Case Report 9 – Scleral RGP contact lens – Keratoconus

26yo indigenous male with bilateral extreme keratoconus

Working in outback Australia – North Queensland and Northern Territory.

OD: +3.75 / -4.75 x 62 (6/9) (UA 6/15)

OS: +3.00 / -4.50 x 135 (6/60-) (UA 6/CF=)

Hallmark Signs

Fleischer Ring
Vogt’s Striae
Central stromal thinning
Prominent Corneal Nerves – easy to see on dark iris backdrop
Anterior Stromal Scars

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Contact lens parameters

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Gelflex 18.50 mini-sclearl RGP in Harmony Plus material
OD: 7.80/12.50/14.50/18.50/+3.50 CT 220um Sag 5774um (6/6=)
OD: 7.50/12.50/14.50/18.50/+2.00 CT 220um Sag 6049um (6/9)
Goal of apical clearance 150-250um

Case Report 9 – Extreme Bilateral Keratoconus: Scleral Lens Rehabilitation in a Remote Australian Patient

Clinical Presentation

26-year-old Indigenous Australian man with advanced bilateral keratoconus.

The patient was working remotely across North Queensland and the Northern Territory, which adds an important practical dimension to the contact-lens management.

Spectacle Refraction

OD: +3.75 / −4.75 × 62 — VA 6/9
Unaided VA: 6/15

OS: +3.00 / −4.50 × 135 — VA 6/60−
Unaided VA: approximately counting fingers

This is an excellent example of why the magnitude of the subjective refractive error does not adequately describe keratoconus severity.

Both eyes have approximately 4.50–4.75 D of manifest cylinder, yet their spectacle-corrected visual outcomes are dramatically different:

OD: 6/9

versus

OS: 6/60−

Why?

Because the limiting factor in the left eye is not simply conventional sphere and cylinder.

It is the degree of irregular corneal optics and higher-order aberration.

Corneal Topography

Figure 1. Original topography from Case Report 9 demonstrating markedly abnormal bilateral corneal geometry. The substantial inter-eye asymmetry is reflected in both spectacle acuity and the scleral lens sagittal depth ultimately required.

In advanced keratoconus, the cornea produces substantial:

irregular astigmatism;
vertical and oblique coma;
trefoil;
asymmetric defocus;
higher-order aberration; and
degradation of retinal-image quality.

Conventional spectacle refraction can correct:

sphere + regular cylinder

but cannot adequately neutralise an irregular anterior corneal surface.

This explains why the left eye remains approximately 6/60− despite a spectacle refraction.

2026 Keratoconus Assessment

The historical page understandably focused on the obvious clinical keratoconus.

Contemporary assessment should go considerably further than simply describing the cornea as:

“Extreme keratoconus.”

Modern documentation should include:

anterior curvature;
posterior elevation;
thinnest pachymetry;
location of the thinnest point;
pachymetric progression;
anterior and posterior radius of curvature;
Belin ABCD staging;
epithelial thickness profile where obtainable;
corneal biomechanics where appropriate;
refraction;
BCVA; and
longitudinal change.

The 2026 Global Consensus on Keratoconus and Ectatic Diseases – Edition 2 reinforces a multimodal approach to diagnosis, progression and management rather than relying on a single Kmax or pachymetry measurement. [1]

Hallmark Clinical Signs of Keratoconus

The original page correctly listed the classical slit-lamp signs:

Fleischer ring;
Vogt striae;
central stromal thinning;
prominent corneal nerves; and
anterior stromal scarring.

These remain important clinical findings for fourth-year optometry students.

Fleischer Ring

A partial or complete ring of epithelial iron deposition around the base of the cone.

It may be subtle and is often easiest to identify using appropriate illumination and cobalt-blue examination.

Vogt Striae

Fine stress lines located predominantly in the:

deep stroma;
Descemet membrane; and
posterior corneal region.

They typically run vertically or obliquely.

They may transiently diminish with gentle pressure on the globe.

Corneal Thinning

The classical corneal hallmark of keratoconus.

However:

Do not simply write “central thinning.”

Many keratoconic cones are inferior, inferotemporal or otherwise decentered.

The thinnest point should therefore be documented tomographically rather than assumed to correspond with the geometrical corneal centre.

Prominent Corneal Nerves

Corneal nerves can appear particularly obvious in keratoconus.

