In vivo confocal laser scanning microscopy of the cornea in dry eye

BACKGROUND

We carried out an investigation into the morphological and quantitative corneal properties in dry eye with various underlying pathologies.

METHODS

Ten patients with aqueous tear deficiency, 8 with dysthyroid ophthalmopathy, 8 with chronic lagophthalmos and 10 normal participants were examined. Confocal microscope images were taken at the centre and at the lower and upper periphery of the cornea. Quantitative and morphological assessments of the epithelium, of the sub-basal nerves, of the stroma and the endothelium were made. The epithelial and corneal thicknesses were measured.

RESULTS

The mean superficial and intermediate epithelial cell densities in the central cornea in the patient groups were significantly lower than in normal participants (p<0.01). The peripheral epithelial thickness was smaller (p<0.01); it was smallest in the lagophthalmos group. The cornea was thinner in the patient groups (p<0.01). For sub-basal nerves, the density had decreased (p<0.05), and in lagophthalmos the number of beadlike formations had increased (p<0.001); in some patients we found irregular branching patterns.

CONCLUSIONS

Dry eye patients showed significant alterations in the cornea, presumably due to increased desquamation of the superficial cell layer. This was most pronounced at the lower periphery of the cornea in patients with exposure keratopathy.

Use of nerve growth factor to treat congenital neurotrophic corneal ulceration

PURPOSE

This study was designed to assess the efficacy of nerve growth factor in the treatment of neurotrophic corneal ulceration in a child with bilateral congenital corneal anesthesia secondary to trigeminal insufficiency.

METHODS

A 5-month-old child presented to the casualty department with a 2-week history of red eyes and right corneal ulceration. Slit-lamp examination showed a central defect in the right corneal epithelium with underlying stromal opacification, only mild conjunctival inflammation with slight decreased tear production, and otherwise apparently normal eyes. Initially this was investigated as an infected ulcer and treated for several weeks as herpetic ulceration with no beneficial effect. Further clinical examination demonstrated bilateral decreased corneal sensation along with decreased facial sensation in keeping with congenital trigeminal nerve insufficiency. Investigation with magnetic resonance imaging showed no obvious abnormality. Conservative treatment with lubricants resulted in progressive right corneal stromal loss, and no healing occurred in the left corneal ulcer. Bilateral large lateral tarsorrhaphies were performed. Despite this, the left corneal ulcer demonstrated no improvement and increasing stromal opacification was noted. Topical nerve growth factor (NGF) was then used to treat the left cornea and resulted in epithelial healing within 1 week. Treatment was continued for a further 10 days after epithelial healing. Despite conventional treatment on 3 separate occasions, further epithelial breakdown occurred. Topical NGF treatment resulted in a rapid improvement and healing of the epithelial defect.'At present, the patient is receiving a 6-month continuous treatment plan of NGF.

RESULTS

Persistent epithelial defects (PED) secondary to neurotrophic ulceration have responded to topical NGF on 3 separate occasions during a 2-year period. The corneal epithelium now remains intact, and the cornea has no vascularization; however, mild anterior stromal opacification has gradually increased despite prolonged NGF treatment.

CONCLUSION

NGF seems to represent a safe and efficacious treatment option to restore the integrity of corneal epithelium in which there is congenital corneal anesthesia because of trigeminal insufficiency. However, this treatment alone is insufficient to prevent progressive anterior stromal opacification.

Mapping the Corneal Sub-basal Nerve Plexus in Keratoconus by In Vivo Laser Scanning Confocal Microscopy

PURPOSE

To produce a two-dimensional reconstruction map of the living corneal sub-basal nerve plexus in keratoconus with in vivo confocal microscopy.

METHODS

Four eyes of four subjects with keratoconus were examined by slit lamp biomicroscopy, Orbscan II slit-scanning elevation topography (Bausch & Lomb Surgical, Rochester, NY), and laser scanning in vivo confocal microscopy with the Heidelberg Retina Tomograph II, Rostock Corneal Module (Heidelberg Engineering, Heidelberg, Germany). Subjects were asked to fixate on targets arranged in a grid to enable in vivo confocal microscopy of the cornea in a wide range of positions.

