Dynamic changes of ocular surface tissue of diabetic dry eye in mice / 中华实验眼科杂志

Objective To explore the occurring and developing characteristics of dry eye syndrome in type 1 diabetic mouse model induced with streptozotocin (STZ)-intraperitoneal injection.Methods Completely randomized design method was performed.Sixty SPF degree male C57BL/6 mice (6-8 weeks old) was randomly divided into diabetic group and control group,which were intraperitoneally injected with citrate buffer and STZ-citrate buffer (50 mg/kg per day),respectively.The average weight,blood glucose level and lacrimal gland weight were examined before injection and 1 month,2 months,4 months after the last injection;meanwhile,phenol cotton thread and rose bengal staining methods were used to check tear formation and ocular surface condition;corneal perception meter was used to test corneal sensitivity;periodic acid-schiff (PAS) staining method was used to test the density of conjunctival goblet cells;histopathological staining and Masson staining methods were used to test the tissue changes of lacrimal gland.Results Compared with before injections,the body weight and lacrimal gland weight in diabetic group were not significantly changed 1 month,2 months and 4 months after injection (all at P＞ 0.05),but these measurements in diabetic group 1 month,2 months and 4 months after injection were significantly lower than those in control group at corresponding time points (all at P＜0.05).Compared with before injections and control group at corresponding time points,the blood glucose level were dramatically higher and the tear formation were significantly decreased in diabetic group at 1 month,2 months,4 months after injection (all at P＜0.05).The ocular surface of diabetic model mice showed positive rose bengal staining 2 months after STZ injections.The corneal sensitivities were significantly lower in diabetic model mice 2 months and 4 months after injection than those before injection and in control group at corresponding time points (all at P＜0.05).The density of conjunctival goblet cells in diabetic group 4 months after injection was significantly decreased than those before injection in diabetic group and 4 months after injection in control group (all at P＜0.05).The apparent collagen fibrosis and inflammatory cell infiltration were observed at lacrimal gland in diabetic model mice 4 months after injection.Conclusions The major early stage manifestations of STZ induced type 1 diabetes mice include retarded growth of lacrimal gland and decreased tear secretion volume,which gradually develop along the course of diabetes;in the later stage,the manifestations include decreased corneal sensitivity,ocular structural damage,structural changes of lacrimal gland and decreased conjunctival goblet cell density.

Changes of lacrimal film after phacoemulsification / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To observe of cataract phacoemulsification and intraocular lens implantation in patients with postoperative tear film, and to explore its clinical significance. METHODS: A total of 106 patients ( 140 eyes ) undergone phacoemulsification were randomly chosen. Subjective dry foreign body sensation were observed at six nodes of period 1d, 1, 2, 3wk, and 1mo. Corneal fluorescein ( FSC ) , basal tear secretion ( SIT ) and tear film break-up time ( BUT) were used to detect functional changes of the tear film. And the correlation between tear film stability and corneal sensitivity was analyzed. RESULTS: Dry eye cumulative score of postoperative 1d, 1, 2wk was higher than preoperative ( t= 8. 53, P=0.000;t=6. 27, P=0. 000; t=9. 02, P=0. 000). There was no significant difference in dry eye cumulative score at postoperative 3wk, 1mo compared with preoperative ( t=1.91, P= 0. 824; t= 1. 27, P= 0. 069). Corneal epithelial fluorescein staining points of postoperative 1d, 1, 2wk were increased compared with preoperative (t=11. 64, P=0. 000;t=9. 61, P=0. 000; t=8. 87, P=0. 001). There was no significant difference in corneal epithelial fluorescein staining points of postoperative 3wk and 1mo compared with preoperative (t=2. 52, P=0. 746; t=1. 16, P=0. 094). Corneal sensitivity detection values of postoperative 1d, 1, 2wk were significantly higher than that of preoperative (t=9.61, P=0.000;t=9.27, P=0.000;t=11.39, P=0.024), and there was no difference postoperative 3wk and 1mo compared with preoperative (t=1. 19, P=0. 562;t=2. 17, P=0. 501). CONCLUSION: Phacoemulsification with intraocular lens implantation will reduce the tear film stability in the short term, but after a long rest will be improved to a certain extent.