This is a recognised clinical feature but is not sufficiently specific to diagnose keratoconus by itself.

The visibility may be particularly striking against a dark iris background.

Anterior Stromal Scarring

Scarring becomes increasingly relevant in more advanced disease.

This matters because a rigid contact lens can neutralise anterior surface irregularity, but it cannot make an optically significant stromal opacity disappear.

Therefore:

The maximum scleral-lens acuity is ultimately limited by the optical potential of the eye behind the new rigid anterior surface.

Why Choose a Scleral Lens?

The left eye is the key.

Spectacle acuity is approximately:

6/60−

That tells us that conventional lower-order optical correction is failing.

A scleral lens provides a completely different optical system.

The lens:

vaults the irregular cornea;
is filled with a fluid reservoir;
provides a regular rigid anterior optical surface; and
substantially neutralises the irregular anterior corneal refracting surface.

This can produce dramatic improvements in vision in advanced keratoconus.

Contemporary systematic-review evidence supports substantial improvement in both visual acuity and vision-related quality of life with scleral lenses in keratoconus. [2]

Historical Scleral Lens Fit

The original page records:

Lens

Gelflex 18.50 mm scleral lens
Harmony Plus material

The historical term was:

“18.50 mini-scleral RGP.”

In 2026 I would simply refer to this as a:

scleral lens

Modern terminology places more emphasis on where the lens lands than on arbitrary diameter labels such as mini-scleral or large scleral.

Right Eye

Figure 2. Original right-eye scleral lens photograph from Case Report 9.

Historical Lens Parameters

OD:
7.80 / 12.50 / 14.50 / 18.50 / +3.50 D

Centre thickness: 220 μm

Sagittal depth: 5774 μm

Visual Outcome

Spectacle: 6/9

Scleral lens: 6/6=

This is an excellent result.

However, the important outcome is not simply:

“He gained a few letters.”

The rigid optical surface may also improve:

visual stability;
contrast;
ghosting;
glare;
mesopic visual performance; and
subjective image quality.

These outcomes may be particularly important in a patient living and working in remote environments.

Left Eye

Figure 3. Original left-eye scleral lens photograph.

The original web page appears to contain a typographical error and labels this second prescription OD.

Given that it follows the left-eye clinical image and represents the second lens in this bilateral case, it should logically be recorded as:

OS

Historical Lens Parameters

OS:
7.50 / 12.50 / 14.50 / 18.50 / +2.00 D

Centre thickness: 220 μm

Sagittal depth: 6049 μm

Visual Outcome

Spectacle: approximately 6/60−

Scleral lens: 6/9

That is the headline result of this case.

6/60 to 6/9 – What Has the Lens Actually Done?

The left eye improves by an enormous amount.

But the scleral lens has not:

removed the keratoconus;
made the cornea structurally normal;
removed stromal tissue;
treated progression; or
changed the underlying biomechanical disease.

It has created a new regular anterior optical surface.

The fluid reservoir effectively masks much of the highly irregular anterior corneal refracting surface.

This is why scleral lenses can produce such dramatic visual rehabilitation in advanced ectasia.

Teaching Point

Contact lenses rehabilitate the optics. They do not treat the ectasia.

Why Is There Still 6/9 Vision OS Rather Than 6/6?

A scleral lens does not guarantee normal optics.

Residual limitation may arise from:

corneal scarring;
posterior corneal irregularity;
internal optical aberration;
amblyopia;
residual higher-order aberration;
lens decentration;
lens flexure;
optic-zone alignment;
retinal pathology; or
other ocular disease.

Modern research demonstrates that conventional rigid lenses can leave substantial residual ocular higher-order aberration, particularly from the posterior cornea and internal optics. [3]

Therefore:

6/9 may represent an excellent endpoint in a severely ectatic eye.

Do not chase 6/6 without first asking why the residual limitation exists.

Conventional Scleral Optics Versus Wavefront-Guided Optics

This has become particularly interesting in 2026.

Traditional scleral lenses create a regular anterior surface but generally use conventional spherical or spherocylindrical optics.

That means residual:

coma;
trefoil;
secondary astigmatism; and
other HOAs

may remain.

Wavefront-guided scleral lenses attempt to measure those residual aberrations while the conventional scleral lens is on the eye and then incorporate the inverse optical correction into the lens.

