Sudi Patel - Academia.edu (original) (raw)

Papers by Sudi Patel

Journal of The British Contact Lens Association, 1992

Journal of The British Contact Lens Association, 1991

Cataract and Refractive Surgery, 2010

Cataract and Refractive Surgery, 2010

Cataract and Refractive Surgery, 2010

J Cataract Refract Surg, 2001

Journal of refractive surgery (Thorofare, N.J.: 1995)

1. J Refract Surg. 2000 May-Jun;16(3):330-5. A model to explain the difference between changes in... more 1. J Refract Surg. 2000 May-Jun;16(3):330-5. A model to explain the difference between changes in refraction and central ocular surface power after laser in situ keratomileusis. Patel S, Alio JL, Perez-Santonja JJ. Refractive ...

Journal of refractive surgery (Thorofare, N.J.: 1995)

To investigate central multifocal presbyLASIK based on the creation of a central hyperpositive ar... more To investigate central multifocal presbyLASIK based on the creation of a central hyperpositive area. Twenty-five patients (50 eyes) underwent presbyLASlK in an open-label, prospective, non-comparative pilot study. Mean patient age was 58 years (range: 51 to 68 years), mean preoperative spherical equivalent refraction was +1.6 +/- 0.63 diopters (D) (range: +0.50 to +3.00 D), and mean spectacle near addition was +2.27 +/- 0.37 D (range: +1.75 to +3.00 D). The ablation pattern was performed with proprietary software from Technovision using an H. Eye Tech. excimer laser platform. Mean postoperative spherical equivalent refraction was -0.37 +/- 0.55 D (range: -1.50 to + 1.00 D) and mean spectacle near addition was +1.72 +/- 0.34 D (range: +1.25 to +2.25 D). After 6 months, 16 (64%) patients achieved a distance uncorrected visual acuity (UCVA) of > or = 20/20 and 18 (72%) patients achieved a near UCVA of > or = 20/40. Seven (28%) patients lost a maximum of 2 lines of best spectacle-corrected visual acuity (BSCVA). The safety index for distance was 0.98 binocular and for near was 0.99 binocular. After 6 months, no significant change was noted in contrast sensitivity at 1.5 cycles/degree. A significant mean reduction was found at spatial frequencies of 3, 6, 12, and 18 cycles/degree (P<.001). There was a significant change in corneal aberrations after surgery. The coefficients for coma increased and the coefficients for spherical aberrations decreased. A significant decrease was noted in point spread function values (P=.0018). Central presbyLASIK may be used to provide improvement in functional near vision in patients with presbyopia associated with low and moderate hyperopia. However, factors involved in the loss of BSCVA in some cases and loss in vision quality should be further clarified prior to its general use.

Optometry and Vision Science, 1990

Optometry and Vision Science, 2012

To compare an objective (VCH-1) with a manual subjective Abbé refractometer (MSAR) and evaluate t... more To compare an objective (VCH-1) with a manual subjective Abbé refractometer (MSAR) and evaluate the refractive index (RI)-hydration (H) relationship for the corneal stroma. Epithelial and endothelial layers were removed from a fresh postmortem ovine corneal buttons. RI was measured at both surfaces using (i) MSAR then (ii) VCH-1. The sample was weighed, slowly dehydrated under controlled conditions (2 h), and RI measures were repeated. Sample was oven dried (90°C) for 3 d to obtain dry weight and hydration at each episode of RI measurement. Average difference between individual pairs of measurements obtained using the two refractometers (ΔRI) was 0.00071 (standard deviation ± 0.0029, 95% confidence interval ± 0.0058). Root mean square difference between measurements obtained by the refractometers was 0.0024. There was no relationship between ΔRI and the mean of each measurement pair (r = 0.201, n = 40, p = 0.214). Linear regression revealed a significant relationship between RI and reciprocal of H at both surfaces as follows: anterior (i) RI = 1.355 + 0.111/H (r = -0.852, n = 20, p = <0.001), (ii) RI = 1.357 + 0.105/H (r = -0.849, n = 20, p = <0.001) and posterior (i) RI = 1.353 + 0.085/H (r = -0.882, n = 20, p = <0.001), (ii) RI = 1.350 + 0.088/H (r = -0.813, n = 20, p = <0.001). VCH-1 measurements are in good agreement with MSAR. RI at the anterior stroma was consistently higher suggesting hydration is lower by 1.10 units (6%) compared with the posterior stroma. Dehydration increased RI at both surfaces by similar rates. Current hypothetical models are useful for predicting RI from H for the posterior, but not the anterior, stroma.