Changes in corneal sensitivity following cross-linking for progressive early-stage keratoconus / Alterações da sensibilidade corneana após cross-linking para ceratocone progressivo em estágio inicial

Purpose: To evaluate changes in corneal sensitivity following corneal cross-linking (CXL) in patients with progressive earlier stage keratoconus. Methods: Thirty-eight eyes of 19 patients (11 women, 8 men) were included in a prospective, nonrandomized clinical study. The mean patient age was 22 years (range, 18-26 years). Inclusion criteria were early stage bilateral progressive keratoconus, a transparent cornea, and a thickness of ≥440 µm in the thinnest area of the cornea. Using the Cochet-Bonnet esthesiometer, central corneal sensitivity was measured before surgery, 7 days after surgery, and once a month thereafter until recovery of baseline preoperative levels. Central corneal sensitivity >40 mm was considered normal. Results: Corneal sensitivity gradually returned to preoperative levels in all treated eyes. The mean central corneal sensitivity was 52.2, 24.0, 38.2, 42.5, 50.0, and 52.5 mm before surgery, 7 days after surgery, and at 1, 2, 3, and 4 months after surgery, respectively. Normal levels of corneal sensation, but not baseline (preoperative) levels, were observed 2 months after surgery. The preoperative levels were observed 3 months after surgery. Conclusions: Our results suggest that central corneal sensitivity can be decreased for as long as 3 months after CXL for progressive earlier stage keratoconus. .

Objetivo: Avaliar as alterações da sensibilidade corneana após cross-linking (CXL) da córnea em pacientes com ceratocone progressivo em estágio inicial. Métodos: Trinta e oito olhos de 19 pacientes (11 mulheres, 8 homens) foram incluídos em um estudo clínico prospectivo, não randomizado. A média de idade dos pacientes era de 22 anos (variação, 18-26 anos). Os critérios de inclusão foram ceratocone progressivo bilateral em estágio inicial, córnea transparente e espessura da córnea ≥440 µm usando o estesiômetro de Cochet-Bonnet, mediu-se a sensibilidade da córnea no pré-operatório, após 7 dias, e uma vez por mês até a recuperação dos níveis pré-operatórios. Foram considerados normais, valores de sensibilidade corneana superiores a 40 mm. Resultados: A sensibilidade da córnea retornou gradualmente aos níveis pré-operatórios em todos os olhos tratados. A média de sensibilidade corneana central foi de 52,2, 24,0, 38,2, 42,5, 50,0 e 52,5 mm, antes da cirurgia, aos 7 dias, e em 1, 2, 3 e 4 meses após a cirurgia, respectivamente. Níveis normais de sensibilidade, mas não os níveis pré-operatórios basais, foram observados dois meses após a cirurgia. Níveis pré-operatórios foram observados três meses após a cirurgia. Conclusão: Nossos resultados sugerem que após CXL para ceratocone progressivo em estágio inicial, a sensibilidade corneana permanece diminuída por até 3 meses. .

The Change of Tear Film in Classification of Diabetic Retinopathy

PURPOSE: To determine the relationship between changes in the tear film according to the classification of diabetic retinopathy in patients with diabetes. METHODS: A total of 117 newly detected diabetic patients were included in this study. The classification of diabetic retinopathy was performed based on the Early Treatment Diabetic Retinopathy Study (ETDRS). The duration of diabetes and HbA1c were also investigated in patients who had undergone panretinal photocoagulation or insulin treatment. To examine the tear film function, we performed the tear break-up time test, the Schirmer I test, and the diagnostic fluorescein staining test of the ocular surface. The Cochet-Bonnet esthesiometer was also employed to examine the corneal sensitivity. RESULTS: As the severity of diabetic retinopathy progressed, the degree of ocular surface fluorescein staining increased significantly. There was no relationship between the duration of diabetes and the results of the tear film function test. Patients who had high blood HgA1c levels showed significant increases in tear break-up time and degree of ocular surface fluorescein staining. The patients who had undergone panretinal photocoagulation showed significant differences in tear break-up time and degree of ocular surface fluorescein staining. CONCLUSIONS: The diabetic patients with progressed diabetic retinopathy, uncontrolled blood HgA1c levels and who had previously undergone panretinal photocoagulation should be managed more carefully since those patients are more susceptible to ocular surface disorder with aggravation of tear film function.

