The Effect of NSAID Pretreatment on Aqueous Humor Prostaglandin E2 Concentration in Eyes Undergoing Femtosecond Laser-Assisted Capsulotomy

PURPOSE

To assess aqueous humor concentration of prostaglandin E2 (PGE2) after capsulotomy creation using a femtosecond laser (FLAC) in patients pretreated with short-term topical ketorolac versus patients without pretreatment.

METHODS

This prospective study comprised consecutive patients scheduled to undergo cataract surgery using a femtosecond laser platform to perform only capsulotomies. An identical protocol for preoperative mydriasis was used for all the eyes included in the study, while aqueous humor was extracted from the anterior chamber of all patients immediately after the initial side port incision. ELISA was performed to quantify aqueous humor PGE2. The patients were divided into 2 groups; in group 1, the patients received short-term topical ketorolac preoperatively, while the patients in group 2 did not receive NSAID pretreatment.

RESULTS

Twenty eyes of 20 patients were included in the study (10 eyes in each group). Mean concentration of aqueous humor PGE2 after FLAC was 392.16 ± 162.00 pg/ml and 622.63 ± 331.84 pg/ml for groups 1 and 2, respectively. A statistically significant difference in aqueous humor PGE2 concentration between the two groups (p < 0.05) was demonstrated, with the eyes that received ketorolac pretreatment demonstrating a lower concentration of PGE2.

CONCLUSION

Short-term topical use of ketorolac prior to FLAC seems to prevent excessive release of PGE2 in the anterior chamber of the eyes that received NSAID pretreatment when compared to the eyes that did not receive NSAIDs preoperatively.

Variability of manual ciliary muscle segmentation in optical coherence tomography images

Optical coherence tomography (OCT) offers new options for imaging the ciliary muscle allowing direct in vivo visualization. However, variation in image quality along the length of the muscle prevents accurate delineation and quantification of the muscle. Quantitative analyses of the muscle are accompanied by variability in segmentation between examiners and between sessions for the same examiner. In processes such as accommodation where changes in muscle thickness may be tens of microns- the equivalent of a small number of image pixels, differences in segmentation can influence the magnitude and potentially the direction of thickness change. A detailed analysis of variability in ciliary muscle thickness measurements was performed to serve as a benchmark for the extent of this variability in studies on the ciliary muscle. Variation between sessions and examiners were found to be insignificant but the magnitude of variation should be considered when interpreting ciliary muscle results.

Flap Amputation with Phototherapeutic Keratectomy (PTK) and Adjuvant Mitomycin C for Severe Post-Lasik Epithelial Ingrowth

Purpose

To report a patient with severe post–laser in situ keratomileusis (LASIK) epithelial ingrowth and keratolysis treated with flap amputation and phototherapeutic keratectomy (PTK) with adjuvant intraoperative mitomycin C (MMC).

Methods

Case report.

Results

A 55-year-old woman was referred to our department due to severe post-LASIK epithelial ingrowth with corneal melting 2 years after primary LASIK. The patient had had two previous attempts for epithelial ingrowth treatment (flap lift and epithelial ingrowth manual removal) that were unsuccessful. Slit lamp biomicroscopy and anterior segment optical coherence tomography showed extensive epithelial ingrowth and keratolysis (thinning of the LASIK flap) while the patient had photophobia and could not tolerate contact lenses. Flap amputation with subsequent PTK (in order to smooth out the corneal irregularities caused by the keratolysis and/or variations in flap thickness) and adjuvant intraoperative MMC application for 2 minutes was performed. There were no intra- or postoperative adverse events seen during the follow-up period. Six months after the procedure, uncorrected visual acuity improved to 20/40 compared with 20/50 preoperatively, while best spectacle-corrected visual acuity improved from 20/40 to 20/32. The topographic astigmatism was decreased from 3.24 diopters (D) to 1.00 D.

Conclusions

Flap amputation with PTK and adjuvant intraoperative MMC is an option for the management of severe post-LASIK epithelial ingrowth with keratolysis.

