Human corneal anatomy redefined: a novel pre-Descemet's layer (Dua's layer).

PURPOSE: To define and characterize a novel pre-Descemet's layer in the human cornea. DESIGN: Clinical and experimental study. PARTICIPANTS: We included 31 human donor sclerocorneal discs, including 6 controls (mean age, 77.7 years). METHODS: Air was injected into the stroma of donor whole globes (n = 4) and sclerocorneal discs (n = 21) as in the clinical deep anterior lamellar keratoplasty procedure with the big bubble (BB) technique. The following experiments were performed: (1) creation of BB followed by peeling of the Descemet's membrane (DM); (2) peeling off of the DM followed by creation of the BB, and (3) creation of the BB and continued inflation until the bubble popped to measure the popping pressure. Tissue obtained from these experiments was subjected to histologic examination. MAIN OUTCOME MEASURES: Demonstration of a novel pre-Descemet's layer (Dua's layer) in the human cornea. RESULTS: Three types of BB were obtained. Type-1, is a well-circumscribed, central dome-shaped elevation up to 8.5 mm in diameter (n = 14). Type-2, is a thin-walled, large BB of maximum 10.5 mm diameter, which always started at the periphery, enlarging centrally to form a large BB (n = 5), and a mixed type (n = 3). With type-1 BB, unlike type-2 BB, it was possible to peel off DM completely without deflating the BB, indicating the presence of an additional layer of tissue. A type-1 BB could be created after first peeling off the DM (n = 5), confirming that DM was not essential to create a type-1 BB. The popping pressure was 1.45 bar and 0.6 bar for type-1 BB and type-2 BB, respectively. Histology confirmed that the cleavage occurred beyond the last row of keratocytes. This layer was acellular, measured 10.15 ± 3.6 microns composed of 5 to 8 lamellae of predominantly type-1 collagen bundles arranged in transverse, longitudinal, and oblique directions. CONCLUSIONS: There exists a novel, well-defined, acellular, strong layer in the pre-Descemet's cornea. This separates along the last row of keratocytes in most cases performed with the BB technique. Its recognition will have considerable impact on posterior corneal surgery and the understanding of corneal biomechanics and posterior corneal pathology such as acute hydrops, Descematocele and pre-Descemet's dystrophies. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Pseudoactinomyces in cervical mucus.

Actinomyces israelii are gram-positive filamentous bacteria forming yellow sulfur granules. They are the most well known complication of intrauterine contraceptive devices (IUCD). Healthcare staff dealing with reporting cervical smears should be aware of pseudoactinomyces entity in a cervical smears and biopsies as it may raise a false alarm to the clinician and may lead to unnecessary removal of IUCD and/or medical treatment.

Spherical implantable collamer lenses for myopia and hyperopia: 126 eyes with 1-year follow up.

BACKGROUND: To report on 1-year follow up of a series of 126 eyes implanted with a spherical implantable collamer lens (ICL). METHODS: Retrospective case note review of 126 eyes (68 patients) undergoing ICL placement by a single surgeon (TG) to correct preoperative mean spherical equivalents between +8.88 and -20.50 D. Main outcome measures included uncorrected visual acuity (UCVA), refraction, best spectacle-corrected VA, unaided binocular vision, adverse events, operative/postoperative complications and patient symptoms. RESULTS: Complete data were available at 1 year on 121 of the 126 eyes (65 out of 68 patients). At 12 months 86% (104/121) had postoperative UCVA better than or equal to preoperative best spectacle-corrected VA, and 98% (118/121) had UCVA within one line of preoperative best spectacle-corrected VA. Ninety-six per cent (116/121) had postoperative UCVA of 6/9 or better, and 100% had postoperative best-corrected visual acuity of 6/12 or better. Ninety-eight per cent (64/65) patients had unaided binocular vision at 1 year of 6/7.5 or better. Average myopia treated was -8.83 D (116 patients), and average hyperopia +7.14 D (10 patients). Two ICLs were replaced because of high vaulting; one eye had increased intraocular pressure that resolved with smaller ICL placement. Four patients had visually insignificant pigment deposits on the ICL at 3/12, but no pigmentary glaucoma. Five patients noticed haloes around lights at night, none preventing driving. CONCLUSIONS: One-year results from this study, the largest reported clinical investigation of the use of ICLs in New Zealand, support the safety, efficacy and predictability of ICL to treat both hyperopic and myopic spherical refractive errors.