RESULTS

A mean of 402 +/- 57 images were obtained for each cornea, to create confluent montages. The mean dimensions of the corneal areas mapped were 6.60 +/- 0.70 mm horizontally and 5.91 +/- 0.72 mm vertically. All corneas exhibited abnormal sub-basal nerve architecture compared with patterns previously observed in normal corneas. At the apex of the cone, a tortuous network of nerve fiber bundles was noted, many of which formed closed loops. At the topographic base of the cone, nerve fiber bundles appeared to follow the contour of the base, with many of the bundles running concentrically in this region. Central sub-basal nerve density was significantly lower in keratoconus corneas (10,478 +/- 2,188 microm/mm2) compared with normal corneas (21,668 +/- 1,411 microm/mm2; Mann-Whitney; P < 0.01).

CONCLUSIONS

This is the first study to elucidate the overall distribution of sub-basal nerves in the living central to midperipheral human cornea in keratoconus, using laser scanning in vivo confocal microscopy.

Herpes zoster ophthalmicus: presenting as giant-cell arteritis

A 74-year-old woman was referred to the authors' clinic with a 1-week suspicion of giant-cell arteritis. Uncomplicated, bilateral temporal artery biopsies were performed 3 days after admission for therapy. Four hours after the procedure she developed vesicular lesions of the face compatible with herpes zoster ophthalmicus. The temporal artery biopsy revealed perineural lymphocytic aggregation. Both giant-cell arteritis and herpes zoster ophthalmicus form part of the differential diagnosis in elderly patients with headache. In such cases, clues from a temporal artery biopsy may aid in diagnosis of herpes zoster. In addition, the patient in this case developed the rash 10 days after onset of symptoms, which is rare as the average time from onset of symptoms to rash in zoster is 3-5 days.

Diagnostic accuracy of trigeminal reflex testing in trigeminal neuralgia

The authors prospectively studied 120 consecutive patients with trigeminal neuralgia (TN) to identify the clinical and laboratory features that most accurately distinguished symptomatic from classic TN. After a standardized evaluation, they identified 24 patients with symptomatic TN. Age, sensory examination, and affected division were not useful in the differential diagnosis. In contrast, electrophysiologic testing of trigeminal reflexes accurately distinguished symptomatic from classic TN (sensitivity 96%, specificity 93%).

Unilateral hypoplasia of the trigeminal ganglion

CASE REPORT

We report a case of unilateral anaesthesia of the V1 (ophthalmic) division of the trigeminal cranial nerve presenting with persistent corneal erosions and ulceration secondary to trigeminal ganglion hypoplasia. The patient had a lifelong history of unexplained left-sided ophthalmic symptoms for which numerous diagnoses were provided. Cranial nerve testing demonstrated partial trigeminal dysfunction on the left side. Further investigation eliminated viral etiologies, and subsequent magnetic resonance imaging determined that the patient had a hypo-plastic left trigeminal ganglion.

COMMENTS

We present the case to alert clinicians to the possibility of this rare condition.

An evaluation of corneal nerve morphology and function in moderate keratoconus

PURPOSE

To investigate corneal nerve morphology and corneal sensitivity in keratoconus.

METHODS

The central cornea of 13 subjects with keratoconus and 13 age-matched control subjects was assessed using in vivo confocal microscopy and corneal aesthesiometry.

RESULTS

Significant differences in corneal nerve fibre density were found between the subjects with keratoconus and the control subjects (keratoconus versus control; 1018.3+/-489.6 microm versus 1820.7+/-789.5 microm; p = 0.006). The mean diameter of nerve fibres in the stroma was found to be greater in subjects with keratoconus compared to control subjects (keratoconus versus control; 10.2+/-4.6 microm versus 5.5+/-1.9 microm; p = 0.007). The orientation of corneal nerve fibres in the subjects with keratoconus appeared to be altered from the predominantly vertical orientation seen in the control subjects. Corneal touch threshold was found to be similar in the two groups, although the subjects with keratoconus using contact lens correction had reduced corneal sensitivity compared to the contact lens-wearing control subjects (keratoconus with contact lenses versus controls with contact lenses; 1.18+/-0.19 g/mm2 versus 0.98+/-0.05 g/mm2; p = 0.03).

CONCLUSION

This study reveals significant reductions in nerve density in the keratoconic cornea. The thickened stromal nerve fibres observed in the keratoconic corneas may explain why prominent corneal nerves are often seen using slit lamp biomicroscopy in keratoconic patients.