Adult chronic myelomonocytic leukemia with trisomy 11: a case report

Chronic myelomonocytic leukemia (cmml) is an indolent disease in the category of myelodysplastic and myeloproliferative neoplasms, which can often evolve into acute leukemic neoplasms. Although cytogenetic abnormalities such as trisomy 8 or absence of chromosome Y are well known, few reports about cmml with trisomy 11 have been published. Here, we report a case of cmml with trisomy 11 as the sole chromosomal abnormality, resulting in a very poor outcome. Based on a bone marrow specimen, cmml-1 with trisomy 11 was diagnosed in a 79-year-old man presenting with anemia and atypical peripheral blood cells. Because of the patient's age, he was followed without receiving anticancer treatment. Two months after his diagnosis, the patient's leucocytosis and anemia rapidly worsened, with increasing numbers of immature peripheral cells, which was strongly suggestive of leukemic transformation. Because of acute kidney injury superimposed on chronic kidney disease that led to poor performance status, cytotoxic chemotherapy was not considered feasible, and the patient was transferred to a hospice care facility.

Enhanced Phosphorylation of Bax and Its Translocation into Mitochondria in the Brains of Individuals Affiliated with Alzheimer's Disease

Background:

Despite increased neuronal death, senile plaques, and neurofibrillary tangles observed in patients suffering from Alzheimer’s disease (AD), the detailed mechanism of cell death in AD is still poorly understood.

Method:

We hypothesized that p38 kinase activates and then phosphorylates Bax, leading to its translocation to mitochondria in AD brains compared to controls. The aim of this study was to investigate the role of p38 kinase in phosphorylation and sub-cellular localization of pro-apoptotic Bax in the frontal cortex of the brains from AD and control subjects. Increased oxidative stress in AD individuals compared to control was evaluated by measuring the levels of carbonylated proteins and oxidized peroxiredoxin, an antioxidant enzyme. The relative amounts of p38 kinase and phospho-Bax in mitochondria in AD brains and controls were determined by immunoblot analysis using the respective antibody against each protein following immunoprecipitation.

Results:

Our results showed that the levels of oxidized peroxiredoxin-SO₃ and carbonylated proteins are significantly elevated in AD brains compared to controls, demonstrating the increased oxidative stress.

Conclusion:

The amount of phospho-p38 kinase is increased in AD brains and the activated p38 kinase appears to phosphorylate Thr residue(s) of Bax, which leads to its mitochondrial translocation, contributing to apoptosis and ultimately, neurodegeneration.

Influence of various levels of milk by-products in weaner diets on growth performance, blood urea nitrogen, diarrhea incidence, and pork quality of weaning to finishing pigs

OBJECTIVE

This study was conducted to evaluate various levels of milk by-product in weaning pig diet on growth performance, blood profiles, carcass characteristics and economic performance for weaning to finishing pigs.

METHODS

A total of 160 weaning pigs ([Yorkshire×Landrace]×Duroc), average 7.01±1.32 kg body weight (BW), were allotted to four treatments by BW and sex in 10 replications with 4 pigs per pen in a randomized complete block design. Pigs were fed each treatment diet with various levels of milk by-product (Phase 1: 0%, 10%, 20%, and 30%, Phase 2: 0%, 5%, 10%, and 15%, respectively). During weaning period (0 to 5 week), weaning pigs were fed experimental diets and all pigs were fed the same commercial feed during growing-finishing period (6 to 14 week).

RESULTS

In the growth trial, BW, average daily gain (ADG), and average daily feed intake (ADFI) in the nursery period (5 weeks) increased as the milk by-product level in the diet increased (linear, p<0.05). Linear increases of pig BW with increasing the milk product levels were observed until late growing period (linear, p = 0.01). However, there were no significant differences in BW at the finishing periods, ADG, ADFI, and gain:feed ratio during the entire growing-finishing periods. The blood urea nitrogen concentration had no significant difference among dietary treatments. High inclusion level of milk by-product in weaner diet decreased crude protein (quadratic, p = 0.05) and crude ash (Linear, p = 0.05) of Longissimus muscle. In addition, cooking loss and water holding capacity increased with increasing milk product levels in the weaner diets (linear, p<0.01; p = 0.05). High milk by-product treatment had higher feed cost per weight gain compared to non-milk by-products treatment (linear, p = 0.01).

CONCLUSION

Supplementation of 10% to 5% milk by-products in weaning pig diet had results equivalent to the 30% to 15% milk treatment and 0% milk by-product supplementation in the diet had no negative influence on growth performance of finishing pigs.

