical outcomes of re-excimer laser phototherapeutic keratectomy (re-PTK) for recurrent disease after initial PTK. Retrospective cohort study with historical comparison group. This study involved 56 patients who underwent re-PTK (mean follow-up period: 47.9 ± 36.2 months) at the Baptist Eye Institute, Kyoto, Japan. In all subjects, corrected-distance visual acuity (CDVA) before and after re-PTK was compared. Postoperative recurrence of corneal lesion with a decrease of CDVA of two lines or more was compared with postoperative best CDVA deemed as a significant relapse. The Kaplan–Meier method was used to compare the recurrence rate post-re-PTK with that after the initial PTK. The disease classification in the 78 eyes was heterozygous-type GCD (hetero-GCD, n = 47 eyes), homozygous-type GCD (homo-GCD, n = 13 eyes), band keratopathy (n = 7 eyes), lattice corneal dystrophy (n = 6 eyes), and other (n = 5 eyes). After re-PTK, homo-GCD recurred statistically significantly earlier than hetero-GCD (P = 0.0042). No significant difference was found in the recurrence rate for all diseases between post-re-PTK and post initial PTK (P > 0.05). Surgical outcomes after re-PTK were nearly equal to those after initial-PTK.

Genotypic Homogeneity in Distinctive Transforming Growth Factor-Beta Induced (TGFBI) Protein Phenotypes.

Background: To evaluate the distribution of the transforming growth factor-beta induced (TGFBI) corneal dystrophies in a multi-ethnic population in Singapore, and to present the different phenotypes with the same genotype. Methods: This study included 32 patients. Slit lamp biomicroscopy was performed for each patient to determine the disease phenotype. Genomic DNA was extracted from the blood samples and the 17 exons of the TGFBI gene were amplified by PCR and sequenced bi-directionally for genotype analysis. Results: Regarding phenotypes, the study patients comprised 11 (34.4%; 8 with R555W and 3 with R124H mutation) patients with granular corneal dystrophy type 1 (GCD1), 6 (18.8%; 5 with R124H and 1 with R124C mutation) patients with GCD2, 13 (40.6%; 7 with R124C, 2 with H626R, 2 with L550P, 1 with A620D and 1 with H572R) patients with lattice corneal dystrophy (LCD) and 2 (6.3%; 1 with R124L and 1 with R124C) patients with Reis–Bückler corneal dystrophy. Regarding genotype, R124H mutation was associated with GCD2 (5 cases; 62.5%) and GCD1 (3 cases; 37.5%). R124C mutation was associated with LCD (7 cases; 87.5%) and GCD2 (1 case; 12.5%). All the 8 cases (100%) of R555W mutation were associated with GCD1. Conclusions: Although the association between genotype and phenotype was good in most cases (65.7%; 21 of 32 patients), genotype/phenotype discrepancy was observed in a significant number.

Malady of lattice

Lattice corneal dystrophy (LCD) is rare, bilateral, slowly progressive, inherited condition characterized by amyloid deposition in the corneal stroma. Recurrent corneal erosions most commonly occur with LCD due to abnormal basement membrane complexes incapable of providing normal structural integrity to the epithelial layer predisposing the cornea to microbial infections such as bacterial and fungal keratitis. Amyloid fibrils have also been postulated to cause tissue damage by stimulating local and nonlocal immune cell infiltration into the tissues and producing pro-inflammatory cytokines leading to sterile inflammation. This case is one of the few rare case reports of sterile infiltrates in LCD Type 1, patients identified after multiple treatment failures to the best of our knowledge.