Optometry and Vision Science, 1995

Optometry and Vision Science, 2006

The purposes of this study are to investigate the tear meniscus height (TMH), lipid layer, and cr... more The purposes of this study are to investigate the tear meniscus height (TMH), lipid layer, and critical dimensions of the lower punctum lacrimale (DPL) in normal human subjects over a large age range; and to determine the shape and general characteristics of the lower punctum lacrimale in a normal population. TMH and DPL were measured using a graticule set at the eyepiece of a slit lamp biomicroscope (magnification 32x). Lipid layer was assessed by interferometry (Tearscope, Keeler). Only one eye (right) of each subject was assessed. All subjects were normals without any tear-related disorders and/or symptoms. Four hundred forty-four subjects were assessed (268 females, age range, 6-91 years; 176 males, age range, 6-91 years). Mean (+/-standard deviation) TMH in females was 0.19 mm (+/-0.11) and in males was 0.19 mm (+/-0.10). TMH was related to age (x): in females, TMH=0.13+0.0009x (r=0.2393, p<0.001); in males, TMH=0.14+0.0008x (r=0.2492, p<0.001). TMH increased from 0.15 mm (+/-0.06) in the young (<20 years) to 0.21 mm (+/-0.10) in the elderly (>80 years). The punctum was closed in 10.8%, slit shaped in 24.3%, oval in 5.4%, and round in 59.5% of all cases. Mean age and TMH of those presenting with closed puncta was significantly higher than those presenting with open puncta (p<0.001). Mean (+/-standard deviation) area of open puncta was 0.008 mm (+/-0.013) in females and 0.010 mm (+/-0.018) in males. The difference was not significant. Diameter of round puncta was inversely related to age in females (r=-0.4985, n=149, p<0.001) but not within the males. A total of 14.6% of females and 12.5% of males presented with no discernible lipid layer. Lipid layer tended to be thinner in older subjects (one-way analysis of variance, F=6.667, p<0.001). There was no clear relationship between TMH and the lipid layer. There is a gradual increase in TMH and shift in size and shape of the punctum lacrimale with advancing years. Age-related changes in the lipid layer are expected to reduce tear volume by way of increased evaporation. On balance, it would appear any effects on tear volume by a thinning lipid layer are outweighed by changes in the puncta.

Optometry and Vision Science, 1989

The clinically diagnosed dry eye generally has an unstable tear film and changes in the corneal e... more The clinically diagnosed dry eye generally has an unstable tear film and changes in the corneal epithelium but, not necessarily, hyposecretion of tears. In normal asymptomatic eyes we found, using a noninvasive technique, a significant relation between precorneal tear film stability and tear production rates (TPR's).

Optometry and Vision Science, 1998

To assess whether impression cytology samples could be used to assess cell conjunctival cell surf... more To assess whether impression cytology samples could be used to assess cell conjunctival cell surface areas, and to obtain an estimate of these for normal appearing cells vs. those with squamous metaplasia. Small sheets of nasal bulbar conjunctival cells (c. 0.03 mm2) were obtained from 17 subjects aged 25 to 78 years by manual application of a 0.45 microm Millipore filter without topical anesthetic. Outlines of cells, visible as a rarefaction of the general cell cytoplasmic staining, were made on an optical overlay and then planimetry was carried out. Reasonable estimates (with +/-2.5%) of the average cell area can be obtained from samples containing contiguous sets of 100 cells. From 14 separate samples of normal cells [subjective assignment of nucleus:cytoplasm (N:C) ratios of 1:1 to 1:2], cell surface area values ranged from 11 to 426 microm2, with an overall average value of 108 +/- 43 microm2. Samples from individuals with symptoms suggestive of borderline dry eye tended to have slightly higher proportions of larger cells (so increasing the average cell area), and there was a trend for samples from older individuals to contain more smaller cells (so decreasing the average cell area). In marked contrast, cells showing evidence of squamous metaplasia and with N:C ratios of 1:6 or higher were found to have an average area of 543 +/- 76 microm2 (range 310 to 1529 microm2). Morphometry of impression cytology specimens is possible. The average cell size in normal individuals is considerably smaller than previously reported (108 vs. 585 microm2), but this is consistent with a range of studies on animal tissue using scanning electron microscopy.