A study on setting of the fatigue limit of temporary dental implants

A temporary dental implant is a medical device which is temporarily used to support a prosthesis such as an artificial tooth used for restoring patient's masticatory function during implant treatment. It is implanted in the oral cavity to substitute for the role of tooth. Due to the aging and westernization of current Korean society, the number of tooth extraction and implantation procedures is increasing, leading to an increase in the use and development of temporary dental implants. Because an implant performs a masticatory function in place of a tooth, a dynamic load is repeatedly put on the implant. Thus, the fatigue of implants is reported to be the most common causes of the fracture thereof. According to the investigation and analysis of the current domestic and international standards, the standard for fatigue of implant fixtures is not separately specified. Although a test method for measuring the fatigue is suggested in an ISO standard, it is a standard for permanent dental implants. Most of the test standards for Korean manufacturers and importers apply 250 N or more based on the guidance for the safety and performance evaluation of dental implants. Therefore, this study is intended to figure out the fatigue standard which can be applied to temporary dental implants when measuring the fatigue according to the test method suggested in the permanent dental implant standard. The results determined that suitable fatigue standards of temporary dental implants should be provided by each manufacturer rather than applying 250 N. This study will be useful for the establishment of the fatigue standards and fatigue test methods of the manufacturers and importers of temporary dental implants.

Various levels of copra meal supplementation with β-Mannanase on growth performance, blood profile, nutrient digestibility, pork quality and economical analysis in growing-finishing pigs

BACKGROUND

To reduce use of main feed ingredient like corn, soy bean meal (SBM) and wheat, alternative ingredients has been studied like copra meal (CM). Production amount of CM which has been high makes CM to be an alternative feed stuff. However, low digestibility on AA and low energy content by high fiber content can be an obstacle for using CM. This experiment was conducted to evaluate the effects of CM supplementation with β-mannanase on growth performance, blood profile, nutrient digestibility, pork quality and economic analysis in growing-finishing pigs.

METHODS

A total of 100 growing pigs ([Yorkshire × Landrace] × Duroc) averaging 31.22 ± 2.04 kg body weight were allotted to 5 different treatments by weight and sex in a randomized complete block (RCB) design in 5 replicate with 4 pigs per pen. Treatments were 1) Control (corn-SBM based diet + 0.1% of β-mannanase (800 IU)), 2) CM10 (10% copra meal + 0.1% β-mannanase (800 IU)), 3) CM15 (15% copra meal + 0.1% β-mannanase (800 IU)), 4) CM20 (20% copra meal + 0.1% β-mannanase (800 IU)) and 5) CM25 (25% copra meal + 0.1% β-mannanase (800 IU)). Four phase feeding program was used: growing I (week 1-3), growing II (week 4-6), finishing I (week 7-9) and finishing II (week 10-12).

RESULTS

In growth performance, there was no significant difference among treatments during whole experimental period. In growingI phase, G:F ratio tended to increase when CM was increased (P = 0.05), but ADG and ADFI tended to decrease in finishingII phase (linear, P = 0.08). Also, increasing CM reduced ADG (linear, P = 0.02) and feed efficiency (linear, P = 0.08) during the whole finishing period. In blood profiles, BUN was linearly increased as CM increased (linear, P = 0.02) at growingII period. In digestibility trial, there was no significant difference in dry matter, crude fat, crude ash and nitrogen digestibility. However, crude protein digestibility was decreased linearly (linear, P = 0.02). In economic analysis, feed cost per weight gain and total feed cost per pig were reduced in overall period when CM was provided by 25% (linear, P = 0.02).

CONCLUSION

CM with 0.1% of β-mannanase (800 IU) could be supplemented instead of corn and SBM up to 25% without detrimental effects on growth performance and pork quality of growing-finishing pigs.

In Vivo Characteristics of Corneal Endothelium/Descemet Membrane Complex for the Diagnosis of Corneal Graft Rejection

PURPOSE

To evaluate the utility of endothelial/Descemet membrane complex (En/DM) characteristics in diagnosing corneal graft rejection.

DESIGN

Diagnostic reliability study.

METHODS

One hundred thirty-nine eyes (96 corneal grafts post penetrating keratoplasty or Descemet stripping automated endothelial keratoplasty: 40 clear, 23 actively rejecting, 24 rejected, and 9 nonimmunologic failed grafts; along with 43 age-matched control eyes) were imaged using high-definition optical coherence tomography. Images were used to describe En/DM and measure central corneal thickness (CCT) and central En/DM thickness (DMT). En/DM rejection index (DRI) was computed to detect the relative En/DM thickening to the entire cornea.