Unilateral Punctate Keratitis Secondary to Wallenberg Syndrome

We studied three patients who developed left unilateral punctate keratitis after suffering left-sided Wallenberg Syndrome. A complex evolution occurred in two of them. In all cases, neurophysiological studies showed damage in the trigeminal sensory component at the bulbar level. Corneal involvement secondary to Wallenberg syndrome is a rare cause of unilateral superficial punctate keratitis. The loss of corneal sensitivity caused by trigeminal neuropathy leads to epithelial erosions that are frequently unobserved by the patient, resulting in a high risk of corneal-ulcer development with the possibility of superinfection. Neurophysiological studies can help to locate the anatomical level of damage at the ophthalmic branch of the trigeminal nerve, confirming the suspected etiology of stroke, and demonstrating that prior vascular involvement coincides with the location of trigeminal nerve damage. In some of these patients, oculofacial pain is a distinctive feature.

Effect of Macrophage Migration Inhibitory Factor on Corneal Sensitivity after Laser In Situ Keratomileusis in Rabbit

PURPOSE: To investigate the effect of macrophage migration inhibitory factor (MIF) on corneal sensitivity after laser in situ keratomileusis (LASIK) surgery. METHODS: New Zealand white rabbits were used in this study. A hinged corneal flap (160-microm thick) was created with a microkeratome, and -3.0 diopter excimer laser ablation was performed. Expressions of MIF mRNA in the corneal epithelial cells and surrounding inflammatory cells were analyzed using reverse transcription polymerase chain reaction at 48 hours after LASIK. After LASIK surgery, the rabbits were topically given either 1) a balanced salt solution (BSS), 2) MIF (100 ng/mL) alone, or 3) a combination of nerve growth factor (NGF, 100 ug/mL), neurotrophine-3 (NT-3, 100 ng/mL), interleukin-6 (IL-6, 5 ng/mL), and leukemia inhibitory factor (LIF, 5 ng/mL) four times a day for three days. Preoperative and postoperative corneal sensitivity at two weeks and at 10 weeks were assessed using the Cochet-Bonnet esthesiometer. RESULTS: Expression of MIF mRNA was 2.5-fold upregulated in the corneal epithelium and 1.5-fold upregulated in the surrounding inflammatory cells as compared with the control eyes. Preoperative baseline corneal sensitivity was 40.56 +/- 2.36 mm. At two weeks after LASIK, corneal sensitivity was 9.17 +/- 5.57 mm in the BSS treated group, 21.92 +/- 2.44 mm in the MIF treated group, and 22.42 +/- 1.59 mm in the neuronal growth factors-treated group (MIF vs. BSS, p < 0.0001; neuronal growth factors vs. BSS, p < 0.0001; MIF vs. neuronal growth factors, p = 0.815). At 10 weeks after LASIK, corneal sensitivity was 15.00 +/- 9.65, 35.00 +/- 5.48, and 29.58 +/- 4.31 mm respectively (MIF vs. BSS, p = 0.0001; neuronal growth factors vs. BSS, p = 0.002; MIF vs. neuronal growth factors, p = 0.192). Treatment with MIF alone could achieve as much of an effect on recovery of corneal sensation as treatment with combination of NGF, NT-3, IL-6, and LIF. CONCLUSIONS: Topically administered MIF plays a significant role in the early recovery of corneal sensitivity after LASIK in the experimental animal model.