Altered Corneal Nerves in Aqueous Tear Deficiency Viewed by In Vivo Confocal Microscopy

PURPOSE

To define the alterations of corneal nerves in aqueous tear deficiency dry eye patients with or without Sjögren syndrome and to identify the relationship between the morphologic changes of corneal nerves and the extent of dry eye.

METHODS

Confocal microscopy was used to examine 38 consecutive aqueous tear deficiency patients (8 Sjögren syndrome and 30 non-Sjögren syndrome) and 30 age- and gender-matched normal controls. Images taken by Confocal2 slit-scanning microscope at subbasal epithelial cell layer of central cornea were analyzed. The number and density of corneal nerves and their size, beads, tortuosity, and branching pattern were compared. These data were correlated with age and the degree of dry eye.

RESULTS

Sjögren syndrome patients showed a significant increase in average nerve number and tortuosity as compared with normal controls (P = 0.031 and 0.021, respectively). Severe nerve tortuosity (grade 4) and nerve branching appeared more frequently in aqueous tear deficiency than in normal subjects (P = 0.024 and 0.042, respectively). A decreased nerve number was observed with age in the normal controls (P = 0.002). However, such a correlation did not exist in aqueous tear deficiency. In aqueous tear deficiency, rose bengal staining score correlated positively with nerve density (P = 0.048) and nerve number (P = 0.001). Corneal fluorescein staining score was also positively correlated with nerve number (P = 0.027).

CONCLUSIONS

Abnormal morphologic changes are observed in aqueous tear deficiency that are more severe in Sjögren syndrome. The distinct changes of corneal nerves include increased nerve number, tortuosity, and chances of branching, suggesting an attempted nerve regeneration. A strong correlation exists between the changes of nerve morphology and the degree of dry eye. These results provide some possible evidence for the abnormal corneal sensation in dry eye.

Ocular Surface Changes in Laser in situ Keratomileusis-induced Neurotrophic Epitheliopathy

PURPOSE

To evaluate the ocular surface changes in patients with laser in situ keratomileusis (LASIK)-induced neurotrophic epitheliopathy.

METHODS

Seven consecutive patients with LASIK-induced neurotrophic epitheliopathy were studied prospectively and compared to a control group (seven consecutive patients who had LASIK- but without neurotrophic epitheliopathy). Bilateral sequential LASIK was performed at a 1-week interval; the first operated eye of each patient was considered for statistical analysis. Blinking, corneal sensitivity, tear break-up time, tear secretion and clearance were measured preoperatively (T0) and postoperatively at 1 week after surgery on the first eye (T1), and 1 week (T2), 1 month (T3), and 3 months (T4) after surgery was performed on the second eye.

RESULTS

Laser in situ keratomileusis-induced neurotrophic epitheliopathy occurred bilaterally in all patients. During follow-up, patients with LASIK-induced neurotrophic epitheliopathy showed a significant decrease in blinking (P = .0002), which was not observed in cases without LASIK-induced neurotrophic epitheliopathy [corrected] Compared to eyes without LASIK-induced neurotrophic epitheliopathy, those with LASIK-induced neurotrophic epitheliopathy revealed lower values of sensitivity in the central cornea preoperatively and early postoperatively (T0, P = .004; T1, P = .003; T2, P = .003). A trend towards reduced sensitivity was also detected in the central cornea in late follow-up and in the superior, temporal, and nasal sectors of the flap at all examinations. No significant differences were observed in break-up time, tear secretion, or clearance within or between the two groups.

CONCLUSION

Decreased blinking seems to be involved in the pathogenesis of LASIK-induced neurotrophic epitheliopathy. The reduction probably depends on the lower levels of corneal sensitivity and induces the epitheliopathy by increasing the ocular surface exposure.

[Analysis of clinical manifestations in nasociliary neuralgia]

OBJECTIVE

To explore the clinical character of nasociliary neuralgia and improve the level of diagnosis and treatment.

METHOD

Forty-three cases with nasociliary neuralgia were diagnosed and treated in our hospital. The clinical data were analyzed retrospectively.

RESULT

It was easy to be misdiagnosed for nasociliary neuralgia,the rate of misdiagnosis was 69.8% (30/43). Performing the resection of upper nasal septum deviation, partial middle turbinetectkomy or/and folded, 43 cases were followed up from 6 to 24 months,the cural rate and the improve rate were 95.3% and 4.7% respectively, with the total effective rate 100.0%.