A 2025 randomised double-masked crossover study of irregular corneas found that wavefront-guided scleral lenses reduced higher-order RMS error by approximately 56% compared with conventional scleral optics and improved mean visual acuity by approximately 0.12 logMAR. [4]

This raises a useful question in the left eye:

If conventional scleral correction produces 6/9 but the cornea is optically clear enough, how much additional visual performance could potentially be recovered using customised higher-order optics?

That is an advanced rather than routine fitting question — but it shows where scleral-lens optics are heading.

Sagittal Depth – The Most Interesting Fitting Number

The sagittal depths were:

OD: 5774 μm

OS: 6049 μm

Difference:

275 μm

Both lenses had an overall diameter of 18.50 mm.

Therefore the left eye required approximately 275 μm more sagittal depth over the same nominal lens diameter.

This is much more informative than simply saying:

“The left cornea is steeper.”

Sagittal height depends on the geometry of the entire surface over the relevant chord, including:

central curvature;
corneal eccentricity;
cone magnitude;
cone position;
peripheral corneal geometry;
limbal geometry; and
anterior scleral shape.

Teaching Principle

Scleral lens fitting is primarily a sagittal-depth problem, not a base-curve problem.

Why Are the Base Curves Different?

Historical central radii:

OD: 7.80 mm

OS: 7.50 mm

The steeper posterior central geometry in the left lens contributes to the overall vault required over the more ectatic cornea.

However, students must avoid thinking:

“Steeper base curve = more scleral clearance.”

A scleral lens is a multi-zone system.

Total sagittal depth depends upon:

central geometry;
transition/limbal geometry;
landing-zone geometry; and
overall diameter.

Two lenses can have the same base curve and dramatically different sagittal depths.

Conversely, two lenses with different base curves can have similar total sagittal depths.

Original Clearance Goal – 150–250 μm

The historical page records:

Goal of apical clearance: 150–250 μm

This remains a reasonable conceptual settled-clearance range in many clinical scleral fits, but it should not be taught as a universal magic number.

Current scleral fitting is better framed as:

Use the minimum clearance that provides complete corneal and limbal vault after settling while maintaining satisfactory physiology and lens performance.

The optimal reservoir depends upon:

corneal geometry;
lens design;
material Dk;
centre thickness;
endothelial function;
wearing time;
ocular-surface disease;
corneal transplantation history; and
degree of lens settling.

Initial Clearance Is Not Final Clearance

Scleral lenses settle during wear.

The conjunctiva compresses under the landing zone and the lens moves progressively closer to the ocular surface.

Therefore:

Clearance after 5 minutes

is not the same as:

Clearance after 2–4 hours.

This is why anterior-segment OCT assessment should distinguish:

initial central clearance;
settled central clearance;
clearance over the actual cone apex;
minimum corneal clearance; and
limbal clearance.

A lens that appears dramatically over-vaulted at insertion may become much more appropriate after settling.

Conversely, a lens that begins with marginal clearance may eventually touch the cornea.

Why More Clearance Is Not Better

A common novice instinct is:

“This is extreme keratoconus, so give it heaps of clearance.”

That is incorrect.

A thicker fluid reservoir increases the distance oxygen must diffuse before reaching the cornea.

QUT research by Iqbal, Fisher, Alonso-Caneiro, Collins and Vincent has demonstrated measurable central and peripheral corneal oedema during scleral lens wear and reinforces the importance of avoiding unnecessarily large reservoirs. [5]

The contemporary principle is:

Enough clearance – not maximum clearance.

Lens Thickness Matters Too

Both historical lenses had a centre thickness of approximately:

220 μm

Oxygen reaching the cornea must cross:

the rigid lens material; and
the post-lens fluid reservoir.

Therefore scleral lens physiology depends on more than simply lens-material Dk.

Important variables include:

material Dk;
lens thickness;
fluid reservoir thickness;
wearing time;
tear exchange;
corneal thickness;
endothelial reserve; and
previous corneal disease.

A high-Dk lens does not give unlimited licence to create an excessively thick reservoir.

Landing Zone – Particularly Important in an 18.5 mm Lens

An 18.50-mm lens lands well beyond the corneal limbus.

