The Ocular Hypertension Treatment Study
"It has since [the publication of the OHTS] been debated whether thin corneas predict the risk only because the IOP is underestimated by tonometry when the cornea is thin or additionally because a thin cornea represents a general weakness of ocular support structures that make the eye more vulnerable to harmful effects of IOP."

"Corneal thickness does not over-ride or eliminate other features of the case that may lead you to an estimate of risk, but simply increases or decreases your estimate based on other factors."

M & T Commentary:
Just as with the "glaucoma scanning devices," no single test or parameter confers or refutes the diagnosis of glaucoma, but they all are cerebrally coalesced by an astute clinician to make sound clinical judgments.

Examining the Evidence
"If we believe from the OHTS data that support structures of the optic nerve are weak in eyes with naturally thin corneas, it would not be expected that the structure of the optic nerve would be affected by acquired alteration of the corneal thickness. For example, if the cornea is thin by virtue of LASIK, the optic nerve is not made weaker, nor is it stronger if the cornea is thickened by edema or by scarring. Such acquired corneal changes may affect the tonometric readings, but not the sturdiness of the optic nerve."

M & T Commentary:
This myth of "LASIK-induced glaucoma" has confused some people, but this nicely explains the situation.

Using the Reported Evidence and Concepts
"The CCT [central corneal thickness] may moderate your assessment of risk in conjunction with age, level of tonometer reading, family history, and other factors you feel affect the patient's risk."

"The evidence that corneal thickness affects the rate of further glaucomatous damage is not as firm for cases of glaucoma as it is for ocular hypertension. Until we know more, the severity of existing damage, family history, and age likely remain the main guides to choosing a percentage of pressure of IOP lowering you would like to achieve."

"It may also be noted that risk assessment at the time that either ocular hypertension or glaucoma is first discovered is not the same as assessing the risk of the patient who has been monitored for several years. As time goes on, the clinical course to date gradually takes an increasingly dominant role in risk assessment and decision making. Therefore, if the eye shows progressive cupping or field loss at an unacceptable rate, the decision to lower the pressure is unaffected by CCT. Similarly, long term stability may be taken as evidence of adequate treatment, no matter how thick or thin the cornea may be."

Summary
"CCT has been identified as a contributing predictive factor for glaucoma development in cases of recently discovered ocular hypertension. The basis for its ability to predict (inaccurate tonometry or weakness of ocular structures) is not known. "

"Often the known clinical course to date is the dominant feature that guides therapeutic decisions in establishing glaucoma, so CCT measurements are typically not helpful, but there are individual cases in which knowing the CCT is very helpful. Before obtaining CCT, one should therefore stop to consider whether the information will assist in making a clinical decision in this particular patient, just as we should for any examination or test we contemplate obtaining. For some patients with ocular hypertension or glaucoma, knowing the CCT will affect the clinical decision, but for others, not."

M & T Commentary:
In the June, 2005 issue of "Eyeworld (page 28), this issue was addressed. Here are a few quotes: "there is value in knowing the corneal thickness with established glaucoma where the decision to treat has already been made. This doctor said she, 'finds it most useful in patients who seem to be progressing but whose IOP seems reasonably well controlled.' In these patients, she often encounters unexpectedly thin corneas, and she revises her target IOP downward. "There are a few patients who may not need [pachymetry], such as patients with stable glaucoma whose optic nerve and visual field status have remained unchanged for years are unlikely to benefit from the measurements." While we agree with these perspectives, we vote to keep life simple and consistent; i.e., every glaucoma suspect, and every patient with glaucoma should have their corneal thickness measured and properly annotated in the chart.

From: Interpreting Relative Risks and Possible Implications for the current 'Mantra': 10% Risk Reduction for Every Millimeter IOP Reduction
by Ravi Thomas, et. al.

"The NNT [number needed to treat] reflects the number of patients we need to treat in order to obtain one benefit or desirable result. All else being equal, the lower the NNT, the better. "

"The relative risk (RR) tells us the risk of an outcome in one group with the risk factor (eg increased IOP) compared to the risk of an outcome in a group without the risk factor (eg normal IOP). A derivation of the RR, the relative risk reduction (RRR) tells us the proportion of the baseline risk that can potentially be removed by treating the risk factor in question."

"A relative risk reduction (or relative risk ) of 50% could mean an 'absolute' reduction from 100% to 50% or from 1% to 0.5%. These figures translate into an NNT of 2 for the first example, versus 200 for the second." All else being equal, we would probably always use the therapy that provides an NNT of 2 and very rarely use one with an NNT of 200."