Effects of the Ottonia martiana Miq. (Piperaceae) extract on dog's ocular surface / Efeitos do extrato de Ottonia martiana Miq. (Piperaceae) sobre a superfície ocular de cães

The anesthetics effects of aqueous extract of Ottonia martiana leaves were studied on the ocular surface of healthy beagle dogs. The dogs were divided in three groups (n=15): control group (CG), proxymetacaine group (PG) and Ottonia group (OG), which were treated with 0.9% saline, 0.5% proxymetacaine hydrochloride ophthalmic solution and O. martiana extract respectively. An oftalmic evaluation was performed before the treatments. Eye drops were instilled at time 0 (T0) and 3 minutes later (T3). Axial corneal sensitivity was evaluated by esthesiometry 5 and 10 minutes after T0. Tear production and intraocular pressure were evaluated 10 minutes after T0. Slit lamp biomicroscopy was performed 10 and 20 minutes after T0 and the eyes were stained with fluorescein 20 minutes after T0. The STT was reduced in PG. Conjunctival hyperemia was observed in 13 animals from PG and constituted the only ocular alteration observed during the study. Esthesiometry revealed a decreased corneal sensitivity for PG and OG. Those results show that the O. martiana extract acts reducing corneal sensitivity in dogs. Moreover, its use does not decrease the tear production and does not cause any clinical ophthalmic alteration.

Estudaram-se os efeitos do extrato das folhas de Ottonia martiana sobre a superfície ocular de cães hígidos da raça Beagle. Compuseram-se três grupos de tratamento (n=15): grupo controle (GC), grupo proximetacaína (GP) e grupo Ottonia (GO), tratados, respectivamente, com solução fisiológica, colírio de cloridrato de proximetacaína a 0,5% e extrato de O. martiana. Após avaliação oftálmica inicial, os tratamentos foram realizados no tempo 0 (T0) e decorridos 3min (T3). Avaliaram-se a sensibilidade axial da córnea por estesiometria (T5 e T10) e a produção lacrimal e a pressão ocular (T10). Realizaram-se a biomicroscopia com lâmpada em fenda (T10 e T20), e o teste do tingimento pela fluoresceína (T20). Relativamente ao teste de Schirmer, observou-se diminuição nos cães do GP. Houve alteração clínica somente nos do GP, em que 13 animais apresentaram hiperemia conjuntival. Relativamente à estesiometria, houve diminuição da sensibilidade corneal nos animais do GP e do GO. Admite-se que o extrato de O. martiana age diminuindo a sensibilidade corneal em cães e que sua utilização não diminui a produção lacrimal, tampouco causa alterações clínicas oftálmicas.

Analysis of Long-Term Change in Corneal Sensitivity after Penetrating Keratoplasty and Associated Tear Film Parameters

PURPOSE: To evaluate the long-term changes in the corneal sensitivity and to analyze which tear film parameters correlate with corneal sensitivity after penetrating keratoplasty (PKP). METHODS: Twenty-eight eyes of 28 patients who underwent PKP were included in the present study. Corneal sensitivity, Schirmer test, tear break-up time, tear clearance rate, and keratoepitheliopathy were evaluated at 1, 3, 6, 12, and 24 months postoperatively. Then, which tear film parameters correlated with corneal sensitivity during the follow-up period were analyzed. RESULTS: Corneal sensitivity was 5.18 +/- 3.96 mm at one month postoperatively and increased to 29.64 +/- 12.39 mm (p < 0.05) at 24 months postoperatively but was still not in the normal range. Tear break-up time and keratoepitheliopathy improved at postoperative three months and six months, respectively, compared with one month postoperatively, and both measures normalized at 24 months postoperatively. Schirmer test results and tear clearance rate were in the normal range during the follow-up period. Corneal sensitivity was correlated with tear break-up time from three to 24 months postoperative and with tear clearance rate from one month to 24 months postoperative (p < 0.05). CONCLUSIONS: Change in corneal sensitivity after penetrating keratoplasty correlates with tear break-up time and tear clearance rate; therefore, tear break-up time and tear clearance rate can be used as parameters for management of dry eye after PKP.