Toric implantable collamer lens for patients with moderate to severe myopic astigmatism: 12-month follow-up.

PURPOSE: To report on the 12-month follow-up of 77 eyes with moderate to high myopic astigmatism implanted with toric implantable collamer lenses (ICLs). METHODS: Retrospective case-note review of 77 eyes from 42 patients undergoing toric ICL placement by one surgeon. Preoperative mean spherical equivalent -2.50 dioptres (D) to -15.00 D myopia and 1.00 D to 7.00 D astigmatism. RESULTS: At 12 months, mean manifest refractive cylinder (MRC) decreased 81% from 2.38 D to 0.44 D. MRC within 1.00 D occurred in 99% (76/77) of eyes, whereas 86% (66/77) had MRC within 0.75 D. 99% (76/77) had postoperative best-corrected visual acuity (BCVA) better than or equal to preoperative values, whereas 78% (60/77) gained up to one line BCVA and 1% (1/77) lost one line BCVA. Uncorrected binocular vision of 6/6 or better occurred in 90% (38/42) of patients compared with binocular BCVA of 6/6 or better in 67% (28/42) preoperatively. One ICL was replaced due to low vaulting. Two eyes with astigmatism of 3.25 D and 3.50 D received subsequent laser in situ keratomileusis (LASIK) to reduce residual small refractive errors. Indications for ICL were: myopia too high for LASIK (73%), cornea too thin for LASIK (44%) and contact lens intolerance (33%). Night halos were reported in 10% (8/77) of eyes at 12 months. One ICL was removed due to unrecognized preoperative glaucoma. There were no cases of cataract formation, or endophthalmitis. CONCLUSION: This study is the largest reported series of toric ICL implantation in New Zealand. It supports the safety, efficacy and predictability of toric ICLs to treat myopic astigmatism.

Depletion of 26S proteasomes in mouse brain neurons causes neurodegeneration and Lewy-like inclusions resembling human pale bodies.

Ubiquitin-positive intraneuronal inclusions are a consistent feature of the major human neurodegenerative diseases, suggesting that dysfunction of the ubiquitin proteasome system is central to disease etiology. Research using inhibitors of the 20S proteasome to model Parkinson's disease is controversial. We report for the first time that specifically 26S proteasomal dysfunction is sufficient to trigger neurodegenerative disease. Here, we describe novel conditional genetic mouse models using the Cre/loxP system to spatially restrict inactivation of Psmc1 (Rpt2/S4) to neurons of either the substantia nigra or forebrain (e.g., cortex, hippocampus, and striatum). PSMC1 is an essential subunit of the 26S proteasome and Psmc1 conditional knock-out mice display 26S proteasome depletion in targeted neurons, in which the 20S proteasome is not affected. Impairment of specifically ubiquitin-mediated protein degradation caused intraneuronal Lewy-like inclusions and extensive neurodegeneration in the nigrostriatal pathway and forebrain regions. Ubiquitin and alpha-synuclein neuropathology was evident, similar to human Lewy bodies, but interestingly, inclusion bodies contained mitochondria. We support this observation by demonstrating mitochondria in an early form of Lewy body (pale body) from Parkinson's disease patients. The results directly confirm that 26S dysfunction in neurons is involved in the pathology of neurodegenerative disease. The model demonstrates that 26S proteasomes are necessary for normal neuronal homeostasis and that 20S proteasome activity is insufficient for neuronal survival. Finally, we are providing the first reproducible genetic platform for identifying new therapeutic targets to slow or prevent neurodegeneration.

Histologic features of transplanted amniotic membrane: implications for corneal wound healing.