At this diameter, the anterior sclera is frequently:

toric;
asymmetric;
non-rotationally symmetric; and
different between quadrants.

Therefore the peripheral fit should be assessed independently from the central vault.

Look for:

conjunctival blanching;
vessel compression;
impingement;
edge lift;
focal stand-off;
rotational instability;
lens flexure;
conjunctival prolapse;
decentration; and
rebound hyperaemia after removal.

QUT Evidence – Toric Landing Zones

This is particularly relevant for QUT students.

A 2024 QUT study by Alexander, Aweke, Bhebhe, Cho, Lay, Ryan, Collins and Vincent experimentally evaluated scleral landing-zone toricity.

Toric landing zones of 100–200 μm reduced:

lens flexure by approximately 62%; and
lens rotation by approximately 77%

compared with a spherical landing zone, without a significant effect on horizontal or vertical decentration under the study conditions. [6]

This demonstrates that the haptic is not simply:

“the bit that holds the lens up.”

Landing-zone geometry can affect both:

mechanical behaviour

and

optics.

Lens Decentration Matters Optically

Scleral lenses commonly decentre slightly, often inferotemporally.

Decentration can alter:

effective optical alignment;
induced aberrations;
front-surface toric orientation;
multifocal optics;
wavefront-guided correction; and
subjective image quality.

QUT research has also demonstrated that scleral-lens centration is affected by fitting parameters including fluid-reservoir depth and lens mass. [7]

This becomes particularly important as optical designs become increasingly customised.

A wavefront-guided lens that rotates or translates unpredictably cannot deliver its intended higher-order correction.

The Positive Lens Powers – Why +3.50 and +2.00?

At first glance, students may expect an advanced keratoconic patient to require a highly minus contact lens.

But this patient’s spectacle refractions are compound hyperopic astigmatic:

OD +3.75 / −4.75 × 62

OS +3.00 / −4.50 × 135

The final scleral powers were:

OD +3.50 D

OS +2.00 D

Again, these should not be obtained by simply taking the spherical equivalent of the spectacle prescription.

The rigid lens creates a fluid lens over the irregular cornea.

Final power therefore depends upon:

manifest refraction;
vertex distance where relevant;
posterior lens geometry;
corneal shape;
tear/fluid-lens effect;
lens position; and
final sphero-cylindrical over-refraction.

The Rule

Fit the geometry first. Then determine the power by over-refraction.

Do not prescribe a specialty rigid lens by simply transposing the spectacle prescription.

Why Are the Two Final Powers So Different?

Despite similar spectacle-cylinder magnitudes:

OD: −4.75 D

OS: −4.50 D

the final scleral lens powers differ by:

1.50 D

Again, because spectacle cylinder does not describe the tear-lens optics created by a rigid lens.

The much more irregular left cornea creates a different fluid-lens relationship.

That is precisely why specialty contact lens power cannot be predicted adequately from manifest cylinder alone.

Remote Australia – This Changes the Management Plan

This is perhaps the most clinically distinctive feature of Case Report 9.

The patient works in:

North Queensland and the Northern Territory.

A technically perfect scleral lens is not a successful prescription if the patient cannot practically maintain it hundreds or thousands of kilometres from specialist care.

The management plan therefore needs to include:

robust insertion/removal training;
spare insertion and removal plungers;
reliable access to preservative-free sterile filling saline;
sufficient cleaning/disinfection products;
a backup pair of lenses where clinically and financially feasible;
access to an up-to-date spectacle backup;
clear instructions for red-eye emergencies;
planned review scheduling around travel;
secure lens storage during heat and transport;
replacement planning; and
a mechanism for urgent local assessment if microbial keratitis is suspected.

Australian research published in 2025 highlights persistent challenges in rural eye-care access and workforce distribution. [8]

Teaching Point

Geography is a clinical variable.

The best lens design on paper is not automatically the best management plan.

Lens Hygiene – Even More Important When Working Remotely

Scleral lenses must be filled with an appropriate:

sterile, preservative-free solution

for application.

Do not fill a scleral lens with:

tap water;
bore water;
rainwater;
bottled drinking water;
homemade saline; or
previously opened non-sterile saline.