Comparison of tear film stability and corneal sensitivity between laser-assisted subepithelial keratectomy with laser in situ keratomileusis / 第二军医大学学报

Objective:To compare the changes in tear film stability and corneal sensitivity after laser-assisted subepithelial keratectomy (LASEK) and laser in situ keratomileusis (LASIK). Methods: Forty eyes of 20 patients underwent LASIK and 40 eyes of 20 patients underwent LASEK to correct mypia. The patients were observed for corneal sensitivity, tear break-up time (BUT) and Schirmer test under local anesthesia before and 1, 3 and 6 months after operation. The results were analyzed statistically. Results: The tear film stability and corneal sensitivity were decreased to some extent in both groups after operation. Compared with before operation, there were significant differences in corneal sensitivity 1, 3 and 6 months after operation and in BUT 1, 3 months after operation in LASIK group (P0.05). Conclusion: Both LASIK and LASEK influence the corneal sensitivity and tear film stability after operation; the influence diminishes with the recovery of the cornea. The influence in LASIK group is more serious and more persistent than that in LASEK group.

Changes of Corneal Nerve Regeneration and Corneal Sensitivity after Corneal Tattooing

PURPOSE: To investigate the changes of corneal nerve innervation and sensitivity after corneal tattooing. METHODS: Twelve New Zealand rabbits were divided into two groups of six subjects each. Tissue marking dye or balanced-salt solution was injected into the corneal stroma in one eye of each subject. Corneal nerve innervation was observed at 3 days and 1, 2, 3, 4, and 6 weeks postoperatively and compared with that of the opposite eyes. Corneal sensitivity was evaluated at 1, 2, and 3 days and 1, 2, 3, 4, and 6 weeks postoperatively and compared to the preoperative values in the same subjects. RESULTS: The ratios of corneal nerve density of the study eyes to those of the control fellow eyes were 1.09 in the central area and 1.06 in the peripheral area in subjects injected with tissue marking dye, and 1.11 and 1.23, respectively, in subjects injected with balanced salt solution, which showed no difference between the two groups. The corneal nerve density tends to increase at 3 days postoperatively (p=0.125), but no significant change was found thereafter. Corneal sensitivity assessed using the Cochet-Bonnet esthesiometer was 2.13+/-0.48 cm preoperatively. At three days postoperatively, it was 2.50+/-0.48 cm in subjects injected with tissue marking dye and 2.33+/-0.26 cm in subjects injected with balanced salt solution. It was significantly increased at 3 days postoperatively (2.42+/-0.36 cm, p=0.031), but there were no significant changes at 7 days or more postoperatively. CONCLUSIONS: Corneal nerve density increased at 3 days after corneal tattooing, and this effect is thought to be related to early postoperative hypersensitivity.

Vogt-Koyanagi-Harada Disease Associated with Bilateral Tonic Pupils in a Pregnant Patient

PURPOSE: We report a case of bilateral tonic pupils and decreased corneal sensitivity in a patient with Vogt-Koyanagi-Harada (VKH) disease during pregnancy. CASE SUMMARY: A 33-year-old Korean woman in the sixth month of pregnancy presented with visual impairment in both eyes. Her best corrected visual acuity was 0.2 in the right eye and 0.125 in the left. Slit-lamp examination revealed cells in the anterior chamber and serous retinal detachments in both eyes. The patient was treated with topical corticosteroid in both eyes and posterior subtenon injection of triamcinolone acetonide in the left eye. The serous retinal detachment resolved completely at 2 months in the left eye and at 3 months in the right. As pigmentation of the retina developed, VKH disease was confirmed. The patient complained of photophobia, and both pupils were found to be enlarged to 8 mm without dilation. Light reflex was absent and near reflex was suppressed and slow. After instillation of 0.125% pilocarpine, the pupils were constricted to 3.5 mm and were diagnosed as tonic pupils. Though the patient's corrected visual acuity improved to 0.8 in the right eye and 1.0 in the left at 6 months, her pupils remained unchanged. Corneal sensitivity was decreased. CONCLUSIONS: Tonic pupils may be complicated with VKH disease even during pregnancy. We recommend examinations of the pupils and corneal sensitivity in patients with VKH disease, especially those complaining of photophobia.