RESULTS

In actively rejecting grafts, DMT and DRI were significantly greater than controls and clear grafts (28, 17, and 17 μm and 1.5, 1 and 1, respectively; P < .001). Rejected grafts had the highest DMT and DRI compared to all groups (59 μm and 2.1; P < .001). DMT and DRI showed excellent accuracy, significantly better than that of CCT, in differentiating actively rejecting from clear grafts (100% and 96% sensitivity; 92.5% and 92.5% specificity), actively rejecting from rejected grafts (88% and 83% sensitivity; 91% and 83% specificity), and nonimmunologic failed from rejected grafts (100% and 100% sensitivity; 88% and 100% specificity). DMT correlated significantly with rejection severity (P < .001).

CONCLUSIONS

In corneal grafts, in vivo relative thickening of the En/DM is diagnostic of graft rejection as measured by DMT and DRI. These indices have excellent accuracy, sensitivity, and specificity in detecting graft immunologic status, superior to CCT. DMT is a quantitative index that correlates accurately with the severity of rejection.

Assessment of eye length changes in accommodation using dynamic extended-depth OCT

It has been suggested that accommodation induces increases in axial eye length which could contribute to the development of myopia. However, it is debated whether changes in eye length occur during accommodation as the degree of change varies widely across literature. In this study, an extended-depth optical coherence tomography (OCT) system that provides dynamic whole eye biometry was utilized to assess changes in lens thickness (LT) and axial eye length (AEL) in young subjects responding to step disaccommodation stimuli of amplitude 2D, 4D, and 6D. The decrease in lens thickness with disaccommodation was strongly correlated with stimulus amplitude. No statistically significant changes in AEL during accommodation were observed.

Intraocular lens power overestimation in a patient with history of circling keratorraphy

We report a case of cataract extraction and intraocular lens (IOL) power overestimation in a patient with history of hyperopia managed with circling keratorraphy. A 65-year-old female presented to our institute complaining of decreased vision in both eyes. The patient had a history of bilateral hyperopia that was managed 20 years ago (1994) with circling keratorraphy. At presentation her uncorrected distance visual acuity (UDVA) was 20/70 and 20/60 in her right eye (OD) and left eye (OS), respectively, while her corrected distance visual acuity (CDVA) was 20/25 OD and 20/25 OS with manifest refraction of −0.50 + 1.50 × 75 OD and +0.50sph + 1.50cyl × 30 OS. Slit lamp examination revealed the presence of a circular intrastromal corneal suture (6 mm diameter) and mild (+1) nuclear sclerosis in both eyes. The patient was scheduled to undergo cataract extraction targeting plano, using a toric IOL; one month after the surgery, the manifest refraction of the operated right eye was −2.00 + 0.50 × 175, reflecting an overestimation of the intraocular lens (IOL) power for the attempted target. Cataract extraction in patients with history of circling keratorraphy for the management of hyperopia results in IOL power overestimation, consistent with that which is seen in patients with other previous hyperopic corneal refractive procedures.

Effects of Femtosecond Laser-Assisted Cataract Pretreatment on Pupil Diameter: A Comparison Between Three Laser Platforms

PURPOSE

To assess pupil diameter before and after femtosecond laser-assisted cataract surgery (FLACS) pretreatment and compare the outcomes of three laser platforms.

METHODS

This prospective observational case series included consecutive patients scheduled to undergo cataract extraction using FLACS between August 2013 and February 2015. All eyes received FLACS pretreatment using three laser platforms: LenSx (Alcon Laboratories, Inc., Fort Worth, TX), Catalys (Abbott Medical Optics Inc., Santa Ana, CA), and Victus (Bausch & Lomb, Inc., Rochester, NY). The same protocol for preoperative medical mydriasis was used for all patients, and pupil diameter was assessed immediately before and 3 minutes after FLACS using a surgical ruler.

RESULTS

A total of 198 eyes of 161 patients were included in the study. Mean pupillary miosis was 1.42 ± 1.26 mm for the LenSx, 0.66 ± 0.89 mm for the Catalys, and 0.14 ± 0.34 mm for the Victus groups. Furthermore, 8 of the 198 eyes (4.0%) demonstrated a pupil diameter of less than 5 mm after FLACS and 48 eyes (24.24%) demonstrated a pupil diameter of 6 mm or less. There was a statistically significant decrease in pupil diameter for all groups individually (P < .05). There was also a statistically significant difference among the three groups (P < .05), with LenSx inducing the highest degree of miosis, followed by Catalys, and finally Victus. A correlation between the pupil diameter before FLACS and degree of FLACS-induced miosis was demonstrated (P < .05), with larger pupil diameter before FLACS associated with greater miosis.

