Human Serum Eye Drops in Eye Alterations: An Insight and a Critical Analysis

Table 2

Published studies on serum eye drops from 2010 to 2014.

Type of component	Study design	Year	Patient number	Corneal disease	Clotting phase	Centrifugation/time	Dilution	Storage	Results	References
100% AS	Single-center; prospective interventional study	2013	181	Corneal epithelial defects after ocular surgery	2 h at RT	3000 g/15 min	None	−20°C three months	It improves corneal healing.	[94]
50% AS	Single-center prospective study	2014	28	Acute and chronic eye pathologies	24–48 h at 4°C	4000 g/10 min	Sterile saline solution	−30°C six months; −20°C; three months	It stabilizes and improves signs and symptoms in eyes previously treated with conventional therapy.	[91]
20% AS, CBS	Double-blind prospective randomized controlled clinical study	2011	33	Ocular chemical burns of grades III, IV, and V	Not provided	1800 g/10 min	Sterile balanced; salt solution	−20.0°C until use	Umbilical cord serum therapy is more effective than AS eye drops or artificial tears in ocular surface restoration after acute chemical injuries.	[112]
20% AS versus AMT	Retrospective study	2014	42	Neurotrophic keratitis; Corneal ulcers	2 h	3000 g/15 min	Sterile saline solution	Not provided	Amniotic membrane transplantation is more effective than AS in deep corneal ulcers with postherpes neurotrophic keratitis.	[105]
100% AS	Not provided	2013	10	PED	2 h at RT	3000 g/15 min	None	4°C	Improvement in corneal healing.	[115]
100% AS	Descriptive prospective observational study	2011	15	Various ocular surface disorders	None	10000 rpm/10 min	None	−20°C three months	Redness, burning, sharp pain, and tired eyes improved in 100% of the patients, whereas dryness and sandy/gritty sensation improved in 92% of the patients.	[69]
20% AS,; 20% no AS	Prospective interventional study	2010	165	PED after PK	30 min	1500 rpm/5 min	Sterile saline solution	−4°C	AS improves healing in patients with potentially delayed epithelial heal.	[93]
20% AS	Prospective, double-blind randomized crossover study	2014	40	Severe DES	2 h at RT	2600 g/10 min	Sterile saline solution	−20°C	AS eye drops are more effective than conventional eye drops for improving tear film stability and subjective comfort in patients with severe DES.	[92]
100% AS; versus normal saline/; artificial tears/; antibiotics; AS	Randomized study	2013	85	DES/SS, DES/no SS, PED	5 min at RT	3000 g/5 min	None versus 50% saline or artificial tears or antibiotic	Not provided	AS was the most effective in decreasing symptoms, corneal epitheliopathy, and promoting fast closure of wound.	[88]
50% AS	Prospective cross-sectional study	2014	34	SS	2 h at RT	3000 g/15 min	Sodium hyaluronate	−70°C until use	AS might not be effective for the treatment of secondary SS because of elevated serum proinflammatory cytokine levels.	[101]
20% AS	Three-month prospective study	2014	17	Severe DES	Not provided	3000 g/15 min	Isotonic buffered saline solution	−20°C four months; 4–8°C one week	The positive effect of AS decreased with time but still persisted up to three months after the end of therapy.	[102]
20% AS	Double-blind prospective randomized controlled clinical study	2011	32	Acute chemical burns	Not provided	180 g/10 min	Sterile balanced solution	−20°C until use	Umbilical cord serum was more effective than AS and artificial tears in ocular surface restitution.	[112]
20% AS versus PRP	Retrospective review	2012	28	DES	Not provided	3000 g/15 min; 200 g/11 min	Sterile saline solution	−20°C until use	The concentrations of GFs in the PRP and AS were not statistically different. PRP could be an effective, novel treatment option for chronic ocular surface disease.	[70]
20% AS versus conventional artificial tears treatment	Double masked randomized; crossover clinical trial	2012	12	Severe DES	2 h at RT	3500 rpm/5 min at 4°C	Sterile saline solution	−20°C	AS achieves better symptom improvement compared to artificial tears in a short-term treatment.	[79]

AS: autologous serum; RT: room temperature; CBS: cord blood serum; AMT: amniotic membrane transplantation; PED: persistent epithelial defects; PK: penetrating keratoplasty; DES: dry eye syndrome, SS: Sjogren’s syndrome; PRP: platelet rich plasma; GFs: growth factors.