PURPOSE: To evaluate the histologic changes occurring in the transplanted amniotic membrane in human eyes. DESIGN: Observational consecutive case series. PARTICIPANTS: Seven consecutive patients who underwent amniotic membrane transplantation (AMT) for bullous keratopathy and subsequently had a penetrating keratoplasty (PK). METHODS: Corneal buttons obtained at PK were examined by light and electron microscopy and by immunohistology with antibodies against CD34 (keratocytes), alpha smooth muscle actin and vimentin (myofibroblasts and fibroblasts respectively). Time from AMT to PK ranged from 2 to 32 months. MAIN OUTCOME MEASURES: Immunophenotypic characteristics of cells populating transplanted amniotic stroma. RESULTS: Amniotic tissue was covered with stratified corneal epithelium with well-defined desmosomes and hemidesmosomes. Transformed corneal stroma-derived cells (CSDCs) could be seen migrating from the anterior stroma, through breaks in the Bowman's zone, into connective tissue of the amniotic membrane. Immunohistology showed that the cells populating amniotic stroma were CD34 negative but positive for vimentin and alpha smooth muscle actin. In 2 samples in which corneal transplants were performed approximately 1 year or more after AMT, some cells in the amniotic stroma showed CD34+ staining. Features of increased metabolic activity and formation of new collagen were seen on electron microscopy. In 2 cases, epithelial cell nests were seen in the amniotic stroma. CONCLUSIONS: The amniotic basement membrane facilitates epithelial cell migration and adhesion. The amniotic stroma supports CSDCs and epithelial cells. Repopulation of the amniotic stroma by CSDCs migrating through breaks in Bowman's zone integrates the amnion with corneal tissue and allows for rebuilding of corneal stroma. Over time, some CSDCs may revert to the resting keratocyte immunophenotype.

Hypocupremia: an under recognized cause of subacute combined degeneration.

It is increasingly evident that a multitude of etiologies can give rise to signal abnormality in the dorsal and lateral columns of the spinal cord, apart from pernicious anemia. We report a case of dorsal and lateral columns signal abnormality related to hypocupremia resulting in progressive sensory ataxia and weakness in the lower and upper limbs, compounded by a recent diagnosis of Sjögren's syndrome.

Randomized, Controlled, Double-Masked, Multicenter, Pilot Study Evaluating Safety and Efficacy of Intranasal Neurostimulation for Dry Eye Disease.

Purpose: We assess the safety and effectiveness of intranasal neurostimulation to promote tear production via the nasolacrimal pathway in subjects with dry eye disease. Methods: A multicenter, randomized, controlled, double-masked pilot study was conducted in adults with dry eye diagnosis and at least one eye with corneal fluorescein staining ≥2 in at least one region or a sum of all regions ≥5 (National Eye Institute grading), basal Schirmer test score ≤10 mm, a cotton-swab stimulated Schirmer score ≥7 mm higher, and an Ocular Surface Disease Index score ≥23. Subjects were randomized to receive active intranasal neurostimulation or sham control intranasal stimulation 4 to 8 times per day. Assessments were scheduled before (unstimulated) and during (stimulated) device application at days 0, 7, 14, 30, and 90. The primary effectiveness endpoint was stimulation-induced change in Schirmer test (with anesthesia) score. Primary safety measure was incidence of device-related adverse events (AEs). Results: Fifty-eight subjects were randomized at nine sites in Australia and New Zealand; 56 completed the 90-day study. Stimulation-induced change in Schirmer score was significantly greater with active intranasal (mean ± SEM, 9.0 ± 2.0) than sham control intranasal stimulation (0.4 ± 0.6; P < 0.001) at day 90. Similar results were observed at days 0, 7, 14, and 30 (P < 0.001). No serious device-related AEs were observed. Mild nosebleed, the most common device-related AE, was reported in five (16.7%) subjects. Conclusions: Intranasal neurostimulation was effective in inducing acute tear production after 90 days of use and generally was well tolerated in subjects with dry eye disease.

Acute angle closure after implantable contact lens insertion unresponsive to surgical peripheral iridectomy.

We present a case of acute angle closure that occurred after insertion of an implantable contact lens (ICL). The apparent papillary-block angle closure did not resolve after 2 patent iridotomies and a surgical iridectomy, but did respond to pupil dilation (not constriction). Ultrasound biomicroscopy revealed abnormally large and irregular ciliary processes that may have contributed to the unusual behavior of the ICL-iris complex. The condition resolved after the ICL was replaced by one with a smaller haptic diameter. Routine ultrasound biomicroscopic assessment of the ciliary body anatomy preoperatively and ICL haptic positioning postoperatively may identify risk factors that could predispose ICL patients to acute angle closure.

Outbreak of diffuse lamellar keratitis caused by marking-pen toxicity.