Ophthalmology, 2005

To examine the effects of ametropia (spherocylindrical), corneal curvature, target anterior chamb... more To examine the effects of ametropia (spherocylindrical), corneal curvature, target anterior chamber depth (ACD), misplacement, and some design features on the performance of positional pseudoaccommodative intraocular lenses (PPAIOLs). Theoretical investigation based on computer models to determine the practical limitations of PPAIOLs. Using a suitable model eye featuring gradient index optics within the cornea, the PPAIOL curvatures were calculated for axial ametropia ranging from -10 diopters (D) to +10 D, where the IOL was located at an ACD of 4.05 mm. The change in refraction (y) of the hypothetical pseudophakic eye was calculated for each millimeter of forward movement (x) of the PPAIOL up to 1 mm from the pole of the corneal back surface. The computations were repeated for a range of hypothetical PPAIOL refractive indices (1.49-1.70), ACDs, equiconvex and meniscus (back surface radius, -10 mm and -25 mm), corneal astigmatism (-1 D to -5 D), and radii (after corneal refractive surgery). Diopter/millimeter values represent the gradient of the relationship between x and y. Mathematical models describe the association between the diopter/millimeter gradient and key clinical dependent variables. (1) For a polymethyl methacrylate (refractive index, 1.49) PPAIOL of equiconvex design and 4.05-mm ACD, the predicted diopter/millimeter value is a function of ametropia (a), where diopter/millimeter = 1.666+0.136a+0.0018a2. (2) For 6-mm ACD and a refractive index of 1.7, diopter/millimeter = 1.836+0.159a+0.0027a2. (3) The equiconvex design benefits hyperopic but not myopic eyes. (4) For PPAIOLs correcting >4 D of astigmatism, more than 0.5 D of residual astigmatism is present at near after 1 mm of IOL displacement. (5) In emmetropic cases, the predicted diopter/millimeter value is a function of the corneal radius (r) where diopter/millimeter = 7.376-1.162r+0.0545r2. (6) Positional pseudoaccommodative IOL misplacement does not significantly affect the accommodative ability. (1) Hyperopic eyes with relatively steep corneas should benefit more from the PPAIOL than myopic eyes with relatively flat corneas. (2) A full, binocular, near refraction should be performed to correct any residual spheroastigmatism in anisometropia and cases in which the PPAIOL is toric.

Ophthalmic and Physiological Optics, 2003

To evaluate the effects of dissolvable collagen punctal plugs on the symptoms, tear stability and... more To evaluate the effects of dissolvable collagen punctal plugs on the symptoms, tear stability and volume in aqueous deficient dry eyes. Sixty-two aqueous deficient dry eye patients of mixed aetiology underwent lacrimal punctal occlusion with dissolvable collagen plugs. The subjects were randomly allocated to one of two treatment groups: group I (n = 36) had their lower puncta occluded and group II (n = 26) had both their upper and lower puncta occluded. The effectiveness of this treatment was clinically assessed by (1). scoring subject symptoms and (2). measuring the tear parameters of tear thinning time (TTT) and tear meniscus height (TMH) as indicators of tear stability and volume, respectively. Following baseline measurements, patients were reviewed at time intervals of 5 and 12 days post-occlusion. A group of age- and gender-matched normals (n = 45) was recruited for comparison (group III). Tear volume and stability were significantly higher in group III compared with I and II at baseline. In the treated groups on both days 5 and 12: (1). symptom score reduced significantly from a median value of 7 to 3 (p = <0.001); (2). tear stability increased significantly from a median value of 3 to 5 s by day 5 (p <or= 0.001); reduced between days 5 and 12 (p < 0.05) and remained below the stability in group III at all times; (c). tear volume increased significantly by day 5 in both treatment groups from a median value of 0.13 to 0.20 mm (p<or=0.001), remained stable by day 12 in group II but reduced in group I (p < 0.05); (d). the increase in tear volume was negatively correlated with pre-treatment tear volume; (e). symptom score correlated with both baseline tear volume and stability. Collagen plugs improved tear status in the aqueous deficient dry eyes. Occluding both upper and lower puncta with temporary collagen plugs offers no practical beneficial gain compared with occluding just the lower punctum.

Ophthalmic and Physiological Optics, 1995

Ophthalmic and Physiological Optics, 1998

To determine the clinical viability of a phenol red impregnated cotton thread in differentiating ... more To determine the clinical viability of a phenol red impregnated cotton thread in differentiating between normal, aqueous deficient and non-aqueous deficient dry eyes.