"However, results from some recent studies have been presented in an isolated manner that might encourage very aggressive lowering of the IOP with possibly detrimental effects. Both OHTS and the EMGT state that each mmHg-lowering of IOP is associated with a 10% lowering of risk. First, we must remember that in both these studies, this conclusion was the result of 'post hoc' analyses; such analyses are always interpreted with care. "

M & T Commentary:
We have all heard that decreasing IOP in the OHTS resulted in a relative risk reduction of about 50%, but, the absolute risk reduction was only about 5% (from roughly 10% to 5% conversion from ocular hypertension to glaucoma.) It is always important to have at least a basic understanding of biostatistics to meaningfully understand study results. Dr. Ravi Thomas nicely gives us a perspective of some of these data concepts.

From: What Does the Sclera Have to Do With Glaucoma?
by C. Ross Ethier, et. al.

"the biomechanics of the corneo-scleral shell affect the optic nerve head quite profoundly. Why? It has to do with the effective stiffness: the thick, solid sclera is much stiffer than both neural tissue and the porous lamina cribrosa. It's as if a wire rope (the sclera) were attached to a thick elastic band (the lamina cribrosa); if you pull on the wire rope, the elastic simply has to follow. The implication is that acute deformities of the lamina cribrosa and neural tissue depend critically on how much the sclera deforms, and hence on the mechanical properties of the sclera."

"we wonder whether this might explain some of the association between central cornea thickness and progression seen in the OHTS study, even after correction of corneal thickness-compensated IOP."

From: Special Editorial on Risk Management
by E. L. Greve, et. al.

1. Weinreb et. al
   "the risk of developing unilateral blindness from ocular hypertension over 15 years ranges from 1.5% to 10.5% untreated, and from 0.3% to 2.4% treated."
   
   "Based on cross-sectional data from the Baltimore Eye Survey (non-institutionalized persons with glaucoma), Quigley et. al. estimated that in the US , an average person who developed initial glaucomatous field loss at age 60 would probably not become legally blind in either eye within his or her lifetime. Thus, only a small proportion of those with glaucoma progress to bilateral blindness in their lifetimes. "
   
   "In a life-table modeling, the average time from first visual field loss to death was estimated to be 13 years for whites and 16 years for blacks.
   
   "In another estimate on a cross-sectional clinic data set, Jay and Murdoch reported that with optimum treatment the interval between early glaucomatous field loss and end-stage glaucoma was 38 years. Using worse eye data, with untreated IOPs in POAG between 21-25mmHg, the average time for untreated glaucoma to progress to near blindness after early field defect was 14 years, and with pressures of 26-30mmHg 7 years."
   
   "In a prospective follow-up study of ten years, Rasker et. al. reported that visual field defects developed in 6% of 125 OHT patients. The mean time to first VF defect was 7±3.4 years. From POAG data, they estimated that eyes with treated ­early glaucoma with progression, end-stage glaucoma may be reached in about 33 years."
   
   "The question whether it is acceptable to wait for the appearance of visual field defects remains unanswered. The goal of glaucoma treatment is to preserve the patient's Quality of Life. One of the clearest factors for development of future blindness is the presence of advanced visual field defects. Such a risk of blindness has not been reported for the presence of early damage. Once early damage has been established and vigorous treatment is installed, recent studies have shown that progress is slow."
   
   M & T Commentary:
   It is evident for most patients that glaucoma is a very slowly progressive disease. Rarely is there ever a need to make hasty decisions regarding glaucoma care.
   
   
2. Friedman et. al. : Comments about risk factors
   "What is a risk factor: the presence of a risk factor indicates that the patient has a higher probability of developing a disease than a population with same age and without the risk factor, e.g. high IOP. WHAT IS NOT A RISK FACTOR: EARLY DISEASE IS NOT A RISK FACTOR, NOR IS SUSPICION OF EARLY DISEASE.
   
   "Suspicion means that there may or may not be early disease. Suspicion is a reason for paying extra attention to the suspect, including careful evaluation of all aspects of the examination, careful baseline documentation and frequent follow-up visits in order to detect possible progression.
   