PURPOSE: To examine the evidence that a series of cases of diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK) was caused by a type of marker pen. SETTING: Eye Institute, Auckland, New Zealand. METHODS: During a 10-week period, 522 consecutive LASIK procedures were performed using a 60 Hz IntraLase femtosecond laser (IntraLase Corp.) to create the LASIK flap and a 217Z 100 Hz excimer laser (Bausch & Lomb) to perform the refractive ablation. As standard practice, a marking pen was used to enable accurate flap realignment. Three weeks after a sudden increase in the incidence of DLK was identified, one of the 5 surgeons performed 5 consecutive bilateral cases using the marking pen in the right eyes but not in the left eyes. RESULTS: Of the 522 LASIK cases (119 without marking pen, 403 with marking pen), DLK developed in 49 (9.4%). No eye treated without the marking pen developed DLK; of those in which the marking pen was used, 49 (12.2%) developed DLK (P<0.0001, Fischer exact test; odds ratio, 27). In the 5 consecutive bilateral cases in which the marking pen was used in the right eye but not the left eye, 4 right eyes and no left eye developed DLK (P=0.03). Forty-five of the 49 eyes with DLK quickly recovered. The other 4 developed central toxic keratopathy. CONCLUSION: There is strong statistical evidence that the marking pen was a factor in the occurrence of DLK.

Learning needs in clinical biochemistry for doctors in foundation years.

BACKGROUND: Most medical school curricula have reduced the amount of time available for teaching in pathology despite the fact that junior staff in the early stages of their training were responsible for requesting the majority of pathology tests on acutely ill hospital patients. So, the lack of specific training in this area means that test requesting may be poorly performed and the results ill understood by these staff. This paper describes a questionnaire, which was designed to assist laboratory staff providing targeted teaching in this area. METHODS: Doctors in Foundation year 1 (F1) and Foundation year 2 (F2) in Sheffield teaching hospitals were given a questionnaire to ascertain how confident they were in requesting and interpreting the results of clinical biochemistry tests. The doctors were also asked about which areas of laboratory medicine they would like to be taught. RESULTS: Responses were received from 82 doctors, about half those in F1 and F2. The survey revealed areas where juniors are less confident in requesting tests and interpreting results. Despite lack of confidence in interpreting the result, 18% were confident about requesting tests. Doctors were also unsure of the effects of common problems like haemolysis on the interpretation of results. More than 70% of the doctors requested specific teaching in these areas. CONCLUSIONS: Foundation doctors have learning needs in clinical biochemistry, addressing which would assist them in patient care. While better training in medical school may help in future, there are specific needs for those on the wards now that require targeted teaching.

Morphological characteristics of the limbal epithelial crypt.

AIM: In 2005 we reported the discovery of a novel anatomical structure at the limbus, which we termed the limbal epithelial crypt (LEC). The purpose of this study was to further evaluate the distribution, immunophenotypical, and ultra structural characteristics of the LEC as a putative niche of stem cells. METHODS: Sequential histological sections of human corneo-scleral limbal rims were examined for the presence and distribution of the LEC. Immunophenotypical characterisation of the LEC cells using a panel of antibodies of interest was undertaken. Transmission electron microscopy of the LEC was used to examine the ultra structural and morphometric features of cells within the LEC and adjacent limbus. RESULTS: A total of 74 LECs were identified in eight corneo-scleral rims. These varied in number, size and distribution within rims. Cells within the crypt demonstrated the following phenotype: CK3-/CK19+/CD 34-/Vimentin+/p63+/Connexin 43+/MIB1 (Ki67)-. Presence of Cx43 was also demonstrated in the rete pegs adjacent to the LEC. Basal cells of the LEC were significantly smaller than basal cells found in adjacent rete pegs and also smaller than suprabasal limbal and central corneal epithelial cells (p<0.05). Morphologically they had a high nuclear:cytoplasmic ratio and were adherent to the underlying basement membrane by means of complex convolutions of cytoplasmic processes. CONCLUSIONS: LECs are sparse but a consistent finding in the human corneo-scleral limbus. The LEC contains a unique sub-population of cells expressing several characteristics that are consistent with it representing a putative stem cell niche.

Multifocal lamellar keratitis following laser in situ keratomileusis.