Ophthalmic and Physiological Optics, 1996

Journal of The British Contact Lens Association, 1992

Journal of The British Contact Lens Association, 1991

Cataract and Refractive Surgery, 2010

Cataract and Refractive Surgery, 2010

Cataract and Refractive Surgery, 2010

J Cataract Refract Surg, 2001

Journal of refractive surgery (Thorofare, N.J.: 1995)

1. J Refract Surg. 2000 May-Jun;16(3):330-5. A model to explain the difference between changes in... more 1. J Refract Surg. 2000 May-Jun;16(3):330-5. A model to explain the difference between changes in refraction and central ocular surface power after laser in situ keratomileusis. Patel S, Alio JL, Perez-Santonja JJ. Refractive ...

Journal of refractive surgery (Thorofare, N.J.: 1995)

To investigate central multifocal presbyLASIK based on the creation of a central hyperpositive ar... more To investigate central multifocal presbyLASIK based on the creation of a central hyperpositive area. Twenty-five patients (50 eyes) underwent presbyLASlK in an open-label, prospective, non-comparative pilot study. Mean patient age was 58 years (range: 51 to 68 years), mean preoperative spherical equivalent refraction was +1.6 +/- 0.63 diopters (D) (range: +0.50 to +3.00 D), and mean spectacle near addition was +2.27 +/- 0.37 D (range: +1.75 to +3.00 D). The ablation pattern was performed with proprietary software from Technovision using an H. Eye Tech. excimer laser platform. Mean postoperative spherical equivalent refraction was -0.37 +/- 0.55 D (range: -1.50 to + 1.00 D) and mean spectacle near addition was +1.72 +/- 0.34 D (range: +1.25 to +2.25 D). After 6 months, 16 (64%) patients achieved a distance uncorrected visual acuity (UCVA) of > or = 20/20 and 18 (72%) patients achieved a near UCVA of > or = 20/40. Seven (28%) patients lost a maximum of 2 lines of best spectacle-corrected visual acuity (BSCVA). The safety index for distance was 0.98 binocular and for near was 0.99 binocular. After 6 months, no significant change was noted in contrast sensitivity at 1.5 cycles/degree. A significant mean reduction was found at spatial frequencies of 3, 6, 12, and 18 cycles/degree (P<.001). There was a significant change in corneal aberrations after surgery. The coefficients for coma increased and the coefficients for spherical aberrations decreased. A significant decrease was noted in point spread function values (P=.0018). Central presbyLASIK may be used to provide improvement in functional near vision in patients with presbyopia associated with low and moderate hyperopia. However, factors involved in the loss of BSCVA in some cases and loss in vision quality should be further clarified prior to its general use.

Optometry and Vision Science, 1990

Optometry and Vision Science, 2012

To compare an objective (VCH-1) with a manual subjective Abbé refractometer (MSAR) and evaluate t... more To compare an objective (VCH-1) with a manual subjective Abbé refractometer (MSAR) and evaluate the refractive index (RI)-hydration (H) relationship for the corneal stroma. Epithelial and endothelial layers were removed from a fresh postmortem ovine corneal buttons. RI was measured at both surfaces using (i) MSAR then (ii) VCH-1. The sample was weighed, slowly dehydrated under controlled conditions (2 h), and RI measures were repeated. Sample was oven dried (90°C) for 3 d to obtain dry weight and hydration at each episode of RI measurement. Average difference between individual pairs of measurements obtained using the two refractometers (ΔRI) was 0.00071 (standard deviation ± 0.0029, 95% confidence interval ± 0.0058). Root mean square difference between measurements obtained by the refractometers was 0.0024. There was no relationship between ΔRI and the mean of each measurement pair (r = 0.201, n = 40, p = 0.214). Linear regression revealed a significant relationship between RI and reciprocal of H at both surfaces as follows: anterior (i) RI = 1.355 + 0.111/H (r = -0.852, n = 20, p = <0.001), (ii) RI = 1.357 + 0.105/H (r = -0.849, n = 20, p = <0.001) and posterior (i) RI = 1.353 + 0.085/H (r = -0.882, n = 20, p = <0.001), (ii) RI = 1.350 + 0.088/H (r = -0.813, n = 20, p = <0.001). VCH-1 measurements are in good agreement with MSAR. RI at the anterior stroma was consistently higher suggesting hydration is lower by 1.10 units (6%) compared with the posterior stroma. Dehydration increased RI at both surfaces by similar rates. Current hypothetical models are useful for predicting RI from H for the posterior, but not the anterior, stroma.

