Schirmer Values Research Articles

Dry Eye after Lasik for Myopia: Incidence and Risk Factors

Patients frequently experience dry eye symptoms after laser-assisted in situ keratomileusis (LASIK). The purpose of this study was to determine the incidence and risk factors of dry eye after myopic LASIK. In this retrospective case series 190 eyes that underwent LASIK were examined for a dry eye syndrome. All patents were asymptomatic for dry eyes before surgery. Assessments included subjective complaints of dry eye, tear break-up time (TBUT), corneal staining, corneal sensitivity test, and Schirmer I test. All values were compared before and at 1 week and 1.3 and 6 months after surgery. For the 190 eyes, chronic dry eye persisting 6 months or more after LASIK was diagnosed in 20 percent of the eyes. Mean patient age was 31 +/- 8 years. The risk for chronic dry eye was significantly associated with higher attempted refractive correction, greater ablation depth, and female sex (p=0.001). Subjective score for dryness was increased after LASIK. The greatest change from preoperative levels for all parameters was noted at 1 week. There were obvious decreases in TBUT and Schirmer value at 1, 3, and 6 months postoperatively relative to preoperative level (p<0.05). The Schirmer I test result was higher at 1 day but without statistical significance (p>0.05), but lower at 1 week and 3 and 6 months (p<0.05) after LASIK. Corneal sensitivity was decreased at 1 month and 3 months, and returned to the preoperative level at 6 months after LASIK. There was a statistically significant effect of age, sex, and mean spherical equivalent refraction on corneal sensitivity (p<0.001). Patients undergoing LASIK for myopia develop dry eye with compromised tear function at least 6 months after surgery. Women and patients requiring higher refractive correction have an increased risk for developing dry eye.

Systemic Immunomodulatory Therapy in Severe Dry Eye Secondary to Inflammation

Purpose: To report four patients with unusually severe acute keratitis sicca secondary to lacrimal tissue and ocular surface inflammation who eventually required systemic immunosuppressive therapy. Methods: Observational case series of four patients with extremely severe acute dry eye syndrome who were profoundly disabled by pain and photophobia (to the extent of staying in dark rooms) despite aggressive conventional therapy. Clinical data including visual acuities, other treatments administered for dry eye, systemic medical conditions, Schirmer and rose bengal staining results, degree of conjunctival injection, and medications were recorded. All four patients were treated with systemic immunomodulatory therapy. Results: All four patients were female with a mean age at presentation of 40 years (range 22–58 years), and all had systemic autoimmune diseases: systemic lupus erythematosus (SLE) and Sjogren's syndrome (n = 2), Sjogren's syndrome (n = 1), rheumatoid arthritis (RA) and psoriasis (n = 1). Schirmer test values at onset ranged from 0 to 2 mm. All patients had failed aggressive lubrication, topical cyclosporine, lid care, and punctual plugs. In two patients, serum tears and hyphrecation punctal occlusion were tried without success. Various systemic immunosuppressive agents were used to control inflammation of the lacrimal glands: methotrexate and cyclosporine A (patient 1), cyclosporine A (patient 2), prednisone (patient 3), and methotrexate and infliximab (patient 4). Treatment with systemic immunomodulatory agents resulted in resolution of the acute inflammatory assault on the lacrimal glands and control of signs and symptoms of keratoconjunctivitis sicca in all four patients, and visual acuities improved in all of them. Post-treatment Schirmer values ranged from 7 to 10 mm. Conclusion: Systemic immunosuppressive agents may be required in the treatment of recalcitrant primary and secondary Sjogren's syndrome caused by systemic autoimmune conditions. We show that systemic immunomodulatory therapy leads to significantly improved tear production and resolution of the keratoconjunctivitis in these rare but severe cases.

Dry eye after LASIK enhancement by flap lifting

Purpose To determine whether dry eye after LASIK recurs after LASIK enhancement. Methods A total of 63 eyes of 42 patients who underwent LASIK enhancement were included in this study. Subjective dry eye symptoms, tear break-up time (BUT), Schirmer test with anesthesia, fluorescein staining of the cornea, and corneal sensitivity were evaluated before and at 1, 3, and 6 months after enhancement. Results The subjective dry eye symptoms remained unchanged before and after LASIK enhancement. Similarly, Schirmer values and tear BUT did not exhibit statistically significant differences between the pre- and post-enhancement values. Compared with the pre-enhancement values, the fluorescein score was higher at 1 month after surgery and further improved at 3 months. In comparison with the pre-enhancement values, the corneal sensitivity was decreased at 1, 3, and 6 months after surgery. Conclusions Patients did not complain of dry eye symptoms and tear functions were not compromised after LASIK enhancement. These results suggest that factors other than the neurotrophic effect may contribute to dry eye after LASIK.