   In the paper by Friedman, et. al., visual field suspicion and disk suspicion are ranked under risk factors. These factors surely are different from IOP which is a risk factor in the true sense of the definition. It seems prudent not to rank a suspicious visual field or disk under risk factors. If we remove suspicious findings from the risk factors, we will find somewhat to our surprise that ONLY a higher IOP, a thinner cornea and older age remain. Assuming that older age is balanced by shorter life expectancy and knowing that the evidence for thinner cornea as an IOP independent risk factor is lacking, WE MAY CONCLUDE FROM THIS PAPER THAT IOP IS THE ONLY RISK FACTOR. Weinreb et. al. write: 'Unfortunately current available data are insufficient to accurately estimate levels of risk in most glaucoma patients.'"
   
   "What does this mean for management of the glaucoma suspect?

M & T: this is really good information...

1. The risk of developing unilateral blindness is relatively low, meaning that only selected high risk ocular hypertension patients should be treated.
   
   
2. Apart from the risk factor 'higher IOP' (corrected for CCT) only field or disk suspicion factors may help up in making a treatment decision (and additionally the presence of pseudoexfoliation).
   
   
3. The follow-up of suspicion factors allows us to let suspicion turn into the certainty of established damage (and changing the diagnosis from suspect to glaucoma) only after progression has been identified (i.e. significant change surpassing long-term variability).
   
   
4. If the Rate of Progression is such that reduction of Quality of Life is expected to occur in the patients lifetime, treatment is justified.

NOTE: Although this is the ideal situation, measurement of Rate of Progression may not be possible. In that case the second best is to confirm progression (e.g. by a series of visual field examinations or by additional disk data)."

M & T Commentary:
It may very well be that the "glaucoma scanning devices" will have their clinical forte in helping us assess progression. We postulate they are better than visual fields at this task, especially in early disease. Visual fields are probably better at following progression once a visual field defect is established (i.e., reliable and consistent upon repeated testing.)

"In practical terms:

1. In the presence of a CCT corrected IOP repeatedly at or over 30mmHg: treat.
   
   
2. In the presence of a CCT corrected IOP repeatedly between 22 and 30mmHg: follow at regular intervals.
   
   
3. In the presence of a CCT corrected IOP between 22-30mmHg and in addition a suspicious field or disc factor, follow at more frequent intervals in order to establish (rate of) progression ."
   
   " 'Because of large interpretation variability of progression it may be reasonable to leave some (low risk) patients untreated and establish a rate of progression first.' This was written for patients with established glaucoma. It is all the more applicable to ocular hypertension ."
   
   "What is the main and most practical reason for early detection of glaucomatous damage: not necessarily the installment of early treatment, BUT the availability of a means of establishing progression and preferably rate (velocity) of progression. This will by itself allow for earlier treatment which is now based on the demonstration of progressive disease.

M & T Commentary:
Notice how experts carefully and systematically assess the patient before treatment. There is rarely ever a need to rush therapeutic intervention.

"In practice, the above approach should be considered for implementation where the infrastructure is available to provide careful follow-up, where the patient is committed to attend regularly and when the variability in the results obtained is small enough to enable identification of progression in a clinically relevant time period. In the absence of appropriate follow-up, consideration should be given to treating those with the risk factor elevated IOP.

"More than 3000 Japanese over 40 years participated (78% participation) in this cross-sectional epidemiology study. The prevalence of POAG was 3.9% of which more that 90% were of the NPG type. The mean CCT was 518mm and not significantly different from non-glaucoma eyes (520mm)

"The non-significance of CCT as a risk factor for glaucoma in this population was confirmed. Of the POAG patients, 93.9% were undiagnosed."

M & T Commentary:
It appears that "failure to diagnosis" glaucoma is not just an American phenomenon.

On Examination Methods - IOP and CCT
Comment by Clive Migdal
"The response to topical medication varies widely amongst individuals, with many factors being responsible for this variability."

"Thinner corneas had a lower measured IOP after four to six weeks of therapy with either beta-blockers or prostaglandins. CCT measurements were not correlated with any of the other parameters investigated. Three possible mechanisms can be postulated by which CCT might influence the measured IOP response to ocular hypertension medications, namely differential pharmacokinetics, lower baseline IOP and differential corneal compliance, with a combination of the latter two hypotheses being most likely."

"Ultimately, the focus of glaucoma management must still be on the optic nerve and visual field. In clinical practice, however, CCT measurements can help the clinician better interpret a patient's response to therapy."