Water exposure remains a recognised risk factor for Acanthamoeba keratitis and other severe contact-lens-associated infections. [9,10]

The patient should also understand:

never shower or swim while wearing the lens unless specifically managed according to clinical advice;
never rinse the lens or lens case with tap water;
disinfect the reusable lens appropriately;
clean insertion/removal devices;
allow accessories to dry appropriately;
never top up old disinfecting solution;
do not use saline as a substitute for disinfection.

The Plunger Is Part of the Hygiene System

This deserves explicit mention in 2026.

A scleral-lens patient’s handling equipment can itself become contaminated.

A 2026 case report documented bilateral Acanthamoeba keratitis associated with contaminated scleral-lens suction applicators that had been rinsed with tap water and stored damp. [10]

For patients working remotely:

The entire contact lens system matters:

lens + case + saline + disinfectant + hands + plungers + storage environment.

Heat and Remote Work

The Australian environment adds practical considerations that are not normally captured by a lens specification.

Patients should avoid leaving:

lens-care solutions;
preservative-free saline;
lenses; or
accessories

in excessively hot vehicles or other environments outside manufacturer storage recommendations.

The patient should carry enough appropriate supplies when working away from major centres rather than assuming suitable products will be available locally.

Dust, Wind and Environmental Exposure

A scleral lens can offer excellent stability in windy or dusty environments compared with a small corneal GP.

However:

It is not an impermeable protective seal.

Environmental exposure can still contribute to:

front-surface deposits;
irritation;
conjunctival inflammation;
lens contamination; and
progressive reservoir turbidity.

The lens should not be regarded as protective eyewear.

Appropriate occupational eye protection may still be required.

Midday Fogging

If this patient reports:

“The lenses are crystal clear in the morning but cloudy by lunchtime.”

consider midday fogging.

Possible contributors include:

inflammatory cells;
mucin;
lipid;
epithelial debris;
tear exchange;
landing-zone misalignment;
ocular allergy;
meibomian gland dysfunction; and
filling-solution characteristics.

Do not simply keep increasing or decreasing the sag without identifying the likely mechanism.

Keratoconus Progression – The Patient Is Only 26

At 26 years of age, progression remains clinically relevant.

The fact that a scleral lens produces:

6/6 OD and 6/9 OS

tells us nothing about whether the underlying ectatic disease is stable.

The patient still requires appropriate surveillance with serial:

tomography;
pachymetry;
posterior elevation;
ABCD parameters;
refraction;
BCVA; and
other progression measures.

If progression is demonstrated, the patient should be assessed for corneal cross-linking where appropriate.

CXL and Scleral Lenses Solve Different Problems

CXL: stabilises progressive ectasia.

Scleral lens: rehabilitates vision.

Neither replaces the other.

Do Not Use the Contact Lens Topography to Assess Progression

Rigid contact lens wear can temporarily alter corneal shape.

Therefore serial keratoconus measurements should be obtained under sufficiently consistent conditions.

If accurate progression analysis is required, an appropriate period without lens wear may be necessary.

The duration depends upon:

lens design;
hours of wear;
duration of habitual wear;
corneal response; and
the magnitude of lens-induced moulding.

Teaching Point

Do not compare:

tomography immediately after a week of heavy scleral wear

with

tomography after several days without lenses

and automatically label every difference:

“keratoconus progression.”

Australian Keratoconus Management Has Changed

A 2026 Australian analysis by Kha, Kandel and Watson describes a substantial shift in keratoconus management.

Australian data show:

decreasing numbers of corneal grafts for keratoconus;
increasing use of CXL;
increasing use of RGP and scleral contact lenses; and
approximately a doubling in the estimated number of RGP and scleral lenses used for keratoconus over recent decades. [11]

This reflects an important modern strategy:

Detect earlier → stabilise progression → rehabilitate optics → delay or avoid transplantation where possible.

This case is an excellent example of the visual-rehabilitation part of that pathway.

Keratoconus and Quality of Life

The left eye went from:

approximately counting fingers unaided

6/9 through a scleral lens.

That should not be regarded simply as a change in an acuity fraction.

Keratoconus can adversely affect:

employment;
driving;
independence;
psychological wellbeing;
social functioning;
near activities;
distance activities; and
overall vision-related quality of life.

Recent systematic reviews confirm that keratoconus has substantial effects on quality of life that extend well beyond high-contrast visual acuity, while specialty contact lenses can produce significant functional benefits. [2,12]

For a young patient living and working remotely, restoring reliable binocular functional vision may materially alter occupational independence.