CONCLUSIONS

FLACS pretreatment seems to induce significant pupillary miosis with all laser platforms assessed in this study. The decrease in pupil diameter after FLACS reached clinical significance for cataract extraction (< 5 mm) in 4.0% of cases, whereas 20.2% of eyes demonstrated small pupil diameter (≤ 6 mm) after FLACS pretreatment.

Anterior Capsulotomy Outcomes: A Comparison Between Two Femtosecond Laser Cataract Surgery Platforms

PURPOSE

To compare capsulotomy outcomes between two femtosecond laser platforms for cataract surgery.

METHODS

This retrospective case series included 205 eyes of 162 consecutive patients (75 male and 87 female) aged 68.32 ± 10.27 years (range: 38 to 92 years) who underwent femtosecond laser-assisted cataract surgery (FLACS) using either the LenSx (Alcon Laboratories, Inc., Fort Worth, TX) or the Catalys (Abbott Medical Optics, Abbott Park, IL) laser platform. Intraoperative assessment of the capsulotomy was performed and graded as one of the following four types: complete treatment pattern (type 1), microadhesions (type 2), incomplete treatment pattern (type 3), and complete pattern but not continuous (type 4).

RESULTS

Ninety-seven eyes underwent FLACS using the LenSx platform and 108 eyes using the Catalys platform. Ninety-four capsulotomies in the LenSx group were graded as type 1 (96.91%), and three were graded as type 2 (3.09%); all capsulotomies in the Catalys group were graded as type 1 (100%). There was no statistically significant difference between the LenSx and Catalys groups (P > .05). No intraoperative complications (specifically, no posterior capsular extension or vitreous loss) were noticed in any of the eyes included in the study.

CONCLUSIONS

The LenSx and Catalys laser platforms demonstrate similar capsulotomy outcomes. The microadhesions that were demonstrated in three cases in the LenSx group did not lead to intraoperative or postoperative complications.

Quantification of the ciliary muscle and crystalline lens interaction during accommodation with synchronous OCT imaging

Two SD-OCT systems and a dual channel accommodation target were combined and precisely synchronized to simultaneously image the anterior segment and the ciliary muscle during dynamic accommodation. The imaging system simultaneously generates two synchronized OCT image sequences of the anterior segment and ciliary muscle with an imaging speed of 13 frames per second. The system was used to acquire OCT image sequences of a non-presbyopic and a pre-presbyopic subject accommodating in response to step changes in vergence. The image sequences were processed to extract dynamic morphological data from the crystalline lens and the ciliary muscle. The synchronization between the OCT systems allowed the precise correlation of anatomical changes occurring in the crystalline lens and ciliary muscle at identical time points during accommodation. To describe the dynamic interaction between the crystalline lens and ciliary muscle, we introduce accommodation state diagrams that display the relation between anatomical changes occurring in the accommodating crystalline lens and ciliary muscle.

Femtosecond laser-assisted cataract surgery in a patient with posterior chamber phakic intraocular lens

We describe a case of modified femtosecond laser settings for cataract extraction in a patient with a posterior chamber phakic intraocular lens (PIOL), to avoid incomplete treatment patterns and treatment displacement. Modification of laser settings (increased depth for the capsulotomy, increased vertical spot spacing for the capsulotomy and increased anterior and posterior capsule safety margins for lens fragmentation) seems to make femtosecond laser-assisted cataract surgery feasible in patients with posterior chamber PIOLs, as complete treatment patterns are achieved.

Herpes Simplex Virus Endotheliitis following Descemet's Membrane Endothelial Keratoplasty

Purpose:

To report a case of herpes simplex virus (HSV) endotheliitis following simultaneous phacoemulsification, intraocular lens (IOL) implantation and descemet's membrane endothelial keratoplasty (DMEK).

Case Report:

A;45 year-old female with corneal endothelial decompensation and a mature cataract, and history of anterior uveitis underwent simultaneous phacoemulsification, IOL implantation and DMEK. Increased corneal edema and descemet's membrane (DM) detachment occurred on postoperative day 3 and 5, respectively. One week after surgery, active keratic precipitates (KPs) appeared. Polymerase chain reaction (PCR) analysis was performed on an aqueous sample which was positive for herpes simplex virus (HSV). After initiating oral acyclovir and frequent topical corticosteroids, the corneal edema resolved and the donor tissue became spontaneously reattached to the recipient corneal stroma.