Comment by James Brandt
"The authors report that those treated with PGAs have, on average, thinner corneas than their untreated counterparts or those treated with other medications. The authors hypothesize that, since the mechanism of PGAs is to modify and partially digest the extracellular matrix of the ciliary muscle, perhaps a similar effect is occurring in the cornea, with a drug-related thinning."

"Since clinicians tend to use the most powerful medications in patients presenting with more advanced disease, a study of this design and size is subject to a selection bias wherein patients treated with PGAs might have thinner corneas on a basis unrelated to drug effect. These criticisms aside, I do believe that the authors are probably correct in suggesting that PGAs likely alter the mechanical properties of the cornea, including CCT and their study provides the first tantalizing data to support this."

On Structure:
Comment by Harry Quiqley:
1) Strain on the lamina is sufficient to damage nerve fibers directly; 2) the sclera is more important than the lamina itself in determining what the lamina will do; 3) the surface of the disc does different things from the lamina; 4) the central retinal artery, the pia, and the cerebrospinal fluid pressure are pretty meaningless to the strain."

On Function and Structure:
Comment by Balwantray Chauhan:
"While modern imaging devices such as scanning laser tomography, optical coherence tomography and scanning laser polarimetry have been in clinical practice for over a decade, longitudinal data from these devices is scantx Mohammandi and colleagues determined whether baseline status with GDx Nerve Fibre Analyzer was predictive of glaucomatous field loss They found that subjects with thinner baseline nerve fibre thickness were at a higher risk of visual field conversion."

"the conversion rate of subjects with thinner nerve fibre layer parameters after four years of follow-up was five to seven times higher than the conversion rate of even the untreated subjects in the Ocular Hypertension Treatment Trial." M & T: So it would seem that a thin (or thinner than average) retinal nerve fiber layer is a risk factor for glaucomatous progression. Baseline NFL measurement would be a wise parameter to have for future comparison.

"The authors were careful to conduct a multivariate analysis that took into account the baseline differences in the optic disc and visual field and still found the baseline GDx parameters to be associated with conversion."

On Risk Factors:
Comment by Tetsuya Yamamoto
"It is well known that optic disc hemorrhages are frequently observed in glaucoma cases. They are more frequently seen in cases with lower intraocular pressure (IOP), i.e., a normal-tension glaucoma. Thus, they are suggestive of the existence of IOP-unrelated pathogenic factors of glaucomatous optic neuropathy. More importantly from a clinical standpoint of view, many glaucoma clinicians believe they are indicators of glaucoma progression."

"One [factor] is that disc hemorrhages more likely develop at relatively lower IOP during follow-up. The results are in good agreement with our experience that disc hemorrhages are observed more commonly in the presence of relatively lower IOP."

On Medical Therapy: Persistency
Comment by Gail Schwartz
"This clinical outcome study by Zhou et. al. evaluates persistency (time on therapy) in patients with primary open-angle glaucoma naïve to therapy in the United Kingdom . Six classes of IOP-lowering agents were analyzed. The database selected was a large UK resource previously established as valid for clinical research, with 2,001 patients meeting selection criteria. From both a patient care and resource management standpoint, the clinician seeks to begin a therapy upon which the patient would remain for the foreseeable future. This entails a combination of efficacy with drug tolerability and patient adherence to therapy. The results supporting greater persistency with latanoprost relative to the other agents in this study, is very much in accordance with the published literature, both United States and European, as noted by the authors."

"As newer prostaglandin agents have entered the market, their inclusion in a future database analysis would also add to the literature.

"Persistency , offering a broader picture than compliance alone, is becoming an increasingly important tool in patient management. Regardless of the quality of the clinical decision making, persistency is required for long term prevention of glaucomatous progression."

On Medical Therapy: Additivity of Prostaglandins
Comment by Carl Camras
"These findings lead the authors to conclude that adding either of the newer prostaglandin (PG) analogs, travoprost (TP; Travatan) or bimatoprost (BP; Lumigan) to the regimen of patients receiving latanoprost (LP; Xalatan) might result in greater ocular hypotensive efficacy. However, these implications must be tempered considerably for many reasons. A very important weakness of the study design was the failure to mask. The study was performed in monkeys. Any illusion to the clinical applicability of the findings in humans represents an extrapolation with questionable validity."

"In conclusion, monkeys simply are not humans. The findings in the present study of monkeys are not consistent with published studies in humans, which fail to demonstrate additivity of the three major PG analogs."