Optometry and Vision Science, 1995

Optometry and Vision Science, 2006

The purposes of this study are to investigate the tear meniscus height (TMH), lipid layer, and cr... more The purposes of this study are to investigate the tear meniscus height (TMH), lipid layer, and critical dimensions of the lower punctum lacrimale (DPL) in normal human subjects over a large age range; and to determine the shape and general characteristics of the lower punctum lacrimale in a normal population. TMH and DPL were measured using a graticule set at the eyepiece of a slit lamp biomicroscope (magnification 32x). Lipid layer was assessed by interferometry (Tearscope, Keeler). Only one eye (right) of each subject was assessed. All subjects were normals without any tear-related disorders and/or symptoms. Four hundred forty-four subjects were assessed (268 females, age range, 6-91 years; 176 males, age range, 6-91 years). Mean (+/-standard deviation) TMH in females was 0.19 mm (+/-0.11) and in males was 0.19 mm (+/-0.10). TMH was related to age (x): in females, TMH=0.13+0.0009x (r=0.2393, p<0.001); in males, TMH=0.14+0.0008x (r=0.2492, p<0.001). TMH increased from 0.15 mm (+/-0.06) in the young (<20 years) to 0.21 mm (+/-0.10) in the elderly (>80 years). The punctum was closed in 10.8%, slit shaped in 24.3%, oval in 5.4%, and round in 59.5% of all cases. Mean age and TMH of those presenting with closed puncta was significantly higher than those presenting with open puncta (p<0.001). Mean (+/-standard deviation) area of open puncta was 0.008 mm (+/-0.013) in females and 0.010 mm (+/-0.018) in males. The difference was not significant. Diameter of round puncta was inversely related to age in females (r=-0.4985, n=149, p<0.001) but not within the males. A total of 14.6% of females and 12.5% of males presented with no discernible lipid layer. Lipid layer tended to be thinner in older subjects (one-way analysis of variance, F=6.667, p<0.001). There was no clear relationship between TMH and the lipid layer. There is a gradual increase in TMH and shift in size and shape of the punctum lacrimale with advancing years. Age-related changes in the lipid layer are expected to reduce tear volume by way of increased evaporation. On balance, it would appear any effects on tear volume by a thinning lipid layer are outweighed by changes in the puncta.

Optometry and Vision Science, 1989

The clinically diagnosed dry eye generally has an unstable tear film and changes in the corneal e... more The clinically diagnosed dry eye generally has an unstable tear film and changes in the corneal epithelium but, not necessarily, hyposecretion of tears. In normal asymptomatic eyes we found, using a noninvasive technique, a significant relation between precorneal tear film stability and tear production rates (TPR's).

Optometry and Vision Science, 1998

To assess whether impression cytology samples could be used to assess cell conjunctival cell surf... more To assess whether impression cytology samples could be used to assess cell conjunctival cell surface areas, and to obtain an estimate of these for normal appearing cells vs. those with squamous metaplasia. Small sheets of nasal bulbar conjunctival cells (c. 0.03 mm2) were obtained from 17 subjects aged 25 to 78 years by manual application of a 0.45 microm Millipore filter without topical anesthetic. Outlines of cells, visible as a rarefaction of the general cell cytoplasmic staining, were made on an optical overlay and then planimetry was carried out. Reasonable estimates (with +/-2.5%) of the average cell area can be obtained from samples containing contiguous sets of 100 cells. From 14 separate samples of normal cells [subjective assignment of nucleus:cytoplasm (N:C) ratios of 1:1 to 1:2], cell surface area values ranged from 11 to 426 microm2, with an overall average value of 108 +/- 43 microm2. Samples from individuals with symptoms suggestive of borderline dry eye tended to have slightly higher proportions of larger cells (so increasing the average cell area), and there was a trend for samples from older individuals to contain more smaller cells (so decreasing the average cell area). In marked contrast, cells showing evidence of squamous metaplasia and with N:C ratios of 1:6 or higher were found to have an average area of 543 +/- 76 microm2 (range 310 to 1529 microm2). Morphometry of impression cytology specimens is possible. The average cell size in normal individuals is considerably smaller than previously reported (108 vs. 585 microm2), but this is consistent with a range of studies on animal tissue using scanning electron microscopy.