Conclusion:

HSV endotheliitis may occur in the early postoperative period after DMEK and manifest as endothelial dysfunction leading to donor detachment. Anti-viral medication may help treat the acute phase and reduce the risk of recurrence.

Intrastromal Corneal Ring Segment Explantation in Patients With Keratoconus: Causes, Technique, and Outcomes

PURPOSE

To assess the causes for intrastromal corneal ring segment (Intacs; Addition Technology Inc., Lombard, IL) explantation in patients with keratoconus, and technique for explantation, long-term outcomes, and secondary procedures to correct visual acuity.

METHODS

Ten eyes of 8 patients with a history of Intacs explantation between 2004 and 2012 were included in a retrospective study performed at the Bascom Palmer Eye Institute, Miami, Florida. Causes of Intacs removal, surgical technique, preoperative and postoperative corneal examination, and uncorrected and corrected distance visual acuity were documented. Additionally, corneal topography (Tomey, Nagoya, Japan) parameters such as average keratometry and corneal cylinder were assessed.

RESULTS

Although the segments were well positioned, the most common cause of Intacs removal was worsening visual acuity (80%). There was no statistically significant difference between pre-Intacs placement, post-Intacs placement, and post-Intacs removal in uncorrected and corrected distance visual acuity, average keratometry, or corneal cylinder, except between 1-year post-Intacs placement corrected distance visual acuity (0.57 logMAR [20/75 Snellen]) and 1-month post-Intacs removal corrected distance visual acuity (0.25 logMAR [20/36 Snellen], P =.03). Four patients underwent penetrating keratoplasty after Intacs removal with good visual outcomes.

CONCLUSION

This study demonstrates the visual and structural outcomes that returned to near baseline after Intacs explantation in keratoconic eyes.

Corneal stromal elasticity and viscoelasticity assessed by atomic force microscopy after different cross linking protocols

The purpose of this study was to evaluate elasticity and viscoelasticity in the anterior and deeper stromal regions of the cornea after cross linking with three different protocols using atomic force microscopy (AFM) through indentation. A total of 40 porcine corneas were used in this study and were divided into 4 groups (10 corneas per group): control (no treatment), Dresden (corneal epithelial debridement, riboflavin pretreatment for 30 min and a 3mw/cm(2) for 30 min UVA irradiation), accelerated (corneal epithelial debridement, riboflavin pretreatment for 30 min and a 30mw/cm(2) for 3 min UVA irradiation), and genipin (corneal epithelial debridement and submersion of anterior surface in a 1% genipin solution for 4 h). Elasticity and viscoelasticity were quantified using AFM through indentation for all corneas, for the anterior stroma and at a depth of 200 μm. For the control, Dresden, accelerated, and genipin groups, respectively, the average Young's modulus for the anterior stromal region was 0.60 ± 0.58 MPa, 1.58 ± 1.04 MPa, 0.86 ± 0.46 MPa, and 1.71 ± 0.51 MPa; the average for the 200 μm stromal depth was 0.08 ± 0.06 MPa, 0.08 ± 0.04 MPa, 0.08 ± 0.04 MPa, and 0.06 ± 0.01 MPa. Corneas crosslinked with the Dresden protocol and genipin were significantly stiffer than controls (p < 0.05) in the anterior region only. For the control, Dresden, Accelerated, and genipin groups, respectively, the average calculated apparent viscosity for the anterior stroma was 88.2 ± 43.7 kPa-s, 8.3 ± 7.1 kPa-s, 8.1 ± 2.3 kPa-s, and 9.5 ± 3.8 kPa-s; the average for the 200 μm stromal depth was 35.0 ± 3.7 kPa-s, 49.6 ± 35.1 kPa-s, 42.4 ± 17.6 kPa-s, and 41.8 ± 37.6 kPa-s. All crosslinking protocols resulted in a decrease in viscosity in the anterior region only (p < 0.05). The effects of cross-linking seem to be limited to the anterior corneal stroma and do not extend to the deeper stromal region. Additionally, the Dresden and genipin protocols seem to produce a stiffer anterior corneal stroma when compared to the accelerated protocol.