M & T Commentary:
At this point in time, if a prostaglandin works well at reducing IOP, we see no reason to try adding another prostaglandin. It is known, but unexplained, that b.i.d. dosing of latanoprost did not perform s well as once daily dosing.

STUDIES
Prevalence of primary open-angle glaucoma in a Spanish population: the Segovia study

CONCLUSION: The prevalence of POAG in this Segovia population is 2.1%, similar to that estimated in previous studies performed predominantly in Caucasian populations.

The prevalence of primary open-angle glaucoma in Japanese: the Tajimi Study

CONCLUSIONS: The prevalence of POAG in this population was 3.9%. In 92% patients with POAG, the IOP was 21mmHg or less.

Is glaucoma associated with motor vehicle collision involvement and driving avoidance?
CONCLUSIONS: Older persons with glaucoma drive at least as safely as, if not more safely than, older persons without glaucoma.

Impact of diabetes on glaucoma screening using frequency-doubling perimetry
PURPOSE: To determine whether diabetes is a potential source of abnormal test results in glaucoma screening by use of frequency-doubling perimetry.

CONCLUSIONS: Frequency-doubling perimetry is abnormal in some patients with diabetes, including some patients with diabetes without clinical evidence of diabetic retinopathy. Abnormal FDT testing in diabetic eyes may not represent glaucomatous visual field loss. Diabetes may be a source of 'false-positive' test results when this technology is used for glaucoma screening.

M & T Commentary:
Caution, and repeat VF testing using standard perimetric technology is in order for diabetic patients who demonstrate questionable results on FDT testing.

Central corneal thickness and measured IOP response to topical ocular hypotensive medication in the Ocular Hypertension Treatment Study
PURPOSE: to determine whether central corneal thickness (CCT) correlates with measured intraocular pressure (IOP) responses to topical hypotensive medication in the Ocular Hypertension Treatment Study (OHTS).

CONCLUSIONS: individuals with thicker corneas had smaller measured IOP response to ocular hypotensive medication than those with normal or thin corneas.

Corneal thicknesses in children
CONCLUSIONS: Pediatric central and paracentral corneal thicknesses increase slowly over time and reach adult thicknesses at 5 to 9 years of age.

Impact of prostaglandin-F2­a­­ ­- analogues and carbonic anhydrase inhibitors on central corneal thickness -- a cross-sectional study on 403 eyes
CONCLUSIONS: The present findings suggest that the topical application of prostaglandin F­2a analogues onto the cornea reduces the central corneal thickness significantly. These changes might be attributed to the effects of PGF­2a analogues on the extracellular matrix of the corneal stroma via upregulation of matrix metalloproteinases. In clinical practice, corneal thinning under local PGF2a analogue treatment could result in underestimation of intraocular pressure levels as measured by applanation tonometry.

M & T Commentary:
Interesting, but further research will need to be done to see if there is clinical relativity to these changes.

Central corneal thickness of Caucasians, Chinese, Hispanics, Filipinos, African Americans, and Japanese in a glaucoma clinic
CONCLUSIONS: Studies examining individual Asian subpopulations in isolation suggest that differences in CCT may exist among different Asian groups. The results of this study indicate that CCT does, in fact, vary among Asian subpopulations; Japanese have thinner corneas than Chinese and Filipinos. Caucasians, Chinese, Hispanics, and Filipinos have comparable CCT measurements, whereas the corneas of African Americans are significantly thinner. Additionally, older individuals; glaucoma suspects; and participants with NTG, POAG, PEX, and CACG have thinner corneas.

Visibility of lamina cribrosa pores and open-angle glaucoma
CONCLUSION: Lamina cribrosa pores are commonly visible in glaucoma suspects and less commonly visible in normals. This association, however, is almost entirely because of an increased visibility associated with larger vertical cup-disk ratio and optic disk size.

Comparison of the Tono-Pen and Goldmann tonometer for measuring intraocular pressure in patients with glaucoma
Combining the analysis for both groups, the Tono-Pen significantly underestimated the IOP when the pressure was > 20mmHg.

CONCLUSIONS: The Tono-Pen cannot replace the Goldmann tonometer in the sense that it will give the same readings of IOP. The accuracy of the Tono-Pen increased, if at least two measurements are taken per eye and then averaged.

Comparison of dynamic contour tonometry with Goldmann applanation tonometry
CONCLUSIONS: IOP measurements by DCT are highly concordant with IOP readings obtained from GAT, but do vary in CCT and have a lower intra- and interobserver variability. DCT seems to be an appropriate method of tonometry for routine clinical use.