CONCLUSION

Most patients with nasociliary neuralgia are middle-aged women. It is similar to ethmoid sinusitis and frontal sinusitis in headache, but no suppurative rhinorrhea. Careful examination of nasal cavity and CT scan in sinus play an important role in avoiding misdiagnosis. The corrective surgery of middle turbinate and nasal septum are effective treatment and the complication of dysosmia can be avoided.

Isolated, benign, intraorbital schwannoma arising from the supraorbital nerve. Case report and review of the literature

The authors describe the rare case of a 65-year-old man, with absent clinical evidence of von Recklinghausen's disease, harbouring an isolated, benign schwannoma of the right supraorbital nerve. The patient presented a progressive, painless proptosis of the eye for the past 2 years, did not complain of any intra- or periorbital pain, and did not experience any form of visual disturbance or field defect. The lesion was completely resected using a fronto-orbitozygomatic approach. The clinicopathological, radiological and surgical features are discussed, and the literature on supraorbital nerve schwannomas reviewed. To the authors' knowledge the fronto-orbitozygomatic approach has not been previously reported for the removal of supraorbital nerve tumors.

Corneal nerve tortuosity in diabetic patients with neuropathy

PURPOSE

Corneal confocal microscopy is a reiterative, rapid, noninvasive in vivo clinical examination technique capable of imaging corneal nerve fibers. Nerve fiber tortuosity may indicate a degenerative and attempted regenerative response of nerve fibers to diabetes. The purpose of this study was to define alterations in the tortuosity of corneal nerve fibers in relation to age, duration of diabetes, glycemic control, and neuropathic severity.

METHODS

The cornea and collected images of the subbasal nerve plexus of 18 diabetic patients (stratified into mild, moderate, and severe neuropathic groups using conventional clinical measures of neuropathy) and 18 age-matched nondiabetic control subjects were scanned, and a novel mathematical paradigm was applied to quantify the extent of nerve tortuosity, which was termed the tortuosity coefficient (TC).

RESULTS

TC was significantly different between the four clinical groups (F(3) = 12.2, P < 0.001). It was significantly greater in the severe neuropathic group than in control subjects (P < 0.003) and in the mild (P < 0.004) and moderate (P < 0.01) neuropathic groups. TC did not correlate significantly with the age (r = -0.003, P > 0.05), duration of diabetes (r = -0.219, P > 0.05), or hemoglobin A1c (HbA1c; r = 0.155, P > 0.05) of diabetic patients.

CONCLUSIONS

Corneal confocal microscopy allows rapid, noninvasive in vivo evaluation of corneal nerve tortuosity. This morphologic abnormality relates to the severity of somatic neuropathy and may reflect an alteration in the degree of degeneration and regeneration in diabetes.

Corneal innervation and morphology in primary Sjögren's syndrome

PURPOSE

To analyze the in vivo morphology of the different corneal sublayers and corneal nerves in primary Sjögren's syndrome (SS).

METHODS

Ten eyes of 10 patients with primary SS and 10 eyes of 10 sex- and age-matched control subjects were investigated. Diagnosis was based on American-European consensus criteria. In vivo confocal microscopy with through-focusing was used to investigate corneal morphology and to measure corneal sublayer thickness.

RESULTS

Epithelial punctate staining with fluorescein was observed in 6 of 10 SS and none of 10 control corneas. In addition, Schirmer I test results were significantly lower in SS. Epithelial thickness did not differ between the SS and control groups. Confocal microscopy revealed patchy alterations or irregularities in surface epithelial cells in 6 of 10 SS corneas, whereas the basal epithelium appeared normal in all corneas. Average corneal thickness was lower in the SS group (515.9 +/- 22.0 micro m) than in the control (547.4 +/- 42.0 micro m; P = 0.050, t-test). Accordingly, the mean intraocular pressure was lower in the SS group (13.9 +/- 2.1 mm Hg) than in the control (16.7 +/- 2.9 mm Hg; P = 0.022). The subbasal nerve plexus and stromal nerve fiber bundles were present in all corneas. No difference was noted in nerve density. However, in 4 of 10 SS eyes, the subbasal nerve plexus showed structures resembling nerve sprouting, suggesting ongoing active neural growth. None of the control corneas exhibited such features. Signs of anterior keratocyte activation were observed in 5 of 10 SS corneas.