Modern Optical Endpoint – More Than 6/6

For the right eye:

6/6= is excellent.

For the left:

6/9 is a major rehabilitation.

But contemporary assessment should also include:

low-contrast VA;
contrast sensitivity;
mesopic acuity;
glare;
ghosting;
monocular diplopia;
visual stability;
front-surface wetting;
wearing time;
comfort; and
patient-reported visual function.

Modern scleral-lens research demonstrates substantial reduction in higher-order aberrations and improved visual function, reinforcing the importance of evaluating visual quality, not simply Snellen acuity. [3,4]

What Would I Do If This Patient Presented in 2026?

1. Establish Current Keratoconus Status

Obtain high-quality tomography.

Document:

anterior and posterior corneal surfaces;
thinnest pachymetry;
pachymetric progression;
ABCD stage;
cone location;
refraction;
BCVA; and
serial change.

2. Consider Biomechanics

Where clinically useful and technically obtainable:

CBI;
TBI;
SSI; and
other biomechanical parameters.

In an extremely ectatic cornea, remember that some automated indices may become less reliable or fall outside validated ranges.

3. Assess Whether CXL Has Been Performed

If not, determine whether progression is documented and whether CXL remains clinically appropriate.

4. Establish the True Scleral Lens Sag

Do not simply replicate a historical lens.

Use:

trial-lens fitting;
anterior-segment OCT;
corneo-scleral profilometry where available; or
a combination.

5. Assess Initial and Settled Clearance

Document:

central clearance;
clearance at the true cone apex;
minimum corneal clearance;
limbal clearance; and
change with settling.

6. Assess the Landing Zone in Every Quadrant

Look for:

blanching;
compression;
edge lift;
impingement;
conjunctival prolapse;
rotation;
flexure; and
decentration.

7. Perform Sphero-Cylindrical Over-Refraction

Do not assume all residual refractive error is spherical.

If clinically significant residual cylinder remains, determine whether it is due to:

internal astigmatism;
lens flexure;
lens decentration; or
genuine residual ocular cylinder.

8. Measure the Optical Ceiling

If the left eye remains 6/9 despite excellent fit and a clear visual axis, assess whether residual HOAs are limiting vision.

Wavefront measurement may help identify whether customised optics could provide additional benefit.

9. Build a Remote-Care Plan

Ensure that the patient has:

adequate saline;
appropriate disinfection products;
spare plungers;
emergency instructions;
backup correction;
planned review dates; and
access to urgent eye care when away.

10. Inspect the Cornea After Lens Removal

Assess:

epithelial staining;
corneal oedema;
limbal staining;
conjunctival compression;
rebound hyperaemia;
impression rings;
neovascularisation; and
any focal mechanical effect.

Clinical Take-Home Points

Similar refractive cylinder does not mean similar keratoconus severity. OD and OS both have approximately 4.5–4.75 D cylinder, yet spectacle acuity differs from 6/9 to 6/60−.
Scleral lenses can provide extraordinary optical rehabilitation in advanced keratoconus.
6/60− to 6/9 is a major clinical outcome.
The scleral lens has corrected the optics — not the disease.
CXL treats progression; the scleral lens treats visual disability.
Think sagittal depth over a defined chord.
OS required approximately 275 μm more sagittal depth than OD despite the same lens diameter.
Base curve alone does not determine scleral-lens clearance.
A 150–250 μm clearance target is not a universal rule. Assess settled clearance, physiology and the individual eye.
More clearance is not automatically safer. Excessive fluid-reservoir thickness increases physiological burden.
Landing-zone geometry influences optics as well as comfort. QUT research demonstrates substantial reductions in lens flexure and rotation with toric landing zones.
A conventional scleral lens may leave residual HOAs. Wavefront-guided optics are an emerging option for selected irregular corneas.
The apparent second “OD” prescription on the historical page should be read as OS.
Remote geography changes the prescription. Supplies, hygiene, backup lenses, emergency access and follow-up are all part of clinical management.
Never use non-sterile water anywhere in the scleral-lens care system.
Do not forget the plungers. Lens accessories can become a source of microbial contamination.
Keratoconus management in Australia is changing. CXL and specialty contact lens use have increased while keratoplasty has decreased.
Treat visual function, not just Snellen acuity.
A technically excellent lens that the patient cannot safely maintain is not a successful fit.
The patient, cornea, lens, environment and access to care all form part of the prescription.