Pressure phosphene self-tonometry: a comparison with Goldmann tonometry in glaucoma patients
CONCLUSIONS: With proper training and technique, self-tonometry with the PPT appears to be accurate up to at least 25mmHg and is reproducible. The PPT was sensitive and specific in detecting elevated IOP of more than 21mmHg. As patients were expected to seek ophthalmic care before self-measured IOP reaches 25mmHg, the PPT may have a value for self-monitoring. Patients rated the PPT as satisfactory for home use. Because the PPT is portable and relatively inexpensive and requires no topical anesthesia or direct contact with the eyeball, it may have potential as an instrument for home self-tonometry.

M & T Commentary:
While it is nice to know this unit is reasonably accurate, its forte is not in absolute IOP measurement, but in detecting the magnitude of diurnal IOP curves. It can be very helpful for this purpose, and is available from Bausch & Lomb.

Goldmann tonometry after hyperopic laser in situ keratomileusis: Comparison between retreated and nonretreated patients
PURPOSE: To identify differences in applanation tonometry between retreated and nonretreated eyes (primary LASIK eyes) 6 months after hyperopic laser in situ keratomileusis.

CONCLUSIONS: After hyperopic laser in situ keratomileusis there was no significant difference in Goldmann applanation tonometry between retreated and primary LASIK eyes.

Impact factors on intraocular pressure measurements in healthy subjects
AIM: To evaluate whether intraocular pressure (IOP) calculation by applanation tonometry is determined more essentially by the subject's neck position or by neck constriction. IOP was measured by applanation tonometry with the TonoPen on sitting participants under four different conditions: with open collar upright (A) or with the head in the headrest of a slit lamp (B), with a tight necktie upright (C) or in a slit lamp position (D). All measurements with neck constriction were performed 3 minutes after placing the necktie.

CONCLUSION: Applanation tonometry may be inaccurate if performed in slit lamp position. In contrast, tight neckties do not significantly affect IOP evaluation in healthy subjects.

M & T Commentary:
This differs from the article recently in the "British Journal of Ophthalmology" showing that a tight necktie could cause an increase in IOP. Nonetheless, slit lamp-mounted applanation tonometry is potentially problematic in obese patients, those with large breasts, blepharospastic patients, and those who simply have difficulty positioning themselves correctly and comfortably into the slit lamp. For this sizable subpopulation, we readily default to a hand-held (Perkins or Kowa) applanation tonometer. It is state-of-the-art Goldmann tonometry, but with a hand-held rendition which greatly facilitates the acquisition of accurate tonometry. We strongly recommend that all practices have one of these units.

Short-wavelength automated perimetry results are correlated with optical coherence tomography retinal nerve fiber layer thickness measurements in glaucomatous eyes
CONCLUSION: Retinal nerve fiber layer thickness measured with OCT is topographically correlated with glaucoma VF defects measured with SWAP.

Intraobserver reproducibility of retinal nerve fiber layer measurements using scanning laser polarimetry and optical coherence-tomography in normal and hypertensive subjects
CONCLUSIONS: Retinal mapping software of both nerve fiber analyzers allows reproducible measurement of RNFL in both healthy and ocular hypertensive eyes, and shows fair correlations and good intraobserver reproducibility. However, in our study, GDx showed a better test-retest correlation.

M & T Commentary:
We love the GDx-VCC and highly recommend it!

Retinal nerve fiber layer thickness measurements with scanning laser polarimetry predict glaucomatous visual field loss
PURPOSE: To assess whether baseline retinal nerve fiber layer (RNFL) measurements obtained with a scanning laser polarimetry, the GDx Nerve Fiber Analyzer, are predictive of development of repeatable glaucomatous visual field damage in glaucoma suspect eyes.

CONCLUSIONS: Thinner baseline SLP RNFL measurements were independent predictors of visual field damage. In addition to thinner SLP RNFL measurements, higher baseline SAP PSD, and baseline glaucomatous stereophotograph assessment each contributed to an increase risk in the development of abnormal visual fields in glaucoma suspect patients. SLP RNFL measurements were independently predictive of future visual loss even when age, IOP, CCT, vertical cup disk ratio, and SAP PSD were included in the model.