The Change of Corneal Sensitivity and Recovery of Corneal Nerve after Cataract Surgery

PURPOSE: To compare corneal sensitivity and recovery of corneal innervations after a temporal clear corneal incision in cataract surgery. METHODS: We measured changes to corneal sensitivity using Cochet-Bonnet esthesiometer in 25 eyes of 20 patients and analyzed corneal nerve density with confocal microscopy in 20 eyes of 20 patients who had undergone cataract surgery. The parameters were measured before, and at 1 week, 1 month, and 3 months after cataract surgery. RESULTS: The mean preoperative corneal sensitivity was 56.40+/-3.39 mm at the temporal corneal incision site, and there was a significantly decreased sensitivity of 29.80+/-2.69 mm and 42.40+/-4.36 mm postoperatively at 1 week and 1 month, respectively. Nonetheless, by three months, corneal sensitivity had returned to 56.00+/-2.89 mm and was not significantly different from measurements prior to the cataract surgery. The mean preoperative subbasal nerve density was 5296+/-1642 micrometer/mm2. After cataract surgery, the subbasal nerve density was significantly reduced to 4113+/-1421, 3555+/-1448, 4198+/-1239 micrometer/mm2 at 1 week, 1 month, and 3 months, respectively. CONCLUSIONS: Corneal sensitivity after cataract surgery returned to near preoperative levels within 3 months before complete restoration of normal corneal innervations. Therefore, regeneration of subbasal nerve fibers (, as determined by confocal microscopy,) requires more time than the return of corneal sensation after cataract surgery.

The Change of Corneal Sensitivity and Recovery of Corneal Nerve after Cataract Surgery

PURPOSE: To compare corneal sensitivity and recovery of corneal innervations after a temporal clear corneal incision in cataract surgery. METHODS: We measured changes to corneal sensitivity using Cochet-Bonnet esthesiometer in 25 eyes of 20 patients and analyzed corneal nerve density with confocal microscopy in 20 eyes of 20 patients who had undergone cataract surgery. The parameters were measured before, and at 1 week, 1 month, and 3 months after cataract surgery. RESULTS: The mean preoperative corneal sensitivity was 56.40+/-3.39 mm at the temporal corneal incision site, and there was a significantly decreased sensitivity of 29.80+/-2.69 mm and 42.40+/-4.36 mm postoperatively at 1 week and 1 month, respectively. Nonetheless, by three months, corneal sensitivity had returned to 56.00+/-2.89 mm and was not significantly different from measurements prior to the cataract surgery. The mean preoperative subbasal nerve density was 5296+/-1642 micrometer/mm2. After cataract surgery, the subbasal nerve density was significantly reduced to 4113+/-1421, 3555+/-1448, 4198+/-1239 micrometer/mm2 at 1 week, 1 month, and 3 months, respectively. CONCLUSIONS: Corneal sensitivity after cataract surgery returned to near preoperative levels within 3 months before complete restoration of normal corneal innervations. Therefore, regeneration of subbasal nerve fibers (, as determined by confocal microscopy,) requires more time than the return of corneal sensation after cataract surgery.

The Changes of Corneal Sensitivity in Diabetic and Nondiabetic Subjects After Phacoemulsification / 医学研究杂志

Objective To study the changes of corneal sensitivity in diabetic and nondiabetic subjects after phacoemulsification. Methods This trial involved 42 diabetic subjects(42eyes)and 46 nondiabetic subjects(46 eyes)with cataract.All eyes were underwent phacoemulsification.Corneal sensitivities were tested before surgery and 1 day,1 week,1 month,3 month,6 month after surgery.Results The corneal sensitivity of diabetic subjects was greatly reduced at 1 day,1 week,1 month,3 month after surgery(P＜0.05),and returned to the preoperative values at 6 month(P＞0.05).The corneal sensitivity of nondiabetic subjects was reduced at 1 day,1 week,1 month af- ter surgery(P＜0.05),and returned to the preoperative values at 3 month(P＞0.05).The corneal sensitivity of diabetic subjects was lower than nondiabetic subjects before surgery(P＜0.05).The reduced range of corneal sensitivity in diabetic subjects was greater than that of nondiabetic subjects(P＜0.05).Conclusions The corneal sensitivity is decreased and the recovery is postponed after poacoemul- sification in diabetic subjects.