Comparison of Corneal Nerve Regeneration and Sensitivity Between LASIK and Laser Epithelial Keratomileusis (LASEK)

To compare changes in corneal nerve fibers and keratocyte density by confocal microscopy after laser-assisted in situ keratomileusis (LASIK) and laser epithelial keratomileusis (LASEK). Prospective, nonrandomized comparative clinical trial. Fifty-six eyes of 28 patients who underwent LASIK and 52 eyes of 26 patients who underwent LASEK were included. Confocal microscopic data of the central cornea, corneal sensitivity, tear film breakup time, and Schirmer values were determined at three and six months after LASIK or LASEK treatment. In the LASIK group, corneal sensitivity was reduced from preoperative levels at six months after surgery. In the LASEK group, however, there was no difference between baseline and six-month postoperative values. The number of subbasal nerve fibers and the keratocyte density were also different in the LASIK and LASEK groups. The regeneration of corneal nerves correlated strongly with the recovery of corneal sensation and keratocyte density in both groups, whereas the tear film breakup time, Schirmer values, and epithelial thickness did not correlate with corneal nerve regeneration in either group. The greater decrease in the number of subbasal nerve fibers in the LASIK group compared with the LASEK group may relate to the greater decrease in corneal sensitivity. The pattern of corneal nerve regeneration and the recovery of corneal sensation after LASEK did not differ greatly from that after photorefractive keratectomy in previous studies.

Dry Eye After LASIK Enhancement by Flap Lifting

To determine whether dry eye after LASIK recurs after LASIK enhancement. A total of 63 eyes of 42 patients who underwent LASIK enhancement were included in this study. Subjective dry eye symptoms, tear break-up time (BUT), Schirmer test with anesthesia, fluorescein staining of the cornea, and corneal sensitivity were evaluated before and at 1, 3, and 6 months after enhancement. The subjective dry eye symptoms remained unchanged before and after LASIK enhancement. Similarly, Schirmer values and tear BUT did not exhibit statistically significant differences between the pre- and post-enhancement values. Compared with the pre-enhancement values, the fluorescein score was higher at 1 month after surgery and further improved at 3 months. In comparison with the pre-enhancement values, the corneal sensitivity was decreased at 1, 3, and 6 months after surgery. Patients did not complain of dry eye symptoms and tear functions were not compromised after LASIK enhancement. These results suggest that factors other than the neurotrophic effect may contribute to dry eye after LASIK.

Nerve Growth Factor Concentration and Implications in Photorefractive Keratectomy vs Laser In Situ Keratomileusis

To determine whether tear nerve growth factor (NGF) concentration correlates with corneal sensation and ocular surface dryness after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). Prospective, nonrandomized comparative clinical trial. Seventy eyes of 35 patients and 76 eyes of 38 patients underwent PRK and LASIK procedures to correct myopia and myopic astigmatism, respectively. Total tear protein level, tear NGF concentration, tear film breakup time (BUT) and Schirmer values were measured before and 1 day, 1 week, 1 month, 3 months, and 6 months after surgery. The postoperative mean tear NGF/total tear protein (NGF/tP) ratio increased in both PRK and LASIK patients compared with preoperative levels (P < .0001). At 1 week and 1 month postoperatively, the NGF/tP ratio was higher in PRK than in LASIK subjects (P < .0001). Before 6 months postoperatively, the mean corneal sensation after LASIK in the ablated zone was lower than the preoperative sensation (P < .0001), but this was not the case in PRK subjects. Mean BUT and Schirmer values were significantly lower in LASIK-treated eyes compared with PRK-treated eyes up to 6 months postoperatively (P < .0001). The early postoperative tear NGF/tP ratio correlated with the postoperative 6-month value of corneal sensation, BUT, and Schirmer values. The difference in the postoperative corneal sensation and ocular surface dryness between PRK-treated and LASIK-treated eyes might be related to the difference in the early postoperative levels of NGF, which is a potent nerve growth stimulator.