Sensitivity and specificity of scanning laser polarimetry using the GDx
CONCLUSIONS: Detection of (early) glaucoma damage by the GDx, evaluated by trained experts, can be extremely high. To optimize its benefit in clinical routine, training in interpreting GDx printouts is highly recommended. Detection of localized NFBD is crucial, even for experts.

Diagnostic accuracy of the GDx VCC for glaucoma
CONCLUSIONS: The GDx VCC allowed easy, rapid, and accurate discrimination between healthy and glaucomatous eyes. The NFI was the best discriminating parameter. The GDx VCC seems to fulfill criteria for a glaucoma screening device.

Comparison of retinal nerve fiber layer thicknesses measured by optical coherence tomography and scanning laser polarimetry (GDx)
CONCLUSIONS: The RNFL thickness obtained using OCT is generally greater that that using GDx. Furthermore, a better correlation between visual function and RNFL thickness was obtained for OCT compared with GDx.

M & T Commentary:
Bottom line - either of these devices can provide valuable information to the glaucoma diagnostic evaluation.

Factors associated with optic disc hemorrhages in glaucoma
CONCLUSIONS: Optic disc hemorrhages were associated with diabetes and aspirin use and were observed at relatively lower IOP during follow-up.

Optic disc hemorrhages detected in a large-scale eye disease screening project
CONCLUSION: Disc hemorrhages occur more frequently in females, in elderly persons, and in glaucoma cases in Japanese aged 40 or older. The intraocular pressure of the eyes with the disc hemorrhages is close to that of the normal population.

Corticosteroids are the main culprits in drug-induced glaucoma
Approximately 18-36% of the general population and 46-92% of patients with primary open-angle glaucoma experience an increase in intraocular pressure (IOP) after topical ocular administration of corticosteroids for 2-4 weeks.

M & T Commentary:
So, isn't it nice that most all inflammatory eye conditions resolve in less than two weeks?

Efficacy and safety of the latanoprost/timolol maleate fixed combination vs concomitant brimonidine and latanoprost therapy
AIMS: To evaluate the efficacy and safety of latanoprost/timolol maleate fixed combination (LTFC) given once daily vs the concomitant therapy of brimonidine twice daily and latanoprost once daily in primary open-angle glaucoma or ocular hypertensive subjects.

CONCLUSION: This study suggests that LTFC and concomitant therapy of brimonidine and latanoprost provide statistically similar diurnal reduction from an untreated baseline.

Comparison of once-daily nonpreserved timolol and timolol maleate gel-forming solution associated with latanoprost
CONCLUSION: This short-term study has demonstrated the equivalence of nonpreserved timolol to timolol maleate gel-forming solution in terms of IOP control.

M & T Commentary:
This was demonstrated to be true a few years ago. There is no reason to prescribe more expensive gel solutions when less expensive, conventional solutions perform just as well.

A persistency and economic analysis of latanoprost, bimatoprost, or beta-blockers in patients with open-angle glaucoma or ocular hypertension
CONCLUSIONS: Patients were more persistent with latanoprost and demonstrated lower intraocular pressures, fewer visits, and fewer medicine changes when compared to bimatoprost or beta-blocker therapy. In contrast, the beta-blocker group provided lower overall cost.

Intraocular pressure, safety and quality of life in glaucoma patients switching to latanoprost from adjunctive and monotherapy treatments
PURPOSE: To evaluate efficacy, safety and quality of life in ocular hypertensive or open-angle glaucoma patients changed to latanoprost from previous therapy.

CONCLUSIONS: In a clinical setting, patients who have their mono- and adjunctive therapy treatment substituted for latanoprost may on average experience reduced IOP, decreased side effects and increased quality of life measures.

The efficacy and safety of once-daily versus once-weekly latanoprost treatment for increased intraocular pressure
We [S. Kurtz, G. Shemesh] evaluated the efficacy and safety of latanoprost eye drops once-weekly, compared to once-daily for improving patient compliance. The difference between post-treatment IOP was insignificant in both groups at each time point. The study group had fewer minor side effects than the control group (1/10 versus 6/10, respectively). Latanoprost treatment once-weekly was as effective, and bore fewer minor side effects, as once-daily treatment after 3 months of follow-up.

Optic nerve and neuroprotection strategies
CONCLUSIONS: A battery of agents now exist that can blunt animal ganglion cell death irrespective of whether the insult was to ganglion cell body or the myelinated axon. Whether this information can be applied for use in patients remains a matter of debate, and major obstacles need to be overcome before laboratory studies may be applied clinically.