Changes in Corneal Sensitivity after Cataract Surgery

PURPOSE: To evaluate the changes in corneal sensitivity following cataract surgery with a limbal incision. METHODS: The sensitivity threshold was measured in 53 eyes following procedures using a superior limbal incision (42 eyes) or a temporal limbal incision (11 eyes). RESULTS: The corneal sensitivity was significantly lower at the superior and temporal limbal incision sites after surgery than at the other sites (p<0.05). That sensitivity recovered 90% of its preoperative level 30 days post-operative. CONCLUSIONS: Corneal sensitivity decreased following cataract surgery using limbal incision. There were no significant differences in either the rate of decrease or recovery of corneal sensitivity according to the incision sites.

The Change of Corneal Sensation and Tear Film Stability after Cataract Surgery in Diabetic Patients

PURPOSE: To evaluate the change of corneal sensitivity and tear film stability before and after cataract surgery using a temporal clear corneal incision in diabetic patients. METHODS: This study included 16 eyes of 16 patients in the diabetic group and 20 eyes of 20 patients in the control group. All patients had phacoemulsification with 3 mm temporal clear corneal incision. All patients were examined for the corneal sensitivity, Schirmer test, tear break-up time, fluorescein staining for ocular surface, and ocular irritation symptom. All values were compared before and after surgery (1, 7, 30, 60, and 90 days). RESULTS: Before surgery, the Schirmer test and tear break-up time were lower in the diabetic group than the normal group, but the difference was not statistically significant. The values of the Schirmer test tended to temporarily increase after surgery and then decrease. The tear break-up time decreased more in the diabetic group than the normal group until postoperative day 7 (P<0.05). The fluorescein staining scores and ocular irritation symptoms were increased in both groups at postoperative day 1 (P<0.05). The temporal corneal sensitivity decreased more in the both groups until postoperative day 7. The central corneal sensitivity decreased more in the diabetic group until postoperative day 7, more in the non diabetic group until postoperative day 1 (P<0.05). Corneal sensitivity decreased more in the diabetic group than the normal group at postoperative day 1 (P<0.05). CONCLUSIONS: Clear corneal incision affected corneal sensitivity and tear film stability in the diabetic group more than the normal group after cataract surgery. The diabetic group experienced temporarily altered corneal sensitivity and tear film stability.

Corneal sensitivity in normal Thai population.

ObjectiveTo measure corneal sensitivity in normal Thai people of different ages using the Cochet – Bonnet aesthesiometer. Methods: This prospective, cross-sectional study was conducted with three hundred normal Thai subjects (600 eyes) who were divided into six groups according to their age. Corneal sensitivity was measured by using a Cochet – Bonnet aesthesiometer at the central cornea. The mean filament length of three measurements was considered to be the corneal sensitivity threshold. Results: There were statistically significant differences in the mean corneal sensitivity of the central cornea among age groups (p < 0.0001). The mean corneal sensitivity decreased with advancing age, and was significantly reduced after the age of sixty. Conclusion: The normal value of corneal sensitivity of the central cornea in the Thai population is the same as those of previous reports from other countries. Normal corneal sensitivity significantly decreased after the age of sixty.