Strip Meniscometry (SM): A New and Simple Method of Tear Meniscus Evaluation

Evaluate role of Strip Meniscometry (SMT) and lower tear meniscus [height (LTMH) & depth (LTMD)] in diagnosis of Dry Eye Disease (DED) and its comparison with TBUT.In a prospective observational cross-sectional study of 120 eyes [60 eyes of 30 DED (Group 1) & 60 eyes of 30 controls (Group 2)] TBUT, Schirmer's, SMT, LTMH and LTMD was done. Subjects >18 years diagnosed with DED (aqueous deficient) as per Tear film and Ocular surface society-Dry Eye Workshop (TFOS DEWS) II protocol and Ocular surface disease Index (OSDI) questionnaire, with no associated systemic risk factor and previous ocular medical/surgical treatment were included as cases and subjects with no history of ocular surface disease as controls. The data was analyzed using t-test & receiver operating characteristic curve.TBUT & Schirmer's values were significantly lower in group 1 (p < 0.05). SMT was 2.28 ± 1.28 (Range 0–6) & 8.11 ± 1.39 (Range 3–10) in group 1 & 2 respectively (p < 0.05). LTMH was 169.32 ± 29.84 μm (Range 85.78–209.11) and 234.41 ± 19.51 μm (Range 203.89–289.53) in Group 1 & 2 respectively (p < 0.05). LTMD was 144.32 ± 33.60 μm (Range 57.49–190.12) and 206.69 ± 14.17 μm (Range 187.12–251.50) in Group 1 & 2 respectively (p < 0.05). The SMT, LTMH and LTMD showed a cutoff value of < 5 mm (AUC 0.994, sensitivity 96.7%, specificity 96.7%), 204.96 μm (AUC 0.998, sensitivity 98.3%, specificity 96.7%) & 190 μm (AUC 0.995, sensitivity 96.7%, specificity 95%) respectively.SMT, ASOCT, LTMD & LTMH are useful non invasive diagnostic tests for DED comparable with TBUT.

Effect of laser in situ keratomileusis on tear secretion and corneal sensitivity. Michaeli A, Slomovic AR, Sakhichand K, Rootman DS, J Refract Surg 2004;20:379–383.

This article describes a prospective study of corneal sensitivity and Schirmer I scores following laser in situ keratomileusis (LASIK). Twenty-three consecutive patients who were asymptomatic for severe dry symptoms prior to surgery were included in the study. All patients underwent Schirmer I test (without anesthetic drops, five minutes, eyes closed) and a filament corneal sensitivity test prior to surgery, three to five days postoperatively, and after one and three months. A non-statistically significant trend toward a reduction in Schirmer values immediately after surgery was noted, with a return to slightly lower than baseline levels by three months. There was no statistically significant correlation of gender, age, and manifest spherical equivalent refraction on Schirmer values. Corneal sensitivity was significantly decreased immediately after surgery (<i>P</i> < .0001) and returned to preoperative levels by three months. When each of the covariants of gender, age, and manifest spherical equivalent were considered individually, only age had a significant effect on the time trend of corneal sensitivity (<i>P</i> = .011). Both Schirmer tear values and corneal sensitivity return to near preoperative levels three months after LASIK.

Effect of laser in situ keratomileusis on tear secretion and corneal sensitivity.

To study changes in corneal sensitivity and Schirmer I scores following laser in situ keratomileusis (LASIK) and the correlation between the two. Twenty-three patients who had LASIK at The Gimbel Eye Center, Toronto, Ontario, Canada, participated in the study. All were asymptomatic for severe dry eyes before surgery. All patients underwent a Schirmer test (without anesthetic), a filament corneal sensitivity test, and slit-lamp microscopy including staining with lissamine green preoperatively and at postoperative time intervals of 3 to 5 days, and 1 and 3 months. No correlation was found between the difference in Schirmer test scores and the difference in corneal sensitivity, at any timepoint. A non-statistically significant trend toward a reduction in Schirmer values immediately after surgery was noted, with a return to slightly lower than baseline levels by 3 months. Corneal sensitivity was significantly decreased immediately after surgery and returned to preoperative levels by 3 months (P<.0001). There was a statistically significant effect of age, gender, and mean spherical equivalent refraction on corneal sensitivity (P<.0001) and a significant effect of age on the time trend (P=.02), but not for Schirmer levels or staining. A significant reduction in corneal sensitivity immediately following surgery occurred, with a return to preoperative levels by 3 months. Schirmer test scores similarly decreased, although without statistical significance, and returned to near preoperative levels after 3 months. A statistically significant correlation between the reduction in tearing and reduction in corneal sensitivity after LASIK was not demonstrated.