Over a period of approximately 7 months, multiple subepithelial spots were noted in one or both corneas of some patients examined 2 to 6 months after laser in situ keratomileusis (LASIK). The lesions appeared identical to adenovirus keratitis. The eyes were quiet, had good vision, and no patient had a history of adenoviral keratoconjunctivitis. In all eyes, the lesions resolved spontaneously or with topical steroid eyedrops. All investigations were negative for adenovirus. Corneal laser scanning in vivo confocal microscopy revealed Langerhans cells in the epithelium, which disappeared after the lesions resolved.

Alcohol delamination of the corneal epithelium: an alternative in the management of recurrent corneal erosions.

PURPOSE: To investigate the efficacy of alcohol delamination in the management of recurrent corneal erosions (RCEs). DESIGN: Prospective single-center consecutive descriptive case series. PARTICIPANTS: Twelve patients with RCEs who did not respond to conservative management were treated with alcohol delamination. METHODS: A consecutive case series of 12 patients with RCEs who did not respond to conservative management were treated by alcohol delamination. A pain score was generated based on a visual analog scale of pain intensity. The duration of pain and frequency were also recorded. Patients were followed up at 1 week, 4 weeks, 3 months, 6 months, and 1 year and then at yearly intervals and monitored for recurrence of symptoms and corneal morphology. The removed epithelial sheet was examined by electron microscopy in 4 patients. INTERVENTION: The affected area of epithelium was peeled off after an application of 20% alcohol for 40 seconds under topical anesthesia. Eyes of patients were treated with an antibiotic and preservative-free artificial tear medication, and a bandage contact lens was inserted until epithelial healing was complete. MAIN OUTCOME MEASURES: Frequency of recurrence of erosions and duration and intensity of symptoms after alcohol delamination were studied. RESULTS: Eleven of the 12 eyes of patients had dramatic relief of symptoms over the follow-up period, ranging from 6 to 40 months. Eight patients were symptom free, and 1 patient had 2 mild symptom episodes in the first posttreatment month before becoming symptom free. The average follow-up period was 23.5 months. There were no residual effects from the application of alcohol noted in any patient. Electron microscopy of removed epithelium showed features of the underlying pathology. The separation of the epithelium occurred at the interface of the subepithelial abnormal deposit and the surface of Bowman's zone. CONCLUSION: Alcohol delamination appears to be a novel, simple, inexpensive treatment for RCEs. Unlike other methods, the removed epithelium is available as a sheet that may be subjected to further examination, though some of the changes observed may reflect the effect of alcohol on the epithelium.

Acanthamoeba keratitis: the role of domestic tap water contamination in the United Kingdom.

PURPOSE: The incidence of acanthamoeba keratitis (AK) in the UK is some 15 times that in the United States and seven times that in Holland. To investigate reasons for this higher frequency, a study of the role of domestic tap water as a potential source of AK was undertaken. METHODS: Tap outlets from the homes of 27 patients with culture-proven AK were sampled and cultured for free-living amoebae (FLA). For all Acanthamoeba isolates, mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs) and cytochrome oxidase (cox 1/2) sequence typing was performed to determine the similarity between corneal and tap water isolates. RESULTS: FLA, including Acanthamoeba, were isolated from 24 (89%) of 27 homes, and the presence within the homes varied significantly with tap water temperature and location: 19 (76%) of 25 bathroom sink cold taps sampled compared with 6 (24%) of 25 hot and 9 (47%) of 19 kitchen cold taps compared with 3 (16%) of 19 of hot kitchen taps. Acanthamoeba were isolated from 8 (30%) of 27 homes (five bathroom sink cold taps, one cloakroom cold tap, one bath, and one bedroom sink mixer [hot/cold] taps). In six cases, identical Acanthamoeba mtDNA profiles were found for the clinical and home tap water isolates. In keeping with UK plumbing practice, 24 of 27 homes had internal roof water storage tanks to supply domestic taps, but the mains fed the kitchen cold tap. CONCLUSIONS: Water storage tanks promote colonization of domestic water with FLA, including Acanthamoeba, and hence increase the risk of AK. This accounts for the significantly greater incidence of AK in the UK and supports advice to avoid using tap water in contact lens care routines.

Alcohol debridement of the corneal epithelium in PRK and LASEK: an electron microscopic study.