CONCLUSIONS

In SS, the corneal surface epithelium was irregular and patchy. Anterior keratocytes frequently showed morphologic features of activation. The subbasal nerve fiber bundles revealed abnormal morphology, and the central corneal thickness was reduced by stromal thinning. The findings confirm epithelial, stromal, and neural abnormalities in the corneas of patients with SS.

In vivo confocal microstructural analysis and surgical management of Brown-Mclean syndrome associated with spontaneous crystalline lens luxation

We report 3 members of an extended family who presented with bilateral peripheral corneal edema consistent with Brown-McLean syndrome. On clinical examination, all eyes demonstrated normal central corneas and marked peripheral edema. In vivo confocal microscopy of the peripheral cornea highlighted similar observations in the 6 eyes including endothelial pigmentation, masked stromal structure due to edema, prominent nerves, and localized basal epithelial edema. In the central cornea, in vivo confocal microscopic observations highlighted large cellular structures with prominent nuclei in groups consisting of several cells of similar appearance. In vivo confocal microscopy may enhance the diagnosis of Brown-McLean syndrome and may be used for dynamic evaluation and postoperative follow-up of the structural corneal changes.

[Bilateral neurotrophic keratitis secondary to encephalic trunk metastasis]

CASE REPORT

We report the case of a 69-year-old man with a lung carcinoma history. The patient showed signs of conjuntival hyperemia, painless bilateral corneal edema, persistent epitelial defects and reported to have decreasing visual acuity for a week. The clinical examination revealed a bilateral neurotrophyc keratitis with both a decreased frequency of blinking and a bilateral atrophy mandibular muscles. Local ocular patology was excluded. Systemic exploration showed a meningeal neoplasic infiltration and metastasis on the initial trigeminal nerve stretch. In our knowledge, this is the first case reported in the literature.

DISCUSSION

Ophthalmic signs should be considered in the diagnosis of systemic pathology.

An unusual case of stabbing eye pain: a case report and review of trigeminal neuralgia

BACKGROUND

Trigeminal neuralgia is a painful neurological disorder that affects one or more of the divisions of the trigeminal nerve. It is characterized by brief attacks of stabbing pain that can be excruciating. These attacks may be triggered by a light touch, shaving, or even eating. There has been much debate over the exact etiology of trigeminal neuralgia. One of the main theories is vascular compression of the trigeminal nerve as it leaves the brainstem. Another theory suggests that intracranial tumors--particularly those located in the posterior fossa--may be the cause. Trigeminal neuralgia is also associated with multiple sclerosis.

CASE REPORT AND REVIEW

A 79-year-old man came to the eye clinic with signs and symptoms consistent with trigeminal neuralgia involving the ophthalmic and maxillary divisions of the nerve. A neurological evaluation confirmed the diagnosis, and proper medical treatment was subsequently implemented to relieve his pain.

CONCLUSION

Patients who manifest symptoms consistent with trigeminal neuralgia should be referred for a neurological evaluation, including MRI. With the proper medical and/or surgical treatment, the quality of life of these patients can increase dramatically.

Effects of cyclophotocoagulation with a neodymium:yttrium-aluminum-garnet laser on corneal sensitivity, intraocular pressure, aqueous tear production, and corneal nerve morphology in eyes of dogs

OBJECTIVE

To determine effects of cyclophotocoagulation via administration of 100 J with a neodymium:yttrium aluminum garnet (Nd:YAG) laser on corneal touch threshold (CTT), intraocular pressure (IOP), aqueous tear production, and corneal nerve morphology in eyes of dogs.

ANIMALS

15 dogs.

PROCEDURE

Noncontact Nd:YAG laser was transsclerally applied (10 applications; 25 W for 0.1 seconds for each application to each of 4 quadrants) to the ciliary body of the left eye of 15 dogs; the right eye was the control eye. Corneal integrity, CTT, tear production as measured by the Schirmer tear test (STT), and IOP were evaluated for 14 days following laser treatment. On day 14, dogs were euthanatized, eyes harvested, and corneas stained with gold chloride. Major nerve bundles were analyzed by use of a drawing tube attached to a light microscope, and maximum diameters were measured by use of image analysis software.