Corneal topography and Schirmer testing in eyes with the Hudson–Stahli line

To evaluate corneal topographic features and tear secretion in eyes with the Hudson-Stahli line. Keratometry, computerized videokeratography and Schirmer testing were performed in 50 cases with bilateral Hudson-Stahli line, and 55 controls without the Hudson-Stahli line. Similar tests were performed in 21 subjects with unilateral Hudson-Stahli line. Corneal topographic features and keratometry in the horizontal meridian were similar in cases and controls, and in fellow eyes of subjects with unilateral Hudson-Stahli line. Keratometry in the vertical meridian in cases (43.01 +/- 2.01) was significantly lesser than in controls (43.94 +/- 1.77) (P = 0.01). This value was not different in fellow eyes of patients with unilateral Hudson-Stahli line. Schirmer testing revealed significantly greater tear secretion in cases (16.72 +/- 4.99 mm) compared to controls (12.57 +/- 3.62 mm) (P < 0.01). In subjects with unilateral Hudson-Stahli line, mean Schirmer values in the eye with the line (17.52 +/- 6.86 mm) were significantly greater than in eyes without (13.67 +/- 4.64 mm) (P = 0.04). Formation of the Hudson-Stahli line may be dependent on the presence of normal tear secretion in the eye.

Lacrimal Function and Ocular Complications in Patients Treated with Systemic Isotretinoin

To evaluate the effect on lacrimal function and ocular complications in patients with severe acne vulgaris during systemic treatment with 13-cis-retinoic acid (isotretinoin). Forty patients with acne vulgaris were treated with systemic isotretinoin at dosages of 0.5-1 mg/kg per day for two months. Full ophthalmologic examination, Schirmer I test, fluorescein break-up (BUT) and microbiological investigations of the conjunctival flora were done before, during the second month and at least one month after the end of the treatment. The average Schirmer values before and after the treatment were 21.6 mm/5 minutes (SD +/- 7.01) and 18.48 mm/5 minutes (SD +/- 7.87) respectively. After the treatment BUT was less than 10 seconds in 50% of the patients and 55% had blepharitis. Subjective symptoms like dryness, itching and contact lens intolerance occurred in 42.5% and colonization of the conjunctiva by Staphylococcus aureus increased significantly during treatment (p= 0.031). All abnormal findings disappeared one month after the cessation of treatment. Isotretinoin causes signs and symptoms of dry eye, probably by reducing meibomian gland function, but ocular complications are generally not serious when low doses are used for a limited time, and are reversible after discontinuation.

Two multicenter, randomized studies of the efficacy and safety of cyclosporine ophthalmic emulsion in moderate to severe dry eye disease

Objective To compare the efficacy and safety of cyclosporin A ([CsA] 0.05% and 0.1% ophthalmic emulsions) to vehicle in patients with moderate to severe dry eye disease. Design Multicenter, randomized, double-masked, parallel-group, 6-month, vehicle-controlled. Participants A total of 877 patients with defined moderate to severe dry eye disease (292 to 293 in each treatment group). Methods Two identical clinical trials; patients were treated twice daily with either CsA, 0.05% or 0.1%, or vehicle. The results of these two trials were combined for analysis. Main outcome measures Efficacy: corneal and interpalpebral dye staining, Schirmer tear test (with and without anesthesia), tear break-up time, Ocular Surface Disease Index (OSDI), facial expression, patient subjective rating scale, symptoms of dry eye, investigator’s evaluation of global response to treatment, treatment success, and daily use of artificial tears. Safety: occurrence of adverse events, best-corrected visual acuity, intraocular pressure, biomicroscopy, and blood trough CsA concentrations. Results Treatment with CsA, 0.05% or 0.1%, gave significantly ( P ≤ 0.05) greater improvements than vehicle in two objective signs of dry eye disease (corneal staining and categorized Schirmer values). CsA 0.05% treatment also gave significantly greater improvements ( P < 0.05) in three subjective measures of dry eye disease (blurred vision, need for concomitant artificial tears, and the physician’s evaluation of global response to treatment). There was no dose-response effect. Both CsA treatments exhibited an excellent safety profile, and there were no significant topical or systemic adverse safety findings. Conclusions The novel ophthalmic formulations CsA 0.05% and 0.1% were safe and effective in the treatment of moderate to severe dry eye disease yielding improvements in both objective and subjective measures. Topical CsA represents a new pharmacologically based treatment for dry eye disease that may provide significant patient benefits.