Corneal Sensation and Tear Film Stability after Cataract Surgery with Temporal Clear Corneal Incision

PURPOSE: To evaluate the change of corneal sensitivity and tear film stability after phacoemulsification with a 3 mm-sized temporal clear corneal incision. METHODS: This study comprised 39 eyes of 30 patients having phacoemulsification with a 3 mm-sized temporal clear corneal incision. All patients were examined for corneal sensitivity, tear break-up time, Schirmer test, fluorescein staining for ocular surface, and ocular irritation symptoms. All values were compared before and at 1, 7, 30, 60, and 90 days after surgery. RESULTS: Central corneal sensitivity was measured 58.6 +/- 3.4 mm, preoperatively. Corneal sensitivities decreased in all areas at postoperative 1 day. Among these, the corneal center and temporal incision sites showed statistically significantly decreased sensitivity of 52.3 +/- 6.5 mm and 39.5 +/- 14.4 mm, respectively (P=.021, P<.001), and the corneal sensitivity of the dry eye group decreased more than that of the normal group(P<.05). All areas of the cornea showed a tendency of improved sensitivity after 7 postoperative days, and the sensitivity of the temporal area returned to the preoperative level at postoperative 2 months. Postoperative Schirmer test and tear break-up time were unchanged compared to preoperative values (P=.14, P=.11). However fluorescein staining scores for the ocular surface increased from 2.95 +/- 1.2 to 4.4 +/- 1.9 (P<.05), and ocular irritation symptoms increased through 1 week (P<.05). CONCLUSIONS: Phacoemulsification with 3 mm-sized clear corneal incision induced local hyposensitivity of the incision site but did not change the tear film stability. However, the patients undergoing cataract surgery temporarily developed ocular surface damage and irritation symptoms. Therefore observation and proper management are required.

The Study for Relationship of Ocular Surface Abnormalities, Corneal Sensitivity and Diabetic Retinopathy in DM

PURPOSE: To evaluate the correlation between the severity of diabetic retinopathy, decrease of corneal sensitivity and conjunctival impression cytology. METHODS: 150 eyes of 75 patients were enrolled. The patients were divided into two groups. The study group is 110 eyes of 55 patients with diabetic retinopathy and the control group is 40 eyes of 20 patients without diabetic retinopathy. The hemoglobin A1C (HbA1C) and fasting plasma glucose (FPG) were measured for the index of diabetic control. Corneal sensitivity was measured with Cochet-Bonnet aesthesiometer, and conjuctival impression cytology and fundus examination were done in two groups after topical anesthesia instillation. The classification of diabetic retinopathy was based on the ETDRS. RESULTS: In corneal sensitivity, the study group was 3.8 +/- 3.6 g/mm2, the control group 1.1 +/- 2.16 g/mm2, showing statistically significant difference (p<0.05). The severity of diabetic retinopathy had negative correlation with corneal sensitivity (R2=0.26, p<0.05). Conjunctival impression cytology had negative correlation with corneal sensitivity (R2=0.41, p<0.05), and positive correlation with retinopathy (R2=0.26, p<0.05). Corneal sensitivity was affected by the hemoglobin A1C (p<0.01), but fasting plasma glucose (p=0.7). CONCLUSIONS: Conjucntival impression cytology had negaitive correlation with corneal sensitivity and positive correlation with diabetic retinopathy. It can be thought that corneal sensitivity is affected by chronic glycemic control.

The Effect of Nerve Growth Factor on Corneal Sensitivity after Laser in Situ Keratomileusis

PURPOSE: To determine if topically administered nerve growth factor (NGF) plays a role in accelerating the recovery of corneal sensitivity after laser in situ keratomileusis (LASIK). METHODS: A prospective double-masked study comparing the effect of topical NGF or balanced salt solution on corneal sensitivity after LASIK in rabbits was performed. Pre- and postoperative corneal sensitivity was assessed using the Cochet-Bonnet esthesiometer. RESULTS: Eyes that were treated with topical NGF demonstrated an earlier and faster recovery of corneal sensitivity after LASIK (p=0.0071). A statistically significant difference in corneal sensitivity was found between the topical NGF and control group at the postoperative time points of 2 weeks (p=0.0098), 3 weeks (p=0.0309), and 4 weeks (p=0.0276). CONCLUSIONS: Our results suggest that topically administered NGF plays a significant role in accelerating corneal reinnervation after LASIK.