RESULTS

All laser-treated eyes had significantly higher CTT values, compared with control eyes. Six of 15 laser-treated eyes developed ulcerative keratitis. On most days, IOP was significantly lower in laser-treated eyes in both morning and evening. Laser-treated eyes had a significant decrease of approximately 1 nerve bundle/corneal quadrant. Values for STT or nerve bundle diameters did not differ significantly.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of 100 J with a Nd:YAG laser effectively reduced IOP while increasing CTT and caused a significant decrease in number, but not diameter, of major corneal nerve bundles. Nerve damage and corneal hypoesthesia are etiologic factors in ulcerative keratitis following Nd:YAG cyclophotocoagulation.

Confocal microscopy in Meretoja syndrome

PURPOSE

To study the correlation between severity of clinical systemic symptoms and the degree of stromal haze and visibility of epithelial and stromal nerves on scanning slit confocal microscopy examination in Meretoja syndrome.

METHODS

Three patients with Meretoja syndrome were examined by slit-lamp microscopy and scanning slit confocal microscopy.

RESULTS

Increased symptoms and abnormal slit-lamp findings correlated positively with confocal microscopic stromal haze intensity and inversely with visibility of epithelial and stromal nerves on confocal examination. A prominent deposit, presumably amyloid, was observed contiguous to a stromal nerve of an affected cornea. In a severely affected cornea, no stromal or epithelial nerves were seen.

CONCLUSION

The results of this study suggest that Meretoja syndrome causes corneal nerve damage and eventual degeneration that correlates with the degree of clinical involvement.

In vivo confocal microscopy after herpes keratitis

PURPOSE

To describe the confocal microscopic findings, with special reference to corneal subbasal nerves, after herpes simplex virus (HSV) keratitis.

METHODS

In this study, 16 HSV eyes and 14 contralateral eyes of 16 patients, diagnosed with unilateral HSV keratitis 1-12 months earlier by the presence of dendritic corneal ulceration or microbiologic confirmation, were examined by in vivo confocal microscopy for evaluation of corneal morphology.

RESULTS

Herpes simplex virus eyes: In 2 eyes the surface epithelial cells appeared large, and no abnormalities were observed in the basal epithelial cells. In 2 eyes subbasal nerve fiber bundles were completely absent, in 3 eyes there was a reduced number of long nerve fiber bundles, and in 11 eyes the subbasal nerve plexus appeared normal. In 10 corneas, highly reflective dendritic structures were found at the level of the basal epithelial cells. Frequently these structures were found in the vicinity of stromal fibrosis. Areas with increased abnormal extracellular matrix were found in 11 eyes. Stromal nerves were not visualized in all corneas, but appeared normal when observed. Contralateral eyes: No abnormalities were observed in the epithelium. All corneas presented with a normal subbasal nerve plexus, but in 2 eyes dendritic particles were observed. Three corneas presented with activated keratocytes and increased amounts of abnormal extracellular matrix.

CONCLUSIONS

When visualized by confocal microscopy, the subbasal nerve plexus appears relatively unaffected in cases with resolved HSV keratitis. Unidentified dendritic structures, presumably Langerhans cells, are frequently seen at the level of the basal epithelium in corneas with a history of herpetic disease.

Laser in situ keratomileusis-induced neurotrophic epitheliopathy

PURPOSE

To report two cases of laser in situ keratomileusis-induced neurotrophic epitheliopathy with punctate epitheliopathy and rose bengal staining of the corneal flap.

METHODS

Interventional case reports.

RESULTS

A 42-year-old woman and a 37-year-old man with no preoperative symptoms or signs of dry eye developed dry eye symptoms and bilateral punctate epithelial erosions as well as rose bengal staining of the corneal flaps after laser in situ keratomileusis. Neither patient had less than 12 mm of wetting with the Schirmer test without anesthesia at any time point between development and resolution of the flap surface abnormalities. The flap surface abnormalities resolved approximately 6 months after laser in situ keratomileusis.

CONCLUSIONS

Laser in situ keratomileusis-induced neurotrophic epitheliopathy may be attributable to loss of trophic influence from severed corneal nerve trunks. The condition typically resolves approximately 6 months after laser in situ keratomileusis or laser in situ keratomileusis retreatment.

Typical ocular findings in a patient with multiple endocrine neoplasia type 2b syndrome

BACKGROUND

Multiple endocrine neoplasia (MEN) type 2b syndrome is accompanied by typical ocular findings; however, the disease is often only diagnosed at an advanced stage by symptoms of C-cell carcinoma or pheochromocytoma and is then fatal in most cases. Therefore, the importance of ophthalmic assessment in making the diagnosis has to be stressed.