Cataract surgery in patients with dry eyes

Purpose: To evaluate the potential causes of postoperative complications and the visual outcome after surgery for age-related cataract in dry eyes.Setting: Tertiary-care multidisciplinary referral medical institution.Methods: The records of 15 patients (21 eyes) with age-related cataract, a Schirmer value of 5.0 mm or less in 5 minutes, and a tear-film breakup time of 5 seconds or less having complications after cataract surgery were reviewed. Patients were assigned to 1 of 2 groups: dry eye with probable secondary Sjögren's syndrome (Group 1); dry eye without connective tissue disorders (Group 2). The surgical procedure, preoperative and postoperative medications, postoperative complications, and final visual outcome were analyzed.Results: Ten eyes (8 patients) in Group 1 and 11 (7 patients) in Group 2 had cataract surgery. In Group 1, postoperative endophthalmitis developed in 3 eyes and peripheral keratolysis in 4; 5 eyes attained a visual acuity between 6/60 and 6/18 2 years after surgery. In Group 2, filamentary keratitis developed in 6 eyes and peripheral keratolysis in 2 eyes; 6 eyes achieved a visual acuity of 6/12 or better 2 years after surgery. A significant decrease in visual acuity occurred between 3 months and 2 years postoperatively in both Group 1 (P= .010) and Group 2 (P .0005).Conclusion: Cataract surgery in dry eyes had fewer complications and better visual outcome in patients who did not have connective tissue disease than in those who did.

Decrease in Corneal Sensitivity and Change in Tear Function in Dry Eye

Our purpose was to investigate the relationship between insufficient tear secretion and decreased corneal sensitivity. We studied 59 patients with dry eye, 15 of whom had Sjögren's syndrome (SS), and 26 healthy subjects. Corneal sensitivity was measured by the esthesiometer of Cochet and Bonnet. Schirmer test with or without anesthesia, tear clearance rate, tear function index, and rose bengal and fluorescein staining were also evaluated. The mean corneal sensitivity of either dry-eye group (4.6 +/- 1.2 and 4.5 +/- 1.2 cm for non-SS and SS dry eye, respectively) was significantly lower than that of the control (5.8 +/- 0.4 cm, p < 0.001). Corneal sensitivity correlated significantly with the Schirmer values with anesthesia and the tear function index in the two dry-eye groups and the control (p < 0.05). There were significant relationships between corneal sensitivity and the rose bengal and fluorescein scores in the three groups (p < 0.05). Hyposecretion of tears in dry eye may lead to pathologic changes in corneal epithelium and a decline in corneal sensitivity. Prompt treatment of dry eye is essential to maintain a normal corneal protective mechanism.

Quantification of lacrimal function after D-shaped field irradiation for retinoblastoma.

To study the quantitative effects of megavoltage external beam irradiation in a D-shaped field in patients with retinoblastoma, biomicroscopy was performed in 61 patients and tear function tests (Schirmer-lactoferrin and lysozyme tests) on 45 eyes in 34 irradiated patients. The results were compared with those obtained in 25 non-irradiated control eyes. The Schirmer test was significantly diminished (p < 0.001) in irradiated eyes, as were the lactoferrin and lysozyme values (p < 0.001). A mild to severe keratitis was found in 17 of the 61 patients (28%). A significant correlation (p < 0.005) was found between the severe keratitis and the mean Schirmer values; the mean lactoferrin and lysozyme values were diminished in all patients but did not correlate significantly with the corneal abnormalities. These quantitative data, obtained in patients treated for retinoblastoma, affirm the qualitative data found in patients irradiated for other reasons such as orbital or sinus tumours. Irradiation for retinoblastoma is not a harmless treatment and serious late side effects have to be considered.