Ophthalmology, 2005

To examine the effects of ametropia (spherocylindrical), corneal curvature, target anterior chamb... more To examine the effects of ametropia (spherocylindrical), corneal curvature, target anterior chamber depth (ACD), misplacement, and some design features on the performance of positional pseudoaccommodative intraocular lenses (PPAIOLs). Theoretical investigation based on computer models to determine the practical limitations of PPAIOLs. Using a suitable model eye featuring gradient index optics within the cornea, the PPAIOL curvatures were calculated for axial ametropia ranging from -10 diopters (D) to +10 D, where the IOL was located at an ACD of 4.05 mm. The change in refraction (y) of the hypothetical pseudophakic eye was calculated for each millimeter of forward movement (x) of the PPAIOL up to 1 mm from the pole of the corneal back surface. The computations were repeated for a range of hypothetical PPAIOL refractive indices (1.49-1.70), ACDs, equiconvex and meniscus (back surface radius, -10 mm and -25 mm), corneal astigmatism (-1 D to -5 D), and radii (after corneal refractive surgery). Diopter/millimeter values represent the gradient of the relationship between x and y. Mathematical models describe the association between the diopter/millimeter gradient and key clinical dependent variables. (1) For a polymethyl methacrylate (refractive index, 1.49) PPAIOL of equiconvex design and 4.05-mm ACD, the predicted diopter/millimeter value is a function of ametropia (a), where diopter/millimeter = 1.666+0.136a+0.0018a2. (2) For 6-mm ACD and a refractive index of 1.7, diopter/millimeter = 1.836+0.159a+0.0027a2. (3) The equiconvex design benefits hyperopic but not myopic eyes. (4) For PPAIOLs correcting >4 D of astigmatism, more than 0.5 D of residual astigmatism is present at near after 1 mm of IOL displacement. (5) In emmetropic cases, the predicted diopter/millimeter value is a function of the corneal radius (r) where diopter/millimeter = 7.376-1.162r+0.0545r2. (6) Positional pseudoaccommodative IOL misplacement does not significantly affect the accommodative ability. (1) Hyperopic eyes with relatively steep corneas should benefit more from the PPAIOL than myopic eyes with relatively flat corneas. (2) A full, binocular, near refraction should be performed to correct any residual spheroastigmatism in anisometropia and cases in which the PPAIOL is toric.

Ophthalmic and Physiological Optics, 2003

To evaluate the effects of dissolvable collagen punctal plugs on the symptoms, tear stability and... more To evaluate the effects of dissolvable collagen punctal plugs on the symptoms, tear stability and volume in aqueous deficient dry eyes. Sixty-two aqueous deficient dry eye patients of mixed aetiology underwent lacrimal punctal occlusion with dissolvable collagen plugs. The subjects were randomly allocated to one of two treatment groups: group I (n = 36) had their lower puncta occluded and group II (n = 26) had both their upper and lower puncta occluded. The effectiveness of this treatment was clinically assessed by (1). scoring subject symptoms and (2). measuring the tear parameters of tear thinning time (TTT) and tear meniscus height (TMH) as indicators of tear stability and volume, respectively. Following baseline measurements, patients were reviewed at time intervals of 5 and 12 days post-occlusion. A group of age- and gender-matched normals (n = 45) was recruited for comparison (group III). Tear volume and stability were significantly higher in group III compared with I and II at baseline. In the treated groups on both days 5 and 12: (1). symptom score reduced significantly from a median value of 7 to 3 (p = <0.001); (2). tear stability increased significantly from a median value of 3 to 5 s by day 5 (p <or= 0.001); reduced between days 5 and 12 (p < 0.05) and remained below the stability in group III at all times; (c). tear volume increased significantly by day 5 in both treatment groups from a median value of 0.13 to 0.20 mm (p<or=0.001), remained stable by day 12 in group II but reduced in group I (p < 0.05); (d). the increase in tear volume was negatively correlated with pre-treatment tear volume; (e). symptom score correlated with both baseline tear volume and stability. Collagen plugs improved tear status in the aqueous deficient dry eyes. Occluding both upper and lower puncta with temporary collagen plugs offers no practical beneficial gain compared with occluding just the lower punctum.

Ophthalmic and Physiological Optics, 1995

Ophthalmic and Physiological Optics, 1998

To determine the clinical viability of a phenol red impregnated cotton thread in differentiating ... more To determine the clinical viability of a phenol red impregnated cotton thread in differentiating between normal, aqueous deficient and non-aqueous deficient dry eyes.

Ophthalmic and Physiological Optics, 1996