METHODS

The history and ocular findings of a patient with MEN 2b syndrome are described, and a brief overview of the syndrome is given.

RESULTS

Slit-lamp examination showed extremely thickened corneal nerves as well as multiple small plexiform and nodular subconjunctival tumors. Both eyes also displayed thickened upper and lower eyelids. A molecular genetic study of the RET proto-oncogene showed a heterozygous ATG to ACG mutation in codon 918 of exon 16.

CONCLUSION

Greatly thickened corneal nerves and subconjunctival tumors may be the first hint of MEN 2b. Whenever greatly thickened corneal nerves are detected, MEN 2b must be ruled out.

Laser in situ keratomileusis-induced (presumed) neurotrophic epitheliopathy

OBJECTIVE

To evaluate tear production, corneal topography, accuracy of refractive correction, and best spectacle-corrected visual acuity in eyes that had moderate to severe rose bengal staining develop on the flap compared with eyes with little or no staining on the flap, the first few months after laser in situ keratomileusis (LASIK). None of the eyes in this study had significant preoperative dry eye disease.

DESIGN

Retrospective case control study.

PARTICIPANTS

Individual eyes of 19 consecutive patients with moderate to severe punctate epithelial erosions and rose bengal staining on the flap 1 to 3 months after LASIK were compared with eyes of 19 concurrent patients who did not have punctate epithelial erosions or more than trace staining on the flap develop.

METHODS

Nonparametric statistical analyses were used to compare tear secretion, corneal topographic irregularity, spherical equivalent, and visual acuity 3 and 6 months after surgery. Some eyes in both groups also had analysis of tear secretion 1 month after surgery.

MAIN OUTCOME MEASURES

Schirmer's test without anesthesia, the topographic corneal irregularity measurement (CIM), the difference between attempted and achieved spherical equivalent, and the loss of best spectacle-corrected visual acuity.

RESULTS

There was no difference in tear production 1, 3, or 6 months after LASIK in patients who had punctate epithelial erosions and rose bengal staining on the flap develop and those who did not. There was no significant difference in the CIM or mean accuracy of the refractive correction in the two groups, but some patients had a transient decrease in best spectacle-corrected visual acuity. Flap rose bengal staining resolved by 6 months after LASIK in most affected patients.

CONCLUSIONS

LASIK-induced rose bengal staining in patients without preexisting dry eye is likely neurotrophic epitheliopathy, because there is no difference in mean tear production between patients who have significant punctate epithelial erosions and rose bengal staining develop on the flap and those who do not. The signs and symptoms of LASIK-induced (presumed) neurotrophic epitheliopathy tend to resolve approximately 6 months after surgery. This disorder tends to be more common and severe in patients with pre-existing dry eye disease.

Corneal morphology and sensitivity in lattice dystrophy type II (familial amyloidosis, Finnish type)

PURPOSE

To describe the corneal abnormalities and to measure different modalities of corneal sensitivity in corneal lattice dystrophy type II (familial amyloidosis, Finnish type, also known as gelsolin-related amyloidosis and originally as Meretoja syndrome).

METHODS

Twenty eyes of 20 patients were examined by in vivo confocal microscopy and noncontact gas esthesiometry.

RESULTS

Pleomorphism of, and dense deposits between or posterior to, the basal epithelial cells were frequently observed, as well as a reduction of long nerve fiber bundles in the subbasal nerve plexus. The anterior stroma was altered in most cases, with fibrosis and abnormal extracellular matrix. In 15 corneas, thick anterior and midstromal filaments, corresponding to lattice lines, and in 11 corneas, thin undulated structures were observed. The average mechanical sensitivity threshold of 12 subjects was increased, and in the remaining 8 subjects there was no response, even to the highest intensity of stimuli used. Three patients did not respond to CO(2), 11 to heat, and 2 to cold, but those patients who responded had normal thresholds. Patients with more long nerve fiber bundles per confocal microscopic image had better mechanical and cold sensitivity than patients with fewer nerve fiber bundles.

CONCLUSIONS

Lattice lines seem to be related to amyloid material and not to corneal nerves. However, the subbasal nerve density appears reduced, which results mainly in a decrease in mechanical and, to a lesser extent, thermal sensitivity. The location of stromal filaments and undulated structures changes with increasing age.