Hornhautdickenmessungen bei Patienten mit Keratoconjunctivitis sicca

The average corneal thickness in a group of patients with KCS did not differ significantly from that in a control group. Within the patient group the corneal thickness decreased with decreasing lysozyme concentrations and also with decreasing Schirmer values, but the correlation was weak in both cases. The average central corneal thickness with severe and very severe KCS was greater than that of patients with mild KCS and the control groups. The average corneal thickness in patients with mild KCS was less than that of the control group, but not significantly so. Because of the comparatively small number of patients with severe KCS, an all over increase in corneal thickness in patients with KCS could not be demonstrated.

Tear function parameters in keratoconjunctivitis sicca with and without the association of Sjögren's syndrome.

In a group of patients with keratoconjunctivitis sicca (KCS) associated with Sjögren's syndrome (SJ) a significant decrease in tear fluid lactoferrin concentration and tear film break-up time was demonstrated in comparison with a matched group in which KCS was not associated with any systemic disease. The Schirmer values were also lower in the SJ of patients and these differences almost reached statistical significance. None of these parameters in itself appeared to be of any clinical value to differentiate between KCS that was or was not associated with SJ. The combination of the tear fluid lactoferrin concentration, the Schirmer I test values and the tear film break-up time, however, provide a basis for differential diagnosis that is clinically of some value.

Intraocular pressure during hemodialysis.

In 14 patients undergoing hemodialysis, the intraocular pressure did not change significantly when measured at hourly intervals for 4 h. There was a loss in body weight because of fluid loss; also the Schirmer values decreased significantly at the conclusion of treatment. Blood osmolality decreased markedly in a linear fashion. The fluctuations of intraocular pressure during hemodialysis were likely dependent on the dynamics of dehydration and hypo-osmolality. Regulatory forces stabilized the intraocular pressure to such a degree that statistical significance in these fluctuations was not reached.

Lysozyme in tears during post-operative inflammation of the eye.

Lysozyme (ly) concentration in tears was measured the day before and the days following intracapsular cataract extraction in 25 patients. A median ly concentration of 1.30 mg/ml was found pre-operatively. On the first post-operative day a significant drop in the median ly concentration was observed (0.58 mg/ml). Thereafter a gradual rise towards pre-operative level was found at the 12th post-operative day. An inverse correlation existed between ly concentrations and Schirmer values during the observation period, and dilution thus seems to be an important cause of the post-operative drop in ly concentration. We observed an inverse relationship between ly level, and the number (%) of patients displaying bacterial colonization of the conjunctival sac 24 h later. The most frequently isolated bacteria were staphylococcus albus and diphteroids. It is proposed that the drop in ly concentration post-operatively may contribute to an increased risk of bacterial colonization of the eye post-operatively.

Lacrimal gland accumulation of 67Ga-citrate in patients with Sjögren's syndrome.

The extent of 67Ga accumulation in the two lacrimal glands in patients with keratoconjunctivitis sicca (KCS) of Sjögren's syndrome was studied. Of the two main groups one consisted of 69 subjects without ophthalmic complaints (control group), the other consisted of 26 patients with KCS of Sjögren's syndrome. Of the 26 patients with KCS, 7 had been diagnosed as probable KCS (probable sub-group) and the other 19 had been diagnosed definite KCS (definite sub-group). About 3 mCi (111 MBq) 67Ga-citrate was injected IV into each subject and this was followed by scintigraphy at 24, 48, and 72 h after the injection of 67Ga. A positive finding in the lacrimal gland was noted in 64 of 69 subjects (92.7%) in the control group and in 7 of 7 patients (100%) with probable KCS. Three of 19 patients with definite KCS (15.7%) showed positive findings under scintigraphy. When the scintigraphic finding in the lacrimal gland is not positive in patients with suspected KCS of Sjögren's syndrome, they can then be diagnosed with little risk as definite KCS cases. Shirmer's test was performed on subjects in the probable and definite groups. There was statistical significance between the positive and equivocal or negative scintigraphic finding and Schirmer's values. These results suggest a correlation between gallium accumulation in the lacrimal gland and the tear production.