PURPOSE: To determine the plane of cleavage of the corneal epithelium and smoothness of underlying stroma, after alcohol debridement in photorefractive keratectomy (PRK) and laser subepithelial keratectomy (LASEK). METHODS: The epithelial flap from six patients undergoing alcohol delamination of corneal epithelium before PRK and the epithelium and stroma from three eye bank donor eyes were fixed and processed for transmission (TEM) and scanning electron microscopy (SEM). The smoothness of the underlying stroma was studied by SEM and the plane of cleavage was determined by morphologic examination and morphometric measurements of basement membrane attached to the epithelial flap, using image-analysis software. RESULTS: A very smooth stromal bed, ideal for PRK was seen in the stroma of all three eye bank donor eyes after alcohol delamination. The plane of cleavage was determined to be at the hemidesmosomal attachments, including the most superficial part of the lamina lucida of the basement membrane. CONCLUSIONS: Alcohol delamination of the corneal epithelium before PRK or LASEK consistently results in a very smooth cleavage at the level of the hemidesmosomal attachments, including the superficial lamina lucida. It leaves behind a very smooth surface, which is ideal for PRK. It also allows for an intact epithelial flap to be lifted as a sheet from the corneal surface and hence is ideally suited for the LASEK technique.

Mechanisms of parasite-induced sex reversal in Gammarus duebeni.

The amphipod Gammarus duebeni is host to the feminising microsporidian parasite Nosema granulosis that converts males into functional females. To test the hypothesis that the parasite acts through endocrine disruption we compared the morphology of the gonad and activity of the androgenic gland, which coordinates male sexual differentiation, in infected and uninfected animals. Male gonad consisted of testis, seminal vesicle and vas deferens that was anchored to the genital papilla on segment 7. The androgenic gland was associated with the distal end of the vas deferens. In female and intersex animals the bi-lobed ovary opened into the oviduct at segment 5, vestigial vas deferens and vestigial androgenic gland were retained. The majority of parasitised individuals (38/39) were either phenotypic females or intersexes with fully developed ovaries and an undifferentiated androgenic gland. Our data suggest that the parasite prevents differentiation of the androgenic gland. In further support of this hypothesis, mass spectrometry of a single androgenic gland from males revealed a dominant molecular ion with a mass/charge ratio of 4818.4+H, corresponding to a peptide of androgenic gland hormone from Armadillidium vulgare. In contrast the vestigial androgenic gland from parasitised and unparasitised females showed only low intensity peaks. Our observations demonstrate that the parasite manipulates host sex by preventing androgenic gland differentiation, androgenic gland hormone production and consequently male differentiation. This is in agreement with observations of A. vulgare with inherited Wolbachia infection, suggesting that phylogenetically distant feminisers manipulate hosts through a common mechanism. The high frequency of infection in intersexes (89.3%) suggests that this phenotype results from incomplete feminisation by the parasite.

The collagen matrix of the human trabecular meshwork is an extension of the novel pre-Descemet's layer (Dua's layer).

BACKGROUND: The trabecular meshwork (TM) located at the angle of the anterior chamber of the eye contributes to aqueous drainage. A novel layer in the posterior part of the human cornea has recently been reported (the pre-Descemet's layer (Dua's layer (PDL)). We examined the peripheral part of this layer in relation to the origin of the TM. METHODS: The PDL and TM of 19 human donor eyes and one exenterated sample were studied. Samples were examined by light and electron microscopy (EM) for tissue architecture and by immunohistology for four matricellular proteins, five collagen types and CD34. RESULTS: EM revealed that beams of collagen emerged from the periphery of PDL on the anterior surface of the Descemet's membrane and divided and subdivided to continue as the beams of the TM. Long-spacing collagen was seen in the PDL and TM. Trabecular cells (CD34-ve) associated with basement membrane were seen in the peripheral part of the PDL and corresponded to the start of the separation of the collagen lamellae of PDL. Collagen VI was present continuously in PDL and extended into the TM. Matricellular proteins were seen predominantly in the TM with only laminin extending into the periphery of PDL. CONCLUSIONS: This study provides an insight into the origins of the collagen core of the TM as an extension of the PDL of the cornea. This finding adds to the knowledge base of the TM and cornea and has the potential to impact future research into the TM and glaucoma.