Peer-Reviewed Reading – QUT Master of Optometry

1. Gomes JAP, Hafezi F, Ambrósio R Jr, et al. Global Consensus on Keratoconus and Ectatic Diseases—Edition 2. Cornea. 2026;45(7):888–908. doi:10.1097/ICO.0000000000004170. PMID: 42228627.

2. Mushtaq A, Alvi I. Long-Term Effectiveness of Scleral Lens Treatment in the Management of Keratoconus: A Systematic Review. Cureus. 2025;17(1). doi:10.7759/cureus.77102. PMID: 39781287.

3. Swartz G, Alam K, Gentle A, Downie LE. Impact of contact lens correction on wavefront aberrations and vision quality in keratoconus. Ophthalmic Physiol Opt. 2025;45:1811–1828. doi:10.1111/opo.70037. PMID: 41159562.

4. Gelles JD, Su B, Kelly D, et al. Visual Improvement With Wavefront-Guided Scleral Lenses for Irregular Corneal Astigmatism. Eye Contact Lens. 2025;51(2):58–64. doi:10.1097/ICL.0000000000001152. PMID: 39661442.

5. Iqbal A, Fisher D, Alonso-Caneiro D, Collins MJ, Vincent SJ. Central and peripheral scleral lens-induced corneal oedema. Ophthalmic Physiol Opt. 2024;44(4):792–800. doi:10.1111/opo.13221. PMID: 37622425.

6. Alexander J, Aweke YB, Bhebhe Z, Cho D, Lay S, Ryan I, Collins MJ, Vincent SJ. The effect of landing zone toricity on scleral lens fitting characteristics and optics. Ophthalmic Physiol Opt. 2024;44(5):867–875. doi:10.1111/opo.13324. PMID: 38699941.

7. Fisher D, Collins MJ, Vincent SJ. The effect of lens and fitting characteristics upon scleral lens centration. Ophthalmic Physiol Opt. 2024;44(7):1530–1538. doi:10.1111/opo.13367. PMID: 39033320.

8. Chen J, Bentley SA, McKendrick AM, Thompson SC, Turner AW, Alam K. Rural eye care access, workforce challenges and opportunities: perspectives of the eye health workforce in Western Australia. Aust J Rural Health. 2025;33. doi:10.1111/ajr.70004.

9. Carnt N, et al. Acanthamoeba keratitis associated with tap water use during contact lens cleaning: manufacturer guidelines need to change. Eye Contact Lens. 2013. PMID: 23392300.

10. Bilateral Acanthamoeba Keratitis Secondary to Contaminated Contact Lens Suction Applicators: A Rare Case of Accessory-Mediated Transmission. Case Rep Ophthalmol. 2026.

11. Kha R, Kandel H, Watson S. Trends in the Management of Keratoconus in Australia. Ophthalmic Physiol Opt. 2026;46:135–142. doi:10.1007/s44402-026-00096-2.

12. Sari D, Kandel H, Kha R, Watson SL. What is the quality-of-life status of patients with keratoconus who have not had a surgical intervention? A systematic review. Eye. 2025;39:3229–3236. doi:10.1038/s41433-025-04053-0. PMID: 41125767.

13. Hadimani S, et al. Quality of life and vision assessment with scleral lenses in keratoconus. 2024. PMID: 38988786.

14. Lim L, Lim EWL. Current perspectives in the management of keratoconus with contact lenses. Eye. 2020;34:2175–2196. doi:10.1038/s41433-020-1065-z.

Particularly Relevant QUT Papers

For this case I would specifically highlight the QUT scleral-lens research:

Alexander et al. 2024

Demonstrates how landing-zone toricity alters lens flexure and rotation.

Iqbal et al. 2024

Demonstrates the physiological consequences of scleral wear and post-lens fluid reservoir characteristics on corneal oedema.

Fisher, Collins & Vincent 2024

Demonstrates how scleral-lens design variables affect lens centration.

These three papers collectively illustrate why modern scleral fitting is not simply:

“Get 200 μm clearance and check the edge.”

The lens must be considered as an integrated:

mechanical + physiological + optical system.